From 23adec554a7648f99c8acc0caf49c66320cd2b84 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:41 +0200 Subject: x86: add notrace annotations to vsyscall. Add the notrace annotations to the vsyscall functions - there we are not in kernel context yet, so the tracer function cannot (and must not) be called. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/vsyscall_64.c | 3 ++- arch/x86/vdso/vclock_gettime.c | 15 ++++++++------- arch/x86/vdso/vgetcpu.c | 3 ++- 3 files changed, 12 insertions(+), 9 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 61efa2f7d56..4063dfa2a02 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -42,7 +42,8 @@ #include #include -#define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr))) +#define __vsyscall(nr) \ + __attribute__ ((unused, __section__(".vsyscall_" #nr))) notrace #define __syscall_clobber "r11","cx","memory" /* diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 23476c2ebfc..5cb8f754c52 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -23,7 +23,7 @@ #define gtod vdso_vsyscall_gtod_data -static long vdso_fallback_gettime(long clock, struct timespec *ts) +notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) { long ret; asm("syscall" : "=a" (ret) : @@ -31,7 +31,7 @@ static long vdso_fallback_gettime(long clock, struct timespec *ts) return ret; } -static inline long vgetns(void) +notrace static inline long vgetns(void) { long v; cycles_t (*vread)(void); @@ -40,7 +40,7 @@ static inline long vgetns(void) return (v * gtod->clock.mult) >> gtod->clock.shift; } -static noinline int do_realtime(struct timespec *ts) +notrace static noinline int do_realtime(struct timespec *ts) { unsigned long seq, ns; do { @@ -54,7 +54,8 @@ static noinline int do_realtime(struct timespec *ts) } /* Copy of the version in kernel/time.c which we cannot directly access */ -static void vset_normalized_timespec(struct timespec *ts, long sec, long nsec) +notrace static void +vset_normalized_timespec(struct timespec *ts, long sec, long nsec) { while (nsec >= NSEC_PER_SEC) { nsec -= NSEC_PER_SEC; @@ -68,7 +69,7 @@ static void vset_normalized_timespec(struct timespec *ts, long sec, long nsec) ts->tv_nsec = nsec; } -static noinline int do_monotonic(struct timespec *ts) +notrace static noinline int do_monotonic(struct timespec *ts) { unsigned long seq, ns, secs; do { @@ -82,7 +83,7 @@ static noinline int do_monotonic(struct timespec *ts) return 0; } -int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) +notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) { if (likely(gtod->sysctl_enabled && gtod->clock.vread)) switch (clock) { @@ -96,7 +97,7 @@ int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) int clock_gettime(clockid_t, struct timespec *) __attribute__((weak, alias("__vdso_clock_gettime"))); -int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) +notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) { long ret; if (likely(gtod->sysctl_enabled && gtod->clock.vread)) { diff --git a/arch/x86/vdso/vgetcpu.c b/arch/x86/vdso/vgetcpu.c index c8097f17f8a..9fbc6b20026 100644 --- a/arch/x86/vdso/vgetcpu.c +++ b/arch/x86/vdso/vgetcpu.c @@ -13,7 +13,8 @@ #include #include "vextern.h" -long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) +notrace long +__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) { unsigned int p; -- cgit v1.2.3-70-g09d2 From 16444a8a40d4c7b4f6de34af0cae1f76a4f6c901 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 12 May 2008 21:20:42 +0200 Subject: ftrace: add basic support for gcc profiler instrumentation If CONFIG_FTRACE is selected and /proc/sys/kernel/ftrace_enabled is set to a non-zero value the ftrace routine will be called everytime we enter a kernel function that is not marked with the "notrace" attribute. The ftrace routine will then call a registered function if a function happens to be registered. [ This code has been highly hacked by Steven Rostedt and Ingo Molnar, so don't blame Arnaldo for all of this ;-) ] Update: It is now possible to register more than one ftrace function. If only one ftrace function is registered, that will be the function that ftrace calls directly. If more than one function is registered, then ftrace will call a function that will loop through the functions to call. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- Makefile | 4 ++ arch/x86/Kconfig | 1 + arch/x86/kernel/entry_32.S | 27 +++++++++ arch/x86/kernel/entry_64.S | 37 ++++++++++++ include/linux/ftrace.h | 38 +++++++++++++ kernel/Makefile | 1 + kernel/trace/Kconfig | 5 ++ kernel/trace/Makefile | 3 + kernel/trace/ftrace.c | 138 +++++++++++++++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 2 + 10 files changed, 256 insertions(+) create mode 100644 include/linux/ftrace.h create mode 100644 kernel/trace/Kconfig create mode 100644 kernel/trace/Makefile create mode 100644 kernel/trace/ftrace.c (limited to 'arch') diff --git a/Makefile b/Makefile index 20b32351906..b4a273f19b5 100644 --- a/Makefile +++ b/Makefile @@ -528,6 +528,10 @@ KBUILD_CFLAGS += -g KBUILD_AFLAGS += -gdwarf-2 endif +ifdef CONFIG_FTRACE +KBUILD_CFLAGS += -pg +endif + # We trigger additional mismatches with less inlining ifdef CONFIG_DEBUG_SECTION_MISMATCH KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fe361ae7ef2..c742dfeb0db 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -23,6 +23,7 @@ config X86 select HAVE_OPROFILE select HAVE_KPROBES select HAVE_KRETPROBES + select HAVE_FTRACE select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) select HAVE_ARCH_KGDB if !X86_VOYAGER diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 2a609dc3271..f47b9b5440d 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1109,6 +1109,33 @@ ENDPROC(xen_failsafe_callback) #endif /* CONFIG_XEN */ +#ifdef CONFIG_FTRACE +ENTRY(mcount) + cmpl $ftrace_stub, ftrace_trace_function + jnz trace + +.globl ftrace_stub +ftrace_stub: + ret + + /* taken from glibc */ +trace: + pushl %eax + pushl %ecx + pushl %edx + movl 0xc(%esp), %eax + movl 0x4(%ebp), %edx + + call *ftrace_trace_function + + popl %edx + popl %ecx + popl %eax + + jmp ftrace_stub +END(mcount) +#endif + .section .rodata,"a" #include "syscall_table_32.S" diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 556a8df522a..f046e0c6488 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -54,6 +54,43 @@ .code64 +#ifdef CONFIG_FTRACE +ENTRY(mcount) + cmpq $ftrace_stub, ftrace_trace_function + jnz trace +.globl ftrace_stub +ftrace_stub: + retq + +trace: + /* taken from glibc */ + subq $0x38, %rsp + movq %rax, (%rsp) + movq %rcx, 8(%rsp) + movq %rdx, 16(%rsp) + movq %rsi, 24(%rsp) + movq %rdi, 32(%rsp) + movq %r8, 40(%rsp) + movq %r9, 48(%rsp) + + movq 0x38(%rsp), %rdi + movq 8(%rbp), %rsi + + call *ftrace_trace_function + + movq 48(%rsp), %r9 + movq 40(%rsp), %r8 + movq 32(%rsp), %rdi + movq 24(%rsp), %rsi + movq 16(%rsp), %rdx + movq 8(%rsp), %rcx + movq (%rsp), %rax + addq $0x38, %rsp + + jmp ftrace_stub +END(mcount) +#endif + #ifndef CONFIG_PREEMPT #define retint_kernel retint_restore_args #endif diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h new file mode 100644 index 00000000000..b96ef14c249 --- /dev/null +++ b/include/linux/ftrace.h @@ -0,0 +1,38 @@ +#ifndef _LINUX_FTRACE_H +#define _LINUX_FTRACE_H + +#ifdef CONFIG_FTRACE + +#include + +#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) +#define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1)) +#define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2)) + +typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip); + +struct ftrace_ops { + ftrace_func_t func; + struct ftrace_ops *next; +}; + +/* + * The ftrace_ops must be a static and should also + * be read_mostly. These functions do modify read_mostly variables + * so use them sparely. Never free an ftrace_op or modify the + * next pointer after it has been registered. Even after unregistering + * it, the next pointer may still be used internally. + */ +int register_ftrace_function(struct ftrace_ops *ops); +int unregister_ftrace_function(struct ftrace_ops *ops); +void clear_ftrace_function(void); + +extern void ftrace_stub(unsigned long a0, unsigned long a1); +extern void mcount(void); + +#else /* !CONFIG_FTRACE */ +# define register_ftrace_function(ops) do { } while (0) +# define unregister_ftrace_function(ops) do { } while (0) +# define clear_ftrace_function(ops) do { } while (0) +#endif /* CONFIG_FTRACE */ +#endif /* _LINUX_FTRACE_H */ diff --git a/kernel/Makefile b/kernel/Makefile index 1c9938addb9..fa05f6d8bdb 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_LATENCYTOP) += latencytop.o +obj-$(CONFIG_FTRACE) += trace/ ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) # According to Alan Modra , the -fno-omit-frame-pointer is diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig new file mode 100644 index 00000000000..8185c91417b --- /dev/null +++ b/kernel/trace/Kconfig @@ -0,0 +1,5 @@ +# +# Architectures that offer an FTRACE implementation should select HAVE_FTRACE: +# +config HAVE_FTRACE + bool diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile new file mode 100644 index 00000000000..bf4fd215a6a --- /dev/null +++ b/kernel/trace/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_FTRACE) += libftrace.o + +libftrace-y := ftrace.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c new file mode 100644 index 00000000000..b6a80b98a3f --- /dev/null +++ b/kernel/trace/ftrace.c @@ -0,0 +1,138 @@ +/* + * Infrastructure for profiling code inserted by 'gcc -pg'. + * + * Copyright (C) 2007-2008 Steven Rostedt + * Copyright (C) 2004-2008 Ingo Molnar + * + * Originally ported from the -rt patch by: + * Copyright (C) 2007 Arnaldo Carvalho de Melo + * + * Based on code in the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ + +#include +#include + +static DEFINE_SPINLOCK(ftrace_func_lock); +static struct ftrace_ops ftrace_list_end __read_mostly = +{ + .func = ftrace_stub, +}; + +static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; +ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; + +/* mcount is defined per arch in assembly */ +EXPORT_SYMBOL(mcount); + +notrace void ftrace_list_func(unsigned long ip, unsigned long parent_ip) +{ + struct ftrace_ops *op = ftrace_list; + + /* in case someone actually ports this to alpha! */ + read_barrier_depends(); + + while (op != &ftrace_list_end) { + /* silly alpha */ + read_barrier_depends(); + op->func(ip, parent_ip); + op = op->next; + }; +} + +/** + * register_ftrace_function - register a function for profiling + * @ops - ops structure that holds the function for profiling. + * + * Register a function to be called by all functions in the + * kernel. + * + * Note: @ops->func and all the functions it calls must be labeled + * with "notrace", otherwise it will go into a + * recursive loop. + */ +int register_ftrace_function(struct ftrace_ops *ops) +{ + unsigned long flags; + + spin_lock_irqsave(&ftrace_func_lock, flags); + ops->next = ftrace_list; + /* + * We are entering ops into the ftrace_list but another + * CPU might be walking that list. We need to make sure + * the ops->next pointer is valid before another CPU sees + * the ops pointer included into the ftrace_list. + */ + smp_wmb(); + ftrace_list = ops; + /* + * For one func, simply call it directly. + * For more than one func, call the chain. + */ + if (ops->next == &ftrace_list_end) + ftrace_trace_function = ops->func; + else + ftrace_trace_function = ftrace_list_func; + spin_unlock_irqrestore(&ftrace_func_lock, flags); + + return 0; +} + +/** + * unregister_ftrace_function - unresgister a function for profiling. + * @ops - ops structure that holds the function to unregister + * + * Unregister a function that was added to be called by ftrace profiling. + */ +int unregister_ftrace_function(struct ftrace_ops *ops) +{ + unsigned long flags; + struct ftrace_ops **p; + int ret = 0; + + spin_lock_irqsave(&ftrace_func_lock, flags); + + /* + * If we are the only function, then the ftrace pointer is + * pointing directly to that function. + */ + if (ftrace_list == ops && ops->next == &ftrace_list_end) { + ftrace_trace_function = ftrace_stub; + ftrace_list = &ftrace_list_end; + goto out; + } + + for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) + if (*p == ops) + break; + + if (*p != ops) { + ret = -1; + goto out; + } + + *p = (*p)->next; + + /* If we only have one func left, then call that directly */ + if (ftrace_list->next == &ftrace_list_end) + ftrace_trace_function = ftrace_list->func; + + out: + spin_unlock_irqrestore(&ftrace_func_lock, flags); + + return 0; +} + +/** + * clear_ftrace_function - reset the ftrace function + * + * This NULLs the ftrace function and in essence stops + * tracing. There may be lag + */ +void clear_ftrace_function(void) +{ + ftrace_trace_function = ftrace_stub; +} diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d2099f41aa1..d8b6279a9b4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -634,6 +634,8 @@ config LATENCYTOP Enable this option if you want to use the LatencyTOP tool to find out which userspace is blocking on what kernel operations. +source kernel/trace/Kconfig + config PROVIDE_OHCI1394_DMA_INIT bool "Remote debugging over FireWire early on boot" depends on PCI && X86 -- cgit v1.2.3-70-g09d2 From 81d68a96a39844853b37f20cc8282d9b65b78ef3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:42 +0200 Subject: ftrace: trace irq disabled critical timings This patch adds latency tracing for critical timings (how long interrupts are disabled for). "irqsoff" is added to /debugfs/tracing/available_tracers Note: tracing_max_latency also holds the max latency for irqsoff (in usecs). (default to large number so one must start latency tracing) tracing_thresh threshold (in usecs) to always print out if irqs off is detected to be longer than stated here. If irq_thresh is non-zero, then max_irq_latency is ignored. Here's an example of a trace with ftrace_enabled = 0 ======= preemption latency trace v1.1.5 on 2.6.24-rc7 Signed-off-by: Ingo Molnar -------------------------------------------------------------------- latency: 100 us, #3/3, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2) ----------------- | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0) ----------------- => started at: _spin_lock_irqsave+0x2a/0xb7 => ended at: _spin_unlock_irqrestore+0x32/0x5f _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / swapper-0 1d.s3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000]) swapper-0 1d.s3 100us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1d.s3 100us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f) vim:ft=help ======= And this is a trace with ftrace_enabled == 1 ======= preemption latency trace v1.1.5 on 2.6.24-rc7 -------------------------------------------------------------------- latency: 102 us, #12/12, CPU#1 | (M:rt VP:0, KP:0, SP:0 HP:0 #P:2) ----------------- | task: swapper-0 (uid:0 nice:0 policy:0 rt_prio:0) ----------------- => started at: _spin_lock_irqsave+0x2a/0xb7 => ended at: _spin_unlock_irqrestore+0x32/0x5f _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / swapper-0 1dNs3 0us+: _spin_lock_irqsave+0x2a/0xb7 (e1000_update_stats+0x47/0x64c [e1000]) swapper-0 1dNs3 46us : e1000_read_phy_reg+0x16/0x225 [e1000] (e1000_update_stats+0x5e2/0x64c [e1000]) swapper-0 1dNs3 46us : e1000_swfw_sync_acquire+0x10/0x99 [e1000] (e1000_read_phy_reg+0x49/0x225 [e1000]) swapper-0 1dNs3 46us : e1000_get_hw_eeprom_semaphore+0x12/0xa6 [e1000] (e1000_swfw_sync_acquire+0x36/0x99 [e1000]) swapper-0 1dNs3 47us : __const_udelay+0x9/0x47 (e1000_read_phy_reg+0x116/0x225 [e1000]) swapper-0 1dNs3 47us+: __delay+0x9/0x50 (__const_udelay+0x45/0x47) swapper-0 1dNs3 97us : preempt_schedule+0xc/0x84 (__delay+0x4e/0x50) swapper-0 1dNs3 98us : e1000_swfw_sync_release+0xc/0x55 [e1000] (e1000_read_phy_reg+0x211/0x225 [e1000]) swapper-0 1dNs3 99us+: e1000_put_hw_eeprom_semaphore+0x9/0x35 [e1000] (e1000_swfw_sync_release+0x50/0x55 [e1000]) swapper-0 1dNs3 101us : _spin_unlock_irqrestore+0xe/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1dNs3 102us : _spin_unlock_irqrestore+0x32/0x5f (e1000_update_stats+0x641/0x64c [e1000]) swapper-0 1dNs3 102us : trace_hardirqs_on_caller+0x75/0x89 (_spin_unlock_irqrestore+0x32/0x5f) vim:ft=help ======= Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/process_64.c | 3 + arch/x86/lib/Makefile | 1 + arch/x86/lib/thunk_32.S | 47 +++++ arch/x86/lib/thunk_64.S | 19 +- include/asm-x86/irqflags.h | 24 +-- include/linux/ftrace.h | 8 + include/linux/irqflags.h | 12 +- kernel/fork.c | 2 +- kernel/lockdep.c | 23 ++- kernel/printk.c | 2 + kernel/trace/Kconfig | 18 ++ kernel/trace/Makefile | 1 + kernel/trace/trace_irqsoff.c | 402 +++++++++++++++++++++++++++++++++++++++++++ 13 files changed, 531 insertions(+), 31 deletions(-) create mode 100644 arch/x86/lib/thunk_32.S create mode 100644 kernel/trace/trace_irqsoff.c (limited to 'arch') diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index e2319f39988..dd349c92f05 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -165,7 +165,10 @@ void cpu_idle(void) */ local_irq_disable(); enter_idle(); + /* Don't trace irqs off for idle */ + stop_critical_timings(); idle(); + start_critical_timings(); /* In many cases the interrupt that ended idle has already called exit_idle. But some idle loops can be woken up without interrupt. */ diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 76f60f52a88..84aa2883fe1 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -5,6 +5,7 @@ obj-$(CONFIG_SMP) := msr-on-cpu.o lib-y := delay_$(BITS).o +lib-y += thunk_$(BITS).o lib-y += usercopy_$(BITS).o getuser_$(BITS).o putuser_$(BITS).o lib-y += memcpy_$(BITS).o diff --git a/arch/x86/lib/thunk_32.S b/arch/x86/lib/thunk_32.S new file mode 100644 index 00000000000..650b11e00ec --- /dev/null +++ b/arch/x86/lib/thunk_32.S @@ -0,0 +1,47 @@ +/* + * Trampoline to trace irqs off. (otherwise CALLER_ADDR1 might crash) + * Copyright 2008 by Steven Rostedt, Red Hat, Inc + * (inspired by Andi Kleen's thunk_64.S) + * Subject to the GNU public license, v.2. No warranty of any kind. + */ + + #include + +#define ARCH_TRACE_IRQS_ON \ + pushl %eax; \ + pushl %ecx; \ + pushl %edx; \ + call trace_hardirqs_on; \ + popl %edx; \ + popl %ecx; \ + popl %eax; + +#define ARCH_TRACE_IRQS_OFF \ + pushl %eax; \ + pushl %ecx; \ + pushl %edx; \ + call trace_hardirqs_off; \ + popl %edx; \ + popl %ecx; \ + popl %eax; + +#ifdef CONFIG_TRACE_IRQFLAGS + /* put return address in eax (arg1) */ + .macro thunk_ra name,func + .globl \name +\name: + pushl %eax + pushl %ecx + pushl %edx + /* Place EIP in the arg1 */ + movl 3*4(%esp), %eax + call \func + popl %edx + popl %ecx + popl %eax + ret + .endm + + thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller + thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller +#endif diff --git a/arch/x86/lib/thunk_64.S b/arch/x86/lib/thunk_64.S index e009251d4e9..bf9a7d5a542 100644 --- a/arch/x86/lib/thunk_64.S +++ b/arch/x86/lib/thunk_64.S @@ -2,6 +2,7 @@ * Save registers before calling assembly functions. This avoids * disturbance of register allocation in some inline assembly constructs. * Copyright 2001,2002 by Andi Kleen, SuSE Labs. + * Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc. * Subject to the GNU public license, v.2. No warranty of any kind. */ @@ -42,8 +43,22 @@ #endif #ifdef CONFIG_TRACE_IRQFLAGS - thunk trace_hardirqs_on_thunk,trace_hardirqs_on - thunk trace_hardirqs_off_thunk,trace_hardirqs_off + /* put return address in rdi (arg1) */ + .macro thunk_ra name,func + .globl \name +\name: + CFI_STARTPROC + SAVE_ARGS + /* SAVE_ARGS pushs 9 elements */ + /* the next element would be the rip */ + movq 9*8(%rsp), %rdi + call \func + jmp restore + CFI_ENDPROC + .endm + + thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller + thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC diff --git a/include/asm-x86/irqflags.h b/include/asm-x86/irqflags.h index c242527f970..24d71b1eb18 100644 --- a/include/asm-x86/irqflags.h +++ b/include/asm-x86/irqflags.h @@ -179,8 +179,6 @@ static inline void trace_hardirqs_fixup(void) * have a reliable stack. x86_64 only. */ #define SWAPGS_UNSAFE_STACK swapgs -#define ARCH_TRACE_IRQS_ON call trace_hardirqs_on_thunk -#define ARCH_TRACE_IRQS_OFF call trace_hardirqs_off_thunk #define ARCH_LOCKDEP_SYS_EXIT call lockdep_sys_exit_thunk #define ARCH_LOCKDEP_SYS_EXIT_IRQ \ TRACE_IRQS_ON; \ @@ -192,24 +190,6 @@ static inline void trace_hardirqs_fixup(void) TRACE_IRQS_OFF; #else -#define ARCH_TRACE_IRQS_ON \ - pushl %eax; \ - pushl %ecx; \ - pushl %edx; \ - call trace_hardirqs_on; \ - popl %edx; \ - popl %ecx; \ - popl %eax; - -#define ARCH_TRACE_IRQS_OFF \ - pushl %eax; \ - pushl %ecx; \ - pushl %edx; \ - call trace_hardirqs_off; \ - popl %edx; \ - popl %ecx; \ - popl %eax; - #define ARCH_LOCKDEP_SYS_EXIT \ pushl %eax; \ pushl %ecx; \ @@ -223,8 +203,8 @@ static inline void trace_hardirqs_fixup(void) #endif #ifdef CONFIG_TRACE_IRQFLAGS -# define TRACE_IRQS_ON ARCH_TRACE_IRQS_ON -# define TRACE_IRQS_OFF ARCH_TRACE_IRQS_OFF +# define TRACE_IRQS_ON call trace_hardirqs_on_thunk; +# define TRACE_IRQS_OFF call trace_hardirqs_off_thunk; #else # define TRACE_IRQS_ON # define TRACE_IRQS_OFF diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index db8a5e7abe4..0a20445dcbc 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -50,4 +50,12 @@ extern void mcount(void); # define CALLER_ADDR5 0UL #endif +#ifdef CONFIG_IRQSOFF_TRACER + extern void notrace time_hardirqs_on(unsigned long a0, unsigned long a1); + extern void notrace time_hardirqs_off(unsigned long a0, unsigned long a1); +#else +# define time_hardirqs_on(a0, a1) do { } while (0) +# define time_hardirqs_off(a0, a1) do { } while (0) +#endif + #endif /* _LINUX_FTRACE_H */ diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index e600c4e9b8c..5b711d4e9fd 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -12,10 +12,10 @@ #define _LINUX_TRACE_IRQFLAGS_H #ifdef CONFIG_TRACE_IRQFLAGS - extern void trace_hardirqs_on(void); - extern void trace_hardirqs_off(void); extern void trace_softirqs_on(unsigned long ip); extern void trace_softirqs_off(unsigned long ip); + extern void trace_hardirqs_on(void); + extern void trace_hardirqs_off(void); # define trace_hardirq_context(p) ((p)->hardirq_context) # define trace_softirq_context(p) ((p)->softirq_context) # define trace_hardirqs_enabled(p) ((p)->hardirqs_enabled) @@ -41,6 +41,14 @@ # define INIT_TRACE_IRQFLAGS #endif +#ifdef CONFIG_IRQSOFF_TRACER + extern void stop_critical_timings(void); + extern void start_critical_timings(void); +#else +# define stop_critical_timings() do { } while (0) +# define start_critical_timings() do { } while (0) +#endif + #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT #include diff --git a/kernel/fork.c b/kernel/fork.c index 19908b26cf8..d66d676dc36 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -909,7 +909,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, rt_mutex_init_task(p); -#ifdef CONFIG_TRACE_IRQFLAGS +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_LOCKDEP) DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); #endif diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 81a4e4a3f08..e21924365ea 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -39,6 +39,7 @@ #include #include #include +#include #include @@ -982,7 +983,7 @@ check_noncircular(struct lock_class *source, unsigned int depth) return 1; } -#ifdef CONFIG_TRACE_IRQFLAGS +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) /* * Forwards and backwards subgraph searching, for the purposes of * proving that two subgraphs can be connected by a new dependency @@ -1680,7 +1681,7 @@ valid_state(struct task_struct *curr, struct held_lock *this, static int mark_lock(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit new_bit); -#ifdef CONFIG_TRACE_IRQFLAGS +#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) /* * print irq inversion bug: @@ -2013,11 +2014,13 @@ void early_boot_irqs_on(void) /* * Hardirqs will be enabled: */ -void trace_hardirqs_on(void) +void notrace trace_hardirqs_on_caller(unsigned long a0) { struct task_struct *curr = current; unsigned long ip; + time_hardirqs_on(CALLER_ADDR0, a0); + if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -2055,16 +2058,23 @@ void trace_hardirqs_on(void) curr->hardirq_enable_event = ++curr->irq_events; debug_atomic_inc(&hardirqs_on_events); } +EXPORT_SYMBOL(trace_hardirqs_on_caller); +void notrace trace_hardirqs_on(void) +{ + trace_hardirqs_on_caller(CALLER_ADDR0); +} EXPORT_SYMBOL(trace_hardirqs_on); /* * Hardirqs were disabled: */ -void trace_hardirqs_off(void) +void notrace trace_hardirqs_off_caller(unsigned long a0) { struct task_struct *curr = current; + time_hardirqs_off(CALLER_ADDR0, a0); + if (unlikely(!debug_locks || current->lockdep_recursion)) return; @@ -2082,7 +2092,12 @@ void trace_hardirqs_off(void) } else debug_atomic_inc(&redundant_hardirqs_off); } +EXPORT_SYMBOL(trace_hardirqs_off_caller); +void notrace trace_hardirqs_off(void) +{ + trace_hardirqs_off_caller(CALLER_ADDR0); +} EXPORT_SYMBOL(trace_hardirqs_off); /* diff --git a/kernel/printk.c b/kernel/printk.c index 8fb01c32aa3..ae7d5b9e535 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1041,7 +1041,9 @@ void release_console_sem(void) _log_end = log_end; con_start = log_end; /* Flush */ spin_unlock(&logbuf_lock); + stop_critical_timings(); /* don't trace print latency */ call_console_drivers(_con_start, _log_end); + start_critical_timings(); local_irq_restore(flags); } console_locked = 0; diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 892ecc94a82..896df1cf6ad 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -26,6 +26,24 @@ config FTRACE (the bootup default), then the overhead of the instructions is very small and not measurable even in micro-benchmarks. +config IRQSOFF_TRACER + bool "Interrupts-off Latency Tracer" + default n + depends on TRACE_IRQFLAGS_SUPPORT + depends on GENERIC_TIME + select TRACE_IRQFLAGS + select TRACING + select TRACER_MAX_TRACE + help + This option measures the time spent in irqs-off critical + sections, with microsecond accuracy. + + The default measurement method is a maximum search, which is + disabled by default and can be runtime (re-)started + via: + + echo 0 > /debugfs/tracing/tracing_max_latency + config SCHED_TRACER bool "Scheduling Latency Tracer" depends on DEBUG_KERNEL diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 5508cdb19ae..46be8647fb6 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -3,6 +3,7 @@ obj-$(CONFIG_FTRACE) += libftrace.o obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o obj-$(CONFIG_FTRACE) += trace_functions.o +obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c new file mode 100644 index 00000000000..a9131b0cf1a --- /dev/null +++ b/kernel/trace/trace_irqsoff.c @@ -0,0 +1,402 @@ +/* + * trace irqs off criticall timings + * + * Copyright (C) 2007-2008 Steven Rostedt + * Copyright (C) 2008 Ingo Molnar + * + * From code in the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 William Lee Irwin III + */ +#include +#include +#include +#include +#include +#include + +#include "trace.h" + +static struct trace_array *irqsoff_trace __read_mostly; +static int tracer_enabled __read_mostly; + +/* + * Sequence count - we record it when starting a measurement and + * skip the latency if the sequence has changed - some other section + * did a maximum and could disturb our measurement with serial console + * printouts, etc. Truly coinciding maximum latencies should be rare + * and what happens together happens separately as well, so this doesnt + * decrease the validity of the maximum found: + */ +static __cacheline_aligned_in_smp unsigned long max_sequence; + +#ifdef CONFIG_FTRACE +/* + * irqsoff uses its own tracer function to keep the overhead down: + */ +static void notrace +irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) +{ + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + + if (likely(!tracer_enabled)) + return; + + local_save_flags(flags); + + if (!irqs_disabled_flags(flags)) + return; + + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) + ftrace(tr, data, ip, parent_ip, flags); + + atomic_dec(&data->disabled); +} + +static struct ftrace_ops trace_ops __read_mostly = +{ + .func = irqsoff_tracer_call, +}; +#endif /* CONFIG_FTRACE */ + +/* + * Should this new latency be reported/recorded? + */ +static int notrace report_latency(cycle_t delta) +{ + if (tracing_thresh) { + if (delta < tracing_thresh) + return 0; + } else { + if (delta <= tracing_max_latency) + return 0; + } + return 1; +} + +static void notrace +check_critical_timing(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long parent_ip, + int cpu) +{ + unsigned long latency, t0, t1; + cycle_t T0, T1, T2, delta; + unsigned long flags; + + /* + * usecs conversion is slow so we try to delay the conversion + * as long as possible: + */ + T0 = data->preempt_timestamp; + T1 = now(cpu); + delta = T1-T0; + + local_save_flags(flags); + + if (!report_latency(delta)) + goto out; + + ftrace(tr, data, CALLER_ADDR0, parent_ip, flags); + /* + * Update the timestamp, because the trace entry above + * might change it (it can only get larger so the latency + * is fair to be reported): + */ + T2 = now(cpu); + + delta = T2-T0; + + latency = nsecs_to_usecs(delta); + + if (data->critical_sequence != max_sequence) + goto out; + + tracing_max_latency = delta; + t0 = nsecs_to_usecs(T0); + t1 = nsecs_to_usecs(T1); + + data->critical_end = parent_ip; + + update_max_tr_single(tr, current, cpu); + + if (tracing_thresh) + printk(KERN_INFO "(%16s-%-5d|#%d): %lu us critical section " + "violates %lu us threshold.\n" + " => started at timestamp %lu: ", + current->comm, current->pid, + raw_smp_processor_id(), + latency, nsecs_to_usecs(tracing_thresh), t0); + else + printk(KERN_INFO "(%16s-%-5d|#%d):" + " new %lu us maximum-latency " + "critical section.\n => started at timestamp %lu: ", + current->comm, current->pid, + raw_smp_processor_id(), + latency, t0); + + print_symbol(KERN_CONT "<%s>\n", data->critical_start); + printk(KERN_CONT " => ended at timestamp %lu: ", t1); + print_symbol(KERN_CONT "<%s>\n", data->critical_end); + dump_stack(); + t1 = nsecs_to_usecs(now(cpu)); + printk(KERN_CONT " => dump-end timestamp %lu\n\n", t1); + + max_sequence++; + +out: + data->critical_sequence = max_sequence; + data->preempt_timestamp = now(cpu); + tracing_reset(data); + ftrace(tr, data, CALLER_ADDR0, parent_ip, flags); +} + +static inline void notrace +start_critical_timing(unsigned long ip, unsigned long parent_ip) +{ + int cpu; + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + + if (likely(!tracer_enabled)) + return; + + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + + if (unlikely(!data) || unlikely(!data->trace) || + data->critical_start || atomic_read(&data->disabled)) + return; + + atomic_inc(&data->disabled); + + data->critical_sequence = max_sequence; + data->preempt_timestamp = now(cpu); + data->critical_start = parent_ip; + tracing_reset(data); + + local_save_flags(flags); + ftrace(tr, data, ip, parent_ip, flags); + + atomic_dec(&data->disabled); +} + +static inline void notrace +stop_critical_timing(unsigned long ip, unsigned long parent_ip) +{ + int cpu; + struct trace_array *tr = irqsoff_trace; + struct trace_array_cpu *data; + unsigned long flags; + + if (likely(!tracer_enabled)) + return; + + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + + if (unlikely(!data) || unlikely(!data->trace) || + !data->critical_start || atomic_read(&data->disabled)) + return; + + atomic_inc(&data->disabled); + local_save_flags(flags); + ftrace(tr, data, ip, parent_ip, flags); + check_critical_timing(tr, data, parent_ip, cpu); + data->critical_start = 0; + atomic_dec(&data->disabled); +} + +void notrace start_critical_timings(void) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} + +void notrace stop_critical_timings(void) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} + +#ifdef CONFIG_PROVE_LOCKING +void notrace time_hardirqs_on(unsigned long a0, unsigned long a1) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + stop_critical_timing(a0, a1); +} + +void notrace time_hardirqs_off(unsigned long a0, unsigned long a1) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + start_critical_timing(a0, a1); +} + +#else /* !CONFIG_PROVE_LOCKING */ + +/* + * Stubs: + */ + +void early_boot_irqs_off(void) +{ +} + +void early_boot_irqs_on(void) +{ +} + +void trace_softirqs_on(unsigned long ip) +{ +} + +void trace_softirqs_off(unsigned long ip) +{ +} + +inline void print_irqtrace_events(struct task_struct *curr) +{ +} + +/* + * We are only interested in hardirq on/off events: + */ +void notrace trace_hardirqs_on(void) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} +EXPORT_SYMBOL(trace_hardirqs_on); + +void notrace trace_hardirqs_off(void) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); +} +EXPORT_SYMBOL(trace_hardirqs_off); + +void notrace trace_hardirqs_on_caller(unsigned long caller_addr) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + stop_critical_timing(CALLER_ADDR0, caller_addr); +} +EXPORT_SYMBOL(trace_hardirqs_on_caller); + +void notrace trace_hardirqs_off_caller(unsigned long caller_addr) +{ + unsigned long flags; + + local_save_flags(flags); + + if (irqs_disabled_flags(flags)) + start_critical_timing(CALLER_ADDR0, caller_addr); +} +EXPORT_SYMBOL(trace_hardirqs_off_caller); + +#endif /* CONFIG_PROVE_LOCKING */ + +static void start_irqsoff_tracer(struct trace_array *tr) +{ + tracer_enabled = 1; + register_ftrace_function(&trace_ops); +} + +static void stop_irqsoff_tracer(struct trace_array *tr) +{ + unregister_ftrace_function(&trace_ops); + tracer_enabled = 0; +} + +static void irqsoff_tracer_init(struct trace_array *tr) +{ + irqsoff_trace = tr; + /* make sure that the tracer is visibel */ + smp_wmb(); + + if (tr->ctrl) + start_irqsoff_tracer(tr); +} + +static void irqsoff_tracer_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_irqsoff_tracer(tr); +} + +static void irqsoff_tracer_ctrl_update(struct trace_array *tr) +{ + if (tr->ctrl) + start_irqsoff_tracer(tr); + else + stop_irqsoff_tracer(tr); +} + +static void notrace irqsoff_tracer_open(struct trace_iterator *iter) +{ + /* stop the trace while dumping */ + if (iter->tr->ctrl) + stop_irqsoff_tracer(iter->tr); +} + +static void notrace irqsoff_tracer_close(struct trace_iterator *iter) +{ + if (iter->tr->ctrl) + start_irqsoff_tracer(iter->tr); +} + +static struct tracer irqsoff_tracer __read_mostly = +{ + .name = "irqsoff", + .init = irqsoff_tracer_init, + .reset = irqsoff_tracer_reset, + .open = irqsoff_tracer_open, + .close = irqsoff_tracer_close, + .ctrl_update = irqsoff_tracer_ctrl_update, + .print_max = 1, +}; + +__init static int init_irqsoff_tracer(void) +{ + register_tracer(&irqsoff_tracer); + + return 0; +} +device_initcall(init_irqsoff_tracer); -- cgit v1.2.3-70-g09d2 From 6cd8a4bb2f97527a9ceb30bc77ea4e959c6a95e3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:42 +0200 Subject: ftrace: trace preempt off critical timings Add preempt off timings. A lot of kernel core code is taken from the RT patch latency trace that was written by Ingo Molnar. This adds "preemptoff" and "preemptirqsoff" to /debugfs/tracing/available_tracers Now instead of just tracing irqs off, preemption off can be selected to be recorded. When this is selected, it shares the same files as irqs off timings. One can either trace preemption off, irqs off, or one or the other off. By echoing "preemptoff" into /debugfs/tracing/current_tracer, recording of preempt off only is performed. "irqsoff" will only record the time irqs are disabled, but "preemptirqsoff" will take the total time irqs or preemption are disabled. Runtime switching of these options is now supported by simpling echoing in the appropriate trace name into /debugfs/tracing/current_tracer. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/process_32.c | 3 + include/linux/ftrace.h | 8 ++ include/linux/irqflags.h | 3 +- include/linux/preempt.h | 2 +- kernel/sched.c | 24 +++++- kernel/trace/Kconfig | 25 ++++++ kernel/trace/Makefile | 1 + kernel/trace/trace_irqsoff.c | 184 +++++++++++++++++++++++++++++++------------ 8 files changed, 197 insertions(+), 53 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index f8476dfbb60..a30aa1f2607 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -185,7 +185,10 @@ void cpu_idle(void) local_irq_disable(); __get_cpu_var(irq_stat).idle_timestamp = jiffies; + /* Don't trace irqs off for idle */ + stop_critical_timings(); idle(); + start_critical_timings(); } tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 0a20445dcbc..740c97dcf9c 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -58,4 +58,12 @@ extern void mcount(void); # define time_hardirqs_off(a0, a1) do { } while (0) #endif +#ifdef CONFIG_PREEMPT_TRACER + extern void notrace trace_preempt_on(unsigned long a0, unsigned long a1); + extern void notrace trace_preempt_off(unsigned long a0, unsigned long a1); +#else +# define trace_preempt_on(a0, a1) do { } while (0) +# define trace_preempt_off(a0, a1) do { } while (0) +#endif + #endif /* _LINUX_FTRACE_H */ diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 5b711d4e9fd..2b1c2e58566 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -41,7 +41,8 @@ # define INIT_TRACE_IRQFLAGS #endif -#ifdef CONFIG_IRQSOFF_TRACER +#if defined(CONFIG_IRQSOFF_TRACER) || \ + defined(CONFIG_PREEMPT_TRACER) extern void stop_critical_timings(void); extern void start_critical_timings(void); #else diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 36b03d50bf4..72b1a10a59b 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -10,7 +10,7 @@ #include #include -#ifdef CONFIG_DEBUG_PREEMPT +#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER) extern void add_preempt_count(int val); extern void sub_preempt_count(int val); #else diff --git a/kernel/sched.c b/kernel/sched.c index 73e60085236..328494e28df 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -70,6 +70,7 @@ #include #include #include +#include #include #include @@ -4365,26 +4366,44 @@ void scheduler_tick(void) #endif } -#if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT) +#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ + defined(CONFIG_PREEMPT_TRACER)) + +static inline unsigned long get_parent_ip(unsigned long addr) +{ + if (in_lock_functions(addr)) { + addr = CALLER_ADDR2; + if (in_lock_functions(addr)) + addr = CALLER_ADDR3; + } + return addr; +} void __kprobes add_preempt_count(int val) { +#ifdef CONFIG_DEBUG_PREEMPT /* * Underflow? */ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) return; +#endif preempt_count() += val; +#ifdef CONFIG_DEBUG_PREEMPT /* * Spinlock count overflowing soon? */ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= PREEMPT_MASK - 10); +#endif + if (preempt_count() == val) + trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); } EXPORT_SYMBOL(add_preempt_count); void __kprobes sub_preempt_count(int val) { +#ifdef CONFIG_DEBUG_PREEMPT /* * Underflow? */ @@ -4396,7 +4415,10 @@ void __kprobes sub_preempt_count(int val) if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && !(preempt_count() & PREEMPT_MASK))) return; +#endif + if (preempt_count() == val) + trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); preempt_count() -= val; } EXPORT_SYMBOL(sub_preempt_count); diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 896df1cf6ad..6430016b98e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -44,6 +44,31 @@ config IRQSOFF_TRACER echo 0 > /debugfs/tracing/tracing_max_latency + (Note that kernel size and overhead increases with this option + enabled. This option and the preempt-off timing option can be + used together or separately.) + +config PREEMPT_TRACER + bool "Preemption-off Latency Tracer" + default n + depends on GENERIC_TIME + depends on PREEMPT + select TRACING + select TRACER_MAX_TRACE + help + This option measures the time spent in preemption off critical + sections, with microsecond accuracy. + + The default measurement method is a maximum search, which is + disabled by default and can be runtime (re-)started + via: + + echo 0 > /debugfs/tracing/tracing_max_latency + + (Note that kernel size and overhead increases with this option + enabled. This option and the irqs-off timing option can be + used together or separately.) + config SCHED_TRACER bool "Scheduling Latency Tracer" depends on DEBUG_KERNEL diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 46be8647fb6..3fec653d653 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o obj-$(CONFIG_FTRACE) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o +obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index a9131b0cf1a..8b1231633dc 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -21,6 +21,36 @@ static struct trace_array *irqsoff_trace __read_mostly; static int tracer_enabled __read_mostly; +static DEFINE_PER_CPU(int, tracing_cpu); + +enum { + TRACER_IRQS_OFF = (1 << 1), + TRACER_PREEMPT_OFF = (1 << 2), +}; + +static int trace_type __read_mostly; + +#ifdef CONFIG_PREEMPT_TRACER +static inline int notrace +preempt_trace(void) +{ + return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count()); +} +#else +# define preempt_trace() (0) +#endif + +#ifdef CONFIG_IRQSOFF_TRACER +static inline int notrace +irq_trace(void) +{ + return ((trace_type & TRACER_IRQS_OFF) && + irqs_disabled()); +} +#else +# define irq_trace() (0) +#endif + /* * Sequence count - we record it when starting a measurement and * skip the latency if the sequence has changed - some other section @@ -44,14 +74,11 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) long disabled; int cpu; - if (likely(!tracer_enabled)) + if (likely(!__get_cpu_var(tracing_cpu))) return; local_save_flags(flags); - if (!irqs_disabled_flags(flags)) - return; - cpu = raw_smp_processor_id(); data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); @@ -171,23 +198,29 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip) if (likely(!tracer_enabled)) return; + if (__get_cpu_var(tracing_cpu)) + return; + cpu = raw_smp_processor_id(); data = tr->data[cpu]; if (unlikely(!data) || unlikely(!data->trace) || - data->critical_start || atomic_read(&data->disabled)) + atomic_read(&data->disabled)) return; atomic_inc(&data->disabled); data->critical_sequence = max_sequence; data->preempt_timestamp = now(cpu); - data->critical_start = parent_ip; + data->critical_start = parent_ip ? : ip; tracing_reset(data); local_save_flags(flags); + ftrace(tr, data, ip, parent_ip, flags); + __get_cpu_var(tracing_cpu) = 1; + atomic_dec(&data->disabled); } @@ -199,7 +232,13 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) struct trace_array_cpu *data; unsigned long flags; - if (likely(!tracer_enabled)) + /* Always clear the tracing cpu on stopping the trace */ + if (unlikely(__get_cpu_var(tracing_cpu))) + __get_cpu_var(tracing_cpu) = 0; + else + return; + + if (!tracer_enabled) return; cpu = raw_smp_processor_id(); @@ -212,49 +251,35 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) atomic_inc(&data->disabled); local_save_flags(flags); ftrace(tr, data, ip, parent_ip, flags); - check_critical_timing(tr, data, parent_ip, cpu); + check_critical_timing(tr, data, parent_ip ? : ip, cpu); data->critical_start = 0; atomic_dec(&data->disabled); } +/* start and stop critical timings used to for stoppage (in idle) */ void notrace start_critical_timings(void) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (preempt_trace() || irq_trace()) start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); } void notrace stop_critical_timings(void) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (preempt_trace() || irq_trace()) stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); } +#ifdef CONFIG_IRQSOFF_TRACER #ifdef CONFIG_PROVE_LOCKING void notrace time_hardirqs_on(unsigned long a0, unsigned long a1) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (!preempt_trace() && irq_trace()) stop_critical_timing(a0, a1); } void notrace time_hardirqs_off(unsigned long a0, unsigned long a1) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (!preempt_trace() && irq_trace()) start_critical_timing(a0, a1); } @@ -289,49 +314,46 @@ inline void print_irqtrace_events(struct task_struct *curr) */ void notrace trace_hardirqs_on(void) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (!preempt_trace() && irq_trace()) stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); } EXPORT_SYMBOL(trace_hardirqs_on); void notrace trace_hardirqs_off(void) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (!preempt_trace() && irq_trace()) start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); } EXPORT_SYMBOL(trace_hardirqs_off); void notrace trace_hardirqs_on_caller(unsigned long caller_addr) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (!preempt_trace() && irq_trace()) stop_critical_timing(CALLER_ADDR0, caller_addr); } EXPORT_SYMBOL(trace_hardirqs_on_caller); void notrace trace_hardirqs_off_caller(unsigned long caller_addr) { - unsigned long flags; - - local_save_flags(flags); - - if (irqs_disabled_flags(flags)) + if (!preempt_trace() && irq_trace()) start_critical_timing(CALLER_ADDR0, caller_addr); } EXPORT_SYMBOL(trace_hardirqs_off_caller); #endif /* CONFIG_PROVE_LOCKING */ +#endif /* CONFIG_IRQSOFF_TRACER */ + +#ifdef CONFIG_PREEMPT_TRACER +void notrace trace_preempt_on(unsigned long a0, unsigned long a1) +{ + stop_critical_timing(a0, a1); +} + +void notrace trace_preempt_off(unsigned long a0, unsigned long a1) +{ + start_critical_timing(a0, a1); +} +#endif /* CONFIG_PREEMPT_TRACER */ static void start_irqsoff_tracer(struct trace_array *tr) { @@ -345,7 +367,7 @@ static void stop_irqsoff_tracer(struct trace_array *tr) tracer_enabled = 0; } -static void irqsoff_tracer_init(struct trace_array *tr) +static void __irqsoff_tracer_init(struct trace_array *tr) { irqsoff_trace = tr; /* make sure that the tracer is visibel */ @@ -382,6 +404,13 @@ static void notrace irqsoff_tracer_close(struct trace_iterator *iter) start_irqsoff_tracer(iter->tr); } +#ifdef CONFIG_IRQSOFF_TRACER +static void irqsoff_tracer_init(struct trace_array *tr) +{ + trace_type = TRACER_IRQS_OFF; + + __irqsoff_tracer_init(tr); +} static struct tracer irqsoff_tracer __read_mostly = { .name = "irqsoff", @@ -392,10 +421,65 @@ static struct tracer irqsoff_tracer __read_mostly = .ctrl_update = irqsoff_tracer_ctrl_update, .print_max = 1, }; +# define register_irqsoff(trace) register_tracer(&trace) +#else +# define register_irqsoff(trace) do { } while (0) +#endif + +#ifdef CONFIG_PREEMPT_TRACER +static void preemptoff_tracer_init(struct trace_array *tr) +{ + trace_type = TRACER_PREEMPT_OFF; + + __irqsoff_tracer_init(tr); +} + +static struct tracer preemptoff_tracer __read_mostly = +{ + .name = "preemptoff", + .init = preemptoff_tracer_init, + .reset = irqsoff_tracer_reset, + .open = irqsoff_tracer_open, + .close = irqsoff_tracer_close, + .ctrl_update = irqsoff_tracer_ctrl_update, + .print_max = 1, +}; +# define register_preemptoff(trace) register_tracer(&trace) +#else +# define register_preemptoff(trace) do { } while (0) +#endif + +#if defined(CONFIG_IRQSOFF_TRACER) && \ + defined(CONFIG_PREEMPT_TRACER) + +static void preemptirqsoff_tracer_init(struct trace_array *tr) +{ + trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF; + + __irqsoff_tracer_init(tr); +} + +static struct tracer preemptirqsoff_tracer __read_mostly = +{ + .name = "preemptirqsoff", + .init = preemptirqsoff_tracer_init, + .reset = irqsoff_tracer_reset, + .open = irqsoff_tracer_open, + .close = irqsoff_tracer_close, + .ctrl_update = irqsoff_tracer_ctrl_update, + .print_max = 1, +}; + +# define register_preemptirqsoff(trace) register_tracer(&trace) +#else +# define register_preemptirqsoff(trace) do { } while (0) +#endif __init static int init_irqsoff_tracer(void) { - register_tracer(&irqsoff_tracer); + register_irqsoff(irqsoff_tracer); + register_preemptoff(preemptoff_tracer); + register_preemptirqsoff(preemptirqsoff_tracer); return 0; } -- cgit v1.2.3-70-g09d2 From 3d0833953e1b98b79ddf491dd49229eef9baeac1 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:42 +0200 Subject: ftrace: dynamic enabling/disabling of function calls This patch adds a feature to dynamically replace the ftrace code with the jmps to allow a kernel with ftrace configured to run as fast as it can without it configured. The way this works, is on bootup (if ftrace is enabled), a ftrace function is registered to record the instruction pointer of all places that call the function. Later, if there's still any code to patch, a kthread is awoken (rate limited to at most once a second) that performs a stop_machine, and replaces all the code that was called with a jmp over the call to ftrace. It only replaces what was found the previous time. Typically the system reaches equilibrium quickly after bootup and there's no code patching needed at all. e.g. call ftrace /* 5 bytes */ is replaced with jmp 3f /* jmp is 2 bytes and we jump 3 forward */ 3: When we want to enable ftrace for function tracing, the IP recording is removed, and stop_machine is called again to replace all the locations of that were recorded back to the call of ftrace. When it is disabled, we replace the code back to the jmp. Allocation is done by the kthread. If the ftrace recording function is called, and we don't have any record slots available, then we simply skip that call. Once a second a new page (if needed) is allocated for recording new ftrace function calls. A large batch is allocated at boot up to get most of the calls there. Because we do this via stop_machine, we don't have to worry about another CPU executing a ftrace call as we modify it. But we do need to worry about NMI's so all functions that might be called via nmi must be annotated with notrace_nmi. When this code is configured in, the NMI code will not call notrace. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/Makefile | 1 + arch/x86/kernel/ftrace.c | 237 +++++++++++++++++++++++++++++++ include/linux/ftrace.h | 18 +++ kernel/trace/Kconfig | 17 +++ kernel/trace/ftrace.c | 356 ++++++++++++++++++++++++++++++++++++++++++----- 5 files changed, 597 insertions(+), 32 deletions(-) create mode 100644 arch/x86/kernel/ftrace.c (limited to 'arch') diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 5e618c3b472..e142091524b 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_X86_MPPARSE) += mpparse.o obj-$(CONFIG_X86_LOCAL_APIC) += apic_$(BITS).o nmi_$(BITS).o obj-$(CONFIG_X86_IO_APIC) += io_apic_$(BITS).o obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o +obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c new file mode 100644 index 00000000000..5dd58136ef0 --- /dev/null +++ b/arch/x86/kernel/ftrace.c @@ -0,0 +1,237 @@ +/* + * Code for replacing ftrace calls with jumps. + * + * Copyright (C) 2007-2008 Steven Rostedt + * + * Thanks goes to Ingo Molnar, for suggesting the idea. + * Mathieu Desnoyers, for suggesting postponing the modifications. + * Arjan van de Ven, for keeping me straight, and explaining to me + * the dangers of modifying code on the run. + */ + +#include +#include +#include +#include +#include +#include + +#define CALL_BACK 5 + +#define JMPFWD 0x03eb + +static unsigned short ftrace_jmp = JMPFWD; + +struct ftrace_record { + struct dyn_ftrace rec; + int failed; +} __attribute__((packed)); + +struct ftrace_page { + struct ftrace_page *next; + int index; + struct ftrace_record records[]; +} __attribute__((packed)); + +#define ENTRIES_PER_PAGE \ + ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct ftrace_record)) + +/* estimate from running different kernels */ +#define NR_TO_INIT 10000 + +#define MCOUNT_ADDR ((long)(&mcount)) + +union ftrace_code_union { + char code[5]; + struct { + char e8; + int offset; + } __attribute__((packed)); +}; + +static struct ftrace_page *ftrace_pages_start; +static struct ftrace_page *ftrace_pages; + +notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip) +{ + struct ftrace_record *rec; + unsigned short save; + + ip -= CALL_BACK; + save = *(short *)ip; + + /* If this was already converted, skip it */ + if (save == JMPFWD) + return NULL; + + if (ftrace_pages->index == ENTRIES_PER_PAGE) { + if (!ftrace_pages->next) + return NULL; + ftrace_pages = ftrace_pages->next; + } + + rec = &ftrace_pages->records[ftrace_pages->index++]; + + return &rec->rec; +} + +static int notrace +ftrace_modify_code(unsigned long ip, unsigned char *old_code, + unsigned char *new_code) +{ + unsigned short old = *(unsigned short *)old_code; + unsigned short new = *(unsigned short *)new_code; + unsigned short replaced; + int faulted = 0; + + /* + * Note: Due to modules and __init, code can + * disappear and change, we need to protect against faulting + * as well as code changing. + * + * No real locking needed, this code is run through + * kstop_machine. + */ + asm volatile ( + "1: lock\n" + " cmpxchg %w3, (%2)\n" + "2:\n" + ".section .fixup, \"ax\"\n" + " movl $1, %0\n" + "3: jmp 2b\n" + ".previous\n" + _ASM_EXTABLE(1b, 3b) + : "=r"(faulted), "=a"(replaced) + : "r"(ip), "r"(new), "0"(faulted), "a"(old) + : "memory"); + sync_core(); + + if (replaced != old) + faulted = 2; + + return faulted; +} + +static int notrace ftrace_calc_offset(long ip) +{ + return (int)(MCOUNT_ADDR - ip); +} + +notrace void ftrace_code_disable(struct dyn_ftrace *rec) +{ + unsigned long ip; + union ftrace_code_union save; + struct ftrace_record *r = + container_of(rec, struct ftrace_record, rec); + + ip = rec->ip; + + save.e8 = 0xe8; + save.offset = ftrace_calc_offset(ip); + + /* move the IP back to the start of the call */ + ip -= CALL_BACK; + + r->failed = ftrace_modify_code(ip, save.code, (char *)&ftrace_jmp); +} + +static void notrace ftrace_replace_code(int saved) +{ + unsigned char *new = NULL, *old = NULL; + struct ftrace_record *rec; + struct ftrace_page *pg; + unsigned long ip; + int i; + + if (saved) + old = (char *)&ftrace_jmp; + else + new = (char *)&ftrace_jmp; + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + for (i = 0; i < pg->index; i++) { + union ftrace_code_union calc; + rec = &pg->records[i]; + + /* don't modify code that has already faulted */ + if (rec->failed) + continue; + + ip = rec->rec.ip; + + calc.e8 = 0xe8; + calc.offset = ftrace_calc_offset(ip); + + if (saved) + new = calc.code; + else + old = calc.code; + + ip -= CALL_BACK; + + rec->failed = ftrace_modify_code(ip, old, new); + } + } + +} + +notrace void ftrace_startup_code(void) +{ + ftrace_replace_code(1); +} + +notrace void ftrace_shutdown_code(void) +{ + ftrace_replace_code(0); +} + +notrace void ftrace_shutdown_replenish(void) +{ + if (ftrace_pages->next) + return; + + /* allocate another page */ + ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); +} + +notrace int ftrace_shutdown_arch_init(void) +{ + struct ftrace_page *pg; + int cnt; + int i; + + /* allocate a few pages */ + ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); + if (!ftrace_pages_start) + return -1; + + /* + * Allocate a few more pages. + * + * TODO: have some parser search vmlinux before + * final linking to find all calls to ftrace. + * Then we can: + * a) know how many pages to allocate. + * and/or + * b) set up the table then. + * + * The dynamic code is still necessary for + * modules. + */ + + pg = ftrace_pages = ftrace_pages_start; + + cnt = NR_TO_INIT / ENTRIES_PER_PAGE; + + for (i = 0; i < cnt; i++) { + pg->next = (void *)get_zeroed_page(GFP_KERNEL); + + /* If we fail, we'll try later anyway */ + if (!pg->next) + break; + + pg = pg->next; + } + + return 0; +} diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 740c97dcf9c..90dbc0ee204 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -32,6 +32,24 @@ extern void mcount(void); # define clear_ftrace_function(ops) do { } while (0) #endif /* CONFIG_FTRACE */ +#ifdef CONFIG_DYNAMIC_FTRACE +# define FTRACE_HASHBITS 10 +# define FTRACE_HASHSIZE (1< +#include +#include +#include +#include +#include #include +#include +#include +#include + +#include "trace.h" -static DEFINE_SPINLOCK(ftrace_func_lock); +static DEFINE_SPINLOCK(ftrace_lock); static struct ftrace_ops ftrace_list_end __read_mostly = { .func = ftrace_stub, @@ -44,21 +53,21 @@ notrace void ftrace_list_func(unsigned long ip, unsigned long parent_ip) } /** - * register_ftrace_function - register a function for profiling - * @ops - ops structure that holds the function for profiling. - * - * Register a function to be called by all functions in the - * kernel. + * clear_ftrace_function - reset the ftrace function * - * Note: @ops->func and all the functions it calls must be labeled - * with "notrace", otherwise it will go into a - * recursive loop. + * This NULLs the ftrace function and in essence stops + * tracing. There may be lag */ -int register_ftrace_function(struct ftrace_ops *ops) +void clear_ftrace_function(void) { - unsigned long flags; + ftrace_trace_function = ftrace_stub; +} + +static int notrace __register_ftrace_function(struct ftrace_ops *ops) +{ + /* Should never be called by interrupts */ + spin_lock(&ftrace_lock); - spin_lock_irqsave(&ftrace_func_lock, flags); ops->next = ftrace_list; /* * We are entering ops into the ftrace_list but another @@ -68,6 +77,7 @@ int register_ftrace_function(struct ftrace_ops *ops) */ smp_wmb(); ftrace_list = ops; + /* * For one func, simply call it directly. * For more than one func, call the chain. @@ -76,28 +86,22 @@ int register_ftrace_function(struct ftrace_ops *ops) ftrace_trace_function = ops->func; else ftrace_trace_function = ftrace_list_func; - spin_unlock_irqrestore(&ftrace_func_lock, flags); + + spin_unlock(&ftrace_lock); return 0; } -/** - * unregister_ftrace_function - unresgister a function for profiling. - * @ops - ops structure that holds the function to unregister - * - * Unregister a function that was added to be called by ftrace profiling. - */ -int unregister_ftrace_function(struct ftrace_ops *ops) +static int notrace __unregister_ftrace_function(struct ftrace_ops *ops) { - unsigned long flags; struct ftrace_ops **p; int ret = 0; - spin_lock_irqsave(&ftrace_func_lock, flags); + spin_lock(&ftrace_lock); /* - * If we are the only function, then the ftrace pointer is - * pointing directly to that function. + * If we are removing the last function, then simply point + * to the ftrace_stub. */ if (ftrace_list == ops && ops->next == &ftrace_list_end) { ftrace_trace_function = ftrace_stub; @@ -117,22 +121,310 @@ int unregister_ftrace_function(struct ftrace_ops *ops) *p = (*p)->next; /* If we only have one func left, then call that directly */ - if (ftrace_list->next == &ftrace_list_end) + if (ftrace_list == &ftrace_list_end || + ftrace_list->next == &ftrace_list_end) ftrace_trace_function = ftrace_list->func; out: - spin_unlock_irqrestore(&ftrace_func_lock, flags); + spin_unlock(&ftrace_lock); + + return ret; +} + +#ifdef CONFIG_DYNAMIC_FTRACE + +static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; + +static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); + +static DEFINE_SPINLOCK(ftrace_shutdown_lock); +static DEFINE_MUTEX(ftraced_lock); + +static int ftraced_trigger; +static int ftraced_suspend; + +static int ftrace_record_suspend; + +static inline int +notrace ftrace_ip_in_hash(unsigned long ip, unsigned long key) +{ + struct dyn_ftrace *p; + struct hlist_node *t; + int found = 0; + + hlist_for_each_entry(p, t, &ftrace_hash[key], node) { + if (p->ip == ip) { + found = 1; + break; + } + } + + return found; +} + +static inline void notrace +ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) +{ + hlist_add_head(&node->node, &ftrace_hash[key]); +} + +static void notrace +ftrace_record_ip(unsigned long ip, unsigned long parent_ip) +{ + struct dyn_ftrace *node; + unsigned long flags; + unsigned long key; + int resched; + int atomic; + + resched = need_resched(); + preempt_disable_notrace(); + + /* We simply need to protect against recursion */ + __get_cpu_var(ftrace_shutdown_disable_cpu)++; + if (__get_cpu_var(ftrace_shutdown_disable_cpu) != 1) + goto out; + + if (unlikely(ftrace_record_suspend)) + goto out; + + key = hash_long(ip, FTRACE_HASHBITS); + + WARN_ON_ONCE(key >= FTRACE_HASHSIZE); + + if (ftrace_ip_in_hash(ip, key)) + goto out; + + atomic = irqs_disabled(); + + spin_lock_irqsave(&ftrace_shutdown_lock, flags); + + /* This ip may have hit the hash before the lock */ + if (ftrace_ip_in_hash(ip, key)) + goto out_unlock; + + /* + * There's a slight race that the ftraced will update the + * hash and reset here. The arch alloc is responsible + * for seeing if the IP has already changed, and if + * it has, the alloc will fail. + */ + node = ftrace_alloc_shutdown_node(ip); + if (!node) + goto out_unlock; + + node->ip = ip; + + ftrace_add_hash(node, key); + + ftraced_trigger = 1; + + out_unlock: + spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); + out: + __get_cpu_var(ftrace_shutdown_disable_cpu)--; + + /* prevent recursion with scheduler */ + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); +} + +static struct ftrace_ops ftrace_shutdown_ops __read_mostly = +{ + .func = ftrace_record_ip, +}; + + +static int notrace __ftrace_modify_code(void *data) +{ + void (*func)(void) = data; + + func(); + return 0; +} + +static void notrace ftrace_run_startup_code(void) +{ + stop_machine_run(__ftrace_modify_code, ftrace_startup_code, NR_CPUS); +} + +static void notrace ftrace_run_shutdown_code(void) +{ + stop_machine_run(__ftrace_modify_code, ftrace_shutdown_code, NR_CPUS); +} + +static void notrace ftrace_startup(void) +{ + mutex_lock(&ftraced_lock); + ftraced_suspend++; + if (ftraced_suspend != 1) + goto out; + __unregister_ftrace_function(&ftrace_shutdown_ops); + + ftrace_run_startup_code(); + out: + mutex_unlock(&ftraced_lock); +} + +static void notrace ftrace_shutdown(void) +{ + mutex_lock(&ftraced_lock); + ftraced_suspend--; + if (ftraced_suspend) + goto out; + + ftrace_run_shutdown_code(); + + __register_ftrace_function(&ftrace_shutdown_ops); + out: + mutex_unlock(&ftraced_lock); +} + +static cycle_t ftrace_update_time; +static unsigned long ftrace_update_cnt; +unsigned long ftrace_update_tot_cnt; + +static int notrace __ftrace_update_code(void *ignore) +{ + struct dyn_ftrace *p; + struct hlist_head head; + struct hlist_node *t; + cycle_t start, stop; + int i; + + /* Don't be calling ftrace ops now */ + __unregister_ftrace_function(&ftrace_shutdown_ops); + + start = now(raw_smp_processor_id()); + ftrace_update_cnt = 0; + + /* No locks needed, the machine is stopped! */ + for (i = 0; i < FTRACE_HASHSIZE; i++) { + if (hlist_empty(&ftrace_hash[i])) + continue; + + head = ftrace_hash[i]; + INIT_HLIST_HEAD(&ftrace_hash[i]); + + /* all CPUS are stopped, we are safe to modify code */ + hlist_for_each_entry(p, t, &head, node) { + ftrace_code_disable(p); + ftrace_update_cnt++; + } + + } + + stop = now(raw_smp_processor_id()); + ftrace_update_time = stop - start; + ftrace_update_tot_cnt += ftrace_update_cnt; + + __register_ftrace_function(&ftrace_shutdown_ops); return 0; } +static void notrace ftrace_update_code(void) +{ + stop_machine_run(__ftrace_update_code, NULL, NR_CPUS); +} + +static int notrace ftraced(void *ignore) +{ + unsigned long usecs; + + set_current_state(TASK_INTERRUPTIBLE); + + while (!kthread_should_stop()) { + + /* check once a second */ + schedule_timeout(HZ); + + mutex_lock(&ftraced_lock); + if (ftraced_trigger && !ftraced_suspend) { + ftrace_record_suspend++; + ftrace_update_code(); + usecs = nsecs_to_usecs(ftrace_update_time); + if (ftrace_update_tot_cnt > 100000) { + ftrace_update_tot_cnt = 0; + pr_info("hm, dftrace overflow: %lu change%s" + " (%lu total) in %lu usec%s\n", + ftrace_update_cnt, + ftrace_update_cnt != 1 ? "s" : "", + ftrace_update_tot_cnt, + usecs, usecs != 1 ? "s" : ""); + WARN_ON_ONCE(1); + } + ftraced_trigger = 0; + ftrace_record_suspend--; + } + mutex_unlock(&ftraced_lock); + + ftrace_shutdown_replenish(); + + set_current_state(TASK_INTERRUPTIBLE); + } + __set_current_state(TASK_RUNNING); + return 0; +} + +static int __init notrace ftrace_shutdown_init(void) +{ + struct task_struct *p; + int ret; + + ret = ftrace_shutdown_arch_init(); + if (ret) + return ret; + + p = kthread_run(ftraced, NULL, "ftraced"); + if (IS_ERR(p)) + return -1; + + __register_ftrace_function(&ftrace_shutdown_ops); + + return 0; +} + +core_initcall(ftrace_shutdown_init); +#else +# define ftrace_startup() do { } while (0) +# define ftrace_shutdown() do { } while (0) +#endif /* CONFIG_DYNAMIC_FTRACE */ + /** - * clear_ftrace_function - reset the ftrace function + * register_ftrace_function - register a function for profiling + * @ops - ops structure that holds the function for profiling. * - * This NULLs the ftrace function and in essence stops - * tracing. There may be lag + * Register a function to be called by all functions in the + * kernel. + * + * Note: @ops->func and all the functions it calls must be labeled + * with "notrace", otherwise it will go into a + * recursive loop. */ -void clear_ftrace_function(void) +int register_ftrace_function(struct ftrace_ops *ops) { - ftrace_trace_function = ftrace_stub; + ftrace_startup(); + + return __register_ftrace_function(ops); +} + +/** + * unregister_ftrace_function - unresgister a function for profiling. + * @ops - ops structure that holds the function to unregister + * + * Unregister a function that was added to be called by ftrace profiling. + */ +int unregister_ftrace_function(struct ftrace_ops *ops) +{ + int ret; + + ret = __unregister_ftrace_function(ops); + + if (ftrace_list == &ftrace_list_end) + ftrace_shutdown(); + + return ret; } -- cgit v1.2.3-70-g09d2 From dfa60aba04dae7833d75b2e2be124bb7cfb8239f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:43 +0200 Subject: ftrace: use nops instead of jmp This patch patches the call to mcount with nops instead of a jmp over the mcount call. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/alternative.c | 4 ++-- arch/x86/kernel/ftrace.c | 40 ++++++++++++++++++++++++---------------- include/asm-x86/alternative.h | 2 ++ 3 files changed, 28 insertions(+), 18 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 65c7857a90d..de240ba2e28 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -143,7 +143,7 @@ static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = { #ifdef CONFIG_X86_64 extern char __vsyscall_0; -static inline const unsigned char*const * find_nop_table(void) +const unsigned char *const *find_nop_table(void) { return boot_cpu_data.x86_vendor != X86_VENDOR_INTEL || boot_cpu_data.x86 < 6 ? k8_nops : p6_nops; @@ -162,7 +162,7 @@ static const struct nop { { -1, NULL } }; -static const unsigned char*const * find_nop_table(void) +const unsigned char *const *find_nop_table(void) { const unsigned char *const *noptable = intel_nops; int i; diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 5dd58136ef0..2e060c58b86 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -16,11 +16,12 @@ #include #include -#define CALL_BACK 5 +#include -#define JMPFWD 0x03eb +#define CALL_BACK 5 -static unsigned short ftrace_jmp = JMPFWD; +/* Long is fine, even if it is only 4 bytes ;-) */ +static long *ftrace_nop; struct ftrace_record { struct dyn_ftrace rec; @@ -55,13 +56,13 @@ static struct ftrace_page *ftrace_pages; notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip) { struct ftrace_record *rec; - unsigned short save; + unsigned long save; ip -= CALL_BACK; - save = *(short *)ip; + save = *(long *)ip; /* If this was already converted, skip it */ - if (save == JMPFWD) + if (save == *ftrace_nop) return NULL; if (ftrace_pages->index == ENTRIES_PER_PAGE) { @@ -79,9 +80,10 @@ static int notrace ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code) { - unsigned short old = *(unsigned short *)old_code; - unsigned short new = *(unsigned short *)new_code; - unsigned short replaced; + unsigned replaced; + unsigned old = *(unsigned *)old_code; /* 4 bytes */ + unsigned new = *(unsigned *)new_code; /* 4 bytes */ + unsigned char newch = new_code[4]; int faulted = 0; /* @@ -94,7 +96,9 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, */ asm volatile ( "1: lock\n" - " cmpxchg %w3, (%2)\n" + " cmpxchg %3, (%2)\n" + " jnz 2f\n" + " movb %b4, 4(%2)\n" "2:\n" ".section .fixup, \"ax\"\n" " movl $1, %0\n" @@ -102,11 +106,12 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, ".previous\n" _ASM_EXTABLE(1b, 3b) : "=r"(faulted), "=a"(replaced) - : "r"(ip), "r"(new), "0"(faulted), "a"(old) + : "r"(ip), "r"(new), "r"(newch), + "0"(faulted), "a"(old) : "memory"); sync_core(); - if (replaced != old) + if (replaced != old && replaced != new) faulted = 2; return faulted; @@ -132,7 +137,7 @@ notrace void ftrace_code_disable(struct dyn_ftrace *rec) /* move the IP back to the start of the call */ ip -= CALL_BACK; - r->failed = ftrace_modify_code(ip, save.code, (char *)&ftrace_jmp); + r->failed = ftrace_modify_code(ip, save.code, (char *)ftrace_nop); } static void notrace ftrace_replace_code(int saved) @@ -144,9 +149,9 @@ static void notrace ftrace_replace_code(int saved) int i; if (saved) - old = (char *)&ftrace_jmp; + old = (char *)ftrace_nop; else - new = (char *)&ftrace_jmp; + new = (char *)ftrace_nop; for (pg = ftrace_pages_start; pg; pg = pg->next) { for (i = 0; i < pg->index; i++) { @@ -194,12 +199,15 @@ notrace void ftrace_shutdown_replenish(void) ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); } -notrace int ftrace_shutdown_arch_init(void) +notrace int __init ftrace_shutdown_arch_init(void) { + const unsigned char *const *noptable = find_nop_table(); struct ftrace_page *pg; int cnt; int i; + ftrace_nop = (unsigned long *)noptable[CALL_BACK]; + /* allocate a few pages */ ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); if (!ftrace_pages_start) diff --git a/include/asm-x86/alternative.h b/include/asm-x86/alternative.h index 1f6a9ca1012..f6aa18eadf7 100644 --- a/include/asm-x86/alternative.h +++ b/include/asm-x86/alternative.h @@ -72,6 +72,8 @@ static inline void alternatives_smp_module_del(struct module *mod) {} static inline void alternatives_smp_switch(int smp) {} #endif /* CONFIG_SMP */ +const unsigned char *const *find_nop_table(void); + /* * Alternative instructions for different CPU types or capabilities. * -- cgit v1.2.3-70-g09d2 From 3c1720f00bb619302ba19d55986ab565e74d06db Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:43 +0200 Subject: ftrace: move memory management out of arch code This patch moves the memory management of the ftrace records out of the arch code and into the generic code making the arch code simpler. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/ftrace.c | 183 ++++++++--------------------------------------- include/linux/ftrace.h | 18 +++-- kernel/trace/ftrace.c | 154 ++++++++++++++++++++++++++++++++++++++- 3 files changed, 192 insertions(+), 163 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 2e060c58b86..b69795efa22 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -23,25 +23,6 @@ /* Long is fine, even if it is only 4 bytes ;-) */ static long *ftrace_nop; -struct ftrace_record { - struct dyn_ftrace rec; - int failed; -} __attribute__((packed)); - -struct ftrace_page { - struct ftrace_page *next; - int index; - struct ftrace_record records[]; -} __attribute__((packed)); - -#define ENTRIES_PER_PAGE \ - ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct ftrace_record)) - -/* estimate from running different kernels */ -#define NR_TO_INIT 10000 - -#define MCOUNT_ADDR ((long)(&mcount)) - union ftrace_code_union { char code[5]; struct { @@ -50,33 +31,41 @@ union ftrace_code_union { } __attribute__((packed)); }; -static struct ftrace_page *ftrace_pages_start; -static struct ftrace_page *ftrace_pages; - -notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip) +notrace int ftrace_ip_converted(unsigned long ip) { - struct ftrace_record *rec; unsigned long save; ip -= CALL_BACK; save = *(long *)ip; - /* If this was already converted, skip it */ - if (save == *ftrace_nop) - return NULL; + return save == *ftrace_nop; +} - if (ftrace_pages->index == ENTRIES_PER_PAGE) { - if (!ftrace_pages->next) - return NULL; - ftrace_pages = ftrace_pages->next; - } +static int notrace ftrace_calc_offset(long ip, long addr) +{ + return (int)(addr - ip); +} - rec = &ftrace_pages->records[ftrace_pages->index++]; +notrace unsigned char *ftrace_nop_replace(void) +{ + return (char *)ftrace_nop; +} + +notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) +{ + static union ftrace_code_union calc; - return &rec->rec; + calc.e8 = 0xe8; + calc.offset = ftrace_calc_offset(ip, addr); + + /* + * No locking needed, this must be called via kstop_machine + * which in essence is like running on a uniprocessor machine. + */ + return calc.code; } -static int notrace +notrace int ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code) { @@ -86,6 +75,9 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char newch = new_code[4]; int faulted = 0; + /* move the IP back to the start of the call */ + ip -= CALL_BACK; + /* * Note: Due to modules and __init, code can * disappear and change, we need to protect against faulting @@ -117,129 +109,12 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, return faulted; } -static int notrace ftrace_calc_offset(long ip) -{ - return (int)(MCOUNT_ADDR - ip); -} - -notrace void ftrace_code_disable(struct dyn_ftrace *rec) -{ - unsigned long ip; - union ftrace_code_union save; - struct ftrace_record *r = - container_of(rec, struct ftrace_record, rec); - - ip = rec->ip; - - save.e8 = 0xe8; - save.offset = ftrace_calc_offset(ip); - - /* move the IP back to the start of the call */ - ip -= CALL_BACK; - - r->failed = ftrace_modify_code(ip, save.code, (char *)ftrace_nop); -} - -static void notrace ftrace_replace_code(int saved) -{ - unsigned char *new = NULL, *old = NULL; - struct ftrace_record *rec; - struct ftrace_page *pg; - unsigned long ip; - int i; - - if (saved) - old = (char *)ftrace_nop; - else - new = (char *)ftrace_nop; - - for (pg = ftrace_pages_start; pg; pg = pg->next) { - for (i = 0; i < pg->index; i++) { - union ftrace_code_union calc; - rec = &pg->records[i]; - - /* don't modify code that has already faulted */ - if (rec->failed) - continue; - - ip = rec->rec.ip; - - calc.e8 = 0xe8; - calc.offset = ftrace_calc_offset(ip); - - if (saved) - new = calc.code; - else - old = calc.code; - - ip -= CALL_BACK; - - rec->failed = ftrace_modify_code(ip, old, new); - } - } - -} - -notrace void ftrace_startup_code(void) -{ - ftrace_replace_code(1); -} - -notrace void ftrace_shutdown_code(void) -{ - ftrace_replace_code(0); -} - -notrace void ftrace_shutdown_replenish(void) -{ - if (ftrace_pages->next) - return; - - /* allocate another page */ - ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); -} - -notrace int __init ftrace_shutdown_arch_init(void) +int __init ftrace_dyn_arch_init(void) { const unsigned char *const *noptable = find_nop_table(); - struct ftrace_page *pg; - int cnt; - int i; ftrace_nop = (unsigned long *)noptable[CALL_BACK]; - /* allocate a few pages */ - ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); - if (!ftrace_pages_start) - return -1; - - /* - * Allocate a few more pages. - * - * TODO: have some parser search vmlinux before - * final linking to find all calls to ftrace. - * Then we can: - * a) know how many pages to allocate. - * and/or - * b) set up the table then. - * - * The dynamic code is still necessary for - * modules. - */ - - pg = ftrace_pages = ftrace_pages_start; - - cnt = NR_TO_INIT / ENTRIES_PER_PAGE; - - for (i = 0; i < cnt; i++) { - pg->next = (void *)get_zeroed_page(GFP_KERNEL); - - /* If we fail, we'll try later anyway */ - if (!pg->next) - break; - - pg = pg->next; - } - return 0; } + diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ccd8537dbdb..d509ad6c9cb 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -42,19 +42,23 @@ extern void mcount(void); # define FTRACE_HASHBITS 10 # define FTRACE_HASHSIZE (1<node, &ftrace_hash[key]); } +static notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip) +{ + /* If this was already converted, skip it */ + if (ftrace_ip_converted(ip)) + return NULL; + + if (ftrace_pages->index == ENTRIES_PER_PAGE) { + if (!ftrace_pages->next) + return NULL; + ftrace_pages = ftrace_pages->next; + } + + return &ftrace_pages->records[ftrace_pages->index++]; +} + static void notrace ftrace_record_ip(unsigned long ip, unsigned long parent_ip) { @@ -252,6 +282,62 @@ static struct ftrace_ops ftrace_shutdown_ops __read_mostly = .func = ftrace_record_ip, }; +#define MCOUNT_ADDR ((long)(&mcount)) + +static void notrace ftrace_replace_code(int saved) +{ + unsigned char *new = NULL, *old = NULL; + struct dyn_ftrace *rec; + struct ftrace_page *pg; + unsigned long ip; + int failed; + int i; + + if (saved) + old = ftrace_nop_replace(); + else + new = ftrace_nop_replace(); + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + + /* don't modify code that has already faulted */ + if (rec->flags & FTRACE_FL_FAILED) + continue; + + ip = rec->ip; + + if (saved) + new = ftrace_call_replace(ip, MCOUNT_ADDR); + else + old = ftrace_call_replace(ip, MCOUNT_ADDR); + + failed = ftrace_modify_code(ip, old, new); + if (failed) + rec->flags |= FTRACE_FL_FAILED; + } + } +} + +static notrace void ftrace_startup_code(void) +{ + ftrace_replace_code(1); +} + +static notrace void ftrace_shutdown_code(void) +{ + ftrace_replace_code(0); +} + +static notrace void ftrace_shutdown_replenish(void) +{ + if (ftrace_pages->next) + return; + + /* allocate another page */ + ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); +} static int notrace __ftrace_modify_code(void *data) { @@ -261,6 +347,23 @@ static int notrace __ftrace_modify_code(void *data) return 0; } +static notrace void +ftrace_code_disable(struct dyn_ftrace *rec, unsigned long addr) +{ + unsigned long ip; + unsigned char *nop, *call; + int failed; + + ip = rec->ip; + + nop = ftrace_nop_replace(); + call = ftrace_call_replace(ip, addr); + + failed = ftrace_modify_code(ip, call, nop); + if (failed) + rec->flags |= FTRACE_FL_FAILED; +} + static void notrace ftrace_run_startup_code(void) { stop_machine_run(__ftrace_modify_code, ftrace_startup_code, NR_CPUS); @@ -346,7 +449,7 @@ static int notrace __ftrace_update_code(void *ignore) /* all CPUS are stopped, we are safe to modify code */ hlist_for_each_entry(p, t, &head, node) { - ftrace_code_disable(p); + ftrace_code_disable(p, MCOUNT_ADDR); ftrace_update_cnt++; } @@ -407,12 +510,59 @@ static int notrace ftraced(void *ignore) return 0; } +static int __init ftrace_dyn_table_alloc(void) +{ + struct ftrace_page *pg; + int cnt; + int i; + int ret; + + ret = ftrace_dyn_arch_init(); + if (ret) + return ret; + + /* allocate a few pages */ + ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); + if (!ftrace_pages_start) + return -1; + + /* + * Allocate a few more pages. + * + * TODO: have some parser search vmlinux before + * final linking to find all calls to ftrace. + * Then we can: + * a) know how many pages to allocate. + * and/or + * b) set up the table then. + * + * The dynamic code is still necessary for + * modules. + */ + + pg = ftrace_pages = ftrace_pages_start; + + cnt = NR_TO_INIT / ENTRIES_PER_PAGE; + + for (i = 0; i < cnt; i++) { + pg->next = (void *)get_zeroed_page(GFP_KERNEL); + + /* If we fail, we'll try later anyway */ + if (!pg->next) + break; + + pg = pg->next; + } + + return 0; +} + static int __init notrace ftrace_shutdown_init(void) { struct task_struct *p; int ret; - ret = ftrace_shutdown_arch_init(); + ret = ftrace_dyn_table_alloc(); if (ret) return ret; -- cgit v1.2.3-70-g09d2 From d61f82d06672f57fca410da6f7fffd15867db622 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:43 +0200 Subject: ftrace: use dynamic patching for updating mcount calls This patch replaces the indirect call to the mcount function pointer with a direct call that will be patched by the dynamic ftrace routines. On boot up, the mcount function calls the ftace_stub function. When the dynamic ftrace code is initialized, the ftrace_stub is replaced with a call to the ftrace_record_ip, which records the instruction pointers of the locations that call it. Later, the ftraced daemon will call kstop_machine and patch all the locations to nops. When a ftrace is enabled, the original calls to mcount will now be set top call ftrace_caller, which will do a direct call to the registered ftrace function. This direct call is also patched when the function that should be called is updated. All patching is performed by a kstop_machine routine to prevent any type of race conditions that is associated with modifying code on the fly. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/entry_32.S | 47 +++++++++++- arch/x86/kernel/entry_64.S | 67 ++++++++++++++++- arch/x86/kernel/ftrace.c | 41 +++++++++- include/linux/ftrace.h | 7 +- kernel/trace/ftrace.c | 183 ++++++++++++++++++++++++++------------------- 5 files changed, 261 insertions(+), 84 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index f47b9b5440d..e6517ce0b82 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1110,10 +1110,50 @@ ENDPROC(xen_failsafe_callback) #endif /* CONFIG_XEN */ #ifdef CONFIG_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE + +ENTRY(mcount) + pushl %eax + pushl %ecx + pushl %edx + movl 0xc(%esp), %eax + +.globl mcount_call +mcount_call: + call ftrace_stub + + popl %edx + popl %ecx + popl %eax + + ret +END(mcount) + +ENTRY(ftrace_caller) + pushl %eax + pushl %ecx + pushl %edx + movl 0xc(%esp), %eax + movl 0x4(%ebp), %edx + +.globl ftrace_call +ftrace_call: + call ftrace_stub + + popl %edx + popl %ecx + popl %eax + +.globl ftrace_stub +ftrace_stub: + ret +END(ftrace_caller) + +#else /* ! CONFIG_DYNAMIC_FTRACE */ + ENTRY(mcount) cmpl $ftrace_stub, ftrace_trace_function jnz trace - .globl ftrace_stub ftrace_stub: ret @@ -1126,7 +1166,7 @@ trace: movl 0xc(%esp), %eax movl 0x4(%ebp), %edx - call *ftrace_trace_function + call *ftrace_trace_function popl %edx popl %ecx @@ -1134,7 +1174,8 @@ trace: jmp ftrace_stub END(mcount) -#endif +#endif /* CONFIG_DYNAMIC_FTRACE */ +#endif /* CONFIG_FTRACE */ .section .rodata,"a" #include "syscall_table_32.S" diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index f046e0c6488..fe25e5febca 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -55,6 +55,70 @@ .code64 #ifdef CONFIG_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE +ENTRY(mcount) + + subq $0x38, %rsp + movq %rax, (%rsp) + movq %rcx, 8(%rsp) + movq %rdx, 16(%rsp) + movq %rsi, 24(%rsp) + movq %rdi, 32(%rsp) + movq %r8, 40(%rsp) + movq %r9, 48(%rsp) + + movq 0x38(%rsp), %rdi + +.globl mcount_call +mcount_call: + call ftrace_stub + + movq 48(%rsp), %r9 + movq 40(%rsp), %r8 + movq 32(%rsp), %rdi + movq 24(%rsp), %rsi + movq 16(%rsp), %rdx + movq 8(%rsp), %rcx + movq (%rsp), %rax + addq $0x38, %rsp + + retq +END(mcount) + +ENTRY(ftrace_caller) + + /* taken from glibc */ + subq $0x38, %rsp + movq %rax, (%rsp) + movq %rcx, 8(%rsp) + movq %rdx, 16(%rsp) + movq %rsi, 24(%rsp) + movq %rdi, 32(%rsp) + movq %r8, 40(%rsp) + movq %r9, 48(%rsp) + + movq 0x38(%rsp), %rdi + movq 8(%rbp), %rsi + +.globl ftrace_call +ftrace_call: + call ftrace_stub + + movq 48(%rsp), %r9 + movq 40(%rsp), %r8 + movq 32(%rsp), %rdi + movq 24(%rsp), %rsi + movq 16(%rsp), %rdx + movq 8(%rsp), %rcx + movq (%rsp), %rax + addq $0x38, %rsp + +.globl ftrace_stub +ftrace_stub: + retq +END(ftrace_caller) + +#else /* ! CONFIG_DYNAMIC_FTRACE */ ENTRY(mcount) cmpq $ftrace_stub, ftrace_trace_function jnz trace @@ -89,7 +153,8 @@ trace: jmp ftrace_stub END(mcount) -#endif +#endif /* CONFIG_DYNAMIC_FTRACE */ +#endif /* CONFIG_FTRACE */ #ifndef CONFIG_PREEMPT #define retint_kernel retint_restore_args diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index b69795efa22..9f44623e007 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -109,10 +109,49 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, return faulted; } -int __init ftrace_dyn_arch_init(void) +notrace int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned long ip = (unsigned long)(&ftrace_call); + unsigned char old[5], *new; + int ret; + + ip += CALL_BACK; + + memcpy(old, &ftrace_call, 5); + new = ftrace_call_replace(ip, (unsigned long)func); + ret = ftrace_modify_code(ip, old, new); + + return ret; +} + +notrace int ftrace_mcount_set(unsigned long *data) +{ + unsigned long ip = (long)(&mcount_call); + unsigned long *addr = data; + unsigned char old[5], *new; + + /* ip is at the location, but modify code will subtact this */ + ip += CALL_BACK; + + /* + * Replace the mcount stub with a pointer to the + * ip recorder function. + */ + memcpy(old, &mcount_call, 5); + new = ftrace_call_replace(ip, *addr); + *addr = ftrace_modify_code(ip, old, new); + + return 0; +} + +int __init ftrace_dyn_arch_init(void *data) { const unsigned char *const *noptable = find_nop_table(); + /* This is running in kstop_machine */ + + ftrace_mcount_set(data); + ftrace_nop = (unsigned long *)noptable[CALL_BACK]; return 0; diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index d509ad6c9cb..b0dd0093058 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -56,9 +56,14 @@ struct dyn_ftrace { extern int ftrace_ip_converted(unsigned long ip); extern unsigned char *ftrace_nop_replace(void); extern unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr); -extern int ftrace_dyn_arch_init(void); +extern int ftrace_dyn_arch_init(void *data); +extern int ftrace_mcount_set(unsigned long *data); extern int ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code); +extern int ftrace_update_ftrace_func(ftrace_func_t func); +extern void ftrace_caller(void); +extern void ftrace_call(void); +extern void mcount_call(void); #endif #ifdef CONFIG_FRAME_POINTER diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f6d9af3bf66..88544f9bc0e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -26,14 +26,8 @@ #include "trace.h" -#ifdef CONFIG_DYNAMIC_FTRACE -# define FTRACE_ENABLED_INIT 1 -#else -# define FTRACE_ENABLED_INIT 0 -#endif - -int ftrace_enabled = FTRACE_ENABLED_INIT; -static int last_ftrace_enabled = FTRACE_ENABLED_INIT; +int ftrace_enabled; +static int last_ftrace_enabled; static DEFINE_SPINLOCK(ftrace_lock); static DEFINE_MUTEX(ftrace_sysctl_lock); @@ -149,6 +143,14 @@ static int notrace __unregister_ftrace_function(struct ftrace_ops *ops) #ifdef CONFIG_DYNAMIC_FTRACE +enum { + FTRACE_ENABLE_CALLS = (1 << 0), + FTRACE_DISABLE_CALLS = (1 << 1), + FTRACE_UPDATE_TRACE_FUNC = (1 << 2), + FTRACE_ENABLE_MCOUNT = (1 << 3), + FTRACE_DISABLE_MCOUNT = (1 << 4), +}; + static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); @@ -199,12 +201,8 @@ ftrace_add_hash(struct dyn_ftrace *node, unsigned long key) hlist_add_head(&node->node, &ftrace_hash[key]); } -static notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip) +static notrace struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) { - /* If this was already converted, skip it */ - if (ftrace_ip_converted(ip)) - return NULL; - if (ftrace_pages->index == ENTRIES_PER_PAGE) { if (!ftrace_pages->next) return NULL; @@ -215,7 +213,7 @@ static notrace struct dyn_ftrace *ftrace_alloc_shutdown_node(unsigned long ip) } static void notrace -ftrace_record_ip(unsigned long ip, unsigned long parent_ip) +ftrace_record_ip(unsigned long ip) { struct dyn_ftrace *node; unsigned long flags; @@ -223,6 +221,9 @@ ftrace_record_ip(unsigned long ip, unsigned long parent_ip) int resched; int atomic; + if (!ftrace_enabled) + return; + resched = need_resched(); preempt_disable_notrace(); @@ -251,11 +252,12 @@ ftrace_record_ip(unsigned long ip, unsigned long parent_ip) /* * There's a slight race that the ftraced will update the - * hash and reset here. The arch alloc is responsible - * for seeing if the IP has already changed, and if - * it has, the alloc will fail. + * hash and reset here. If it is already converted, skip it. */ - node = ftrace_alloc_shutdown_node(ip); + if (ftrace_ip_converted(ip)) + goto out_unlock; + + node = ftrace_alloc_dyn_node(ip); if (!node) goto out_unlock; @@ -277,11 +279,7 @@ ftrace_record_ip(unsigned long ip, unsigned long parent_ip) preempt_enable_notrace(); } -static struct ftrace_ops ftrace_shutdown_ops __read_mostly = -{ - .func = ftrace_record_ip, -}; - +#define FTRACE_ADDR ((long)(&ftrace_caller)) #define MCOUNT_ADDR ((long)(&mcount)) static void notrace ftrace_replace_code(int saved) @@ -309,9 +307,9 @@ static void notrace ftrace_replace_code(int saved) ip = rec->ip; if (saved) - new = ftrace_call_replace(ip, MCOUNT_ADDR); + new = ftrace_call_replace(ip, FTRACE_ADDR); else - old = ftrace_call_replace(ip, MCOUNT_ADDR); + old = ftrace_call_replace(ip, FTRACE_ADDR); failed = ftrace_modify_code(ip, old, new); if (failed) @@ -320,16 +318,6 @@ static void notrace ftrace_replace_code(int saved) } } -static notrace void ftrace_startup_code(void) -{ - ftrace_replace_code(1); -} - -static notrace void ftrace_shutdown_code(void) -{ - ftrace_replace_code(0); -} - static notrace void ftrace_shutdown_replenish(void) { if (ftrace_pages->next) @@ -339,16 +327,8 @@ static notrace void ftrace_shutdown_replenish(void) ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); } -static int notrace __ftrace_modify_code(void *data) -{ - void (*func)(void) = data; - - func(); - return 0; -} - static notrace void -ftrace_code_disable(struct dyn_ftrace *rec, unsigned long addr) +ftrace_code_disable(struct dyn_ftrace *rec) { unsigned long ip; unsigned char *nop, *call; @@ -357,67 +337,113 @@ ftrace_code_disable(struct dyn_ftrace *rec, unsigned long addr) ip = rec->ip; nop = ftrace_nop_replace(); - call = ftrace_call_replace(ip, addr); + call = ftrace_call_replace(ip, MCOUNT_ADDR); failed = ftrace_modify_code(ip, call, nop); if (failed) rec->flags |= FTRACE_FL_FAILED; } -static void notrace ftrace_run_startup_code(void) +static int notrace __ftrace_modify_code(void *data) { - stop_machine_run(__ftrace_modify_code, ftrace_startup_code, NR_CPUS); + unsigned long addr; + int *command = data; + + if (*command & FTRACE_ENABLE_CALLS) + ftrace_replace_code(1); + else if (*command & FTRACE_DISABLE_CALLS) + ftrace_replace_code(0); + + if (*command & FTRACE_UPDATE_TRACE_FUNC) + ftrace_update_ftrace_func(ftrace_trace_function); + + if (*command & FTRACE_ENABLE_MCOUNT) { + addr = (unsigned long)ftrace_record_ip; + ftrace_mcount_set(&addr); + } else if (*command & FTRACE_DISABLE_MCOUNT) { + addr = (unsigned long)ftrace_stub; + ftrace_mcount_set(&addr); + } + + return 0; } -static void notrace ftrace_run_shutdown_code(void) +static void notrace ftrace_run_update_code(int command) { - stop_machine_run(__ftrace_modify_code, ftrace_shutdown_code, NR_CPUS); + stop_machine_run(__ftrace_modify_code, &command, NR_CPUS); } +static ftrace_func_t saved_ftrace_func; + static void notrace ftrace_startup(void) { + int command = 0; + mutex_lock(&ftraced_lock); ftraced_suspend++; - if (ftraced_suspend != 1) + if (ftraced_suspend == 1) + command |= FTRACE_ENABLE_CALLS; + + if (saved_ftrace_func != ftrace_trace_function) { + saved_ftrace_func = ftrace_trace_function; + command |= FTRACE_UPDATE_TRACE_FUNC; + } + + if (!command || !ftrace_enabled) goto out; - __unregister_ftrace_function(&ftrace_shutdown_ops); - if (ftrace_enabled) - ftrace_run_startup_code(); + ftrace_run_update_code(command); out: mutex_unlock(&ftraced_lock); } static void notrace ftrace_shutdown(void) { + int command = 0; + mutex_lock(&ftraced_lock); ftraced_suspend--; - if (ftraced_suspend) - goto out; + if (!ftraced_suspend) + command |= FTRACE_DISABLE_CALLS; - if (ftrace_enabled) - ftrace_run_shutdown_code(); + if (saved_ftrace_func != ftrace_trace_function) { + saved_ftrace_func = ftrace_trace_function; + command |= FTRACE_UPDATE_TRACE_FUNC; + } - __register_ftrace_function(&ftrace_shutdown_ops); + if (!command || !ftrace_enabled) + goto out; + + ftrace_run_update_code(command); out: mutex_unlock(&ftraced_lock); } static void notrace ftrace_startup_sysctl(void) { + int command = FTRACE_ENABLE_MCOUNT; + mutex_lock(&ftraced_lock); + /* Force update next time */ + saved_ftrace_func = NULL; /* ftraced_suspend is true if we want ftrace running */ if (ftraced_suspend) - ftrace_run_startup_code(); + command |= FTRACE_ENABLE_CALLS; + + ftrace_run_update_code(command); mutex_unlock(&ftraced_lock); } static void notrace ftrace_shutdown_sysctl(void) { + int command = FTRACE_DISABLE_MCOUNT; + mutex_lock(&ftraced_lock); /* ftraced_suspend is true if ftrace is running */ if (ftraced_suspend) - ftrace_run_shutdown_code(); + command |= FTRACE_DISABLE_CALLS; + + ftrace_run_update_code(command); mutex_unlock(&ftraced_lock); } @@ -430,11 +456,13 @@ static int notrace __ftrace_update_code(void *ignore) struct dyn_ftrace *p; struct hlist_head head; struct hlist_node *t; + int save_ftrace_enabled; cycle_t start, stop; int i; - /* Don't be calling ftrace ops now */ - __unregister_ftrace_function(&ftrace_shutdown_ops); + /* Don't be recording funcs now */ + save_ftrace_enabled = ftrace_enabled; + ftrace_enabled = 0; start = now(raw_smp_processor_id()); ftrace_update_cnt = 0; @@ -449,7 +477,7 @@ static int notrace __ftrace_update_code(void *ignore) /* all CPUS are stopped, we are safe to modify code */ hlist_for_each_entry(p, t, &head, node) { - ftrace_code_disable(p, MCOUNT_ADDR); + ftrace_code_disable(p); ftrace_update_cnt++; } @@ -459,7 +487,7 @@ static int notrace __ftrace_update_code(void *ignore) ftrace_update_time = stop - start; ftrace_update_tot_cnt += ftrace_update_cnt; - __register_ftrace_function(&ftrace_shutdown_ops); + ftrace_enabled = save_ftrace_enabled; return 0; } @@ -515,11 +543,6 @@ static int __init ftrace_dyn_table_alloc(void) struct ftrace_page *pg; int cnt; int i; - int ret; - - ret = ftrace_dyn_arch_init(); - if (ret) - return ret; /* allocate a few pages */ ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); @@ -557,11 +580,19 @@ static int __init ftrace_dyn_table_alloc(void) return 0; } -static int __init notrace ftrace_shutdown_init(void) +static int __init notrace ftrace_dynamic_init(void) { struct task_struct *p; + unsigned long addr; int ret; + addr = (unsigned long)ftrace_record_ip; + stop_machine_run(ftrace_dyn_arch_init, &addr, NR_CPUS); + + /* ftrace_dyn_arch_init places the return code in addr */ + if (addr) + return addr; + ret = ftrace_dyn_table_alloc(); if (ret) return ret; @@ -570,12 +601,12 @@ static int __init notrace ftrace_shutdown_init(void) if (IS_ERR(p)) return -1; - __register_ftrace_function(&ftrace_shutdown_ops); + last_ftrace_enabled = ftrace_enabled = 1; return 0; } -core_initcall(ftrace_shutdown_init); +core_initcall(ftrace_dynamic_init); #else # define ftrace_startup() do { } while (0) # define ftrace_shutdown() do { } while (0) @@ -599,9 +630,8 @@ int register_ftrace_function(struct ftrace_ops *ops) int ret; mutex_lock(&ftrace_sysctl_lock); - ftrace_startup(); - ret = __register_ftrace_function(ops); + ftrace_startup(); mutex_unlock(&ftrace_sysctl_lock); return ret; @@ -619,10 +649,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops) mutex_lock(&ftrace_sysctl_lock); ret = __unregister_ftrace_function(ops); - - if (ftrace_list == &ftrace_list_end) - ftrace_shutdown(); - + ftrace_shutdown(); mutex_unlock(&ftrace_sysctl_lock); return ret; -- cgit v1.2.3-70-g09d2 From f43fdad8627fec2d21df92799b254dceb66c9c3c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 21:20:43 +0200 Subject: ftrace: fix kexec disable the tracer while kexec pulls the rug from under the old kernel. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/machine_kexec_32.c | 4 ++++ arch/x86/kernel/machine_kexec_64.c | 4 ++++ include/linux/ftrace.h | 7 +++++++ 3 files changed, 15 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c index d0b234c9fc3..88923fd7a6f 100644 --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -11,6 +11,8 @@ #include #include #include +#include + #include #include #include @@ -107,6 +109,8 @@ NORET_TYPE void machine_kexec(struct kimage *image) unsigned long page_list[PAGES_NR]; void *control_page; + tracer_disable(); + /* Interrupts aren't acceptable while we reboot */ local_irq_disable(); diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 576a03db451..1558fdc174f 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -11,6 +11,8 @@ #include #include #include +#include + #include #include #include @@ -184,6 +186,8 @@ NORET_TYPE void machine_kexec(struct kimage *image) unsigned long page_list[PAGES_NR]; void *control_page; + tracer_disable(); + /* Interrupts aren't acceptable while we reboot */ local_irq_disable(); diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index f5911d2d42c..a42390c1d6e 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -68,6 +68,13 @@ extern void ftrace_call(void); extern void mcount_call(void); #endif +static inline void tracer_disable(void) +{ +#ifdef CONFIG_FTRACE + ftrace_enabled = 0; +#endif +} + #ifdef CONFIG_FRAME_POINTER /* TODO: need to fix this for ARM */ # define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0)) -- cgit v1.2.3-70-g09d2 From a56be3fe2f65f9f776e727bfd382e35db75911d6 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:56 +0200 Subject: ftrace: fix the fault label in updating code The fault label to jump to on fault of updating the code was misplaced preventing the fault from being recorded. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 9f44623e007..498608c015f 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -93,8 +93,8 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, " movb %b4, 4(%2)\n" "2:\n" ".section .fixup, \"ax\"\n" - " movl $1, %0\n" - "3: jmp 2b\n" + "3: movl $1, %0\n" + " jmp 2b\n" ".previous\n" _ASM_EXTABLE(1b, 3b) : "=r"(faulted), "=a"(replaced) -- cgit v1.2.3-70-g09d2 From 8f0f996e80b980fba07d11961d96a5fefb60976a Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:20:56 +0200 Subject: ftrace: dont write protect kernel text Dynamic ftrace cant work when the kernel has its text write protected. This patch keeps the kernel from being write protected when dynamic ftrace is in place. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/init_32.c | 4 ++++ arch/x86/mm/init_64.c | 10 ++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index ec30d10154b..f96eca21ad8 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -710,6 +710,8 @@ void mark_rodata_ro(void) unsigned long start = PFN_ALIGN(_text); unsigned long size = PFN_ALIGN(_etext) - start; +#ifndef CONFIG_DYNAMIC_FTRACE + /* Dynamic tracing modifies the kernel text section */ set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); printk(KERN_INFO "Write protecting the kernel text: %luk\n", size >> 10); @@ -722,6 +724,8 @@ void mark_rodata_ro(void) printk(KERN_INFO "Testing CPA: write protecting again\n"); set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); #endif +#endif /* CONFIG_DYNAMIC_FTRACE */ + start += size; size = (unsigned long)__end_rodata - start; set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 32ba13b0f81..41824e776b6 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -766,6 +766,13 @@ EXPORT_SYMBOL_GPL(rodata_test_data); void mark_rodata_ro(void) { unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata); + unsigned long rodata_start = + ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; + +#ifdef CONFIG_DYNAMIC_FTRACE + /* Dynamic tracing modifies the kernel text section */ + start = rodata_start; +#endif printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", (end - start) >> 10); @@ -775,8 +782,7 @@ void mark_rodata_ro(void) * The rodata section (but not the kernel text!) should also be * not-executable. */ - start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; - set_memory_nx(start, (end - start) >> PAGE_SHIFT); + set_memory_nx(rodata_start, (end - start) >> PAGE_SHIFT); rodata_test(); -- cgit v1.2.3-70-g09d2 From 86069782d62e731b4835a0cf8eb7d1d0e17cf306 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:56 +0200 Subject: x86: add a list for custom page fault handlers. Provides kernel modules a way to register custom page fault handlers. On every page fault this will call a list of registered functions. The functions may handle the fault and force do_page_fault() to return immediately. This functionality is similar to the now removed page fault notifiers. Custom page fault handlers are used by debugging and reverse engineering tools. Mmiotrace is one such tool and a patch to add it into the tree will follow. The custom page fault handlers are called earlier in do_page_fault() than the page fault notifiers were. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 8 +++++++ arch/x86/mm/fault.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ include/asm-x86/kdebug.h | 9 ++++++++ 3 files changed, 73 insertions(+) (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index ac1e31ba479..9431a839984 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -168,6 +168,14 @@ config IOMMU_LEAK Add a simple leak tracer to the IOMMU code. This is useful when you are debugging a buggy device driver that leaks IOMMU mappings. +config PAGE_FAULT_HANDLERS + bool "Custom page fault handlers" + depends on DEBUG_KERNEL + help + Allow the use of custom page fault handlers. A kernel module may + register a function that is called on every page fault. Custom + handlers are used by some debugging and reverse engineering tools. + # # IO delay types: # diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index fd7e1798c75..343f5c1aacc 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -49,6 +49,60 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) +#ifdef CONFIG_PAGE_FAULT_HANDLERS +static HLIST_HEAD(pf_handlers); /* protected by RCU */ +static DEFINE_SPINLOCK(pf_handlers_writer); + +void register_page_fault_handler(struct pf_handler *new_pfh) +{ + unsigned long flags; + spin_lock_irqsave(&pf_handlers_writer, flags); + hlist_add_head_rcu(&new_pfh->hlist, &pf_handlers); + spin_unlock_irqrestore(&pf_handlers_writer, flags); +} +EXPORT_SYMBOL_GPL(register_page_fault_handler); + +/** + * unregister_page_fault_handler: + * The caller must ensure @old_pfh is not in use anymore before freeing it. + * This function does not guarantee it. The list of handlers is protected by + * RCU, so you can do this by e.g. calling synchronize_rcu(). + */ +void unregister_page_fault_handler(struct pf_handler *old_pfh) +{ + unsigned long flags; + spin_lock_irqsave(&pf_handlers_writer, flags); + hlist_del_rcu(&old_pfh->hlist); + spin_unlock_irqrestore(&pf_handlers_writer, flags); +} +EXPORT_SYMBOL_GPL(unregister_page_fault_handler); +#endif + +/* returns non-zero if do_page_fault() should return */ +static int handle_custom_pf(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ +#ifdef CONFIG_PAGE_FAULT_HANDLERS + int ret = 0; + struct pf_handler *cur; + struct hlist_node *ncur; + + if (hlist_empty(&pf_handlers)) + return 0; + + rcu_read_lock(); + hlist_for_each_entry_rcu(cur, ncur, &pf_handlers, hlist) { + ret = cur->handler(regs, error_code, address); + if (ret) + break; + } + rcu_read_unlock(); + return ret; +#else + return 0; +#endif +} + static inline int notify_page_fault(struct pt_regs *regs) { #ifdef CONFIG_KPROBES @@ -601,6 +655,8 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (notify_page_fault(regs)) return; + if (handle_custom_pf(regs, error_code, address)) + return; /* * We fault-in kernel-space virtual memory on-demand. The diff --git a/include/asm-x86/kdebug.h b/include/asm-x86/kdebug.h index 96651bb59ba..a80f2d6cc73 100644 --- a/include/asm-x86/kdebug.h +++ b/include/asm-x86/kdebug.h @@ -35,4 +35,13 @@ extern void show_regs(struct pt_regs *regs); extern unsigned long oops_begin(void); extern void oops_end(unsigned long, struct pt_regs *, int signr); +struct pf_handler { + struct hlist_node hlist; + int (*handler)(struct pt_regs *regs, unsigned long error_code, + unsigned long address); +}; + +extern void register_page_fault_handler(struct pf_handler *new_pfh); +extern void unregister_page_fault_handler(struct pf_handler *old_pfh); + #endif -- cgit v1.2.3-70-g09d2 From 72b59d67f80983f7bb587b086fb4cb1bc95263a4 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:01 +0200 Subject: x86_64: fix kernel rodata NX setting Without CONFIG_DYNAMIC_FTRACE, mark_rodata_ro() would mark a wrong number of pages as no-execute. The bug was introduced in the patch "ftrace: dont write protect kernel text". The symptom was machine reboot after a CPU hotplug. Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/init_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 41824e776b6..295be1d07b8 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -782,7 +782,7 @@ void mark_rodata_ro(void) * The rodata section (but not the kernel text!) should also be * not-executable. */ - set_memory_nx(rodata_start, (end - start) >> PAGE_SHIFT); + set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT); rodata_test(); -- cgit v1.2.3-70-g09d2 From 2f1dafe50cc4e58a239fd81bd47f87f32042a1ee Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:01 +0200 Subject: x86: fix SMP alternatives: use mutex instead of spinlock, text_poke is sleepable text_poke is sleepable. The original fix by Mathieu Desnoyers . Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/alternative.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index de240ba2e28..2763cb37b55 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1,6 +1,6 @@ #include #include -#include +#include #include #include #include @@ -279,7 +279,7 @@ struct smp_alt_module { struct list_head next; }; static LIST_HEAD(smp_alt_modules); -static DEFINE_SPINLOCK(smp_alt); +static DEFINE_MUTEX(smp_alt); static int smp_mode = 1; /* protected by smp_alt */ void alternatives_smp_module_add(struct module *mod, char *name, @@ -312,12 +312,12 @@ void alternatives_smp_module_add(struct module *mod, char *name, __func__, smp->locks, smp->locks_end, smp->text, smp->text_end, smp->name); - spin_lock(&smp_alt); + mutex_lock(&smp_alt); list_add_tail(&smp->next, &smp_alt_modules); if (boot_cpu_has(X86_FEATURE_UP)) alternatives_smp_unlock(smp->locks, smp->locks_end, smp->text, smp->text_end); - spin_unlock(&smp_alt); + mutex_unlock(&smp_alt); } void alternatives_smp_module_del(struct module *mod) @@ -327,17 +327,17 @@ void alternatives_smp_module_del(struct module *mod) if (smp_alt_once || noreplace_smp) return; - spin_lock(&smp_alt); + mutex_lock(&smp_alt); list_for_each_entry(item, &smp_alt_modules, next) { if (mod != item->mod) continue; list_del(&item->next); - spin_unlock(&smp_alt); + mutex_unlock(&smp_alt); DPRINTK("%s: %s\n", __func__, item->name); kfree(item); return; } - spin_unlock(&smp_alt); + mutex_unlock(&smp_alt); } void alternatives_smp_switch(int smp) @@ -359,7 +359,7 @@ void alternatives_smp_switch(int smp) return; BUG_ON(!smp && (num_online_cpus() > 1)); - spin_lock(&smp_alt); + mutex_lock(&smp_alt); /* * Avoid unnecessary switches because it forces JIT based VMs to @@ -383,7 +383,7 @@ void alternatives_smp_switch(int smp) mod->text, mod->text_end); } smp_mode = smp; - spin_unlock(&smp_alt); + mutex_unlock(&smp_alt); } #endif -- cgit v1.2.3-70-g09d2 From d05f5f9906740474eb768823004ffcd775b12ca6 Mon Sep 17 00:00:00 2001 From: David Miller Date: Tue, 13 May 2008 22:06:59 -0700 Subject: sparc64: add ftrace support. Signed-off-by: David S. Miller Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/sparc64/Kconfig | 1 + arch/sparc64/Kconfig.debug | 2 +- arch/sparc64/kernel/Makefile | 1 + arch/sparc64/kernel/ftrace.c | 99 ++++++++++++++++++++++++++++++++++++++++++++ arch/sparc64/lib/mcount.S | 58 ++++++++++++++++++++++++-- 5 files changed, 156 insertions(+), 5 deletions(-) create mode 100644 arch/sparc64/kernel/ftrace.c (limited to 'arch') diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig index eb36f3b746b..a480df6e601 100644 --- a/arch/sparc64/Kconfig +++ b/arch/sparc64/Kconfig @@ -11,6 +11,7 @@ config SPARC config SPARC64 bool default y + select HAVE_FTRACE select HAVE_IDE select HAVE_LMB select HAVE_ARCH_KGDB diff --git a/arch/sparc64/Kconfig.debug b/arch/sparc64/Kconfig.debug index 6a4d28a4076..d6d32d178fc 100644 --- a/arch/sparc64/Kconfig.debug +++ b/arch/sparc64/Kconfig.debug @@ -33,7 +33,7 @@ config DEBUG_PAGEALLOC config MCOUNT bool - depends on STACK_DEBUG + depends on STACK_DEBUG || FTRACE default y config FRAME_POINTER diff --git a/arch/sparc64/kernel/Makefile b/arch/sparc64/kernel/Makefile index ec4f5ebb1ca..418b5782096 100644 --- a/arch/sparc64/kernel/Makefile +++ b/arch/sparc64/kernel/Makefile @@ -14,6 +14,7 @@ obj-y := process.o setup.o cpu.o idprom.o \ power.o sbus.o sparc64_ksyms.o chmc.o \ visemul.o prom.o of_device.o hvapi.o sstate.o mdesc.o +obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_PCI) += ebus.o pci_common.o \ pci_psycho.o pci_sabre.o pci_schizo.o \ diff --git a/arch/sparc64/kernel/ftrace.c b/arch/sparc64/kernel/ftrace.c new file mode 100644 index 00000000000..f449e6df6c4 --- /dev/null +++ b/arch/sparc64/kernel/ftrace.c @@ -0,0 +1,99 @@ +#include +#include +#include +#include +#include +#include + +static const u32 ftrace_nop = 0x01000000; + +notrace int ftrace_ip_converted(unsigned long ip) +{ + u32 insn = *(u32 *) ip; + + return (insn == ftrace_nop); +} + +notrace unsigned char *ftrace_nop_replace(void) +{ + return (char *)&ftrace_nop; +} + +notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) +{ + static u32 call; + s32 off; + + off = ((s32)addr - (s32)ip); + call = 0x40000000 | ((u32)off >> 2); + + return (unsigned char *) &call; +} + +notrace int +ftrace_modify_code(unsigned long ip, unsigned char *old_code, + unsigned char *new_code) +{ + u32 old = *(u32 *)old_code; + u32 new = *(u32 *)new_code; + u32 replaced; + int faulted; + + __asm__ __volatile__( + "1: cas [%[ip]], %[old], %[new]\n" + " flush %[ip]\n" + " mov 0, %[faulted]\n" + "2:\n" + " .section .fixup,#alloc,#execinstr\n" + " .align 4\n" + "3: sethi %%hi(2b), %[faulted]\n" + " jmpl %[faulted] + %%lo(2b), %%g0\n" + " mov 1, %[faulted]\n" + " .previous\n" + " .section __ex_table,\"a\"\n" + " .align 4\n" + " .word 1b, 3b\n" + " .previous\n" + : "=r" (replaced), [faulted] "=r" (faulted) + : [new] "0" (new), [old] "r" (old), [ip] "r" (ip) + : "memory"); + + if (replaced != old && replaced != new) + faulted = 2; + + return faulted; +} + +notrace int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned long ip = (unsigned long)(&ftrace_call); + unsigned char old[4], *new; + + memcpy(old, &ftrace_call, 4); + new = ftrace_call_replace(ip, (unsigned long)func); + return ftrace_modify_code(ip, old, new); +} + +notrace int ftrace_mcount_set(unsigned long *data) +{ + unsigned long ip = (long)(&mcount_call); + unsigned long *addr = data; + unsigned char old[4], *new; + + /* + * Replace the mcount stub with a pointer to the + * ip recorder function. + */ + memcpy(old, &mcount_call, 4); + new = ftrace_call_replace(ip, *addr); + *addr = ftrace_modify_code(ip, old, new); + + return 0; +} + + +int __init ftrace_dyn_arch_init(void *data) +{ + ftrace_mcount_set(data); + return 0; +} diff --git a/arch/sparc64/lib/mcount.S b/arch/sparc64/lib/mcount.S index 9e4534b485c..7735a7a6053 100644 --- a/arch/sparc64/lib/mcount.S +++ b/arch/sparc64/lib/mcount.S @@ -28,10 +28,13 @@ ovstack: .skip OVSTACKSIZE #endif .text - .align 32 - .globl mcount, _mcount -mcount: + .align 32 + .globl _mcount + .type _mcount,#function + .globl mcount + .type mcount,#function _mcount: +mcount: #ifdef CONFIG_STACK_DEBUG /* * Check whether %sp is dangerously low. @@ -55,6 +58,53 @@ _mcount: or %g3, %lo(panicstring), %o0 call prom_halt nop +1: +#endif +#ifdef CONFIG_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE + mov %o7, %o0 + .globl mcount_call +mcount_call: + call ftrace_stub + mov %o0, %o7 +#else + sethi %hi(ftrace_trace_function), %g1 + sethi %hi(ftrace_stub), %g2 + ldx [%g1 + %lo(ftrace_trace_function)], %g1 + or %g2, %lo(ftrace_stub), %g2 + cmp %g1, %g2 + be,pn %icc, 1f + mov %i7, %o1 + jmpl %g1, %g0 + mov %o7, %o0 + /* not reached */ +1: #endif -1: retl +#endif + retl nop + .size _mcount,.-_mcount + .size mcount,.-mcount + +#ifdef CONFIG_FTRACE + .globl ftrace_stub + .type ftrace_stub,#function +ftrace_stub: + retl + nop + .size ftrace_stub,.-ftrace_stub +#ifdef CONFIG_DYNAMIC_FTRACE + .globl ftrace_caller + .type ftrace_caller,#function +ftrace_caller: + mov %i7, %o1 + mov %o7, %o0 + .globl ftrace_call +ftrace_call: + call ftrace_stub + mov %o0, %o7 + retl + nop + .size ftrace_caller,.-ftrace_caller +#endif +#endif -- cgit v1.2.3-70-g09d2 From 37135677e653537ffc6e7def679443272a1c03c3 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 14 May 2008 08:10:31 +0200 Subject: ftrace: fix mcount export bug David S. Miller noticed the following bug: the -pg instrumentation function callback is named differently on each platform. On x86 it is mcount, on sparc it is _mcount. So the export does not make sense in kernel/trace/ftrace.c - move it to x86. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/i386_ksyms_32.c | 9 ++++++++- arch/x86/kernel/x8664_ksyms_64.c | 11 +++++++++-- kernel/trace/ftrace.c | 3 --- 3 files changed, 17 insertions(+), 6 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c index deb43785e92..29999dbb754 100644 --- a/arch/x86/kernel/i386_ksyms_32.c +++ b/arch/x86/kernel/i386_ksyms_32.c @@ -1,7 +1,14 @@ +#include #include + #include -#include #include +#include + +#ifdef CONFIG_FTRACE +/* mcount is defined in assembly */ +EXPORT_SYMBOL(mcount); +#endif /* Networking helper routines. */ EXPORT_SYMBOL(csum_partial_copy_generic); diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index f6c05d0410f..122885bc5f3 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -1,15 +1,22 @@ /* Exports for assembly files. All C exports should go in the respective C files. */ +#include #include -#include #include +#include + #include -#include #include +#include #include +#ifdef CONFIG_FTRACE +/* mcount is defined in assembly */ +EXPORT_SYMBOL(mcount); +#endif + EXPORT_SYMBOL(kernel_thread); EXPORT_SYMBOL(__get_user_1); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 07b2a14943f..a3e47f43f8a 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -50,9 +50,6 @@ static struct ftrace_ops ftrace_list_end __read_mostly = static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; -/* mcount is defined per arch in assembly */ -EXPORT_SYMBOL(mcount); - void ftrace_list_func(unsigned long ip, unsigned long parent_ip) { struct ftrace_ops *op = ftrace_list; -- cgit v1.2.3-70-g09d2 From 4e491d14f2506b218d678935c25a7027b79178b1 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 14 May 2008 23:49:44 -0400 Subject: ftrace: support for PowerPC This patch adds full support for ftrace for PowerPC (both 64 and 32 bit). This includes dynamic tracing and function filtering. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/powerpc/Kconfig | 3 +- arch/powerpc/kernel/Makefile | 14 +++ arch/powerpc/kernel/entry_32.S | 130 ++++++++++++++++++++++++ arch/powerpc/kernel/entry_64.S | 62 ++++++++++++ arch/powerpc/kernel/ftrace.c | 165 +++++++++++++++++++++++++++++++ arch/powerpc/kernel/io.c | 3 +- arch/powerpc/kernel/irq.c | 6 +- arch/powerpc/kernel/setup_32.c | 11 ++- arch/powerpc/kernel/setup_64.c | 5 + arch/powerpc/platforms/powermac/Makefile | 5 + kernel/trace/trace_selftest.c | 11 ++- 11 files changed, 405 insertions(+), 10 deletions(-) create mode 100644 arch/powerpc/kernel/ftrace.c (limited to 'arch') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3934e265940..62d034adbd4 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -105,11 +105,12 @@ config ARCH_NO_VIRT_TO_BUS config PPC bool default y + select HAVE_FTRACE select HAVE_IDE - select HAVE_OPROFILE select HAVE_KPROBES select HAVE_KRETPROBES select HAVE_LMB + select HAVE_OPROFILE config EARLY_PRINTK bool diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 2346d271fbf..f3f5e264143 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -12,6 +12,18 @@ CFLAGS_prom_init.o += -fPIC CFLAGS_btext.o += -fPIC endif +ifdef CONFIG_FTRACE +# Do not trace early boot code +CFLAGS_REMOVE_cputable.o = -pg +CFLAGS_REMOVE_prom_init.o = -pg + +ifdef CONFIG_DYNAMIC_FTRACE +# dynamic ftrace setup. +CFLAGS_REMOVE_ftrace.o = -pg +endif + +endif + obj-y := cputable.o ptrace.o syscalls.o \ irq.o align.o signal_32.o pmc.o vdso.o \ init_task.o process.o systbl.o idle.o \ @@ -78,6 +90,8 @@ obj-$(CONFIG_KEXEC) += machine_kexec.o crash.o \ obj-$(CONFIG_AUDIT) += audit.o obj64-$(CONFIG_AUDIT) += compat_audit.o +obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o + obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o ifneq ($(CONFIG_PPC_INDIRECT_IO),y) diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 0c8614d9875..0e6221889ca 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1035,3 +1035,133 @@ machine_check_in_rtas: /* XXX load up BATs and panic */ #endif /* CONFIG_PPC_RTAS */ + +#ifdef CONFIG_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE +_GLOBAL(mcount) +_GLOBAL(_mcount) + stwu r1,-48(r1) + stw r3, 12(r1) + stw r4, 16(r1) + stw r5, 20(r1) + stw r6, 24(r1) + mflr r3 + stw r7, 28(r1) + mfcr r5 + stw r8, 32(r1) + stw r9, 36(r1) + stw r10,40(r1) + stw r3, 44(r1) + stw r5, 8(r1) + .globl mcount_call +mcount_call: + bl ftrace_stub + nop + lwz r6, 8(r1) + lwz r0, 44(r1) + lwz r3, 12(r1) + mtctr r0 + lwz r4, 16(r1) + mtcr r6 + lwz r5, 20(r1) + lwz r6, 24(r1) + lwz r0, 52(r1) + lwz r7, 28(r1) + lwz r8, 32(r1) + mtlr r0 + lwz r9, 36(r1) + lwz r10,40(r1) + addi r1, r1, 48 + bctr + +_GLOBAL(ftrace_caller) + /* Based off of objdump optput from glibc */ + stwu r1,-48(r1) + stw r3, 12(r1) + stw r4, 16(r1) + stw r5, 20(r1) + stw r6, 24(r1) + mflr r3 + lwz r4, 52(r1) + mfcr r5 + stw r7, 28(r1) + stw r8, 32(r1) + stw r9, 36(r1) + stw r10,40(r1) + stw r3, 44(r1) + stw r5, 8(r1) +.globl ftrace_call +ftrace_call: + bl ftrace_stub + nop + lwz r6, 8(r1) + lwz r0, 44(r1) + lwz r3, 12(r1) + mtctr r0 + lwz r4, 16(r1) + mtcr r6 + lwz r5, 20(r1) + lwz r6, 24(r1) + lwz r0, 52(r1) + lwz r7, 28(r1) + lwz r8, 32(r1) + mtlr r0 + lwz r9, 36(r1) + lwz r10,40(r1) + addi r1, r1, 48 + bctr +#else +_GLOBAL(mcount) +_GLOBAL(_mcount) + stwu r1,-48(r1) + stw r3, 12(r1) + stw r4, 16(r1) + stw r5, 20(r1) + stw r6, 24(r1) + mflr r3 + lwz r4, 52(r1) + mfcr r5 + stw r7, 28(r1) + stw r8, 32(r1) + stw r9, 36(r1) + stw r10,40(r1) + stw r3, 44(r1) + stw r5, 8(r1) + + LOAD_REG_ADDR(r5, ftrace_trace_function) +#if 0 + mtctr r3 + mr r1, r5 + bctrl +#endif + lwz r5,0(r5) +#if 1 + mtctr r5 + bctrl +#else + bl ftrace_stub +#endif + nop + + lwz r6, 8(r1) + lwz r0, 44(r1) + lwz r3, 12(r1) + mtctr r0 + lwz r4, 16(r1) + mtcr r6 + lwz r5, 20(r1) + lwz r6, 24(r1) + lwz r0, 52(r1) + lwz r7, 28(r1) + lwz r8, 32(r1) + mtlr r0 + lwz r9, 36(r1) + lwz r10,40(r1) + addi r1, r1, 48 + bctr +#endif + +_GLOBAL(ftrace_stub) + blr + +#endif /* CONFIG_MCOUNT */ diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index c0db5b769e5..2c4d9e056ea 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -870,3 +870,65 @@ _GLOBAL(enter_prom) ld r0,16(r1) mtlr r0 blr + +#ifdef CONFIG_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE +_GLOBAL(mcount) +_GLOBAL(_mcount) + /* Taken from output of objdump from lib64/glibc */ + mflr r3 + stdu r1, -112(r1) + std r3, 128(r1) + .globl mcount_call +mcount_call: + bl ftrace_stub + nop + ld r0, 128(r1) + mtlr r0 + addi r1, r1, 112 + blr + +_GLOBAL(ftrace_caller) + /* Taken from output of objdump from lib64/glibc */ + mflr r3 + ld r11, 0(r1) + stdu r1, -112(r1) + std r3, 128(r1) + ld r4, 16(r11) +.globl ftrace_call +ftrace_call: + bl ftrace_stub + nop + ld r0, 128(r1) + mtlr r0 + addi r1, r1, 112 +_GLOBAL(ftrace_stub) + blr +#else +_GLOBAL(mcount) + blr + +_GLOBAL(_mcount) + /* Taken from output of objdump from lib64/glibc */ + mflr r3 + ld r11, 0(r1) + stdu r1, -112(r1) + std r3, 128(r1) + ld r4, 16(r11) + + + LOAD_REG_ADDR(r5,ftrace_trace_function) + ld r5,0(r5) + ld r5,0(r5) + mtctr r5 + bctrl + + nop + ld r0, 128(r1) + mtlr r0 + addi r1, r1, 112 +_GLOBAL(ftrace_stub) + blr + +#endif +#endif diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c new file mode 100644 index 00000000000..5a4993fefa4 --- /dev/null +++ b/arch/powerpc/kernel/ftrace.c @@ -0,0 +1,165 @@ +/* + * Code for replacing ftrace calls with jumps. + * + * Copyright (C) 2007-2008 Steven Rostedt + * + * Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box. + * + */ + +#include +#include +#include +#include +#include +#include + +#include + +#define CALL_BACK 4 + +static unsigned int ftrace_nop = 0x60000000; + +#ifdef CONFIG_PPC32 +# define GET_ADDR(addr) addr +#else +/* PowerPC64's functions are data that points to the functions */ +# define GET_ADDR(addr) *(unsigned long *)addr +#endif + +notrace int ftrace_ip_converted(unsigned long ip) +{ + unsigned int save; + + ip -= CALL_BACK; + save = *(unsigned int *)ip; + + return save == ftrace_nop; +} + +static unsigned int notrace ftrace_calc_offset(long ip, long addr) +{ + return (int)((addr + CALL_BACK) - ip); +} + +notrace unsigned char *ftrace_nop_replace(void) +{ + return (char *)&ftrace_nop; +} + +notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) +{ + static unsigned int op; + + addr = GET_ADDR(addr); + + /* Set to "bl addr" */ + op = 0x48000001 | (ftrace_calc_offset(ip, addr) & 0x03fffffe); + + /* + * No locking needed, this must be called via kstop_machine + * which in essence is like running on a uniprocessor machine. + */ + return (unsigned char *)&op; +} + +#ifdef CONFIG_PPC64 +# define _ASM_ALIGN " .align 3 " +# define _ASM_PTR " .llong " +#else +# define _ASM_ALIGN " .align 2 " +# define _ASM_PTR " .long " +#endif + +notrace int +ftrace_modify_code(unsigned long ip, unsigned char *old_code, + unsigned char *new_code) +{ + unsigned replaced; + unsigned old = *(unsigned *)old_code; + unsigned new = *(unsigned *)new_code; + int faulted = 0; + + /* move the IP back to the start of the call */ + ip -= CALL_BACK; + + /* + * Note: Due to modules and __init, code can + * disappear and change, we need to protect against faulting + * as well as code changing. + * + * No real locking needed, this code is run through + * kstop_machine. + */ + asm volatile ( + "1: lwz %1, 0(%2)\n" + " cmpw %1, %5\n" + " bne 2f\n" + " stwu %3, 0(%2)\n" + "2:\n" + ".section .fixup, \"ax\"\n" + "3: li %0, 1\n" + " b 2b\n" + ".previous\n" + ".section __ex_table,\"a\"\n" + _ASM_ALIGN "\n" + _ASM_PTR "1b, 3b\n" + ".previous" + : "=r"(faulted), "=r"(replaced) + : "r"(ip), "r"(new), + "0"(faulted), "r"(old) + : "memory"); + + if (replaced != old && replaced != new) + faulted = 2; + + if (!faulted) + flush_icache_range(ip, ip + 8); + + return faulted; +} + +notrace int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned long ip = (unsigned long)(&ftrace_call); + unsigned char old[4], *new; + int ret; + + ip += CALL_BACK; + + memcpy(old, &ftrace_call, 4); + new = ftrace_call_replace(ip, (unsigned long)func); + ret = ftrace_modify_code(ip, old, new); + + return ret; +} + +notrace int ftrace_mcount_set(unsigned long *data) +{ + unsigned long ip = (long)(&mcount_call); + unsigned long *addr = data; + unsigned char old[4], *new; + + /* ip is at the location, but modify code will subtact this */ + ip += CALL_BACK; + + /* + * Replace the mcount stub with a pointer to the + * ip recorder function. + */ + memcpy(old, &mcount_call, 4); + new = ftrace_call_replace(ip, *addr); + *addr = ftrace_modify_code(ip, old, new); + + return 0; +} + +int __init ftrace_dyn_arch_init(void *data) +{ + /* This is running in kstop_machine */ + + ftrace_mcount_set(data); + + return 0; +} + diff --git a/arch/powerpc/kernel/io.c b/arch/powerpc/kernel/io.c index e31aca9208e..1882bf419fa 100644 --- a/arch/powerpc/kernel/io.c +++ b/arch/powerpc/kernel/io.c @@ -120,7 +120,8 @@ EXPORT_SYMBOL(_outsl_ns); #define IO_CHECK_ALIGN(v,a) ((((unsigned long)(v)) & ((a) - 1)) == 0) -void _memset_io(volatile void __iomem *addr, int c, unsigned long n) +notrace void +_memset_io(volatile void __iomem *addr, int c, unsigned long n) { void *p = (void __force *)addr; u32 lc = c; diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 2f73f705d56..6e01eb0a331 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -98,7 +98,7 @@ EXPORT_SYMBOL(irq_desc); int distribute_irqs = 1; -static inline unsigned long get_hard_enabled(void) +static inline notrace unsigned long get_hard_enabled(void) { unsigned long enabled; @@ -108,13 +108,13 @@ static inline unsigned long get_hard_enabled(void) return enabled; } -static inline void set_soft_enabled(unsigned long enable) +static inline notrace void set_soft_enabled(unsigned long enable) { __asm__ __volatile__("stb %0,%1(13)" : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled))); } -void raw_local_irq_restore(unsigned long en) +notrace void raw_local_irq_restore(unsigned long en) { /* * get_paca()->soft_enabled = en; diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 5112a4aa801..22f8e2bacd3 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -47,6 +47,11 @@ #include #endif +#ifdef CONFIG_FTRACE +extern void _mcount(void); +EXPORT_SYMBOL(_mcount); +#endif + extern void bootx_init(unsigned long r4, unsigned long phys); int boot_cpuid; @@ -81,7 +86,7 @@ int ucache_bsize; * from the address that it was linked at, so we must use RELOC/PTRRELOC * to access static data (including strings). -- paulus */ -unsigned long __init early_init(unsigned long dt_ptr) +notrace unsigned long __init early_init(unsigned long dt_ptr) { unsigned long offset = reloc_offset(); struct cpu_spec *spec; @@ -111,7 +116,7 @@ unsigned long __init early_init(unsigned long dt_ptr) * This is called very early on the boot process, after a minimal * MMU environment has been set up but before MMU_init is called. */ -void __init machine_init(unsigned long dt_ptr, unsigned long phys) +notrace void __init machine_init(unsigned long dt_ptr, unsigned long phys) { /* Enable early debugging if any specified (see udbg.h) */ udbg_early_init(); @@ -133,7 +138,7 @@ void __init machine_init(unsigned long dt_ptr, unsigned long phys) #ifdef CONFIG_BOOKE_WDT /* Checks wdt=x and wdt_period=xx command-line option */ -int __init early_parse_wdt(char *p) +notrace int __init early_parse_wdt(char *p) { if (p && strncmp(p, "0", 1) != 0) booke_wdt_enabled = 1; diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 098fd96a394..277bf18cbbc 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -85,6 +85,11 @@ struct ppc64_caches ppc64_caches = { }; EXPORT_SYMBOL_GPL(ppc64_caches); +#ifdef CONFIG_FTRACE +extern void _mcount(void); +EXPORT_SYMBOL(_mcount); +#endif + /* * These are used in binfmt_elf.c to put aux entries on the stack * for each elf executable being started. diff --git a/arch/powerpc/platforms/powermac/Makefile b/arch/powerpc/platforms/powermac/Makefile index 4d72c8f7215..89774177b20 100644 --- a/arch/powerpc/platforms/powermac/Makefile +++ b/arch/powerpc/platforms/powermac/Makefile @@ -1,5 +1,10 @@ CFLAGS_bootx_init.o += -fPIC +ifdef CONFIG_FTRACE +# Do not trace early boot code +CFLAGS_REMOVE_bootx_init.o = -pg +endif + obj-y += pic.o setup.o time.o feature.o pci.o \ sleep.o low_i2c.o cache.o pfunc_core.o \ pfunc_base.o diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index a5f6001c333..3877dd9102f 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -123,6 +123,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, int ret; int save_ftrace_enabled = ftrace_enabled; int save_tracer_enabled = tracer_enabled; + char *func_name; /* The ftrace test PASSED */ printk(KERN_CONT "PASSED\n"); @@ -142,9 +143,15 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, return ret; } + /* + * Some archs *cough*PowerPC*cough* add charachters to the + * start of the function names. We simply put a '*' to + * accomodate them. + */ + func_name = "*" STR(DYN_FTRACE_TEST_NAME); + /* filter only on our function */ - ftrace_set_filter(STR(DYN_FTRACE_TEST_NAME), - sizeof(STR(DYN_FTRACE_TEST_NAME)), 1); + ftrace_set_filter(func_name, strlen(func_name), 1); /* enable tracing */ tr->ctrl = 1; -- cgit v1.2.3-70-g09d2 From 7fa09f24b477ad41b821713eba757b3aa7a2864a Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 14 May 2008 21:30:32 -0400 Subject: ftrace: use the new kbuild CFLAGS_REMOVE for x86/kernel directory This patch removes the Makefile turd and uses the nice CFLAGS_REMOVE macro in the x86/kernel directory. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/Makefile | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index e142091524b..739d49acd2f 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -6,6 +6,13 @@ extra-y := head_$(BITS).o head$(BITS).o init_task.o vmlinux.lds CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE) +ifdef CONFIG_FTRACE +# Do not profile debug utilities +CFLAGS_REMOVE_tsc_64.o = -pg +CFLAGS_REMOVE_tsc_32.o = -pg +CFLAGS_REMOVE_rtc.o = -pg +endif + # # vsyscalls (which work on the user stack) should have # no stack-protector checks: -- cgit v1.2.3-70-g09d2 From 677aa9f77e8de3791b481a0cec6c8b84d1eec626 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 17 May 2008 00:01:36 -0400 Subject: ftrace: add have dynamic ftrace config for archs Now that ftrace is being ported to other architectures, it has become apparent that DYNAMIC_FTRACE is dependent on whether or not that architecture implements dynamic ftrace. FTRACE itself may be ported to an architecture without porting dynamic ftrace. This patch adds HAVE_DYNAMIC_FTRACE to allow architectures to port ftrace without having to also port the dynamic aspect as well. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/powerpc/Kconfig | 1 + arch/sparc64/Kconfig | 1 + arch/x86/Kconfig | 1 + kernel/trace/Kconfig | 4 ++++ 4 files changed, 7 insertions(+) (limited to 'arch') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 62d034adbd4..a5e9912e2d3 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -105,6 +105,7 @@ config ARCH_NO_VIRT_TO_BUS config PPC bool default y + select HAVE_DYNAMIC_FTRACE select HAVE_FTRACE select HAVE_IDE select HAVE_KPROBES diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig index a480df6e601..fca9246470b 100644 --- a/arch/sparc64/Kconfig +++ b/arch/sparc64/Kconfig @@ -11,6 +11,7 @@ config SPARC config SPARC64 bool default y + select HAVE_DYNAMIC_FTRACE select HAVE_FTRACE select HAVE_IDE select HAVE_LMB diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c742dfeb0db..fc86c54e791 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -23,6 +23,7 @@ config X86 select HAVE_OPROFILE select HAVE_KPROBES select HAVE_KRETPROBES + select HAVE_DYNAMIC_FTRACE select HAVE_FTRACE select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) select HAVE_ARCH_KGDB if !X86_VOYAGER diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index f3005717bcd..5c2295b29f2 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -4,6 +4,9 @@ config HAVE_FTRACE bool +config HAVE_DYNAMIC_FTRACE + bool + config TRACER_MAX_TRACE bool @@ -94,6 +97,7 @@ config CONTEXT_SWITCH_TRACER config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FTRACE + depends on HAVE_DYNAMIC_FTRACE default y help This option will modify all the calls to ftrace dynamically -- cgit v1.2.3-70-g09d2 From 8b7d89d02ef3c6a7c73d6596f28cea7632850af4 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:56 +0200 Subject: x86: mmiotrace - trace memory mapped IO Mmiotrace is a tool for trapping memory mapped IO (MMIO) accesses within the kernel. It is used for debugging and especially for reverse engineering evil binary drivers. Mmiotrace works by wrapping the ioremap family of kernel functions and marking the returned pages as not present. Access to the IO memory triggers a page fault, which will be handled by mmiotrace's custom page fault handler. This will single-step the faulted instruction with the MMIO page marked as present. Access logs are directed to user space via relay and debug_fs. This page fault approach is necessary, because binary drivers have readl/writel etc. calls inlined and therefore extremely difficult to trap with with e.g. kprobes. This patch depends on the custom page fault handlers patch. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 27 ++ arch/x86/kernel/Makefile | 2 + arch/x86/kernel/init_task.c | 1 + arch/x86/kernel/mmiotrace/Makefile | 4 + arch/x86/kernel/mmiotrace/kmmio.c | 391 ++++++++++++++++++++++ arch/x86/kernel/mmiotrace/kmmio.h | 58 ++++ arch/x86/kernel/mmiotrace/mmio-mod.c | 527 ++++++++++++++++++++++++++++++ arch/x86/kernel/mmiotrace/pf_in.c | 489 +++++++++++++++++++++++++++ arch/x86/kernel/mmiotrace/pf_in.h | 39 +++ arch/x86/kernel/mmiotrace/testmmiotrace.c | 77 +++++ include/linux/mmiotrace.h | 62 ++++ 11 files changed, 1677 insertions(+) create mode 100644 arch/x86/kernel/mmiotrace/Makefile create mode 100644 arch/x86/kernel/mmiotrace/kmmio.c create mode 100644 arch/x86/kernel/mmiotrace/kmmio.h create mode 100644 arch/x86/kernel/mmiotrace/mmio-mod.c create mode 100644 arch/x86/kernel/mmiotrace/pf_in.c create mode 100644 arch/x86/kernel/mmiotrace/pf_in.h create mode 100644 arch/x86/kernel/mmiotrace/testmmiotrace.c create mode 100644 include/linux/mmiotrace.h (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 9431a839984..7c6496e2225 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -176,6 +176,33 @@ config PAGE_FAULT_HANDLERS register a function that is called on every page fault. Custom handlers are used by some debugging and reverse engineering tools. +config MMIOTRACE + tristate "Memory mapped IO tracing" + depends on DEBUG_KERNEL && PAGE_FAULT_HANDLERS && RELAY && DEBUG_FS + default n + help + This will build a kernel module called mmiotrace. + + Mmiotrace traces Memory Mapped I/O access and is meant for debugging + and reverse engineering. The kernel module offers wrapped + versions of the ioremap family of functions. The driver to be traced + must be modified to call these wrappers. A user space program is + required to collect the MMIO data. + + See http://nouveau.freedesktop.org/wiki/MmioTrace + If you are not helping to develop drivers, say N. + +config MMIOTRACE_TEST + tristate "Test module for mmiotrace" + depends on MMIOTRACE && m + default n + help + This is a dumb module for testing mmiotrace. It is very dangerous + as it will write garbage to IO memory starting at a given address. + However, it should be safe to use on e.g. unused portion of VRAM. + + Say N, unless you absolutely know what you are doing. + # # IO delay types: # diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 739d49acd2f..a51ac153685 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -79,6 +79,8 @@ obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_VM86) += vm86_32.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +obj-$(CONFIG_MMIOTRACE) += mmiotrace/ + obj-$(CONFIG_HPET_TIMER) += hpet.o obj-$(CONFIG_K8_NB) += k8.o diff --git a/arch/x86/kernel/init_task.c b/arch/x86/kernel/init_task.c index a4f93b4120c..027a5b6a12b 100644 --- a/arch/x86/kernel/init_task.c +++ b/arch/x86/kernel/init_task.c @@ -15,6 +15,7 @@ static struct signal_struct init_signals = INIT_SIGNALS(init_signals); static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); struct mm_struct init_mm = INIT_MM(init_mm); EXPORT_UNUSED_SYMBOL(init_mm); /* will be removed in 2.6.26 */ +EXPORT_SYMBOL_GPL(init_mm); /* * Initial thread structure. diff --git a/arch/x86/kernel/mmiotrace/Makefile b/arch/x86/kernel/mmiotrace/Makefile new file mode 100644 index 00000000000..d6905f7f981 --- /dev/null +++ b/arch/x86/kernel/mmiotrace/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_MMIOTRACE) += mmiotrace.o +mmiotrace-objs := pf_in.o kmmio.o mmio-mod.o + +obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c new file mode 100644 index 00000000000..8ba48f9c91b --- /dev/null +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -0,0 +1,391 @@ +/* Support for MMIO probes. + * Benfit many code from kprobes + * (C) 2002 Louis Zhuang . + * 2007 Alexander Eichner + * 2008 Pekka Paalanen + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kmmio.h" + +#define KMMIO_HASH_BITS 6 +#define KMMIO_TABLE_SIZE (1 << KMMIO_HASH_BITS) +#define KMMIO_PAGE_HASH_BITS 4 +#define KMMIO_PAGE_TABLE_SIZE (1 << KMMIO_PAGE_HASH_BITS) + +struct kmmio_context { + struct kmmio_fault_page *fpage; + struct kmmio_probe *probe; + unsigned long saved_flags; + int active; +}; + +static int kmmio_page_fault(struct pt_regs *regs, unsigned long error_code, + unsigned long address); +static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, + void *args); + +static DEFINE_SPINLOCK(kmmio_lock); + +/* These are protected by kmmio_lock */ +unsigned int kmmio_count; +static unsigned int handler_registered; +static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE]; +static LIST_HEAD(kmmio_probes); + +static struct kmmio_context kmmio_ctx[NR_CPUS]; + +static struct pf_handler kmmio_pf_hook = { + .handler = kmmio_page_fault +}; + +static struct notifier_block nb_die = { + .notifier_call = kmmio_die_notifier +}; + +int init_kmmio(void) +{ + int i; + for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) + INIT_LIST_HEAD(&kmmio_page_table[i]); + + register_die_notifier(&nb_die); + return 0; +} + +void cleanup_kmmio(void) +{ + /* + * Assume the following have been already cleaned by calling + * unregister_kmmio_probe() appropriately: + * kmmio_page_table, kmmio_probes + */ + if (handler_registered) { + unregister_page_fault_handler(&kmmio_pf_hook); + synchronize_rcu(); + } + unregister_die_notifier(&nb_die); +} + +/* + * this is basically a dynamic stabbing problem: + * Could use the existing prio tree code or + * Possible better implementations: + * The Interval Skip List: A Data Structure for Finding All Intervals That + * Overlap a Point (might be simple) + * Space Efficient Dynamic Stabbing with Fast Queries - Mikkel Thorup + */ +/* Get the kmmio at this addr (if any). You must be holding kmmio_lock. */ +static struct kmmio_probe *get_kmmio_probe(unsigned long addr) +{ + struct kmmio_probe *p; + list_for_each_entry(p, &kmmio_probes, list) { + if (addr >= p->addr && addr <= (p->addr + p->len)) + return p; + } + return NULL; +} + +static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) +{ + struct list_head *head, *tmp; + + page &= PAGE_MASK; + head = &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)]; + list_for_each(tmp, head) { + struct kmmio_fault_page *p + = list_entry(tmp, struct kmmio_fault_page, list); + if (p->page == page) + return p; + } + + return NULL; +} + +static void arm_kmmio_fault_page(unsigned long page, int *large) +{ + unsigned long address = page & PAGE_MASK; + pgd_t *pgd = pgd_offset_k(address); + pud_t *pud = pud_offset(pgd, address); + pmd_t *pmd = pmd_offset(pud, address); + pte_t *pte = pte_offset_kernel(pmd, address); + + if (pmd_large(*pmd)) { + set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_PRESENT)); + if (large) + *large = 1; + } else { + set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); + } + + __flush_tlb_one(page); +} + +static void disarm_kmmio_fault_page(unsigned long page, int *large) +{ + unsigned long address = page & PAGE_MASK; + pgd_t *pgd = pgd_offset_k(address); + pud_t *pud = pud_offset(pgd, address); + pmd_t *pmd = pmd_offset(pud, address); + pte_t *pte = pte_offset_kernel(pmd, address); + + if (large && *large) { + set_pmd(pmd, __pmd(pmd_val(*pmd) | _PAGE_PRESENT)); + *large = 0; + } else { + set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); + } + + __flush_tlb_one(page); +} + +/* + * Interrupts are disabled on entry as trap3 is an interrupt gate + * and they remain disabled thorough out this function. + */ +static int kmmio_handler(struct pt_regs *regs, unsigned long addr) +{ + struct kmmio_context *ctx; + int cpu; + + /* + * Preemption is now disabled to prevent process switch during + * single stepping. We can only handle one active kmmio trace + * per cpu, so ensure that we finish it before something else + * gets to run. + * + * XXX what if an interrupt occurs between returning from + * do_page_fault() and entering the single-step exception handler? + * And that interrupt triggers a kmmio trap? + */ + preempt_disable(); + cpu = smp_processor_id(); + ctx = &kmmio_ctx[cpu]; + + /* interrupts disabled and CPU-local data => atomicity guaranteed. */ + if (ctx->active) { + /* + * This avoids a deadlock with kmmio_lock. + * If this page fault really was due to kmmio trap, + * all hell breaks loose. + */ + printk(KERN_EMERG "mmiotrace: recursive probe hit on CPU %d, " + "for address %lu. Ignoring.\n", + cpu, addr); + goto no_kmmio; + } + ctx->active++; + + /* + * Acquire the kmmio lock to prevent changes affecting + * get_kmmio_fault_page() and get_kmmio_probe(), since we save their + * returned pointers. + * The lock is released in post_kmmio_handler(). + * XXX: could/should get_kmmio_*() be using RCU instead of spinlock? + */ + spin_lock(&kmmio_lock); + + ctx->fpage = get_kmmio_fault_page(addr); + if (!ctx->fpage) { + /* this page fault is not caused by kmmio */ + goto no_kmmio_locked; + } + + ctx->probe = get_kmmio_probe(addr); + ctx->saved_flags = (regs->flags & (TF_MASK|IF_MASK)); + + if (ctx->probe && ctx->probe->pre_handler) + ctx->probe->pre_handler(ctx->probe, regs, addr); + + regs->flags |= TF_MASK; + regs->flags &= ~IF_MASK; + + /* We hold lock, now we set present bit in PTE and single step. */ + disarm_kmmio_fault_page(ctx->fpage->page, NULL); + + return 1; + +no_kmmio_locked: + spin_unlock(&kmmio_lock); + ctx->active--; +no_kmmio: + preempt_enable_no_resched(); + /* page fault not handled by kmmio */ + return 0; +} + +/* + * Interrupts are disabled on entry as trap1 is an interrupt gate + * and they remain disabled thorough out this function. + * And we hold kmmio lock. + */ +static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) +{ + int cpu = smp_processor_id(); + struct kmmio_context *ctx = &kmmio_ctx[cpu]; + + if (!ctx->active) + return 0; + + if (ctx->probe && ctx->probe->post_handler) + ctx->probe->post_handler(ctx->probe, condition, regs); + + arm_kmmio_fault_page(ctx->fpage->page, NULL); + + regs->flags &= ~TF_MASK; + regs->flags |= ctx->saved_flags; + + /* These were acquired in kmmio_handler(). */ + ctx->active--; + spin_unlock(&kmmio_lock); + preempt_enable_no_resched(); + + /* + * if somebody else is singlestepping across a probe point, flags + * will have TF set, in which case, continue the remaining processing + * of do_debug, as if this is not a probe hit. + */ + if (regs->flags & TF_MASK) + return 0; + + return 1; +} + +static int add_kmmio_fault_page(unsigned long page) +{ + struct kmmio_fault_page *f; + + page &= PAGE_MASK; + f = get_kmmio_fault_page(page); + if (f) { + f->count++; + return 0; + } + + f = kmalloc(sizeof(*f), GFP_ATOMIC); + if (!f) + return -1; + + f->count = 1; + f->page = page; + list_add(&f->list, + &kmmio_page_table[hash_long(f->page, KMMIO_PAGE_HASH_BITS)]); + + arm_kmmio_fault_page(f->page, NULL); + + return 0; +} + +static void release_kmmio_fault_page(unsigned long page) +{ + struct kmmio_fault_page *f; + + page &= PAGE_MASK; + f = get_kmmio_fault_page(page); + if (!f) + return; + + f->count--; + if (!f->count) { + disarm_kmmio_fault_page(f->page, NULL); + list_del(&f->list); + } +} + +int register_kmmio_probe(struct kmmio_probe *p) +{ + int ret = 0; + unsigned long size = 0; + + spin_lock_irq(&kmmio_lock); + kmmio_count++; + if (get_kmmio_probe(p->addr)) { + ret = -EEXIST; + goto out; + } + list_add(&p->list, &kmmio_probes); + /*printk("adding fault pages...\n");*/ + while (size < p->len) { + if (add_kmmio_fault_page(p->addr + size)) + printk(KERN_ERR "mmio: Unable to set page fault.\n"); + size += PAGE_SIZE; + } + + if (!handler_registered) { + register_page_fault_handler(&kmmio_pf_hook); + handler_registered++; + } + +out: + spin_unlock_irq(&kmmio_lock); + /* + * XXX: What should I do here? + * Here was a call to global_flush_tlb(), but it does not exist + * anymore. + */ + return ret; +} + +void unregister_kmmio_probe(struct kmmio_probe *p) +{ + unsigned long size = 0; + + spin_lock_irq(&kmmio_lock); + while (size < p->len) { + release_kmmio_fault_page(p->addr + size); + size += PAGE_SIZE; + } + list_del(&p->list); + kmmio_count--; + spin_unlock_irq(&kmmio_lock); +} + +/* + * According to 2.6.20, mainly x86_64 arch: + * This is being called from do_page_fault(), via the page fault notifier + * chain. The chain is called for both user space faults and kernel space + * faults (address >= TASK_SIZE64), except not on faults serviced by + * vmalloc_fault(). + * + * We may be in an interrupt or a critical section. Also prefecthing may + * trigger a page fault. We may be in the middle of process switch. + * The page fault hook functionality has put us inside RCU read lock. + * + * Local interrupts are disabled, so preemption cannot happen. + * Do not enable interrupts, do not sleep, and watch out for other CPUs. + */ +static int kmmio_page_fault(struct pt_regs *regs, unsigned long error_code, + unsigned long address) +{ + if (is_kmmio_active()) + if (kmmio_handler(regs, address) == 1) + return -1; + return 0; +} + +static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, + void *args) +{ + struct die_args *arg = args; + + if (val == DIE_DEBUG) + if (post_kmmio_handler(arg->err, arg->regs) == 1) + return NOTIFY_STOP; + + return NOTIFY_DONE; +} diff --git a/arch/x86/kernel/mmiotrace/kmmio.h b/arch/x86/kernel/mmiotrace/kmmio.h new file mode 100644 index 00000000000..85b7f68a3b8 --- /dev/null +++ b/arch/x86/kernel/mmiotrace/kmmio.h @@ -0,0 +1,58 @@ +#ifndef _LINUX_KMMIO_H +#define _LINUX_KMMIO_H + +#include +#include +#include +#include +#include +#include +#include + +struct kmmio_probe; +struct kmmio_fault_page; +struct pt_regs; + +typedef void (*kmmio_pre_handler_t)(struct kmmio_probe *, + struct pt_regs *, unsigned long addr); +typedef void (*kmmio_post_handler_t)(struct kmmio_probe *, + unsigned long condition, struct pt_regs *); + +struct kmmio_probe { + struct list_head list; + + /* start location of the probe point */ + unsigned long addr; + + /* length of the probe region */ + unsigned long len; + + /* Called before addr is executed. */ + kmmio_pre_handler_t pre_handler; + + /* Called after addr is executed, unless... */ + kmmio_post_handler_t post_handler; +}; + +struct kmmio_fault_page { + struct list_head list; + + /* location of the fault page */ + unsigned long page; + + int count; +}; + +/* kmmio is active by some kmmio_probes? */ +static inline int is_kmmio_active(void) +{ + extern unsigned int kmmio_count; + return kmmio_count; +} + +int init_kmmio(void); +void cleanup_kmmio(void); +int register_kmmio_probe(struct kmmio_probe *p); +void unregister_kmmio_probe(struct kmmio_probe *p); + +#endif /* _LINUX_KMMIO_H */ diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c new file mode 100644 index 00000000000..73561fe85f0 --- /dev/null +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -0,0 +1,527 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) IBM Corporation, 2005 + * Jeff Muizelaar, 2006, 2007 + * Pekka Paalanen, 2008 + * + * Derived from the read-mod example from relay-examples by Tom Zanussi. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* for ISA_START_ADDRESS */ + +#include "kmmio.h" +#include "pf_in.h" + +/* This app's relay channel files will appear in /debug/mmio-trace */ +#define APP_DIR "mmio-trace" +/* the marker injection file in /proc */ +#define MARKER_FILE "mmio-marker" + +#define MODULE_NAME "mmiotrace" + +struct trap_reason { + unsigned long addr; + unsigned long ip; + enum reason_type type; + int active_traces; +}; + +static struct trap_reason pf_reason[NR_CPUS]; +static struct mm_io_header_rw cpu_trace[NR_CPUS]; + +static struct file_operations mmio_fops = { + .owner = THIS_MODULE, +}; + +static const size_t subbuf_size = 256*1024; +static struct rchan *chan; +static struct dentry *dir; +static int suspended; /* XXX should this be per cpu? */ +static struct proc_dir_entry *proc_marker_file; + +/* module parameters */ +static unsigned int n_subbufs = 32*4; +static unsigned long filter_offset; +static int nommiotrace; +static int ISA_trace; +static int trace_pc; + +module_param(n_subbufs, uint, 0); +module_param(filter_offset, ulong, 0); +module_param(nommiotrace, bool, 0); +module_param(ISA_trace, bool, 0); +module_param(trace_pc, bool, 0); + +MODULE_PARM_DESC(n_subbufs, "Number of 256kB buffers, default 128."); +MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); +MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); +MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); +MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); + +static void record_timestamp(struct mm_io_header *header) +{ + struct timespec now; + + getnstimeofday(&now); + header->sec = now.tv_sec; + header->nsec = now.tv_nsec; +} + +/* + * Write callback for the /proc entry: + * Read a marker and write it to the mmio trace log + */ +static int write_marker(struct file *file, const char __user *buffer, + unsigned long count, void *data) +{ + char *event = NULL; + struct mm_io_header *headp; + int len = (count > 65535) ? 65535 : count; + + event = kzalloc(sizeof(*headp) + len, GFP_KERNEL); + if (!event) + return -ENOMEM; + + headp = (struct mm_io_header *)event; + headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT); + headp->data_len = len; + record_timestamp(headp); + + if (copy_from_user(event + sizeof(*headp), buffer, len)) { + kfree(event); + return -EFAULT; + } + + relay_write(chan, event, sizeof(*headp) + len); + kfree(event); + return len; +} + +static void print_pte(unsigned long address) +{ + pgd_t *pgd = pgd_offset_k(address); + pud_t *pud = pud_offset(pgd, address); + pmd_t *pmd = pmd_offset(pud, address); + if (pmd_large(*pmd)) { + printk(KERN_EMERG MODULE_NAME ": 4MB pages are not " + "currently supported: %lx\n", + address); + BUG(); + } + printk(KERN_DEBUG MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n", + address, + pte_val(*pte_offset_kernel(pmd, address)), + pte_val(*pte_offset_kernel(pmd, address)) & _PAGE_PRESENT); +} + +/* + * For some reason the pre/post pairs have been called in an + * unmatched order. Report and die. + */ +static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) +{ + const unsigned long cpu = smp_processor_id(); + printk(KERN_EMERG MODULE_NAME ": unexpected fault for address: %lx, " + "last fault for address: %lx\n", + addr, pf_reason[cpu].addr); + print_pte(addr); +#ifdef __i386__ + print_symbol(KERN_EMERG "faulting EIP is at %s\n", regs->ip); + print_symbol(KERN_EMERG "last faulting EIP was at %s\n", + pf_reason[cpu].ip); + printk(KERN_EMERG + "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", + regs->ax, regs->bx, regs->cx, regs->dx); + printk(KERN_EMERG + "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", + regs->si, regs->di, regs->bp, regs->sp); +#else + print_symbol(KERN_EMERG "faulting RIP is at %s\n", regs->ip); + print_symbol(KERN_EMERG "last faulting RIP was at %s\n", + pf_reason[cpu].ip); + printk(KERN_EMERG "rax: %016lx rcx: %016lx rdx: %016lx\n", + regs->ax, regs->cx, regs->dx); + printk(KERN_EMERG "rsi: %016lx rdi: %016lx " + "rbp: %016lx rsp: %016lx\n", + regs->si, regs->di, regs->bp, regs->sp); +#endif + BUG(); +} + +static void pre(struct kmmio_probe *p, struct pt_regs *regs, + unsigned long addr) +{ + const unsigned long cpu = smp_processor_id(); + const unsigned long instptr = instruction_pointer(regs); + const enum reason_type type = get_ins_type(instptr); + + /* it doesn't make sense to have more than one active trace per cpu */ + if (pf_reason[cpu].active_traces) + die_kmmio_nesting_error(regs, addr); + else + pf_reason[cpu].active_traces++; + + pf_reason[cpu].type = type; + pf_reason[cpu].addr = addr; + pf_reason[cpu].ip = instptr; + + cpu_trace[cpu].header.type = MMIO_MAGIC; + cpu_trace[cpu].header.pid = 0; + cpu_trace[cpu].header.data_len = sizeof(struct mm_io_rw); + cpu_trace[cpu].rw.address = addr; + + /* + * Only record the program counter when requested. + * It may taint clean-room reverse engineering. + */ + if (trace_pc) + cpu_trace[cpu].rw.pc = instptr; + else + cpu_trace[cpu].rw.pc = 0; + + record_timestamp(&cpu_trace[cpu].header); + + switch (type) { + case REG_READ: + cpu_trace[cpu].header.type |= + (MMIO_READ << MMIO_OPCODE_SHIFT) | + (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); + break; + case REG_WRITE: + cpu_trace[cpu].header.type |= + (MMIO_WRITE << MMIO_OPCODE_SHIFT) | + (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); + cpu_trace[cpu].rw.value = get_ins_reg_val(instptr, regs); + break; + case IMM_WRITE: + cpu_trace[cpu].header.type |= + (MMIO_WRITE << MMIO_OPCODE_SHIFT) | + (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); + cpu_trace[cpu].rw.value = get_ins_imm_val(instptr); + break; + default: + { + unsigned char *ip = (unsigned char *)instptr; + cpu_trace[cpu].header.type |= + (MMIO_UNKNOWN_OP << MMIO_OPCODE_SHIFT); + cpu_trace[cpu].rw.value = (*ip) << 16 | + *(ip + 1) << 8 | + *(ip + 2); + } + } +} + +static void post(struct kmmio_probe *p, unsigned long condition, + struct pt_regs *regs) +{ + const unsigned long cpu = smp_processor_id(); + + /* this should always return the active_trace count to 0 */ + pf_reason[cpu].active_traces--; + if (pf_reason[cpu].active_traces) { + printk(KERN_EMERG MODULE_NAME ": unexpected post handler"); + BUG(); + } + + switch (pf_reason[cpu].type) { + case REG_READ: + cpu_trace[cpu].rw.value = get_ins_reg_val(pf_reason[cpu].ip, + regs); + break; + default: + break; + } + relay_write(chan, &cpu_trace[cpu], sizeof(struct mm_io_header_rw)); +} + +/* + * subbuf_start() relay callback. + * + * Defined so that we know when events are dropped due to the buffer-full + * condition. + */ +static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf, + void *prev_subbuf, size_t prev_padding) +{ + if (relay_buf_full(buf)) { + if (!suspended) { + suspended = 1; + printk(KERN_ERR MODULE_NAME + ": cpu %d buffer full!!!\n", + smp_processor_id()); + } + return 0; + } else if (suspended) { + suspended = 0; + printk(KERN_ERR MODULE_NAME + ": cpu %d buffer no longer full.\n", + smp_processor_id()); + } + + return 1; +} + +/* file_create() callback. Creates relay file in debugfs. */ +static struct dentry *create_buf_file_handler(const char *filename, + struct dentry *parent, + int mode, + struct rchan_buf *buf, + int *is_global) +{ + struct dentry *buf_file; + + mmio_fops.read = relay_file_operations.read; + mmio_fops.open = relay_file_operations.open; + mmio_fops.poll = relay_file_operations.poll; + mmio_fops.mmap = relay_file_operations.mmap; + mmio_fops.release = relay_file_operations.release; + mmio_fops.splice_read = relay_file_operations.splice_read; + + buf_file = debugfs_create_file(filename, mode, parent, buf, + &mmio_fops); + + return buf_file; +} + +/* file_remove() default callback. Removes relay file in debugfs. */ +static int remove_buf_file_handler(struct dentry *dentry) +{ + debugfs_remove(dentry); + return 0; +} + +static struct rchan_callbacks relay_callbacks = { + .subbuf_start = subbuf_start_handler, + .create_buf_file = create_buf_file_handler, + .remove_buf_file = remove_buf_file_handler, +}; + +/* + * create_channel - creates channel /debug/APP_DIR/cpuXXX + * Returns channel on success, NULL otherwise + */ +static struct rchan *create_channel(unsigned size, unsigned n) +{ + return relay_open("cpu", dir, size, n, &relay_callbacks, NULL); +} + +/* destroy_channel - destroys channel /debug/APP_DIR/cpuXXX */ +static void destroy_channel(void) +{ + if (chan) { + relay_close(chan); + chan = NULL; + } +} + +struct remap_trace { + struct list_head list; + struct kmmio_probe probe; +}; +static LIST_HEAD(trace_list); +static DEFINE_SPINLOCK(trace_list_lock); + +static void do_ioremap_trace_core(unsigned long offset, unsigned long size, + void __iomem *addr) +{ + struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); + struct mm_io_header_map event = { + .header = { + .type = MMIO_MAGIC | + (MMIO_PROBE << MMIO_OPCODE_SHIFT), + .sec = 0, + .nsec = 0, + .pid = 0, + .data_len = sizeof(struct mm_io_map) + }, + .map = { + .phys = offset, + .addr = (unsigned long)addr, + .len = size, + .pc = 0 + } + }; + record_timestamp(&event.header); + + *trace = (struct remap_trace) { + .probe = { + .addr = (unsigned long)addr, + .len = size, + .pre_handler = pre, + .post_handler = post, + } + }; + + relay_write(chan, &event, sizeof(event)); + spin_lock(&trace_list_lock); + list_add_tail(&trace->list, &trace_list); + spin_unlock(&trace_list_lock); + if (!nommiotrace) + register_kmmio_probe(&trace->probe); +} + +static void ioremap_trace_core(unsigned long offset, unsigned long size, + void __iomem *addr) +{ + if ((filter_offset) && (offset != filter_offset)) + return; + + /* Don't trace the low PCI/ISA area, it's always mapped.. */ + if (!ISA_trace && (offset < ISA_END_ADDRESS) && + (offset + size > ISA_START_ADDRESS)) { + printk(KERN_NOTICE MODULE_NAME ": Ignoring map of low " + "PCI/ISA area (0x%lx-0x%lx)\n", + offset, offset + size); + return; + } + do_ioremap_trace_core(offset, size, addr); +} + +void __iomem *ioremap_cache_trace(unsigned long offset, unsigned long size) +{ + void __iomem *p = ioremap_cache(offset, size); + printk(KERN_DEBUG MODULE_NAME ": ioremap_cache(0x%lx, 0x%lx) = %p\n", + offset, size, p); + ioremap_trace_core(offset, size, p); + return p; +} +EXPORT_SYMBOL(ioremap_cache_trace); + +void __iomem *ioremap_nocache_trace(unsigned long offset, unsigned long size) +{ + void __iomem *p = ioremap_nocache(offset, size); + printk(KERN_DEBUG MODULE_NAME ": ioremap_nocache(0x%lx, 0x%lx) = %p\n", + offset, size, p); + ioremap_trace_core(offset, size, p); + return p; +} +EXPORT_SYMBOL(ioremap_nocache_trace); + +void iounmap_trace(volatile void __iomem *addr) +{ + struct mm_io_header_map event = { + .header = { + .type = MMIO_MAGIC | + (MMIO_UNPROBE << MMIO_OPCODE_SHIFT), + .sec = 0, + .nsec = 0, + .pid = 0, + .data_len = sizeof(struct mm_io_map) + }, + .map = { + .phys = 0, + .addr = (unsigned long)addr, + .len = 0, + .pc = 0 + } + }; + struct remap_trace *trace; + struct remap_trace *tmp; + printk(KERN_DEBUG MODULE_NAME ": Unmapping %p.\n", addr); + record_timestamp(&event.header); + + spin_lock(&trace_list_lock); + list_for_each_entry_safe(trace, tmp, &trace_list, list) { + if ((unsigned long)addr == trace->probe.addr) { + if (!nommiotrace) + unregister_kmmio_probe(&trace->probe); + list_del(&trace->list); + kfree(trace); + break; + } + } + spin_unlock(&trace_list_lock); + relay_write(chan, &event, sizeof(event)); + iounmap(addr); +} +EXPORT_SYMBOL(iounmap_trace); + +static void clear_trace_list(void) +{ + struct remap_trace *trace; + struct remap_trace *tmp; + + spin_lock(&trace_list_lock); + list_for_each_entry_safe(trace, tmp, &trace_list, list) { + printk(KERN_WARNING MODULE_NAME ": purging non-iounmapped " + "trace @0x%08lx, size 0x%lx.\n", + trace->probe.addr, trace->probe.len); + if (!nommiotrace) + unregister_kmmio_probe(&trace->probe); + list_del(&trace->list); + kfree(trace); + break; + } + spin_unlock(&trace_list_lock); +} + +static int __init init(void) +{ + if (n_subbufs < 2) + return -EINVAL; + + dir = debugfs_create_dir(APP_DIR, NULL); + if (!dir) { + printk(KERN_ERR MODULE_NAME + ": Couldn't create relay app directory.\n"); + return -ENOMEM; + } + + chan = create_channel(subbuf_size, n_subbufs); + if (!chan) { + debugfs_remove(dir); + printk(KERN_ERR MODULE_NAME + ": relay app channel creation failed\n"); + return -ENOMEM; + } + + init_kmmio(); + + proc_marker_file = create_proc_entry(MARKER_FILE, 0, NULL); + if (proc_marker_file) + proc_marker_file->write_proc = write_marker; + + printk(KERN_DEBUG MODULE_NAME ": loaded.\n"); + if (nommiotrace) + printk(KERN_DEBUG MODULE_NAME ": MMIO tracing disabled.\n"); + if (ISA_trace) + printk(KERN_WARNING MODULE_NAME + ": Warning! low ISA range will be traced.\n"); + return 0; +} + +static void __exit cleanup(void) +{ + printk(KERN_DEBUG MODULE_NAME ": unload...\n"); + clear_trace_list(); + cleanup_kmmio(); + remove_proc_entry(MARKER_FILE, NULL); + destroy_channel(); + if (dir) + debugfs_remove(dir); +} + +module_init(init); +module_exit(cleanup); +MODULE_LICENSE("GPL"); diff --git a/arch/x86/kernel/mmiotrace/pf_in.c b/arch/x86/kernel/mmiotrace/pf_in.c new file mode 100644 index 00000000000..67ea520dde6 --- /dev/null +++ b/arch/x86/kernel/mmiotrace/pf_in.c @@ -0,0 +1,489 @@ +/* + * Fault Injection Test harness (FI) + * Copyright (C) Intel Crop. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + * USA. + * + */ + +/* $Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp $ + * Copyright by Intel Crop., 2002 + * Louis Zhuang (louis.zhuang@intel.com) + * + * Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007 + */ + +#include +#include /* struct pt_regs */ +#include "pf_in.h" + +#ifdef __i386__ +/* IA32 Manual 3, 2-1 */ +static unsigned char prefix_codes[] = { + 0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64, + 0x65, 0x2E, 0x3E, 0x66, 0x67 +}; +/* IA32 Manual 3, 3-432*/ +static unsigned int reg_rop[] = { + 0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +static unsigned int reg_wop[] = { 0x88, 0x89 }; +static unsigned int imm_wop[] = { 0xC6, 0xC7 }; +/* IA32 Manual 3, 3-432*/ +static unsigned int rw8[] = { 0x88, 0x8A, 0xC6 }; +static unsigned int rw32[] = { + 0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F }; +static unsigned int mw16[] = { 0xB70F, 0xBF0F }; +static unsigned int mw32[] = { 0x89, 0x8B, 0xC7 }; +static unsigned int mw64[] = {}; +#else /* not __i386__ */ +static unsigned char prefix_codes[] = { + 0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36, + 0xF0, 0xF3, 0xF2, + /* REX Prefixes */ + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, + 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f +}; +/* AMD64 Manual 3, Appendix A*/ +static unsigned int reg_rop[] = { + 0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +static unsigned int reg_wop[] = { 0x88, 0x89 }; +static unsigned int imm_wop[] = { 0xC6, 0xC7 }; +static unsigned int rw8[] = { 0xC6, 0x88, 0x8A }; +static unsigned int rw32[] = { + 0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +/* 8 bit only */ +static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F }; +/* 16 bit only */ +static unsigned int mw16[] = { 0xB70F, 0xBF0F }; +/* 16 or 32 bit */ +static unsigned int mw32[] = { 0xC7 }; +/* 16, 32 or 64 bit */ +static unsigned int mw64[] = { 0x89, 0x8B }; +#endif /* not __i386__ */ + +static int skip_prefix(unsigned char *addr, int *shorted, int *enlarged, + int *rexr) +{ + int i; + unsigned char *p = addr; + *shorted = 0; + *enlarged = 0; + *rexr = 0; + +restart: + for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) { + if (*p == prefix_codes[i]) { + if (*p == 0x66) + *shorted = 1; +#ifdef __amd64__ + if ((*p & 0xf8) == 0x48) + *enlarged = 1; + if ((*p & 0xf4) == 0x44) + *rexr = 1; +#endif + p++; + goto restart; + } + } + + return (p - addr); +} + +static int get_opcode(unsigned char *addr, unsigned int *opcode) +{ + int len; + + if (*addr == 0x0F) { + /* 0x0F is extension instruction */ + *opcode = *(unsigned short *)addr; + len = 2; + } else { + *opcode = *addr; + len = 1; + } + + return len; +} + +#define CHECK_OP_TYPE(opcode, array, type) \ + for (i = 0; i < ARRAY_SIZE(array); i++) { \ + if (array[i] == opcode) { \ + rv = type; \ + goto exit; \ + } \ + } + +enum reason_type get_ins_type(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char *p; + int shorted, enlarged, rexr; + int i; + enum reason_type rv = OTHERS; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + + CHECK_OP_TYPE(opcode, reg_rop, REG_READ); + CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE); + CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE); + +exit: + return rv; +} +#undef CHECK_OP_TYPE + +static unsigned int get_ins_reg_width(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char *p; + int i, shorted, enlarged, rexr; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + + for (i = 0; i < ARRAY_SIZE(rw8); i++) + if (rw8[i] == opcode) + return 1; + + for (i = 0; i < ARRAY_SIZE(rw32); i++) + if (rw32[i] == opcode) + return (shorted ? 2 : (enlarged ? 8 : 4)); + + printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode); + return 0; +} + +unsigned int get_ins_mem_width(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char *p; + int i, shorted, enlarged, rexr; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + + for (i = 0; i < ARRAY_SIZE(mw8); i++) + if (mw8[i] == opcode) + return 1; + + for (i = 0; i < ARRAY_SIZE(mw16); i++) + if (mw16[i] == opcode) + return 2; + + for (i = 0; i < ARRAY_SIZE(mw32); i++) + if (mw32[i] == opcode) + return shorted ? 2 : 4; + + for (i = 0; i < ARRAY_SIZE(mw64); i++) + if (mw64[i] == opcode) + return shorted ? 2 : (enlarged ? 8 : 4); + + printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode); + return 0; +} + +/* + * Define register ident in mod/rm byte. + * Note: these are NOT the same as in ptrace-abi.h. + */ +enum { + arg_AL = 0, + arg_CL = 1, + arg_DL = 2, + arg_BL = 3, + arg_AH = 4, + arg_CH = 5, + arg_DH = 6, + arg_BH = 7, + + arg_AX = 0, + arg_CX = 1, + arg_DX = 2, + arg_BX = 3, + arg_SP = 4, + arg_BP = 5, + arg_SI = 6, + arg_DI = 7, +#ifdef __amd64__ + arg_R8 = 8, + arg_R9 = 9, + arg_R10 = 10, + arg_R11 = 11, + arg_R12 = 12, + arg_R13 = 13, + arg_R14 = 14, + arg_R15 = 15 +#endif +}; + +static unsigned char *get_reg_w8(int no, struct pt_regs *regs) +{ + unsigned char *rv = NULL; + + switch (no) { + case arg_AL: + rv = (unsigned char *)®s->ax; + break; + case arg_BL: + rv = (unsigned char *)®s->bx; + break; + case arg_CL: + rv = (unsigned char *)®s->cx; + break; + case arg_DL: + rv = (unsigned char *)®s->dx; + break; + case arg_AH: + rv = 1 + (unsigned char *)®s->ax; + break; + case arg_BH: + rv = 1 + (unsigned char *)®s->bx; + break; + case arg_CH: + rv = 1 + (unsigned char *)®s->cx; + break; + case arg_DH: + rv = 1 + (unsigned char *)®s->dx; + break; +#ifdef __amd64__ + case arg_R8: + rv = (unsigned char *)®s->r8; + break; + case arg_R9: + rv = (unsigned char *)®s->r9; + break; + case arg_R10: + rv = (unsigned char *)®s->r10; + break; + case arg_R11: + rv = (unsigned char *)®s->r11; + break; + case arg_R12: + rv = (unsigned char *)®s->r12; + break; + case arg_R13: + rv = (unsigned char *)®s->r13; + break; + case arg_R14: + rv = (unsigned char *)®s->r14; + break; + case arg_R15: + rv = (unsigned char *)®s->r15; + break; +#endif + default: + printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no); + break; + } + return rv; +} + +static unsigned long *get_reg_w32(int no, struct pt_regs *regs) +{ + unsigned long *rv = NULL; + + switch (no) { + case arg_AX: + rv = ®s->ax; + break; + case arg_BX: + rv = ®s->bx; + break; + case arg_CX: + rv = ®s->cx; + break; + case arg_DX: + rv = ®s->dx; + break; + case arg_SP: + rv = ®s->sp; + break; + case arg_BP: + rv = ®s->bp; + break; + case arg_SI: + rv = ®s->si; + break; + case arg_DI: + rv = ®s->di; + break; +#ifdef __amd64__ + case arg_R8: + rv = ®s->r8; + break; + case arg_R9: + rv = ®s->r9; + break; + case arg_R10: + rv = ®s->r10; + break; + case arg_R11: + rv = ®s->r11; + break; + case arg_R12: + rv = ®s->r12; + break; + case arg_R13: + rv = ®s->r13; + break; + case arg_R14: + rv = ®s->r14; + break; + case arg_R15: + rv = ®s->r15; + break; +#endif + default: + printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no); + } + + return rv; +} + +unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs) +{ + unsigned int opcode; + unsigned char mod_rm; + int reg; + unsigned char *p; + int i, shorted, enlarged, rexr; + unsigned long rv; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + for (i = 0; i < ARRAY_SIZE(reg_rop); i++) + if (reg_rop[i] == opcode) { + rv = REG_READ; + goto do_work; + } + + for (i = 0; i < ARRAY_SIZE(reg_wop); i++) + if (reg_wop[i] == opcode) { + rv = REG_WRITE; + goto do_work; + } + + printk(KERN_ERR "mmiotrace: Not a register instruction, opcode " + "0x%02x\n", opcode); + goto err; + +do_work: + mod_rm = *p; + reg = ((mod_rm >> 3) & 0x7) | (rexr << 3); + switch (get_ins_reg_width(ins_addr)) { + case 1: + return *get_reg_w8(reg, regs); + + case 2: + return *(unsigned short *)get_reg_w32(reg, regs); + + case 4: + return *(unsigned int *)get_reg_w32(reg, regs); + +#ifdef __amd64__ + case 8: + return *(unsigned long *)get_reg_w32(reg, regs); +#endif + + default: + printk(KERN_ERR "mmiotrace: Error width# %d\n", reg); + } + +err: + return 0; +} + +unsigned long get_ins_imm_val(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char mod_rm; + unsigned char mod; + unsigned char *p; + int i, shorted, enlarged, rexr; + unsigned long rv; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + for (i = 0; i < ARRAY_SIZE(imm_wop); i++) + if (imm_wop[i] == opcode) { + rv = IMM_WRITE; + goto do_work; + } + + printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode " + "0x%02x\n", opcode); + goto err; + +do_work: + mod_rm = *p; + mod = mod_rm >> 6; + p++; + switch (mod) { + case 0: + /* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2) */ + /* AMD64: XXX Check for address size prefix? */ + if ((mod_rm & 0x7) == 0x5) + p += 4; + break; + + case 1: + p += 1; + break; + + case 2: + p += 4; + break; + + case 3: + default: + printk(KERN_ERR "mmiotrace: not a memory access instruction " + "at 0x%lx, rm_mod=0x%02x\n", + ins_addr, mod_rm); + } + + switch (get_ins_reg_width(ins_addr)) { + case 1: + return *(unsigned char *)p; + + case 2: + return *(unsigned short *)p; + + case 4: + return *(unsigned int *)p; + +#ifdef __amd64__ + case 8: + return *(unsigned long *)p; +#endif + + default: + printk(KERN_ERR "mmiotrace: Error: width.\n"); + } + +err: + return 0; +} diff --git a/arch/x86/kernel/mmiotrace/pf_in.h b/arch/x86/kernel/mmiotrace/pf_in.h new file mode 100644 index 00000000000..e05341a51a2 --- /dev/null +++ b/arch/x86/kernel/mmiotrace/pf_in.h @@ -0,0 +1,39 @@ +/* + * Fault Injection Test harness (FI) + * Copyright (C) Intel Crop. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + * USA. + * + */ + +#ifndef __PF_H_ +#define __PF_H_ + +enum reason_type { + NOT_ME, /* page fault is not in regions */ + NOTHING, /* access others point in regions */ + REG_READ, /* read from addr to reg */ + REG_WRITE, /* write from reg to addr */ + IMM_WRITE, /* write from imm to addr */ + OTHERS /* Other instructions can not intercept */ +}; + +enum reason_type get_ins_type(unsigned long ins_addr); +unsigned int get_ins_mem_width(unsigned long ins_addr); +unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs); +unsigned long get_ins_imm_val(unsigned long ins_addr); + +#endif /* __PF_H_ */ diff --git a/arch/x86/kernel/mmiotrace/testmmiotrace.c b/arch/x86/kernel/mmiotrace/testmmiotrace.c new file mode 100644 index 00000000000..40e66b0e648 --- /dev/null +++ b/arch/x86/kernel/mmiotrace/testmmiotrace.c @@ -0,0 +1,77 @@ +/* + * Written by Pekka Paalanen, 2008 + */ +#include +#include + +extern void __iomem *ioremap_nocache_trace(unsigned long offset, + unsigned long size); +extern void iounmap_trace(volatile void __iomem *addr); + +#define MODULE_NAME "testmmiotrace" + +static unsigned long mmio_address; +module_param(mmio_address, ulong, 0); +MODULE_PARM_DESC(mmio_address, "Start address of the mapping of 16 kB."); + +static void do_write_test(void __iomem *p) +{ + unsigned int i; + for (i = 0; i < 256; i++) + iowrite8(i, p + i); + for (i = 1024; i < (5 * 1024); i += 2) + iowrite16(i * 12 + 7, p + i); + for (i = (5 * 1024); i < (16 * 1024); i += 4) + iowrite32(i * 212371 + 13, p + i); +} + +static void do_read_test(void __iomem *p) +{ + unsigned int i; + volatile unsigned int v; + for (i = 0; i < 256; i++) + v = ioread8(p + i); + for (i = 1024; i < (5 * 1024); i += 2) + v = ioread16(p + i); + for (i = (5 * 1024); i < (16 * 1024); i += 4) + v = ioread32(p + i); +} + +static void do_test(void) +{ + void __iomem *p = ioremap_nocache_trace(mmio_address, 0x4000); + if (!p) { + printk(KERN_ERR MODULE_NAME ": could not ioremap IO memory, " + "aborting.\n"); + return; + } + do_write_test(p); + do_read_test(p); + iounmap_trace(p); +} + +static int __init init(void) +{ + if (mmio_address == 0) { + printk(KERN_ERR MODULE_NAME ": you have to use the module " + "argument mmio_address.\n"); + printk(KERN_ERR MODULE_NAME ": DO NOT LOAD THIS MODULE UNLESS" + " YOU REALLY KNOW WHAT YOU ARE DOING!\n"); + return -ENXIO; + } + + printk(KERN_WARNING MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx " + "in PCI address space, and writing " + "rubbish in there.\n", mmio_address); + do_test(); + return 0; +} + +static void __exit cleanup(void) +{ + printk(KERN_DEBUG MODULE_NAME ": unloaded.\n"); +} + +module_init(init); +module_exit(cleanup); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h new file mode 100644 index 00000000000..cb247825f3e --- /dev/null +++ b/include/linux/mmiotrace.h @@ -0,0 +1,62 @@ +#ifndef MMIOTRACE_H +#define MMIOTRACE_H + +#include + +#define MMIO_VERSION 0x04 + +/* mm_io_header.type */ +#define MMIO_OPCODE_MASK 0xff +#define MMIO_OPCODE_SHIFT 0 +#define MMIO_WIDTH_MASK 0xff00 +#define MMIO_WIDTH_SHIFT 8 +#define MMIO_MAGIC (0x6f000000 | (MMIO_VERSION<<16)) +#define MMIO_MAGIC_MASK 0xffff0000 + +enum mm_io_opcode { /* payload type: */ + MMIO_READ = 0x1, /* struct mm_io_rw */ + MMIO_WRITE = 0x2, /* struct mm_io_rw */ + MMIO_PROBE = 0x3, /* struct mm_io_map */ + MMIO_UNPROBE = 0x4, /* struct mm_io_map */ + MMIO_MARKER = 0x5, /* raw char data */ + MMIO_UNKNOWN_OP = 0x6, /* struct mm_io_rw */ +}; + +struct mm_io_header { + __u32 type; + __u32 sec; /* timestamp */ + __u32 nsec; + __u32 pid; /* PID of the process, or 0 for kernel core */ + __u16 data_len; /* length of the following payload */ +}; + +struct mm_io_rw { + __u64 address; /* virtual address of register */ + __u64 value; + __u64 pc; /* optional program counter */ +}; + +struct mm_io_map { + __u64 phys; /* base address in PCI space */ + __u64 addr; /* base virtual address */ + __u64 len; /* mapping size */ + __u64 pc; /* optional program counter */ +}; + + +/* + * These structures are used to allow a single relay_write() + * call to write a full packet. + */ + +struct mm_io_header_rw { + struct mm_io_header header; + struct mm_io_rw rw; +} __attribute__((packed)); + +struct mm_io_header_map { + struct mm_io_header header; + struct mm_io_map map; +} __attribute__((packed)); + +#endif /* MMIOTRACE_H */ -- cgit v1.2.3-70-g09d2 From 75bb88350e0501b3cf5ac096a1008757844414a9 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:56 +0200 Subject: x86 mmiotrace: use lookup_address() Use lookup_address() from pageattr.c instead of doing the same manually. Also had to EXPORT_SYMBOL_GPL(lookup_address) to make this work for modules. This also fixes "undefined symbol 'init_mm'" compile error for x86_32. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/mmiotrace/kmmio.c | 46 ++++++++++++++++++++++++------------ arch/x86/kernel/mmiotrace/mmio-mod.c | 19 +++++++++------ arch/x86/mm/pageattr.c | 1 + 3 files changed, 44 insertions(+), 22 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index 8ba48f9c91b..28411dadb8b 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "kmmio.h" @@ -117,40 +118,55 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) return NULL; } -static void arm_kmmio_fault_page(unsigned long page, int *large) +static void arm_kmmio_fault_page(unsigned long page, int *page_level) { unsigned long address = page & PAGE_MASK; - pgd_t *pgd = pgd_offset_k(address); - pud_t *pud = pud_offset(pgd, address); - pmd_t *pmd = pmd_offset(pud, address); - pte_t *pte = pte_offset_kernel(pmd, address); + int level; + pte_t *pte = lookup_address(address, &level); - if (pmd_large(*pmd)) { + if (!pte) { + printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n", + __FUNCTION__, page); + return; + } + + if (level == PG_LEVEL_2M) { + pmd_t *pmd = (pmd_t *)pte; set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_PRESENT)); - if (large) - *large = 1; } else { + /* PG_LEVEL_4K */ set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); } + if (page_level) + *page_level = level; + __flush_tlb_one(page); } -static void disarm_kmmio_fault_page(unsigned long page, int *large) +static void disarm_kmmio_fault_page(unsigned long page, int *page_level) { unsigned long address = page & PAGE_MASK; - pgd_t *pgd = pgd_offset_k(address); - pud_t *pud = pud_offset(pgd, address); - pmd_t *pmd = pmd_offset(pud, address); - pte_t *pte = pte_offset_kernel(pmd, address); + int level; + pte_t *pte = lookup_address(address, &level); - if (large && *large) { + if (!pte) { + printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n", + __FUNCTION__, page); + return; + } + + if (level == PG_LEVEL_2M) { + pmd_t *pmd = (pmd_t *)pte; set_pmd(pmd, __pmd(pmd_val(*pmd) | _PAGE_PRESENT)); - *large = 0; } else { + /* PG_LEVEL_4K */ set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); } + if (page_level) + *page_level = level; + __flush_tlb_one(page); } diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index 73561fe85f0..e43947d218a 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -120,19 +120,24 @@ static int write_marker(struct file *file, const char __user *buffer, static void print_pte(unsigned long address) { - pgd_t *pgd = pgd_offset_k(address); - pud_t *pud = pud_offset(pgd, address); - pmd_t *pmd = pmd_offset(pud, address); - if (pmd_large(*pmd)) { + int level; + pte_t *pte = lookup_address(address, &level); + + if (!pte) { + printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n", + __FUNCTION__, address); + return; + } + + if (level == PG_LEVEL_2M) { printk(KERN_EMERG MODULE_NAME ": 4MB pages are not " "currently supported: %lx\n", address); BUG(); } printk(KERN_DEBUG MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n", - address, - pte_val(*pte_offset_kernel(pmd, address)), - pte_val(*pte_offset_kernel(pmd, address)) & _PAGE_PRESENT); + address, pte_val(*pte), + pte_val(*pte) & _PAGE_PRESENT); } /* diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 60bcb5b6a37..57970f2935c 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -227,6 +227,7 @@ pte_t *lookup_address(unsigned long address, unsigned int *level) return pte_offset_kernel(pmd, address); } +EXPORT_SYMBOL_GPL(lookup_address); /* * Set the new pmd in all the pgds we know about: -- cgit v1.2.3-70-g09d2 From fe1ffafa80f6673101c6560c2bacfe3df10372ee Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:56 +0200 Subject: x86 mmiotrace: fix relay-buffer-full flag for SMP Relay has per-cpu buffers, but mmiotrace was using only a single flag for detecting buffer full/not-full transitions. The new code makes this per-cpu and actually counts missed events. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/mmiotrace/mmio-mod.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index e43947d218a..0019dcdf615 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -29,6 +29,7 @@ #include #include #include /* for ISA_START_ADDRESS */ +#include #include "kmmio.h" #include "pf_in.h" @@ -47,9 +48,13 @@ struct trap_reason { int active_traces; }; +/* Accessed per-cpu. */ static struct trap_reason pf_reason[NR_CPUS]; static struct mm_io_header_rw cpu_trace[NR_CPUS]; +/* Access to this is not per-cpu. */ +static atomic_t dropped[NR_CPUS]; + static struct file_operations mmio_fops = { .owner = THIS_MODULE, }; @@ -57,7 +62,6 @@ static struct file_operations mmio_fops = { static const size_t subbuf_size = 256*1024; static struct rchan *chan; static struct dentry *dir; -static int suspended; /* XXX should this be per cpu? */ static struct proc_dir_entry *proc_marker_file; /* module parameters */ @@ -269,19 +273,21 @@ static void post(struct kmmio_probe *p, unsigned long condition, static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf, void *prev_subbuf, size_t prev_padding) { + unsigned int cpu = buf->cpu; + atomic_t *drop = &dropped[cpu]; + int count; if (relay_buf_full(buf)) { - if (!suspended) { - suspended = 1; - printk(KERN_ERR MODULE_NAME - ": cpu %d buffer full!!!\n", - smp_processor_id()); + if (atomic_inc_return(drop) == 1) { + printk(KERN_ERR MODULE_NAME ": cpu %d buffer full!\n", + cpu); } return 0; - } else if (suspended) { - suspended = 0; + } else if ((count = atomic_read(drop))) { printk(KERN_ERR MODULE_NAME - ": cpu %d buffer no longer full.\n", - smp_processor_id()); + ": cpu %d buffer no longer full, " + "missed %d events.\n", + cpu, count); + atomic_sub(count, drop); } return 1; -- cgit v1.2.3-70-g09d2 From 10c43d2eb50c9a5ad60388b9d3c41c31150049e6 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: x86: explicit call to mmiotrace in do_page_fault() The custom page fault handler list is replaced with a single function pointer. All related functions and variables are renamed for mmiotrace. Signed-off-by: Pekka Paalanen Cc: Christoph Hellwig Cc: Arjan van de Ven Cc: pq@iki.fi Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 14 ++++----- arch/x86/kernel/mmiotrace/kmmio.c | 14 ++++----- arch/x86/mm/fault.c | 66 ++++++++++++++++++++------------------- include/asm-x86/kdebug.h | 12 +++---- 4 files changed, 52 insertions(+), 54 deletions(-) (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 7c6496e2225..9491c0ae03a 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -168,20 +168,18 @@ config IOMMU_LEAK Add a simple leak tracer to the IOMMU code. This is useful when you are debugging a buggy device driver that leaks IOMMU mappings. -config PAGE_FAULT_HANDLERS - bool "Custom page fault handlers" - depends on DEBUG_KERNEL - help - Allow the use of custom page fault handlers. A kernel module may - register a function that is called on every page fault. Custom - handlers are used by some debugging and reverse engineering tools. +config MMIOTRACE_HOOKS + bool + default n config MMIOTRACE tristate "Memory mapped IO tracing" - depends on DEBUG_KERNEL && PAGE_FAULT_HANDLERS && RELAY && DEBUG_FS + depends on DEBUG_KERNEL && RELAY && DEBUG_FS + select MMIOTRACE_HOOKS default n help This will build a kernel module called mmiotrace. + Making this a built-in is heavily discouraged. Mmiotrace traces Memory Mapped I/O access and is meant for debugging and reverse engineering. The kernel module offers wrapped diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index 28411dadb8b..e759f7c3878 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -51,10 +51,6 @@ static LIST_HEAD(kmmio_probes); static struct kmmio_context kmmio_ctx[NR_CPUS]; -static struct pf_handler kmmio_pf_hook = { - .handler = kmmio_page_fault -}; - static struct notifier_block nb_die = { .notifier_call = kmmio_die_notifier }; @@ -77,7 +73,8 @@ void cleanup_kmmio(void) * kmmio_page_table, kmmio_probes */ if (handler_registered) { - unregister_page_fault_handler(&kmmio_pf_hook); + if (mmiotrace_unregister_pf(&kmmio_page_fault)) + BUG(); synchronize_rcu(); } unregister_die_notifier(&nb_die); @@ -343,8 +340,11 @@ int register_kmmio_probe(struct kmmio_probe *p) } if (!handler_registered) { - register_page_fault_handler(&kmmio_pf_hook); - handler_registered++; + if (mmiotrace_register_pf(&kmmio_page_fault)) + printk(KERN_ERR "mmiotrace: Cannot register page " + "fault handler.\n"); + else + handler_registered++; } out: diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 343f5c1aacc..e9a086a1a9f 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -49,53 +49,55 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) -#ifdef CONFIG_PAGE_FAULT_HANDLERS -static HLIST_HEAD(pf_handlers); /* protected by RCU */ -static DEFINE_SPINLOCK(pf_handlers_writer); +#ifdef CONFIG_MMIOTRACE_HOOKS +static pf_handler_func mmiotrace_pf_handler; /* protected by RCU */ +static DEFINE_SPINLOCK(mmiotrace_handler_lock); -void register_page_fault_handler(struct pf_handler *new_pfh) +int mmiotrace_register_pf(pf_handler_func new_pfh) { + int ret = 0; unsigned long flags; - spin_lock_irqsave(&pf_handlers_writer, flags); - hlist_add_head_rcu(&new_pfh->hlist, &pf_handlers); - spin_unlock_irqrestore(&pf_handlers_writer, flags); + spin_lock_irqsave(&mmiotrace_handler_lock, flags); + if (mmiotrace_pf_handler) + ret = -EBUSY; + else + mmiotrace_pf_handler = new_pfh; + spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); + return ret; } -EXPORT_SYMBOL_GPL(register_page_fault_handler); +EXPORT_SYMBOL_GPL(mmiotrace_register_pf); /** - * unregister_page_fault_handler: + * mmiotrace_unregister_pf: * The caller must ensure @old_pfh is not in use anymore before freeing it. - * This function does not guarantee it. The list of handlers is protected by - * RCU, so you can do this by e.g. calling synchronize_rcu(). + * This function does not guarantee it. The handler function pointer is + * protected by RCU, so you can do this by e.g. calling synchronize_rcu(). */ -void unregister_page_fault_handler(struct pf_handler *old_pfh) +int mmiotrace_unregister_pf(pf_handler_func old_pfh) { + int ret = 0; unsigned long flags; - spin_lock_irqsave(&pf_handlers_writer, flags); - hlist_del_rcu(&old_pfh->hlist); - spin_unlock_irqrestore(&pf_handlers_writer, flags); + spin_lock_irqsave(&mmiotrace_handler_lock, flags); + if (mmiotrace_pf_handler != old_pfh) + ret = -EPERM; + else + mmiotrace_pf_handler = NULL; + spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); + return ret; } -EXPORT_SYMBOL_GPL(unregister_page_fault_handler); -#endif +EXPORT_SYMBOL_GPL(mmiotrace_unregister_pf); +#endif /* CONFIG_MMIOTRACE_HOOKS */ /* returns non-zero if do_page_fault() should return */ -static int handle_custom_pf(struct pt_regs *regs, unsigned long error_code, - unsigned long address) +static inline int call_mmiotrace(struct pt_regs *regs, + unsigned long error_code, + unsigned long address) { -#ifdef CONFIG_PAGE_FAULT_HANDLERS +#ifdef CONFIG_MMIOTRACE_HOOKS int ret = 0; - struct pf_handler *cur; - struct hlist_node *ncur; - - if (hlist_empty(&pf_handlers)) - return 0; - rcu_read_lock(); - hlist_for_each_entry_rcu(cur, ncur, &pf_handlers, hlist) { - ret = cur->handler(regs, error_code, address); - if (ret) - break; - } + if (mmiotrace_pf_handler) + ret = mmiotrace_pf_handler(regs, error_code, address); rcu_read_unlock(); return ret; #else @@ -655,7 +657,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (notify_page_fault(regs)) return; - if (handle_custom_pf(regs, error_code, address)) + if (call_mmiotrace(regs, error_code, address)) return; /* diff --git a/include/asm-x86/kdebug.h b/include/asm-x86/kdebug.h index a80f2d6cc73..7063281040d 100644 --- a/include/asm-x86/kdebug.h +++ b/include/asm-x86/kdebug.h @@ -35,13 +35,11 @@ extern void show_regs(struct pt_regs *regs); extern unsigned long oops_begin(void); extern void oops_end(unsigned long, struct pt_regs *, int signr); -struct pf_handler { - struct hlist_node hlist; - int (*handler)(struct pt_regs *regs, unsigned long error_code, - unsigned long address); -}; +typedef int (*pf_handler_func)(struct pt_regs *regs, + unsigned long error_code, + unsigned long address); -extern void register_page_fault_handler(struct pf_handler *new_pfh); -extern void unregister_page_fault_handler(struct pf_handler *old_pfh); +extern int mmiotrace_register_pf(pf_handler_func new_pfh); +extern int mmiotrace_unregister_pf(pf_handler_func old_pfh); #endif -- cgit v1.2.3-70-g09d2 From f513638030ca384b0bace4df64f0b82f6ae1e4c6 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: x86 mmiotrace: Use percpu instead of arrays. Signed-off-by: Pekka Paalanen Cc: Eric Dumazet Cc: pq@iki.fi Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/mmiotrace/kmmio.c | 27 ++++++------ arch/x86/kernel/mmiotrace/mmio-mod.c | 80 +++++++++++++++++++----------------- 2 files changed, 58 insertions(+), 49 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index e759f7c3878..5e239d0b846 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -49,7 +50,8 @@ static unsigned int handler_registered; static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE]; static LIST_HEAD(kmmio_probes); -static struct kmmio_context kmmio_ctx[NR_CPUS]; +/* Accessed per-cpu */ +static DEFINE_PER_CPU(struct kmmio_context, kmmio_ctx); static struct notifier_block nb_die = { .notifier_call = kmmio_die_notifier @@ -173,8 +175,7 @@ static void disarm_kmmio_fault_page(unsigned long page, int *page_level) */ static int kmmio_handler(struct pt_regs *regs, unsigned long addr) { - struct kmmio_context *ctx; - int cpu; + struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); /* * Preemption is now disabled to prevent process switch during @@ -187,8 +188,6 @@ static int kmmio_handler(struct pt_regs *regs, unsigned long addr) * And that interrupt triggers a kmmio trap? */ preempt_disable(); - cpu = smp_processor_id(); - ctx = &kmmio_ctx[cpu]; /* interrupts disabled and CPU-local data => atomicity guaranteed. */ if (ctx->active) { @@ -199,7 +198,7 @@ static int kmmio_handler(struct pt_regs *regs, unsigned long addr) */ printk(KERN_EMERG "mmiotrace: recursive probe hit on CPU %d, " "for address %lu. Ignoring.\n", - cpu, addr); + smp_processor_id(), addr); goto no_kmmio; } ctx->active++; @@ -231,6 +230,7 @@ static int kmmio_handler(struct pt_regs *regs, unsigned long addr) /* We hold lock, now we set present bit in PTE and single step. */ disarm_kmmio_fault_page(ctx->fpage->page, NULL); + put_cpu_var(kmmio_ctx); return 1; no_kmmio_locked: @@ -238,6 +238,7 @@ no_kmmio_locked: ctx->active--; no_kmmio: preempt_enable_no_resched(); + put_cpu_var(kmmio_ctx); /* page fault not handled by kmmio */ return 0; } @@ -249,11 +250,11 @@ no_kmmio: */ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) { - int cpu = smp_processor_id(); - struct kmmio_context *ctx = &kmmio_ctx[cpu]; + int ret = 0; + struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); if (!ctx->active) - return 0; + goto out; if (ctx->probe && ctx->probe->post_handler) ctx->probe->post_handler(ctx->probe, condition, regs); @@ -273,10 +274,12 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) * will have TF set, in which case, continue the remaining processing * of do_debug, as if this is not a probe hit. */ - if (regs->flags & TF_MASK) - return 0; + if (!(regs->flags & TF_MASK)) + ret = 1; - return 1; +out: + put_cpu_var(kmmio_ctx); + return ret; } static int add_kmmio_fault_page(unsigned long page) diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index 0019dcdf615..f9c609266d8 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -30,6 +30,7 @@ #include #include /* for ISA_START_ADDRESS */ #include +#include #include "kmmio.h" #include "pf_in.h" @@ -49,11 +50,11 @@ struct trap_reason { }; /* Accessed per-cpu. */ -static struct trap_reason pf_reason[NR_CPUS]; -static struct mm_io_header_rw cpu_trace[NR_CPUS]; +static DEFINE_PER_CPU(struct trap_reason, pf_reason); +static DEFINE_PER_CPU(struct mm_io_header_rw, cpu_trace); /* Access to this is not per-cpu. */ -static atomic_t dropped[NR_CPUS]; +static DEFINE_PER_CPU(atomic_t, dropped); static struct file_operations mmio_fops = { .owner = THIS_MODULE, @@ -150,15 +151,15 @@ static void print_pte(unsigned long address) */ static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) { - const unsigned long cpu = smp_processor_id(); + const struct trap_reason *my_reason = &get_cpu_var(pf_reason); printk(KERN_EMERG MODULE_NAME ": unexpected fault for address: %lx, " "last fault for address: %lx\n", - addr, pf_reason[cpu].addr); + addr, my_reason->addr); print_pte(addr); #ifdef __i386__ print_symbol(KERN_EMERG "faulting EIP is at %s\n", regs->ip); print_symbol(KERN_EMERG "last faulting EIP was at %s\n", - pf_reason[cpu].ip); + my_reason->ip); printk(KERN_EMERG "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", regs->ax, regs->bx, regs->cx, regs->dx); @@ -168,100 +169,105 @@ static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) #else print_symbol(KERN_EMERG "faulting RIP is at %s\n", regs->ip); print_symbol(KERN_EMERG "last faulting RIP was at %s\n", - pf_reason[cpu].ip); + my_reason->ip); printk(KERN_EMERG "rax: %016lx rcx: %016lx rdx: %016lx\n", regs->ax, regs->cx, regs->dx); printk(KERN_EMERG "rsi: %016lx rdi: %016lx " "rbp: %016lx rsp: %016lx\n", regs->si, regs->di, regs->bp, regs->sp); #endif + put_cpu_var(pf_reason); BUG(); } static void pre(struct kmmio_probe *p, struct pt_regs *regs, unsigned long addr) { - const unsigned long cpu = smp_processor_id(); + struct trap_reason *my_reason = &get_cpu_var(pf_reason); + struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace); const unsigned long instptr = instruction_pointer(regs); const enum reason_type type = get_ins_type(instptr); /* it doesn't make sense to have more than one active trace per cpu */ - if (pf_reason[cpu].active_traces) + if (my_reason->active_traces) die_kmmio_nesting_error(regs, addr); else - pf_reason[cpu].active_traces++; + my_reason->active_traces++; - pf_reason[cpu].type = type; - pf_reason[cpu].addr = addr; - pf_reason[cpu].ip = instptr; + my_reason->type = type; + my_reason->addr = addr; + my_reason->ip = instptr; - cpu_trace[cpu].header.type = MMIO_MAGIC; - cpu_trace[cpu].header.pid = 0; - cpu_trace[cpu].header.data_len = sizeof(struct mm_io_rw); - cpu_trace[cpu].rw.address = addr; + my_trace->header.type = MMIO_MAGIC; + my_trace->header.pid = 0; + my_trace->header.data_len = sizeof(struct mm_io_rw); + my_trace->rw.address = addr; /* * Only record the program counter when requested. * It may taint clean-room reverse engineering. */ if (trace_pc) - cpu_trace[cpu].rw.pc = instptr; + my_trace->rw.pc = instptr; else - cpu_trace[cpu].rw.pc = 0; + my_trace->rw.pc = 0; - record_timestamp(&cpu_trace[cpu].header); + record_timestamp(&my_trace->header); switch (type) { case REG_READ: - cpu_trace[cpu].header.type |= + my_trace->header.type |= (MMIO_READ << MMIO_OPCODE_SHIFT) | (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); break; case REG_WRITE: - cpu_trace[cpu].header.type |= + my_trace->header.type |= (MMIO_WRITE << MMIO_OPCODE_SHIFT) | (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); - cpu_trace[cpu].rw.value = get_ins_reg_val(instptr, regs); + my_trace->rw.value = get_ins_reg_val(instptr, regs); break; case IMM_WRITE: - cpu_trace[cpu].header.type |= + my_trace->header.type |= (MMIO_WRITE << MMIO_OPCODE_SHIFT) | (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); - cpu_trace[cpu].rw.value = get_ins_imm_val(instptr); + my_trace->rw.value = get_ins_imm_val(instptr); break; default: { unsigned char *ip = (unsigned char *)instptr; - cpu_trace[cpu].header.type |= + my_trace->header.type |= (MMIO_UNKNOWN_OP << MMIO_OPCODE_SHIFT); - cpu_trace[cpu].rw.value = (*ip) << 16 | - *(ip + 1) << 8 | - *(ip + 2); + my_trace->rw.value = (*ip) << 16 | *(ip + 1) << 8 | + *(ip + 2); } } + put_cpu_var(cpu_trace); + put_cpu_var(pf_reason); } static void post(struct kmmio_probe *p, unsigned long condition, struct pt_regs *regs) { - const unsigned long cpu = smp_processor_id(); + struct trap_reason *my_reason = &get_cpu_var(pf_reason); + struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace); /* this should always return the active_trace count to 0 */ - pf_reason[cpu].active_traces--; - if (pf_reason[cpu].active_traces) { + my_reason->active_traces--; + if (my_reason->active_traces) { printk(KERN_EMERG MODULE_NAME ": unexpected post handler"); BUG(); } - switch (pf_reason[cpu].type) { + switch (my_reason->type) { case REG_READ: - cpu_trace[cpu].rw.value = get_ins_reg_val(pf_reason[cpu].ip, - regs); + my_trace->rw.value = get_ins_reg_val(my_reason->ip, regs); break; default: break; } - relay_write(chan, &cpu_trace[cpu], sizeof(struct mm_io_header_rw)); + relay_write(chan, my_trace, sizeof(*my_trace)); + put_cpu_var(cpu_trace); + put_cpu_var(pf_reason); } /* @@ -274,7 +280,7 @@ static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf, void *prev_subbuf, size_t prev_padding) { unsigned int cpu = buf->cpu; - atomic_t *drop = &dropped[cpu]; + atomic_t *drop = &per_cpu(dropped, cpu); int count; if (relay_buf_full(buf)) { if (atomic_inc_return(drop) == 1) { -- cgit v1.2.3-70-g09d2 From 0fd0e3da4557c479b820b9a4a7afa25b4637ddf2 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: x86: mmiotrace full patch, preview 1 kmmio.c handles the list of mmio probes with callbacks, list of traced pages, and attaching into the page fault handler and die notifier. It arms, traps and disarms the given pages, this is the core of mmiotrace. mmio-mod.c is a user interface, hooking into ioremap functions and registering the mmio probes. It also decodes the required information from trapped mmio accesses via the pre and post callbacks in each probe. Currently, hooking into ioremap functions works by redefining the symbols of the target (binary) kernel module, so that it calls the traced versions of the functions. The most notable changes done since the last discussion are: - kmmio.c is a built-in, not part of the module - direct call from fault.c to kmmio.c, removing all dynamic hooks - prepare for unregistering probes at any time - make kmmio re-initializable and accessible to more than one user - rewrite kmmio locking to remove all spinlocks from page fault path Can I abuse call_rcu() like I do in kmmio.c:unregister_kmmio_probe() or is there a better way? The function called via call_rcu() itself calls call_rcu() again, will this work or break? There I need a second grace period for RCU after the first grace period for page faults. Mmiotrace itself (mmio-mod.c) is still a module, I am going to attack that next. At some point I will start looking into how to make mmiotrace a tracer component of ftrace (thanks for the hint, Ingo). Ftrace should make the user space part of mmiotracing as simple as 'cat /debug/trace/mmio > dump.txt'. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/init_task.c | 1 - arch/x86/kernel/mmiotrace/Makefile | 8 +- arch/x86/kernel/mmiotrace/kmmio.c | 349 ++++++++++++++++++++---------- arch/x86/kernel/mmiotrace/kmmio.h | 58 ----- arch/x86/kernel/mmiotrace/mmio-mod.c | 81 ++++--- arch/x86/kernel/mmiotrace/pf_in.c | 2 +- arch/x86/kernel/mmiotrace/testmmiotrace.c | 13 +- arch/x86/mm/fault.c | 59 +---- include/asm-x86/kdebug.h | 7 - include/linux/mmiotrace.h | 38 ++++ 10 files changed, 335 insertions(+), 281 deletions(-) delete mode 100644 arch/x86/kernel/mmiotrace/kmmio.h (limited to 'arch') diff --git a/arch/x86/kernel/init_task.c b/arch/x86/kernel/init_task.c index 027a5b6a12b..a4f93b4120c 100644 --- a/arch/x86/kernel/init_task.c +++ b/arch/x86/kernel/init_task.c @@ -15,7 +15,6 @@ static struct signal_struct init_signals = INIT_SIGNALS(init_signals); static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); struct mm_struct init_mm = INIT_MM(init_mm); EXPORT_UNUSED_SYMBOL(init_mm); /* will be removed in 2.6.26 */ -EXPORT_SYMBOL_GPL(init_mm); /* * Initial thread structure. diff --git a/arch/x86/kernel/mmiotrace/Makefile b/arch/x86/kernel/mmiotrace/Makefile index d6905f7f981..cf1e747b463 100644 --- a/arch/x86/kernel/mmiotrace/Makefile +++ b/arch/x86/kernel/mmiotrace/Makefile @@ -1,4 +1,4 @@ -obj-$(CONFIG_MMIOTRACE) += mmiotrace.o -mmiotrace-objs := pf_in.o kmmio.o mmio-mod.o - -obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o +obj-$(CONFIG_MMIOTRACE_HOOKS) += kmmio.o +obj-$(CONFIG_MMIOTRACE) += mmiotrace.o +mmiotrace-objs := pf_in.o mmio-mod.o +obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index 5e239d0b846..539a9b19588 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -6,6 +6,7 @@ */ #include +#include #include #include #include @@ -17,70 +18,119 @@ #include #include #include +#include #include #include #include #include #include -#include "kmmio.h" +#include -#define KMMIO_HASH_BITS 6 -#define KMMIO_TABLE_SIZE (1 << KMMIO_HASH_BITS) #define KMMIO_PAGE_HASH_BITS 4 #define KMMIO_PAGE_TABLE_SIZE (1 << KMMIO_PAGE_HASH_BITS) +struct kmmio_fault_page { + struct list_head list; + struct kmmio_fault_page *release_next; + unsigned long page; /* location of the fault page */ + + /* + * Number of times this page has been registered as a part + * of a probe. If zero, page is disarmed and this may be freed. + * Used only by writers (RCU). + */ + int count; +}; + +struct kmmio_delayed_release { + struct rcu_head rcu; + struct kmmio_fault_page *release_list; +}; + struct kmmio_context { struct kmmio_fault_page *fpage; struct kmmio_probe *probe; unsigned long saved_flags; + unsigned long addr; int active; }; -static int kmmio_page_fault(struct pt_regs *regs, unsigned long error_code, - unsigned long address); static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, void *args); +static DECLARE_MUTEX(kmmio_init_mutex); static DEFINE_SPINLOCK(kmmio_lock); /* These are protected by kmmio_lock */ +static int kmmio_initialized; unsigned int kmmio_count; -static unsigned int handler_registered; + +/* Read-protected by RCU, write-protected by kmmio_lock. */ static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE]; static LIST_HEAD(kmmio_probes); +static struct list_head *kmmio_page_list(unsigned long page) +{ + return &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)]; +} + /* Accessed per-cpu */ static DEFINE_PER_CPU(struct kmmio_context, kmmio_ctx); +/* protected by kmmio_init_mutex */ static struct notifier_block nb_die = { .notifier_call = kmmio_die_notifier }; -int init_kmmio(void) +/** + * Makes sure kmmio is initialized and usable. + * This must be called before any other kmmio function defined here. + * May sleep. + */ +void reference_kmmio(void) { - int i; - for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) - INIT_LIST_HEAD(&kmmio_page_table[i]); - - register_die_notifier(&nb_die); - return 0; + down(&kmmio_init_mutex); + spin_lock_irq(&kmmio_lock); + if (!kmmio_initialized) { + int i; + for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) + INIT_LIST_HEAD(&kmmio_page_table[i]); + if (register_die_notifier(&nb_die)) + BUG(); + } + kmmio_initialized++; + spin_unlock_irq(&kmmio_lock); + up(&kmmio_init_mutex); } +EXPORT_SYMBOL_GPL(reference_kmmio); -void cleanup_kmmio(void) +/** + * Clean up kmmio after use. This must be called for every call to + * reference_kmmio(). All probes registered after the corresponding + * reference_kmmio() must have been unregistered when calling this. + * May sleep. + */ +void unreference_kmmio(void) { - /* - * Assume the following have been already cleaned by calling - * unregister_kmmio_probe() appropriately: - * kmmio_page_table, kmmio_probes - */ - if (handler_registered) { - if (mmiotrace_unregister_pf(&kmmio_page_fault)) - BUG(); - synchronize_rcu(); + bool unreg = false; + + down(&kmmio_init_mutex); + spin_lock_irq(&kmmio_lock); + + if (kmmio_initialized == 1) { + BUG_ON(is_kmmio_active()); + unreg = true; } - unregister_die_notifier(&nb_die); + kmmio_initialized--; + BUG_ON(kmmio_initialized < 0); + spin_unlock_irq(&kmmio_lock); + + if (unreg) + unregister_die_notifier(&nb_die); /* calls sync_rcu() */ + up(&kmmio_init_mutex); } +EXPORT_SYMBOL(unreference_kmmio); /* * this is basically a dynamic stabbing problem: @@ -90,33 +140,33 @@ void cleanup_kmmio(void) * Overlap a Point (might be simple) * Space Efficient Dynamic Stabbing with Fast Queries - Mikkel Thorup */ -/* Get the kmmio at this addr (if any). You must be holding kmmio_lock. */ +/* Get the kmmio at this addr (if any). You must be holding RCU read lock. */ static struct kmmio_probe *get_kmmio_probe(unsigned long addr) { struct kmmio_probe *p; - list_for_each_entry(p, &kmmio_probes, list) { + list_for_each_entry_rcu(p, &kmmio_probes, list) { if (addr >= p->addr && addr <= (p->addr + p->len)) return p; } return NULL; } +/* You must be holding RCU read lock. */ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) { - struct list_head *head, *tmp; + struct list_head *head; + struct kmmio_fault_page *p; page &= PAGE_MASK; - head = &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)]; - list_for_each(tmp, head) { - struct kmmio_fault_page *p - = list_entry(tmp, struct kmmio_fault_page, list); + head = kmmio_page_list(page); + list_for_each_entry_rcu(p, head, list) { if (p->page == page) return p; } - return NULL; } +/** Mark the given page as not present. Access to it will trigger a fault. */ static void arm_kmmio_fault_page(unsigned long page, int *page_level) { unsigned long address = page & PAGE_MASK; @@ -124,8 +174,8 @@ static void arm_kmmio_fault_page(unsigned long page, int *page_level) pte_t *pte = lookup_address(address, &level); if (!pte) { - printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n", - __FUNCTION__, page); + pr_err("kmmio: Error in %s: no pte for page 0x%08lx\n", + __func__, page); return; } @@ -143,6 +193,7 @@ static void arm_kmmio_fault_page(unsigned long page, int *page_level) __flush_tlb_one(page); } +/** Mark the given page as present. */ static void disarm_kmmio_fault_page(unsigned long page, int *page_level) { unsigned long address = page & PAGE_MASK; @@ -150,8 +201,8 @@ static void disarm_kmmio_fault_page(unsigned long page, int *page_level) pte_t *pte = lookup_address(address, &level); if (!pte) { - printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n", - __FUNCTION__, page); + pr_err("kmmio: Error in %s: no pte for page 0x%08lx\n", + __func__, page); return; } @@ -169,13 +220,25 @@ static void disarm_kmmio_fault_page(unsigned long page, int *page_level) __flush_tlb_one(page); } +/* + * This is being called from do_page_fault(). + * + * We may be in an interrupt or a critical section. Also prefecthing may + * trigger a page fault. We may be in the middle of process switch. + * We cannot take any locks, because we could be executing especially + * within a kmmio critical section. + * + * Local interrupts are disabled, so preemption cannot happen. + * Do not enable interrupts, do not sleep, and watch out for other CPUs. + */ /* * Interrupts are disabled on entry as trap3 is an interrupt gate * and they remain disabled thorough out this function. */ -static int kmmio_handler(struct pt_regs *regs, unsigned long addr) +int kmmio_handler(struct pt_regs *regs, unsigned long addr) { - struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); + struct kmmio_context *ctx; + struct kmmio_fault_page *faultpage; /* * Preemption is now disabled to prevent process switch during @@ -186,40 +249,40 @@ static int kmmio_handler(struct pt_regs *regs, unsigned long addr) * XXX what if an interrupt occurs between returning from * do_page_fault() and entering the single-step exception handler? * And that interrupt triggers a kmmio trap? + * XXX If we tracing an interrupt service routine or whatever, is + * this enough to keep it on the current cpu? */ preempt_disable(); - /* interrupts disabled and CPU-local data => atomicity guaranteed. */ + rcu_read_lock(); + faultpage = get_kmmio_fault_page(addr); + if (!faultpage) { + /* + * Either this page fault is not caused by kmmio, or + * another CPU just pulled the kmmio probe from under + * our feet. In the latter case all hell breaks loose. + */ + goto no_kmmio; + } + + ctx = &get_cpu_var(kmmio_ctx); if (ctx->active) { /* - * This avoids a deadlock with kmmio_lock. + * Prevent overwriting already in-flight context. * If this page fault really was due to kmmio trap, * all hell breaks loose. */ - printk(KERN_EMERG "mmiotrace: recursive probe hit on CPU %d, " - "for address %lu. Ignoring.\n", + pr_emerg("kmmio: recursive probe hit on CPU %d, " + "for address 0x%08lx. Ignoring.\n", smp_processor_id(), addr); - goto no_kmmio; + goto no_kmmio_ctx; } ctx->active++; - /* - * Acquire the kmmio lock to prevent changes affecting - * get_kmmio_fault_page() and get_kmmio_probe(), since we save their - * returned pointers. - * The lock is released in post_kmmio_handler(). - * XXX: could/should get_kmmio_*() be using RCU instead of spinlock? - */ - spin_lock(&kmmio_lock); - - ctx->fpage = get_kmmio_fault_page(addr); - if (!ctx->fpage) { - /* this page fault is not caused by kmmio */ - goto no_kmmio_locked; - } - + ctx->fpage = faultpage; ctx->probe = get_kmmio_probe(addr); ctx->saved_flags = (regs->flags & (TF_MASK|IF_MASK)); + ctx->addr = addr; if (ctx->probe && ctx->probe->pre_handler) ctx->probe->pre_handler(ctx->probe, regs, addr); @@ -227,46 +290,62 @@ static int kmmio_handler(struct pt_regs *regs, unsigned long addr) regs->flags |= TF_MASK; regs->flags &= ~IF_MASK; - /* We hold lock, now we set present bit in PTE and single step. */ + /* Now we set present bit in PTE and single step. */ disarm_kmmio_fault_page(ctx->fpage->page, NULL); put_cpu_var(kmmio_ctx); + rcu_read_unlock(); return 1; -no_kmmio_locked: - spin_unlock(&kmmio_lock); - ctx->active--; +no_kmmio_ctx: + put_cpu_var(kmmio_ctx); no_kmmio: + rcu_read_unlock(); preempt_enable_no_resched(); - put_cpu_var(kmmio_ctx); - /* page fault not handled by kmmio */ - return 0; + return 0; /* page fault not handled by kmmio */ } /* * Interrupts are disabled on entry as trap1 is an interrupt gate * and they remain disabled thorough out this function. - * And we hold kmmio lock. + * This must always get called as the pair to kmmio_handler(). */ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) { int ret = 0; + struct kmmio_probe *probe; + struct kmmio_fault_page *faultpage; struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); if (!ctx->active) goto out; + rcu_read_lock(); + + faultpage = get_kmmio_fault_page(ctx->addr); + probe = get_kmmio_probe(ctx->addr); + if (faultpage != ctx->fpage || probe != ctx->probe) { + /* + * The trace setup changed after kmmio_handler() and before + * running this respective post handler. User does not want + * the result anymore. + */ + ctx->probe = NULL; + ctx->fpage = NULL; + } + if (ctx->probe && ctx->probe->post_handler) ctx->probe->post_handler(ctx->probe, condition, regs); - arm_kmmio_fault_page(ctx->fpage->page, NULL); + if (ctx->fpage) + arm_kmmio_fault_page(ctx->fpage->page, NULL); regs->flags &= ~TF_MASK; regs->flags |= ctx->saved_flags; /* These were acquired in kmmio_handler(). */ ctx->active--; - spin_unlock(&kmmio_lock); + BUG_ON(ctx->active); preempt_enable_no_resched(); /* @@ -277,11 +356,13 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) if (!(regs->flags & TF_MASK)) ret = 1; + rcu_read_unlock(); out: put_cpu_var(kmmio_ctx); return ret; } +/* You must be holding kmmio_lock. */ static int add_kmmio_fault_page(unsigned long page) { struct kmmio_fault_page *f; @@ -289,6 +370,8 @@ static int add_kmmio_fault_page(unsigned long page) page &= PAGE_MASK; f = get_kmmio_fault_page(page); if (f) { + if (!f->count) + arm_kmmio_fault_page(f->page, NULL); f->count++; return 0; } @@ -299,15 +382,16 @@ static int add_kmmio_fault_page(unsigned long page) f->count = 1; f->page = page; - list_add(&f->list, - &kmmio_page_table[hash_long(f->page, KMMIO_PAGE_HASH_BITS)]); + list_add_rcu(&f->list, kmmio_page_list(f->page)); arm_kmmio_fault_page(f->page, NULL); return 0; } -static void release_kmmio_fault_page(unsigned long page) +/* You must be holding kmmio_lock. */ +static void release_kmmio_fault_page(unsigned long page, + struct kmmio_fault_page **release_list) { struct kmmio_fault_page *f; @@ -317,9 +401,11 @@ static void release_kmmio_fault_page(unsigned long page) return; f->count--; + BUG_ON(f->count < 0); if (!f->count) { disarm_kmmio_fault_page(f->page, NULL); - list_del(&f->list); + f->release_next = *release_list; + *release_list = f; } } @@ -334,68 +420,113 @@ int register_kmmio_probe(struct kmmio_probe *p) ret = -EEXIST; goto out; } - list_add(&p->list, &kmmio_probes); - /*printk("adding fault pages...\n");*/ + list_add_rcu(&p->list, &kmmio_probes); while (size < p->len) { if (add_kmmio_fault_page(p->addr + size)) - printk(KERN_ERR "mmio: Unable to set page fault.\n"); + pr_err("kmmio: Unable to set page fault.\n"); size += PAGE_SIZE; } - - if (!handler_registered) { - if (mmiotrace_register_pf(&kmmio_page_fault)) - printk(KERN_ERR "mmiotrace: Cannot register page " - "fault handler.\n"); - else - handler_registered++; - } - out: spin_unlock_irq(&kmmio_lock); /* * XXX: What should I do here? * Here was a call to global_flush_tlb(), but it does not exist - * anymore. + * anymore. It seems it's not needed after all. */ return ret; } +EXPORT_SYMBOL(register_kmmio_probe); +static void rcu_free_kmmio_fault_pages(struct rcu_head *head) +{ + struct kmmio_delayed_release *dr = container_of( + head, + struct kmmio_delayed_release, + rcu); + struct kmmio_fault_page *p = dr->release_list; + while (p) { + struct kmmio_fault_page *next = p->release_next; + BUG_ON(p->count); + kfree(p); + p = next; + } + kfree(dr); +} + +static void remove_kmmio_fault_pages(struct rcu_head *head) +{ + struct kmmio_delayed_release *dr = container_of( + head, + struct kmmio_delayed_release, + rcu); + struct kmmio_fault_page *p = dr->release_list; + struct kmmio_fault_page **prevp = &dr->release_list; + unsigned long flags; + spin_lock_irqsave(&kmmio_lock, flags); + while (p) { + if (!p->count) + list_del_rcu(&p->list); + else + *prevp = p->release_next; + prevp = &p->release_next; + p = p->release_next; + } + spin_unlock_irqrestore(&kmmio_lock, flags); + /* This is the real RCU destroy call. */ + call_rcu(&dr->rcu, rcu_free_kmmio_fault_pages); +} + +/* + * Remove a kmmio probe. You have to synchronize_rcu() before you can be + * sure that the callbacks will not be called anymore. + * + * Unregistering a kmmio fault page has three steps: + * 1. release_kmmio_fault_page() + * Disarm the page, wait a grace period to let all faults finish. + * 2. remove_kmmio_fault_pages() + * Remove the pages from kmmio_page_table. + * 3. rcu_free_kmmio_fault_pages() + * Actally free the kmmio_fault_page structs as with RCU. + */ void unregister_kmmio_probe(struct kmmio_probe *p) { unsigned long size = 0; + struct kmmio_fault_page *release_list = NULL; + struct kmmio_delayed_release *drelease; spin_lock_irq(&kmmio_lock); while (size < p->len) { - release_kmmio_fault_page(p->addr + size); + release_kmmio_fault_page(p->addr + size, &release_list); size += PAGE_SIZE; } - list_del(&p->list); + list_del_rcu(&p->list); kmmio_count--; spin_unlock_irq(&kmmio_lock); -} -/* - * According to 2.6.20, mainly x86_64 arch: - * This is being called from do_page_fault(), via the page fault notifier - * chain. The chain is called for both user space faults and kernel space - * faults (address >= TASK_SIZE64), except not on faults serviced by - * vmalloc_fault(). - * - * We may be in an interrupt or a critical section. Also prefecthing may - * trigger a page fault. We may be in the middle of process switch. - * The page fault hook functionality has put us inside RCU read lock. - * - * Local interrupts are disabled, so preemption cannot happen. - * Do not enable interrupts, do not sleep, and watch out for other CPUs. - */ -static int kmmio_page_fault(struct pt_regs *regs, unsigned long error_code, - unsigned long address) -{ - if (is_kmmio_active()) - if (kmmio_handler(regs, address) == 1) - return -1; - return 0; + drelease = kmalloc(sizeof(*drelease), GFP_ATOMIC); + if (!drelease) { + pr_crit("kmmio: leaking kmmio_fault_page objects.\n"); + return; + } + drelease->release_list = release_list; + + /* + * This is not really RCU here. We have just disarmed a set of + * pages so that they cannot trigger page faults anymore. However, + * we cannot remove the pages from kmmio_page_table, + * because a probe hit might be in flight on another CPU. The + * pages are collected into a list, and they will be removed from + * kmmio_page_table when it is certain that no probe hit related to + * these pages can be in flight. RCU grace period sounds like a + * good choice. + * + * If we removed the pages too early, kmmio page fault handler might + * not find the respective kmmio_fault_page and determine it's not + * a kmmio fault, when it actually is. This would lead to madness. + */ + call_rcu(&drelease->rcu, remove_kmmio_fault_pages); } +EXPORT_SYMBOL(unregister_kmmio_probe); static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, void *args) diff --git a/arch/x86/kernel/mmiotrace/kmmio.h b/arch/x86/kernel/mmiotrace/kmmio.h deleted file mode 100644 index 85b7f68a3b8..00000000000 --- a/arch/x86/kernel/mmiotrace/kmmio.h +++ /dev/null @@ -1,58 +0,0 @@ -#ifndef _LINUX_KMMIO_H -#define _LINUX_KMMIO_H - -#include -#include -#include -#include -#include -#include -#include - -struct kmmio_probe; -struct kmmio_fault_page; -struct pt_regs; - -typedef void (*kmmio_pre_handler_t)(struct kmmio_probe *, - struct pt_regs *, unsigned long addr); -typedef void (*kmmio_post_handler_t)(struct kmmio_probe *, - unsigned long condition, struct pt_regs *); - -struct kmmio_probe { - struct list_head list; - - /* start location of the probe point */ - unsigned long addr; - - /* length of the probe region */ - unsigned long len; - - /* Called before addr is executed. */ - kmmio_pre_handler_t pre_handler; - - /* Called after addr is executed, unless... */ - kmmio_post_handler_t post_handler; -}; - -struct kmmio_fault_page { - struct list_head list; - - /* location of the fault page */ - unsigned long page; - - int count; -}; - -/* kmmio is active by some kmmio_probes? */ -static inline int is_kmmio_active(void) -{ - extern unsigned int kmmio_count; - return kmmio_count; -} - -int init_kmmio(void); -void cleanup_kmmio(void); -int register_kmmio_probe(struct kmmio_probe *p); -void unregister_kmmio_probe(struct kmmio_probe *p); - -#endif /* _LINUX_KMMIO_H */ diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index f9c609266d8..e1a508588f0 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -32,7 +32,6 @@ #include #include -#include "kmmio.h" #include "pf_in.h" /* This app's relay channel files will appear in /debug/mmio-trace */ @@ -129,18 +128,17 @@ static void print_pte(unsigned long address) pte_t *pte = lookup_address(address, &level); if (!pte) { - printk(KERN_ERR "Error in %s: no pte for page 0x%08lx\n", - __FUNCTION__, address); + pr_err(MODULE_NAME ": Error in %s: no pte for page 0x%08lx\n", + __func__, address); return; } if (level == PG_LEVEL_2M) { - printk(KERN_EMERG MODULE_NAME ": 4MB pages are not " - "currently supported: %lx\n", - address); + pr_emerg(MODULE_NAME ": 4MB pages are not currently " + "supported: %lx\n", address); BUG(); } - printk(KERN_DEBUG MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n", + pr_info(MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n", address, pte_val(*pte), pte_val(*pte) & _PAGE_PRESENT); } @@ -152,7 +150,7 @@ static void print_pte(unsigned long address) static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) { const struct trap_reason *my_reason = &get_cpu_var(pf_reason); - printk(KERN_EMERG MODULE_NAME ": unexpected fault for address: %lx, " + pr_emerg(MODULE_NAME ": unexpected fault for address: %lx, " "last fault for address: %lx\n", addr, my_reason->addr); print_pte(addr); @@ -160,20 +158,17 @@ static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) print_symbol(KERN_EMERG "faulting EIP is at %s\n", regs->ip); print_symbol(KERN_EMERG "last faulting EIP was at %s\n", my_reason->ip); - printk(KERN_EMERG - "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", + pr_emerg("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", regs->ax, regs->bx, regs->cx, regs->dx); - printk(KERN_EMERG - "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", + pr_emerg("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", regs->si, regs->di, regs->bp, regs->sp); #else print_symbol(KERN_EMERG "faulting RIP is at %s\n", regs->ip); print_symbol(KERN_EMERG "last faulting RIP was at %s\n", my_reason->ip); - printk(KERN_EMERG "rax: %016lx rcx: %016lx rdx: %016lx\n", + pr_emerg("rax: %016lx rcx: %016lx rdx: %016lx\n", regs->ax, regs->cx, regs->dx); - printk(KERN_EMERG "rsi: %016lx rdi: %016lx " - "rbp: %016lx rsp: %016lx\n", + pr_emerg("rsi: %016lx rdi: %016lx rbp: %016lx rsp: %016lx\n", regs->si, regs->di, regs->bp, regs->sp); #endif put_cpu_var(pf_reason); @@ -251,10 +246,15 @@ static void post(struct kmmio_probe *p, unsigned long condition, struct trap_reason *my_reason = &get_cpu_var(pf_reason); struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace); + /* + * XXX: This might not get called, if the probe is removed while + * trace hit is on flight. + */ + /* this should always return the active_trace count to 0 */ my_reason->active_traces--; if (my_reason->active_traces) { - printk(KERN_EMERG MODULE_NAME ": unexpected post handler"); + pr_emerg(MODULE_NAME ": unexpected post handler"); BUG(); } @@ -283,16 +283,15 @@ static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf, atomic_t *drop = &per_cpu(dropped, cpu); int count; if (relay_buf_full(buf)) { - if (atomic_inc_return(drop) == 1) { - printk(KERN_ERR MODULE_NAME ": cpu %d buffer full!\n", - cpu); - } + if (atomic_inc_return(drop) == 1) + pr_err(MODULE_NAME ": cpu %d buffer full!\n", cpu); return 0; - } else if ((count = atomic_read(drop))) { - printk(KERN_ERR MODULE_NAME - ": cpu %d buffer no longer full, " - "missed %d events.\n", - cpu, count); + } + count = atomic_read(drop); + if (count) { + pr_err(MODULE_NAME ": cpu %d buffer no longer full, " + "missed %d events.\n", + cpu, count); atomic_sub(count, drop); } @@ -407,8 +406,8 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, /* Don't trace the low PCI/ISA area, it's always mapped.. */ if (!ISA_trace && (offset < ISA_END_ADDRESS) && (offset + size > ISA_START_ADDRESS)) { - printk(KERN_NOTICE MODULE_NAME ": Ignoring map of low " - "PCI/ISA area (0x%lx-0x%lx)\n", + pr_notice(MODULE_NAME ": Ignoring map of low PCI/ISA area " + "(0x%lx-0x%lx)\n", offset, offset + size); return; } @@ -418,7 +417,7 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, void __iomem *ioremap_cache_trace(unsigned long offset, unsigned long size) { void __iomem *p = ioremap_cache(offset, size); - printk(KERN_DEBUG MODULE_NAME ": ioremap_cache(0x%lx, 0x%lx) = %p\n", + pr_debug(MODULE_NAME ": ioremap_cache(0x%lx, 0x%lx) = %p\n", offset, size, p); ioremap_trace_core(offset, size, p); return p; @@ -428,7 +427,7 @@ EXPORT_SYMBOL(ioremap_cache_trace); void __iomem *ioremap_nocache_trace(unsigned long offset, unsigned long size) { void __iomem *p = ioremap_nocache(offset, size); - printk(KERN_DEBUG MODULE_NAME ": ioremap_nocache(0x%lx, 0x%lx) = %p\n", + pr_debug(MODULE_NAME ": ioremap_nocache(0x%lx, 0x%lx) = %p\n", offset, size, p); ioremap_trace_core(offset, size, p); return p; @@ -455,7 +454,7 @@ void iounmap_trace(volatile void __iomem *addr) }; struct remap_trace *trace; struct remap_trace *tmp; - printk(KERN_DEBUG MODULE_NAME ": Unmapping %p.\n", addr); + pr_debug(MODULE_NAME ": Unmapping %p.\n", addr); record_timestamp(&event.header); spin_lock(&trace_list_lock); @@ -481,7 +480,7 @@ static void clear_trace_list(void) spin_lock(&trace_list_lock); list_for_each_entry_safe(trace, tmp, &trace_list, list) { - printk(KERN_WARNING MODULE_NAME ": purging non-iounmapped " + pr_warning(MODULE_NAME ": purging non-iounmapped " "trace @0x%08lx, size 0x%lx.\n", trace->probe.addr, trace->probe.len); if (!nommiotrace) @@ -500,39 +499,37 @@ static int __init init(void) dir = debugfs_create_dir(APP_DIR, NULL); if (!dir) { - printk(KERN_ERR MODULE_NAME - ": Couldn't create relay app directory.\n"); + pr_err(MODULE_NAME ": Couldn't create relay app directory.\n"); return -ENOMEM; } chan = create_channel(subbuf_size, n_subbufs); if (!chan) { debugfs_remove(dir); - printk(KERN_ERR MODULE_NAME - ": relay app channel creation failed\n"); + pr_err(MODULE_NAME ": relay app channel creation failed\n"); return -ENOMEM; } - init_kmmio(); + reference_kmmio(); proc_marker_file = create_proc_entry(MARKER_FILE, 0, NULL); if (proc_marker_file) proc_marker_file->write_proc = write_marker; - printk(KERN_DEBUG MODULE_NAME ": loaded.\n"); + pr_debug(MODULE_NAME ": loaded.\n"); if (nommiotrace) - printk(KERN_DEBUG MODULE_NAME ": MMIO tracing disabled.\n"); + pr_info(MODULE_NAME ": MMIO tracing disabled.\n"); if (ISA_trace) - printk(KERN_WARNING MODULE_NAME - ": Warning! low ISA range will be traced.\n"); + pr_warning(MODULE_NAME ": Warning! low ISA range will be " + "traced.\n"); return 0; } static void __exit cleanup(void) { - printk(KERN_DEBUG MODULE_NAME ": unload...\n"); + pr_debug(MODULE_NAME ": unload...\n"); clear_trace_list(); - cleanup_kmmio(); + unreference_kmmio(); remove_proc_entry(MARKER_FILE, NULL); destroy_channel(); if (dir) diff --git a/arch/x86/kernel/mmiotrace/pf_in.c b/arch/x86/kernel/mmiotrace/pf_in.c index 67ea520dde6..efa1911e20c 100644 --- a/arch/x86/kernel/mmiotrace/pf_in.c +++ b/arch/x86/kernel/mmiotrace/pf_in.c @@ -19,7 +19,7 @@ * */ -/* $Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp $ +/* Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp * Copyright by Intel Crop., 2002 * Louis Zhuang (louis.zhuang@intel.com) * diff --git a/arch/x86/kernel/mmiotrace/testmmiotrace.c b/arch/x86/kernel/mmiotrace/testmmiotrace.c index 40e66b0e648..5ecff578672 100644 --- a/arch/x86/kernel/mmiotrace/testmmiotrace.c +++ b/arch/x86/kernel/mmiotrace/testmmiotrace.c @@ -41,8 +41,7 @@ static void do_test(void) { void __iomem *p = ioremap_nocache_trace(mmio_address, 0x4000); if (!p) { - printk(KERN_ERR MODULE_NAME ": could not ioremap IO memory, " - "aborting.\n"); + pr_err(MODULE_NAME ": could not ioremap, aborting.\n"); return; } do_write_test(p); @@ -53,14 +52,14 @@ static void do_test(void) static int __init init(void) { if (mmio_address == 0) { - printk(KERN_ERR MODULE_NAME ": you have to use the module " - "argument mmio_address.\n"); - printk(KERN_ERR MODULE_NAME ": DO NOT LOAD THIS MODULE UNLESS" + pr_err(MODULE_NAME ": you have to use the module argument " + "mmio_address.\n"); + pr_err(MODULE_NAME ": DO NOT LOAD THIS MODULE UNLESS" " YOU REALLY KNOW WHAT YOU ARE DOING!\n"); return -ENXIO; } - printk(KERN_WARNING MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx " + pr_warning(MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx " "in PCI address space, and writing " "rubbish in there.\n", mmio_address); do_test(); @@ -69,7 +68,7 @@ static int __init init(void) static void __exit cleanup(void) { - printk(KERN_DEBUG MODULE_NAME ": unloaded.\n"); + pr_debug(MODULE_NAME ": unloaded.\n"); } module_init(init); diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e9a086a1a9f..8c828a68d3b 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -49,60 +50,14 @@ #define PF_RSVD (1<<3) #define PF_INSTR (1<<4) -#ifdef CONFIG_MMIOTRACE_HOOKS -static pf_handler_func mmiotrace_pf_handler; /* protected by RCU */ -static DEFINE_SPINLOCK(mmiotrace_handler_lock); - -int mmiotrace_register_pf(pf_handler_func new_pfh) -{ - int ret = 0; - unsigned long flags; - spin_lock_irqsave(&mmiotrace_handler_lock, flags); - if (mmiotrace_pf_handler) - ret = -EBUSY; - else - mmiotrace_pf_handler = new_pfh; - spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); - return ret; -} -EXPORT_SYMBOL_GPL(mmiotrace_register_pf); - -/** - * mmiotrace_unregister_pf: - * The caller must ensure @old_pfh is not in use anymore before freeing it. - * This function does not guarantee it. The handler function pointer is - * protected by RCU, so you can do this by e.g. calling synchronize_rcu(). - */ -int mmiotrace_unregister_pf(pf_handler_func old_pfh) -{ - int ret = 0; - unsigned long flags; - spin_lock_irqsave(&mmiotrace_handler_lock, flags); - if (mmiotrace_pf_handler != old_pfh) - ret = -EPERM; - else - mmiotrace_pf_handler = NULL; - spin_unlock_irqrestore(&mmiotrace_handler_lock, flags); - return ret; -} -EXPORT_SYMBOL_GPL(mmiotrace_unregister_pf); -#endif /* CONFIG_MMIOTRACE_HOOKS */ - -/* returns non-zero if do_page_fault() should return */ -static inline int call_mmiotrace(struct pt_regs *regs, - unsigned long error_code, - unsigned long address) +static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr) { #ifdef CONFIG_MMIOTRACE_HOOKS - int ret = 0; - rcu_read_lock(); - if (mmiotrace_pf_handler) - ret = mmiotrace_pf_handler(regs, error_code, address); - rcu_read_unlock(); - return ret; -#else - return 0; + if (unlikely(is_kmmio_active())) + if (kmmio_handler(regs, addr) == 1) + return -1; #endif + return 0; } static inline int notify_page_fault(struct pt_regs *regs) @@ -657,7 +612,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (notify_page_fault(regs)) return; - if (call_mmiotrace(regs, error_code, address)) + if (unlikely(kmmio_fault(regs, address))) return; /* diff --git a/include/asm-x86/kdebug.h b/include/asm-x86/kdebug.h index 7063281040d..96651bb59ba 100644 --- a/include/asm-x86/kdebug.h +++ b/include/asm-x86/kdebug.h @@ -35,11 +35,4 @@ extern void show_regs(struct pt_regs *regs); extern unsigned long oops_begin(void); extern void oops_end(unsigned long, struct pt_regs *, int signr); -typedef int (*pf_handler_func)(struct pt_regs *regs, - unsigned long error_code, - unsigned long address); - -extern int mmiotrace_register_pf(pf_handler_func new_pfh); -extern int mmiotrace_unregister_pf(pf_handler_func old_pfh); - #endif diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index 6ec288f1fe2..d87a6cd8b68 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -3,6 +3,44 @@ #include +#ifdef __KERNEL__ + +#include + +struct kmmio_probe; +struct pt_regs; + +typedef void (*kmmio_pre_handler_t)(struct kmmio_probe *, + struct pt_regs *, unsigned long addr); +typedef void (*kmmio_post_handler_t)(struct kmmio_probe *, + unsigned long condition, struct pt_regs *); + +struct kmmio_probe { + struct list_head list; + unsigned long addr; /* start location of the probe point */ + unsigned long len; /* length of the probe region */ + kmmio_pre_handler_t pre_handler; /* Called before addr is executed. */ + kmmio_post_handler_t post_handler; /* Called after addr is executed */ +}; + +/* kmmio is active by some kmmio_probes? */ +static inline int is_kmmio_active(void) +{ + extern unsigned int kmmio_count; + return kmmio_count; +} + +extern void reference_kmmio(void); +extern void unreference_kmmio(void); +extern int register_kmmio_probe(struct kmmio_probe *p); +extern void unregister_kmmio_probe(struct kmmio_probe *p); + +/* Called from page fault handler. */ +extern int kmmio_handler(struct pt_regs *regs, unsigned long addr); + +#endif /* __KERNEL__ */ + + /* * If you change anything here, you must bump MMIO_VERSION. * This is the relay data format for user space. -- cgit v1.2.3-70-g09d2 From d61fc44853f46fb002228b18aa5f30db21fcd4ac Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: x86: mmiotrace, preview 2 Kconfig.debug, Makefile and testmmiotrace.c style fixes. Use real mutex instead of mutex. Fix failure path in register probe func. kmmio: RCU read-locked over single stepping. Generate mapping id's. Make mmio-mod.c built-in and rewrite its locking. Add debugfs file to enable/disable mmiotracing. kmmio: use irqsave spinlocks. Lots of cleanups in mmio-mod.c Marker file moved from /proc into debugfs. Call mmiotrace entrypoints directly from ioremap.c. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 20 +- arch/x86/kernel/mmiotrace/Makefile | 2 +- arch/x86/kernel/mmiotrace/kmmio.c | 72 +++--- arch/x86/kernel/mmiotrace/mmio-mod.c | 397 ++++++++++++++++++++---------- arch/x86/kernel/mmiotrace/testmmiotrace.c | 15 +- arch/x86/mm/ioremap.c | 9 +- include/linux/mmiotrace.h | 18 +- 7 files changed, 332 insertions(+), 201 deletions(-) (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 9491c0ae03a..aa0d6462b1f 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -170,22 +170,19 @@ config IOMMU_LEAK config MMIOTRACE_HOOKS bool - default n config MMIOTRACE - tristate "Memory mapped IO tracing" + bool "Memory mapped IO tracing" depends on DEBUG_KERNEL && RELAY && DEBUG_FS select MMIOTRACE_HOOKS - default n + default y help - This will build a kernel module called mmiotrace. - Making this a built-in is heavily discouraged. - - Mmiotrace traces Memory Mapped I/O access and is meant for debugging - and reverse engineering. The kernel module offers wrapped - versions of the ioremap family of functions. The driver to be traced - must be modified to call these wrappers. A user space program is - required to collect the MMIO data. + Mmiotrace traces Memory Mapped I/O access and is meant for + debugging and reverse engineering. It is called from the ioremap + implementation and works via page faults. A user space program is + required to collect the MMIO data from debugfs files. + Tracing is disabled by default and can be enabled from a debugfs + file. See http://nouveau.freedesktop.org/wiki/MmioTrace If you are not helping to develop drivers, say N. @@ -193,7 +190,6 @@ config MMIOTRACE config MMIOTRACE_TEST tristate "Test module for mmiotrace" depends on MMIOTRACE && m - default n help This is a dumb module for testing mmiotrace. It is very dangerous as it will write garbage to IO memory starting at a given address. diff --git a/arch/x86/kernel/mmiotrace/Makefile b/arch/x86/kernel/mmiotrace/Makefile index cf1e747b463..dbcd8d50fb8 100644 --- a/arch/x86/kernel/mmiotrace/Makefile +++ b/arch/x86/kernel/mmiotrace/Makefile @@ -1,4 +1,4 @@ obj-$(CONFIG_MMIOTRACE_HOOKS) += kmmio.o obj-$(CONFIG_MMIOTRACE) += mmiotrace.o -mmiotrace-objs := pf_in.o mmio-mod.o +mmiotrace-y := pf_in.o mmio-mod.o obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index 539a9b19588..efb46793308 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -59,7 +60,7 @@ struct kmmio_context { static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, void *args); -static DECLARE_MUTEX(kmmio_init_mutex); +static DEFINE_MUTEX(kmmio_init_mutex); static DEFINE_SPINLOCK(kmmio_lock); /* These are protected by kmmio_lock */ @@ -90,7 +91,7 @@ static struct notifier_block nb_die = { */ void reference_kmmio(void) { - down(&kmmio_init_mutex); + mutex_lock(&kmmio_init_mutex); spin_lock_irq(&kmmio_lock); if (!kmmio_initialized) { int i; @@ -101,7 +102,7 @@ void reference_kmmio(void) } kmmio_initialized++; spin_unlock_irq(&kmmio_lock); - up(&kmmio_init_mutex); + mutex_unlock(&kmmio_init_mutex); } EXPORT_SYMBOL_GPL(reference_kmmio); @@ -115,7 +116,7 @@ void unreference_kmmio(void) { bool unreg = false; - down(&kmmio_init_mutex); + mutex_lock(&kmmio_init_mutex); spin_lock_irq(&kmmio_lock); if (kmmio_initialized == 1) { @@ -128,7 +129,7 @@ void unreference_kmmio(void) if (unreg) unregister_die_notifier(&nb_die); /* calls sync_rcu() */ - up(&kmmio_init_mutex); + mutex_unlock(&kmmio_init_mutex); } EXPORT_SYMBOL(unreference_kmmio); @@ -244,17 +245,13 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) * Preemption is now disabled to prevent process switch during * single stepping. We can only handle one active kmmio trace * per cpu, so ensure that we finish it before something else - * gets to run. - * - * XXX what if an interrupt occurs between returning from - * do_page_fault() and entering the single-step exception handler? - * And that interrupt triggers a kmmio trap? - * XXX If we tracing an interrupt service routine or whatever, is - * this enough to keep it on the current cpu? + * gets to run. We also hold the RCU read lock over single + * stepping to avoid looking up the probe and kmmio_fault_page + * again. */ preempt_disable(); - rcu_read_lock(); + faultpage = get_kmmio_fault_page(addr); if (!faultpage) { /* @@ -287,14 +284,24 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) if (ctx->probe && ctx->probe->pre_handler) ctx->probe->pre_handler(ctx->probe, regs, addr); + /* + * Enable single-stepping and disable interrupts for the faulting + * context. Local interrupts must not get enabled during stepping. + */ regs->flags |= TF_MASK; regs->flags &= ~IF_MASK; /* Now we set present bit in PTE and single step. */ disarm_kmmio_fault_page(ctx->fpage->page, NULL); + /* + * If another cpu accesses the same page while we are stepping, + * the access will not be caught. It will simply succeed and the + * only downside is we lose the event. If this becomes a problem, + * the user should drop to single cpu before tracing. + */ + put_cpu_var(kmmio_ctx); - rcu_read_unlock(); return 1; no_kmmio_ctx: @@ -313,32 +320,15 @@ no_kmmio: static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) { int ret = 0; - struct kmmio_probe *probe; - struct kmmio_fault_page *faultpage; struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); if (!ctx->active) goto out; - rcu_read_lock(); - - faultpage = get_kmmio_fault_page(ctx->addr); - probe = get_kmmio_probe(ctx->addr); - if (faultpage != ctx->fpage || probe != ctx->probe) { - /* - * The trace setup changed after kmmio_handler() and before - * running this respective post handler. User does not want - * the result anymore. - */ - ctx->probe = NULL; - ctx->fpage = NULL; - } - if (ctx->probe && ctx->probe->post_handler) ctx->probe->post_handler(ctx->probe, condition, regs); - if (ctx->fpage) - arm_kmmio_fault_page(ctx->fpage->page, NULL); + arm_kmmio_fault_page(ctx->fpage->page, NULL); regs->flags &= ~TF_MASK; regs->flags |= ctx->saved_flags; @@ -346,6 +336,7 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) /* These were acquired in kmmio_handler(). */ ctx->active--; BUG_ON(ctx->active); + rcu_read_unlock(); preempt_enable_no_resched(); /* @@ -355,8 +346,6 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) */ if (!(regs->flags & TF_MASK)) ret = 1; - - rcu_read_unlock(); out: put_cpu_var(kmmio_ctx); return ret; @@ -411,15 +400,16 @@ static void release_kmmio_fault_page(unsigned long page, int register_kmmio_probe(struct kmmio_probe *p) { + unsigned long flags; int ret = 0; unsigned long size = 0; - spin_lock_irq(&kmmio_lock); - kmmio_count++; + spin_lock_irqsave(&kmmio_lock, flags); if (get_kmmio_probe(p->addr)) { ret = -EEXIST; goto out; } + kmmio_count++; list_add_rcu(&p->list, &kmmio_probes); while (size < p->len) { if (add_kmmio_fault_page(p->addr + size)) @@ -427,7 +417,7 @@ int register_kmmio_probe(struct kmmio_probe *p) size += PAGE_SIZE; } out: - spin_unlock_irq(&kmmio_lock); + spin_unlock_irqrestore(&kmmio_lock, flags); /* * XXX: What should I do here? * Here was a call to global_flush_tlb(), but it does not exist @@ -478,7 +468,8 @@ static void remove_kmmio_fault_pages(struct rcu_head *head) /* * Remove a kmmio probe. You have to synchronize_rcu() before you can be - * sure that the callbacks will not be called anymore. + * sure that the callbacks will not be called anymore. Only after that + * you may actually release your struct kmmio_probe. * * Unregistering a kmmio fault page has three steps: * 1. release_kmmio_fault_page() @@ -490,18 +481,19 @@ static void remove_kmmio_fault_pages(struct rcu_head *head) */ void unregister_kmmio_probe(struct kmmio_probe *p) { + unsigned long flags; unsigned long size = 0; struct kmmio_fault_page *release_list = NULL; struct kmmio_delayed_release *drelease; - spin_lock_irq(&kmmio_lock); + spin_lock_irqsave(&kmmio_lock, flags); while (size < p->len) { release_kmmio_fault_page(p->addr + size, &release_list); size += PAGE_SIZE; } list_del_rcu(&p->list); kmmio_count--; - spin_unlock_irq(&kmmio_lock); + spin_unlock_irqrestore(&kmmio_lock, flags); drelease = kmalloc(sizeof(*drelease), GFP_ATOMIC); if (!drelease) { diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index e1a508588f0..738644061e4 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -19,6 +19,8 @@ * * Derived from the read-mod example from relay-examples by Tom Zanussi. */ +#define DEBUG 1 + #include #include #include @@ -34,12 +36,12 @@ #include "pf_in.h" -/* This app's relay channel files will appear in /debug/mmio-trace */ -#define APP_DIR "mmio-trace" -/* the marker injection file in /proc */ -#define MARKER_FILE "mmio-marker" +#define NAME "mmiotrace: " -#define MODULE_NAME "mmiotrace" +/* This app's relay channel files will appear in /debug/mmio-trace */ +static const char APP_DIR[] = "mmio-trace"; +/* the marker injection file in /debug/APP_DIR */ +static const char MARKER_FILE[] = "mmio-marker"; struct trap_reason { unsigned long addr; @@ -48,6 +50,15 @@ struct trap_reason { int active_traces; }; +struct remap_trace { + struct list_head list; + struct kmmio_probe probe; + unsigned long phys; + unsigned long id; +}; + +static const size_t subbuf_size = 256*1024; + /* Accessed per-cpu. */ static DEFINE_PER_CPU(struct trap_reason, pf_reason); static DEFINE_PER_CPU(struct mm_io_header_rw, cpu_trace); @@ -55,33 +66,53 @@ static DEFINE_PER_CPU(struct mm_io_header_rw, cpu_trace); /* Access to this is not per-cpu. */ static DEFINE_PER_CPU(atomic_t, dropped); -static struct file_operations mmio_fops = { - .owner = THIS_MODULE, -}; +static struct dentry *dir; +static struct dentry *enabled_file; +static struct dentry *marker_file; -static const size_t subbuf_size = 256*1024; +static DEFINE_MUTEX(mmiotrace_mutex); +static DEFINE_SPINLOCK(trace_lock); +static atomic_t mmiotrace_enabled; +static LIST_HEAD(trace_list); /* struct remap_trace */ static struct rchan *chan; -static struct dentry *dir; -static struct proc_dir_entry *proc_marker_file; + +/* + * Locking in this file: + * - mmiotrace_mutex enforces enable/disable_mmiotrace() critical sections. + * - mmiotrace_enabled may be modified only when holding mmiotrace_mutex + * and trace_lock. + * - Routines depending on is_enabled() must take trace_lock. + * - trace_list users must hold trace_lock. + * - is_enabled() guarantees that chan is valid. + * - pre/post callbacks assume the effect of is_enabled() being true. + */ /* module parameters */ -static unsigned int n_subbufs = 32*4; -static unsigned long filter_offset; -static int nommiotrace; -static int ISA_trace; -static int trace_pc; +static unsigned int n_subbufs = 32*4; +static unsigned long filter_offset; +static int nommiotrace; +static int ISA_trace; +static int trace_pc; +static int enable_now; module_param(n_subbufs, uint, 0); module_param(filter_offset, ulong, 0); module_param(nommiotrace, bool, 0); module_param(ISA_trace, bool, 0); module_param(trace_pc, bool, 0); +module_param(enable_now, bool, 0); MODULE_PARM_DESC(n_subbufs, "Number of 256kB buffers, default 128."); MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); +MODULE_PARM_DESC(enable_now, "Start mmiotracing immediately on module load."); + +static bool is_enabled(void) +{ + return atomic_read(&mmiotrace_enabled); +} static void record_timestamp(struct mm_io_header *header) { @@ -93,15 +124,15 @@ static void record_timestamp(struct mm_io_header *header) } /* - * Write callback for the /proc entry: + * Write callback for the debugfs entry: * Read a marker and write it to the mmio trace log */ -static int write_marker(struct file *file, const char __user *buffer, - unsigned long count, void *data) +static ssize_t write_marker(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) { char *event = NULL; struct mm_io_header *headp; - int len = (count > 65535) ? 65535 : count; + ssize_t len = (count > 65535) ? 65535 : count; event = kzalloc(sizeof(*headp) + len, GFP_KERNEL); if (!event) @@ -117,7 +148,12 @@ static int write_marker(struct file *file, const char __user *buffer, return -EFAULT; } - relay_write(chan, event, sizeof(*headp) + len); + spin_lock_irq(&trace_lock); + if (is_enabled()) + relay_write(chan, event, sizeof(*headp) + len); + else + len = -EINVAL; + spin_unlock_irq(&trace_lock); kfree(event); return len; } @@ -128,19 +164,18 @@ static void print_pte(unsigned long address) pte_t *pte = lookup_address(address, &level); if (!pte) { - pr_err(MODULE_NAME ": Error in %s: no pte for page 0x%08lx\n", + pr_err(NAME "Error in %s: no pte for page 0x%08lx\n", __func__, address); return; } if (level == PG_LEVEL_2M) { - pr_emerg(MODULE_NAME ": 4MB pages are not currently " - "supported: %lx\n", address); + pr_emerg(NAME "4MB pages are not currently supported: " + "0x%08lx\n", address); BUG(); } - pr_info(MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n", - address, pte_val(*pte), - pte_val(*pte) & _PAGE_PRESENT); + pr_info(NAME "pte for 0x%lx: 0x%lx 0x%lx\n", address, pte_val(*pte), + pte_val(*pte) & _PAGE_PRESENT); } /* @@ -150,22 +185,18 @@ static void print_pte(unsigned long address) static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) { const struct trap_reason *my_reason = &get_cpu_var(pf_reason); - pr_emerg(MODULE_NAME ": unexpected fault for address: %lx, " - "last fault for address: %lx\n", + pr_emerg(NAME "unexpected fault for address: 0x%08lx, " + "last fault for address: 0x%08lx\n", addr, my_reason->addr); print_pte(addr); + print_symbol(KERN_EMERG "faulting IP is at %s\n", regs->ip); + print_symbol(KERN_EMERG "last faulting IP was at %s\n", my_reason->ip); #ifdef __i386__ - print_symbol(KERN_EMERG "faulting EIP is at %s\n", regs->ip); - print_symbol(KERN_EMERG "last faulting EIP was at %s\n", - my_reason->ip); pr_emerg("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", regs->ax, regs->bx, regs->cx, regs->dx); pr_emerg("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", regs->si, regs->di, regs->bp, regs->sp); #else - print_symbol(KERN_EMERG "faulting RIP is at %s\n", regs->ip); - print_symbol(KERN_EMERG "last faulting RIP was at %s\n", - my_reason->ip); pr_emerg("rax: %016lx rcx: %016lx rdx: %016lx\n", regs->ax, regs->cx, regs->dx); pr_emerg("rsi: %016lx rdi: %016lx rbp: %016lx rsp: %016lx\n", @@ -197,6 +228,10 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs, my_trace->header.pid = 0; my_trace->header.data_len = sizeof(struct mm_io_rw); my_trace->rw.address = addr; + /* + * struct remap_trace *trace = p->user_data; + * phys = addr - trace->probe.addr + trace->phys; + */ /* * Only record the program counter when requested. @@ -246,15 +281,10 @@ static void post(struct kmmio_probe *p, unsigned long condition, struct trap_reason *my_reason = &get_cpu_var(pf_reason); struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace); - /* - * XXX: This might not get called, if the probe is removed while - * trace hit is on flight. - */ - /* this should always return the active_trace count to 0 */ my_reason->active_traces--; if (my_reason->active_traces) { - pr_emerg(MODULE_NAME ": unexpected post handler"); + pr_emerg(NAME "unexpected post handler"); BUG(); } @@ -284,20 +314,23 @@ static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf, int count; if (relay_buf_full(buf)) { if (atomic_inc_return(drop) == 1) - pr_err(MODULE_NAME ": cpu %d buffer full!\n", cpu); + pr_err(NAME "cpu %d buffer full!\n", cpu); return 0; } count = atomic_read(drop); if (count) { - pr_err(MODULE_NAME ": cpu %d buffer no longer full, " - "missed %d events.\n", - cpu, count); + pr_err(NAME "cpu %d buffer no longer full, missed %d events.\n", + cpu, count); atomic_sub(count, drop); } return 1; } +static struct file_operations mmio_fops = { + .owner = THIS_MODULE, +}; + /* file_create() callback. Creates relay file in debugfs. */ static struct dentry *create_buf_file_handler(const char *filename, struct dentry *parent, @@ -333,34 +366,10 @@ static struct rchan_callbacks relay_callbacks = { .remove_buf_file = remove_buf_file_handler, }; -/* - * create_channel - creates channel /debug/APP_DIR/cpuXXX - * Returns channel on success, NULL otherwise - */ -static struct rchan *create_channel(unsigned size, unsigned n) -{ - return relay_open("cpu", dir, size, n, &relay_callbacks, NULL); -} - -/* destroy_channel - destroys channel /debug/APP_DIR/cpuXXX */ -static void destroy_channel(void) -{ - if (chan) { - relay_close(chan); - chan = NULL; - } -} - -struct remap_trace { - struct list_head list; - struct kmmio_probe probe; -}; -static LIST_HEAD(trace_list); -static DEFINE_SPINLOCK(trace_list_lock); - -static void do_ioremap_trace_core(unsigned long offset, unsigned long size, +static void ioremap_trace_core(unsigned long offset, unsigned long size, void __iomem *addr) { + static atomic_t next_id; struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); struct mm_io_header_map event = { .header = { @@ -380,61 +389,49 @@ static void do_ioremap_trace_core(unsigned long offset, unsigned long size, }; record_timestamp(&event.header); + if (!trace) { + pr_err(NAME "kmalloc failed in ioremap\n"); + return; + } + *trace = (struct remap_trace) { .probe = { .addr = (unsigned long)addr, .len = size, .pre_handler = pre, .post_handler = post, - } + .user_data = trace + }, + .phys = offset, + .id = atomic_inc_return(&next_id) }; + spin_lock_irq(&trace_lock); + if (!is_enabled()) + goto not_enabled; + relay_write(chan, &event, sizeof(event)); - spin_lock(&trace_list_lock); list_add_tail(&trace->list, &trace_list); - spin_unlock(&trace_list_lock); if (!nommiotrace) register_kmmio_probe(&trace->probe); + +not_enabled: + spin_unlock_irq(&trace_lock); } -static void ioremap_trace_core(unsigned long offset, unsigned long size, - void __iomem *addr) +void +mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) { - if ((filter_offset) && (offset != filter_offset)) + if (!is_enabled()) /* recheck and proper locking in *_core() */ return; - /* Don't trace the low PCI/ISA area, it's always mapped.. */ - if (!ISA_trace && (offset < ISA_END_ADDRESS) && - (offset + size > ISA_START_ADDRESS)) { - pr_notice(MODULE_NAME ": Ignoring map of low PCI/ISA area " - "(0x%lx-0x%lx)\n", - offset, offset + size); + pr_debug(NAME "ioremap_*(0x%lx, 0x%lx) = %p\n", offset, size, addr); + if ((filter_offset) && (offset != filter_offset)) return; - } - do_ioremap_trace_core(offset, size, addr); -} - -void __iomem *ioremap_cache_trace(unsigned long offset, unsigned long size) -{ - void __iomem *p = ioremap_cache(offset, size); - pr_debug(MODULE_NAME ": ioremap_cache(0x%lx, 0x%lx) = %p\n", - offset, size, p); - ioremap_trace_core(offset, size, p); - return p; + ioremap_trace_core(offset, size, addr); } -EXPORT_SYMBOL(ioremap_cache_trace); -void __iomem *ioremap_nocache_trace(unsigned long offset, unsigned long size) -{ - void __iomem *p = ioremap_nocache(offset, size); - pr_debug(MODULE_NAME ": ioremap_nocache(0x%lx, 0x%lx) = %p\n", - offset, size, p); - ioremap_trace_core(offset, size, p); - return p; -} -EXPORT_SYMBOL(ioremap_nocache_trace); - -void iounmap_trace(volatile void __iomem *addr) +static void iounmap_trace_core(volatile void __iomem *addr) { struct mm_io_header_map event = { .header = { @@ -454,84 +451,212 @@ void iounmap_trace(volatile void __iomem *addr) }; struct remap_trace *trace; struct remap_trace *tmp; - pr_debug(MODULE_NAME ": Unmapping %p.\n", addr); + struct remap_trace *found_trace = NULL; + + pr_debug(NAME "Unmapping %p.\n", addr); record_timestamp(&event.header); - spin_lock(&trace_list_lock); + spin_lock_irq(&trace_lock); + if (!is_enabled()) + goto not_enabled; + list_for_each_entry_safe(trace, tmp, &trace_list, list) { if ((unsigned long)addr == trace->probe.addr) { if (!nommiotrace) unregister_kmmio_probe(&trace->probe); list_del(&trace->list); - kfree(trace); + found_trace = trace; break; } } - spin_unlock(&trace_list_lock); relay_write(chan, &event, sizeof(event)); - iounmap(addr); + +not_enabled: + spin_unlock_irq(&trace_lock); + if (found_trace) { + synchronize_rcu(); /* unregister_kmmio_probe() requirement */ + kfree(found_trace); + } +} + +void mmiotrace_iounmap(volatile void __iomem *addr) +{ + might_sleep(); + if (is_enabled()) /* recheck and proper locking in *_core() */ + iounmap_trace_core(addr); } -EXPORT_SYMBOL(iounmap_trace); static void clear_trace_list(void) { struct remap_trace *trace; struct remap_trace *tmp; - spin_lock(&trace_list_lock); - list_for_each_entry_safe(trace, tmp, &trace_list, list) { - pr_warning(MODULE_NAME ": purging non-iounmapped " + /* + * No locking required, because the caller ensures we are in a + * critical section via mutex, and is_enabled() is false, + * i.e. nothing can traverse or modify this list. + * Caller also ensures is_enabled() cannot change. + */ + list_for_each_entry(trace, &trace_list, list) { + pr_notice(NAME "purging non-iounmapped " "trace @0x%08lx, size 0x%lx.\n", trace->probe.addr, trace->probe.len); if (!nommiotrace) unregister_kmmio_probe(&trace->probe); + } + synchronize_rcu(); /* unregister_kmmio_probe() requirement */ + + list_for_each_entry_safe(trace, tmp, &trace_list, list) { list_del(&trace->list); kfree(trace); + } +} + +static ssize_t read_enabled_file_bool(struct file *file, + char __user *user_buf, size_t count, loff_t *ppos) +{ + char buf[3]; + + if (is_enabled()) + buf[0] = '1'; + else + buf[0] = '0'; + buf[1] = '\n'; + buf[2] = '\0'; + return simple_read_from_buffer(user_buf, count, ppos, buf, 2); +} + +static void enable_mmiotrace(void); +static void disable_mmiotrace(void); + +static ssize_t write_enabled_file_bool(struct file *file, + const char __user *user_buf, size_t count, loff_t *ppos) +{ + char buf[32]; + int buf_size = min(count, (sizeof(buf)-1)); + + if (copy_from_user(buf, user_buf, buf_size)) + return -EFAULT; + + switch (buf[0]) { + case 'y': + case 'Y': + case '1': + enable_mmiotrace(); + break; + case 'n': + case 'N': + case '0': + disable_mmiotrace(); break; } - spin_unlock(&trace_list_lock); + + return count; +} + +/* this ripped from kernel/kprobes.c */ +static struct file_operations fops_enabled = { + .owner = THIS_MODULE, + .read = read_enabled_file_bool, + .write = write_enabled_file_bool +}; + +static struct file_operations fops_marker = { + .owner = THIS_MODULE, + .write = write_marker +}; + +static void enable_mmiotrace(void) +{ + mutex_lock(&mmiotrace_mutex); + if (is_enabled()) + goto out; + + chan = relay_open("cpu", dir, subbuf_size, n_subbufs, + &relay_callbacks, NULL); + if (!chan) { + pr_err(NAME "relay app channel creation failed.\n"); + goto out; + } + + reference_kmmio(); + + marker_file = debugfs_create_file("marker", 0660, dir, NULL, + &fops_marker); + if (!marker_file) + pr_err(NAME "marker file creation failed.\n"); + + if (nommiotrace) + pr_info(NAME "MMIO tracing disabled.\n"); + if (ISA_trace) + pr_warning(NAME "Warning! low ISA range will be traced.\n"); + spin_lock_irq(&trace_lock); + atomic_inc(&mmiotrace_enabled); + spin_unlock_irq(&trace_lock); + pr_info(NAME "enabled.\n"); +out: + mutex_unlock(&mmiotrace_mutex); +} + +static void disable_mmiotrace(void) +{ + mutex_lock(&mmiotrace_mutex); + if (!is_enabled()) + goto out; + + spin_lock_irq(&trace_lock); + atomic_dec(&mmiotrace_enabled); + BUG_ON(is_enabled()); + spin_unlock_irq(&trace_lock); + + clear_trace_list(); /* guarantees: no more kmmio callbacks */ + unreference_kmmio(); + if (marker_file) { + debugfs_remove(marker_file); + marker_file = NULL; + } + if (chan) { + relay_close(chan); + chan = NULL; + } + + pr_info(NAME "disabled.\n"); +out: + mutex_unlock(&mmiotrace_mutex); } static int __init init(void) { + pr_debug(NAME "load...\n"); if (n_subbufs < 2) return -EINVAL; dir = debugfs_create_dir(APP_DIR, NULL); if (!dir) { - pr_err(MODULE_NAME ": Couldn't create relay app directory.\n"); + pr_err(NAME "Couldn't create relay app directory.\n"); return -ENOMEM; } - chan = create_channel(subbuf_size, n_subbufs); - if (!chan) { + enabled_file = debugfs_create_file("enabled", 0600, dir, NULL, + &fops_enabled); + if (!enabled_file) { + pr_err(NAME "Couldn't create enabled file.\n"); debugfs_remove(dir); - pr_err(MODULE_NAME ": relay app channel creation failed\n"); return -ENOMEM; } - reference_kmmio(); - - proc_marker_file = create_proc_entry(MARKER_FILE, 0, NULL); - if (proc_marker_file) - proc_marker_file->write_proc = write_marker; + if (enable_now) + enable_mmiotrace(); - pr_debug(MODULE_NAME ": loaded.\n"); - if (nommiotrace) - pr_info(MODULE_NAME ": MMIO tracing disabled.\n"); - if (ISA_trace) - pr_warning(MODULE_NAME ": Warning! low ISA range will be " - "traced.\n"); return 0; } static void __exit cleanup(void) { - pr_debug(MODULE_NAME ": unload...\n"); - clear_trace_list(); - unreference_kmmio(); - remove_proc_entry(MARKER_FILE, NULL); - destroy_channel(); + pr_debug(NAME "unload...\n"); + if (enabled_file) + debugfs_remove(enabled_file); + disable_mmiotrace(); if (dir) debugfs_remove(dir); } diff --git a/arch/x86/kernel/mmiotrace/testmmiotrace.c b/arch/x86/kernel/mmiotrace/testmmiotrace.c index 5ecff578672..cfa60b227c8 100644 --- a/arch/x86/kernel/mmiotrace/testmmiotrace.c +++ b/arch/x86/kernel/mmiotrace/testmmiotrace.c @@ -4,10 +4,6 @@ #include #include -extern void __iomem *ioremap_nocache_trace(unsigned long offset, - unsigned long size); -extern void iounmap_trace(volatile void __iomem *addr); - #define MODULE_NAME "testmmiotrace" static unsigned long mmio_address; @@ -28,25 +24,24 @@ static void do_write_test(void __iomem *p) static void do_read_test(void __iomem *p) { unsigned int i; - volatile unsigned int v; for (i = 0; i < 256; i++) - v = ioread8(p + i); + ioread8(p + i); for (i = 1024; i < (5 * 1024); i += 2) - v = ioread16(p + i); + ioread16(p + i); for (i = (5 * 1024); i < (16 * 1024); i += 4) - v = ioread32(p + i); + ioread32(p + i); } static void do_test(void) { - void __iomem *p = ioremap_nocache_trace(mmio_address, 0x4000); + void __iomem *p = ioremap_nocache(mmio_address, 0x4000); if (!p) { pr_err(MODULE_NAME ": could not ioremap, aborting.\n"); return; } do_write_test(p); do_read_test(p); - iounmap_trace(p); + iounmap(p); } static int __init init(void) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 71bb3159031..8927c878544 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -126,6 +127,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, unsigned long new_prot_val; pgprot_t prot; int retval; + void __iomem *ret_addr; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; @@ -233,7 +235,10 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, return NULL; } - return (void __iomem *) (vaddr + offset); + ret_addr = (void __iomem *) (vaddr + offset); + mmiotrace_ioremap(phys_addr, size, ret_addr); + + return ret_addr; } /** @@ -325,6 +330,8 @@ void iounmap(volatile void __iomem *addr) addr = (volatile void __iomem *) (PAGE_MASK & (unsigned long __force)addr); + mmiotrace_iounmap(addr); + /* Use the vm area unlocked, assuming the caller ensures there isn't another iounmap for the same address in parallel. Reuse of the virtual address is prevented by diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index d87a6cd8b68..cb5efd0c7f5 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -16,11 +16,12 @@ typedef void (*kmmio_post_handler_t)(struct kmmio_probe *, unsigned long condition, struct pt_regs *); struct kmmio_probe { - struct list_head list; + struct list_head list; /* kmmio internal list */ unsigned long addr; /* start location of the probe point */ unsigned long len; /* length of the probe region */ kmmio_pre_handler_t pre_handler; /* Called before addr is executed. */ kmmio_post_handler_t post_handler; /* Called after addr is executed */ + void *user_data; }; /* kmmio is active by some kmmio_probes? */ @@ -38,6 +39,21 @@ extern void unregister_kmmio_probe(struct kmmio_probe *p); /* Called from page fault handler. */ extern int kmmio_handler(struct pt_regs *regs, unsigned long addr); +/* Called from ioremap.c */ +#ifdef CONFIG_MMIOTRACE +extern void +mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr); +extern void mmiotrace_iounmap(volatile void __iomem *addr); +#else +static inline void +mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) +{ +} +static inline void mmiotrace_iounmap(volatile void __iomem *addr) +{ +} +#endif /* CONFIG_MMIOTRACE_HOOKS */ + #endif /* __KERNEL__ */ -- cgit v1.2.3-70-g09d2 From f984b51e0779a6dd30feedc41404013ca54e5d05 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: ftrace: add mmiotrace plugin On Sat, 22 Mar 2008 13:07:47 +0100 Ingo Molnar wrote: > > > i'd suggest the following: pull x86.git and sched-devel.git into a > > > single tree [the two will combine without rejects]. Then try to add a > > > kernel/tracing/trace_mmiotrace.c ftrace plugin. The trace_sysprof.c > > > plugin might be a good example. > > > > I did this and now I have mmiotrace enabled/disabled via the tracing > > framework (what do we call this, since ftrace is one of the tracers?). > > cool! could you send the patches for that? (even if they are not fully > functional yet) Patch attached in the end. Nice to see how much code disappeared. I tried to mark all the features I had to break with XXX-comments. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 3 +- arch/x86/kernel/mmiotrace/mmio-mod.c | 208 +++++------------------------------ include/linux/mmiotrace.h | 6 + kernel/trace/Makefile | 1 + kernel/trace/trace_mmiotrace.c | 84 ++++++++++++++ 5 files changed, 123 insertions(+), 179 deletions(-) create mode 100644 kernel/trace/trace_mmiotrace.c (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index aa0d6462b1f..7e4b8494078 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -173,7 +173,8 @@ config MMIOTRACE_HOOKS config MMIOTRACE bool "Memory mapped IO tracing" - depends on DEBUG_KERNEL && RELAY && DEBUG_FS + depends on DEBUG_KERNEL && RELAY + select TRACING select MMIOTRACE_HOOKS default y help diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index 738644061e4..c7a67d7e482 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -22,9 +22,8 @@ #define DEBUG 1 #include -#include #include -#include +#include #include #include #include @@ -63,18 +62,18 @@ static const size_t subbuf_size = 256*1024; static DEFINE_PER_CPU(struct trap_reason, pf_reason); static DEFINE_PER_CPU(struct mm_io_header_rw, cpu_trace); +#if 0 /* XXX: no way gather this info anymore */ /* Access to this is not per-cpu. */ static DEFINE_PER_CPU(atomic_t, dropped); +#endif static struct dentry *dir; -static struct dentry *enabled_file; static struct dentry *marker_file; static DEFINE_MUTEX(mmiotrace_mutex); static DEFINE_SPINLOCK(trace_lock); static atomic_t mmiotrace_enabled; static LIST_HEAD(trace_list); /* struct remap_trace */ -static struct rchan *chan; /* * Locking in this file: @@ -93,36 +92,24 @@ static unsigned long filter_offset; static int nommiotrace; static int ISA_trace; static int trace_pc; -static int enable_now; module_param(n_subbufs, uint, 0); module_param(filter_offset, ulong, 0); module_param(nommiotrace, bool, 0); module_param(ISA_trace, bool, 0); module_param(trace_pc, bool, 0); -module_param(enable_now, bool, 0); MODULE_PARM_DESC(n_subbufs, "Number of 256kB buffers, default 128."); MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); -MODULE_PARM_DESC(enable_now, "Start mmiotracing immediately on module load."); static bool is_enabled(void) { return atomic_read(&mmiotrace_enabled); } -static void record_timestamp(struct mm_io_header *header) -{ - struct timespec now; - - getnstimeofday(&now); - header->sec = now.tv_sec; - header->nsec = now.tv_nsec; -} - /* * Write callback for the debugfs entry: * Read a marker and write it to the mmio trace log @@ -141,7 +128,6 @@ static ssize_t write_marker(struct file *file, const char __user *buffer, headp = (struct mm_io_header *)event; headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT); headp->data_len = len; - record_timestamp(headp); if (copy_from_user(event + sizeof(*headp), buffer, len)) { kfree(event); @@ -149,9 +135,11 @@ static ssize_t write_marker(struct file *file, const char __user *buffer, } spin_lock_irq(&trace_lock); +#if 0 /* XXX: convert this to use tracing */ if (is_enabled()) relay_write(chan, event, sizeof(*headp) + len); else +#endif len = -EINVAL; spin_unlock_irq(&trace_lock); kfree(event); @@ -242,7 +230,11 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs, else my_trace->rw.pc = 0; - record_timestamp(&my_trace->header); + /* + * XXX: the timestamp recorded will be *after* the tracing has been + * done, not at the time we hit the instruction. SMP implications + * on event ordering? + */ switch (type) { case REG_READ: @@ -295,77 +287,19 @@ static void post(struct kmmio_probe *p, unsigned long condition, default: break; } - relay_write(chan, my_trace, sizeof(*my_trace)); + + /* + * XXX: Several required values are ignored: + * - mapping id + * - program counter + * Also the address should be physical, not virtual. + */ + mmio_trace_record(my_trace->header.type, my_trace->rw.address, + my_trace->rw.value); put_cpu_var(cpu_trace); put_cpu_var(pf_reason); } -/* - * subbuf_start() relay callback. - * - * Defined so that we know when events are dropped due to the buffer-full - * condition. - */ -static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf, - void *prev_subbuf, size_t prev_padding) -{ - unsigned int cpu = buf->cpu; - atomic_t *drop = &per_cpu(dropped, cpu); - int count; - if (relay_buf_full(buf)) { - if (atomic_inc_return(drop) == 1) - pr_err(NAME "cpu %d buffer full!\n", cpu); - return 0; - } - count = atomic_read(drop); - if (count) { - pr_err(NAME "cpu %d buffer no longer full, missed %d events.\n", - cpu, count); - atomic_sub(count, drop); - } - - return 1; -} - -static struct file_operations mmio_fops = { - .owner = THIS_MODULE, -}; - -/* file_create() callback. Creates relay file in debugfs. */ -static struct dentry *create_buf_file_handler(const char *filename, - struct dentry *parent, - int mode, - struct rchan_buf *buf, - int *is_global) -{ - struct dentry *buf_file; - - mmio_fops.read = relay_file_operations.read; - mmio_fops.open = relay_file_operations.open; - mmio_fops.poll = relay_file_operations.poll; - mmio_fops.mmap = relay_file_operations.mmap; - mmio_fops.release = relay_file_operations.release; - mmio_fops.splice_read = relay_file_operations.splice_read; - - buf_file = debugfs_create_file(filename, mode, parent, buf, - &mmio_fops); - - return buf_file; -} - -/* file_remove() default callback. Removes relay file in debugfs. */ -static int remove_buf_file_handler(struct dentry *dentry) -{ - debugfs_remove(dentry); - return 0; -} - -static struct rchan_callbacks relay_callbacks = { - .subbuf_start = subbuf_start_handler, - .create_buf_file = create_buf_file_handler, - .remove_buf_file = remove_buf_file_handler, -}; - static void ioremap_trace_core(unsigned long offset, unsigned long size, void __iomem *addr) { @@ -387,7 +321,6 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, .pc = 0 } }; - record_timestamp(&event.header); if (!trace) { pr_err(NAME "kmalloc failed in ioremap\n"); @@ -410,7 +343,10 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, if (!is_enabled()) goto not_enabled; - relay_write(chan, &event, sizeof(event)); + /* + * XXX: Insufficient data recorded! + */ + mmio_trace_record(event.header.type, event.map.addr, event.map.len); list_add_tail(&trace->list, &trace_list); if (!nommiotrace) register_kmmio_probe(&trace->probe); @@ -454,7 +390,6 @@ static void iounmap_trace_core(volatile void __iomem *addr) struct remap_trace *found_trace = NULL; pr_debug(NAME "Unmapping %p.\n", addr); - record_timestamp(&event.header); spin_lock_irq(&trace_lock); if (!is_enabled()) @@ -469,7 +404,8 @@ static void iounmap_trace_core(volatile void __iomem *addr) break; } } - relay_write(chan, &event, sizeof(event)); + mmio_trace_record(event.header.type, event.map.addr, + found_trace ? found_trace->id : -1); not_enabled: spin_unlock_irq(&trace_lock); @@ -512,77 +448,23 @@ static void clear_trace_list(void) } } -static ssize_t read_enabled_file_bool(struct file *file, - char __user *user_buf, size_t count, loff_t *ppos) -{ - char buf[3]; - - if (is_enabled()) - buf[0] = '1'; - else - buf[0] = '0'; - buf[1] = '\n'; - buf[2] = '\0'; - return simple_read_from_buffer(user_buf, count, ppos, buf, 2); -} - -static void enable_mmiotrace(void); -static void disable_mmiotrace(void); - -static ssize_t write_enabled_file_bool(struct file *file, - const char __user *user_buf, size_t count, loff_t *ppos) -{ - char buf[32]; - int buf_size = min(count, (sizeof(buf)-1)); - - if (copy_from_user(buf, user_buf, buf_size)) - return -EFAULT; - - switch (buf[0]) { - case 'y': - case 'Y': - case '1': - enable_mmiotrace(); - break; - case 'n': - case 'N': - case '0': - disable_mmiotrace(); - break; - } - - return count; -} - -/* this ripped from kernel/kprobes.c */ -static struct file_operations fops_enabled = { - .owner = THIS_MODULE, - .read = read_enabled_file_bool, - .write = write_enabled_file_bool -}; - static struct file_operations fops_marker = { .owner = THIS_MODULE, .write = write_marker }; -static void enable_mmiotrace(void) +void enable_mmiotrace(void) { mutex_lock(&mmiotrace_mutex); if (is_enabled()) goto out; - chan = relay_open("cpu", dir, subbuf_size, n_subbufs, - &relay_callbacks, NULL); - if (!chan) { - pr_err(NAME "relay app channel creation failed.\n"); - goto out; - } - reference_kmmio(); +#if 0 /* XXX: tracing does not support text entries */ marker_file = debugfs_create_file("marker", 0660, dir, NULL, &fops_marker); +#endif if (!marker_file) pr_err(NAME "marker file creation failed.\n"); @@ -598,7 +480,7 @@ out: mutex_unlock(&mmiotrace_mutex); } -static void disable_mmiotrace(void) +void disable_mmiotrace(void) { mutex_lock(&mmiotrace_mutex); if (!is_enabled()) @@ -615,17 +497,13 @@ static void disable_mmiotrace(void) debugfs_remove(marker_file); marker_file = NULL; } - if (chan) { - relay_close(chan); - chan = NULL; - } pr_info(NAME "disabled.\n"); out: mutex_unlock(&mmiotrace_mutex); } -static int __init init(void) +int __init init_mmiotrace(void) { pr_debug(NAME "load...\n"); if (n_subbufs < 2) @@ -636,31 +514,5 @@ static int __init init(void) pr_err(NAME "Couldn't create relay app directory.\n"); return -ENOMEM; } - - enabled_file = debugfs_create_file("enabled", 0600, dir, NULL, - &fops_enabled); - if (!enabled_file) { - pr_err(NAME "Couldn't create enabled file.\n"); - debugfs_remove(dir); - return -ENOMEM; - } - - if (enable_now) - enable_mmiotrace(); - return 0; } - -static void __exit cleanup(void) -{ - pr_debug(NAME "unload...\n"); - if (enabled_file) - debugfs_remove(enabled_file); - disable_mmiotrace(); - if (dir) - debugfs_remove(dir); -} - -module_init(init); -module_exit(cleanup); -MODULE_LICENSE("GPL"); diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index cb5efd0c7f5..579b3b06c90 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -54,6 +54,12 @@ static inline void mmiotrace_iounmap(volatile void __iomem *addr) } #endif /* CONFIG_MMIOTRACE_HOOKS */ +/* in kernel/trace/trace_mmiotrace.c */ +extern int __init init_mmiotrace(void); +extern void enable_mmiotrace(void); +extern void disable_mmiotrace(void); +extern void mmio_trace_record(u32 type, unsigned long addr, unsigned long arg); + #endif /* __KERNEL__ */ diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index d9efbbfa2bd..c44a7dce908 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -18,5 +18,6 @@ obj-$(CONFIG_FTRACE) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o +obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c new file mode 100644 index 00000000000..e4dd03cc5aa --- /dev/null +++ b/kernel/trace/trace_mmiotrace.c @@ -0,0 +1,84 @@ +/* + * Memory mapped I/O tracing + * + * Copyright (C) 2008 Pekka Paalanen + */ + +#define DEBUG 1 + +#include +#include + +#include "trace.h" + +extern void +__trace_special(void *__tr, void *__data, + unsigned long arg1, unsigned long arg2, unsigned long arg3); + +static struct trace_array *mmio_trace_array; + + +static void mmio_trace_init(struct trace_array *tr) +{ + pr_debug("in %s\n", __func__); + mmio_trace_array = tr; + if (tr->ctrl) + enable_mmiotrace(); +} + +static void mmio_trace_reset(struct trace_array *tr) +{ + pr_debug("in %s\n", __func__); + if (tr->ctrl) + disable_mmiotrace(); +} + +static void mmio_trace_ctrl_update(struct trace_array *tr) +{ + pr_debug("in %s\n", __func__); + if (tr->ctrl) + enable_mmiotrace(); + else + disable_mmiotrace(); +} + +static struct tracer mmio_tracer __read_mostly = +{ + .name = "mmiotrace", + .init = mmio_trace_init, + .reset = mmio_trace_reset, + .ctrl_update = mmio_trace_ctrl_update, +}; + +__init static int init_mmio_trace(void) +{ + int ret = init_mmiotrace(); + if (ret) + return ret; + return register_tracer(&mmio_tracer); +} +device_initcall(init_mmio_trace); + +void mmio_trace_record(u32 type, unsigned long addr, unsigned long arg) +{ + struct trace_array *tr = mmio_trace_array; + struct trace_array_cpu *data = tr->data[smp_processor_id()]; + + if (!current || current->pid == 0) { + /* + * XXX: This is a problem. We need to able to record, no + * matter what. tracing_generic_entry_update() would crash. + */ + static unsigned limit; + if (limit++ < 12) + pr_err("Error in %s: no current.\n", __func__); + return; + } + if (!tr || !data) { + static unsigned limit; + if (limit++ < 12) + pr_err("%s: no tr or data\n", __func__); + return; + } + __trace_special(tr, data, type, addr, arg); +} -- cgit v1.2.3-70-g09d2 From bd8ac686c73c7e925fcfe0b02dc4e7b947127864 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:57 +0200 Subject: ftrace: mmiotrace, updates here is a patch that makes mmiotrace work almost well within the tracing framework. The patch applies on top of my previous patch. I have my own output formatting in place now. Summary of changes: - fix the NULL dereference that was due to not calling tracing_reset() - add print_line() callback into struct tracer - implement print_line() for mmiotrace, producing up-to-spec text - add my output header, but that is not really called in the right place - rewrote the main structs in mmiotrace - added two new trace entry types: TRACE_MMIO_RW and TRACE_MMIO_MAP - made some functions in trace.c non-static - check current==NULL in tracing_generic_entry_update() - fix(?) comparison in trace_seq_printf() Things seem to work fine except a few issues. Markers (text lines injected into mmiotrace log) are missing, I did not feel hacking them in before we have variable length entries. My output header is printed only for 'trace' file, but not 'trace_pipe'. For some reason, despite my quick fix, iter->trace is NULL in print_trace_line() when called from 'trace_pipe' file, which means I don't get proper output formatting. I only tried by loading nouveau.ko, which just detects the card, and that is traced fine. I didn't try further. Map, two reads and unmap. Works perfectly. I am missing the information about overflows, I'd prefer to have a counter for lost events. I didn't try, but I guess currently there is no way of knowning when it overflows? So, not too far from being fully operational, it seems :-) And looking at the diffstat, there also is some 700-900 lines of user space code that just became obsolete. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 2 +- arch/x86/kernel/mmiotrace/mmio-mod.c | 140 ++++++++++---------------------- include/linux/mmiotrace.h | 85 ++++++-------------- kernel/trace/trace.c | 34 ++++++++ kernel/trace/trace.h | 14 ++++ kernel/trace/trace_mmiotrace.c | 151 ++++++++++++++++++++++++++++------- 6 files changed, 238 insertions(+), 188 deletions(-) (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 7e4b8494078..1d6de0d67f9 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -173,7 +173,7 @@ config MMIOTRACE_HOOKS config MMIOTRACE bool "Memory mapped IO tracing" - depends on DEBUG_KERNEL && RELAY + depends on DEBUG_KERNEL select TRACING select MMIOTRACE_HOOKS default y diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index c7a67d7e482..62abc281a51 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -37,11 +37,6 @@ #define NAME "mmiotrace: " -/* This app's relay channel files will appear in /debug/mmio-trace */ -static const char APP_DIR[] = "mmio-trace"; -/* the marker injection file in /debug/APP_DIR */ -static const char MARKER_FILE[] = "mmio-marker"; - struct trap_reason { unsigned long addr; unsigned long ip; @@ -56,18 +51,15 @@ struct remap_trace { unsigned long id; }; -static const size_t subbuf_size = 256*1024; - /* Accessed per-cpu. */ static DEFINE_PER_CPU(struct trap_reason, pf_reason); -static DEFINE_PER_CPU(struct mm_io_header_rw, cpu_trace); +static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace); #if 0 /* XXX: no way gather this info anymore */ /* Access to this is not per-cpu. */ static DEFINE_PER_CPU(atomic_t, dropped); #endif -static struct dentry *dir; static struct dentry *marker_file; static DEFINE_MUTEX(mmiotrace_mutex); @@ -82,24 +74,21 @@ static LIST_HEAD(trace_list); /* struct remap_trace */ * and trace_lock. * - Routines depending on is_enabled() must take trace_lock. * - trace_list users must hold trace_lock. - * - is_enabled() guarantees that chan is valid. + * - is_enabled() guarantees that mmio_trace_record is allowed. * - pre/post callbacks assume the effect of is_enabled() being true. */ /* module parameters */ -static unsigned int n_subbufs = 32*4; static unsigned long filter_offset; static int nommiotrace; static int ISA_trace; static int trace_pc; -module_param(n_subbufs, uint, 0); module_param(filter_offset, ulong, 0); module_param(nommiotrace, bool, 0); module_param(ISA_trace, bool, 0); module_param(trace_pc, bool, 0); -MODULE_PARM_DESC(n_subbufs, "Number of 256kB buffers, default 128."); MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); @@ -110,6 +99,7 @@ static bool is_enabled(void) return atomic_read(&mmiotrace_enabled); } +#if 0 /* XXX: needs rewrite */ /* * Write callback for the debugfs entry: * Read a marker and write it to the mmio trace log @@ -145,6 +135,7 @@ static ssize_t write_marker(struct file *file, const char __user *buffer, kfree(event); return len; } +#endif static void print_pte(unsigned long address) { @@ -198,9 +189,10 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs, unsigned long addr) { struct trap_reason *my_reason = &get_cpu_var(pf_reason); - struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace); + struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); const unsigned long instptr = instruction_pointer(regs); const enum reason_type type = get_ins_type(instptr); + struct remap_trace *trace = p->user_data; /* it doesn't make sense to have more than one active trace per cpu */ if (my_reason->active_traces) @@ -212,23 +204,17 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs, my_reason->addr = addr; my_reason->ip = instptr; - my_trace->header.type = MMIO_MAGIC; - my_trace->header.pid = 0; - my_trace->header.data_len = sizeof(struct mm_io_rw); - my_trace->rw.address = addr; - /* - * struct remap_trace *trace = p->user_data; - * phys = addr - trace->probe.addr + trace->phys; - */ + my_trace->phys = addr - trace->probe.addr + trace->phys; + my_trace->map_id = trace->id; /* * Only record the program counter when requested. * It may taint clean-room reverse engineering. */ if (trace_pc) - my_trace->rw.pc = instptr; + my_trace->pc = instptr; else - my_trace->rw.pc = 0; + my_trace->pc = 0; /* * XXX: the timestamp recorded will be *after* the tracing has been @@ -238,28 +224,25 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs, switch (type) { case REG_READ: - my_trace->header.type |= - (MMIO_READ << MMIO_OPCODE_SHIFT) | - (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); + my_trace->opcode = MMIO_READ; + my_trace->width = get_ins_mem_width(instptr); break; case REG_WRITE: - my_trace->header.type |= - (MMIO_WRITE << MMIO_OPCODE_SHIFT) | - (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); - my_trace->rw.value = get_ins_reg_val(instptr, regs); + my_trace->opcode = MMIO_WRITE; + my_trace->width = get_ins_mem_width(instptr); + my_trace->value = get_ins_reg_val(instptr, regs); break; case IMM_WRITE: - my_trace->header.type |= - (MMIO_WRITE << MMIO_OPCODE_SHIFT) | - (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT); - my_trace->rw.value = get_ins_imm_val(instptr); + my_trace->opcode = MMIO_WRITE; + my_trace->width = get_ins_mem_width(instptr); + my_trace->value = get_ins_imm_val(instptr); break; default: { unsigned char *ip = (unsigned char *)instptr; - my_trace->header.type |= - (MMIO_UNKNOWN_OP << MMIO_OPCODE_SHIFT); - my_trace->rw.value = (*ip) << 16 | *(ip + 1) << 8 | + my_trace->opcode = MMIO_UNKNOWN_OP; + my_trace->width = 0; + my_trace->value = (*ip) << 16 | *(ip + 1) << 8 | *(ip + 2); } } @@ -271,7 +254,7 @@ static void post(struct kmmio_probe *p, unsigned long condition, struct pt_regs *regs) { struct trap_reason *my_reason = &get_cpu_var(pf_reason); - struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace); + struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); /* this should always return the active_trace count to 0 */ my_reason->active_traces--; @@ -282,20 +265,13 @@ static void post(struct kmmio_probe *p, unsigned long condition, switch (my_reason->type) { case REG_READ: - my_trace->rw.value = get_ins_reg_val(my_reason->ip, regs); + my_trace->value = get_ins_reg_val(my_reason->ip, regs); break; default: break; } - /* - * XXX: Several required values are ignored: - * - mapping id - * - program counter - * Also the address should be physical, not virtual. - */ - mmio_trace_record(my_trace->header.type, my_trace->rw.address, - my_trace->rw.value); + mmio_trace_rw(my_trace); put_cpu_var(cpu_trace); put_cpu_var(pf_reason); } @@ -305,21 +281,11 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, { static atomic_t next_id; struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); - struct mm_io_header_map event = { - .header = { - .type = MMIO_MAGIC | - (MMIO_PROBE << MMIO_OPCODE_SHIFT), - .sec = 0, - .nsec = 0, - .pid = 0, - .data_len = sizeof(struct mm_io_map) - }, - .map = { - .phys = offset, - .addr = (unsigned long)addr, - .len = size, - .pc = 0 - } + struct mmiotrace_map map = { + .phys = offset, + .virt = (unsigned long)addr, + .len = size, + .opcode = MMIO_PROBE }; if (!trace) { @@ -338,15 +304,13 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, .phys = offset, .id = atomic_inc_return(&next_id) }; + map.map_id = trace->id; spin_lock_irq(&trace_lock); if (!is_enabled()) goto not_enabled; - /* - * XXX: Insufficient data recorded! - */ - mmio_trace_record(event.header.type, event.map.addr, event.map.len); + mmio_trace_mapping(&map); list_add_tail(&trace->list, &trace_list); if (!nommiotrace) register_kmmio_probe(&trace->probe); @@ -369,21 +333,11 @@ mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) static void iounmap_trace_core(volatile void __iomem *addr) { - struct mm_io_header_map event = { - .header = { - .type = MMIO_MAGIC | - (MMIO_UNPROBE << MMIO_OPCODE_SHIFT), - .sec = 0, - .nsec = 0, - .pid = 0, - .data_len = sizeof(struct mm_io_map) - }, - .map = { - .phys = 0, - .addr = (unsigned long)addr, - .len = 0, - .pc = 0 - } + struct mmiotrace_map map = { + .phys = 0, + .virt = (unsigned long)addr, + .len = 0, + .opcode = MMIO_UNPROBE }; struct remap_trace *trace; struct remap_trace *tmp; @@ -404,8 +358,8 @@ static void iounmap_trace_core(volatile void __iomem *addr) break; } } - mmio_trace_record(event.header.type, event.map.addr, - found_trace ? found_trace->id : -1); + map.map_id = (found_trace) ? found_trace->id : -1; + mmio_trace_mapping(&map); not_enabled: spin_unlock_irq(&trace_lock); @@ -448,10 +402,12 @@ static void clear_trace_list(void) } } +#if 0 /* XXX: out of order */ static struct file_operations fops_marker = { .owner = THIS_MODULE, .write = write_marker }; +#endif void enable_mmiotrace(void) { @@ -464,9 +420,9 @@ void enable_mmiotrace(void) #if 0 /* XXX: tracing does not support text entries */ marker_file = debugfs_create_file("marker", 0660, dir, NULL, &fops_marker); -#endif if (!marker_file) pr_err(NAME "marker file creation failed.\n"); +#endif if (nommiotrace) pr_info(NAME "MMIO tracing disabled.\n"); @@ -502,17 +458,3 @@ void disable_mmiotrace(void) out: mutex_unlock(&mmiotrace_mutex); } - -int __init init_mmiotrace(void) -{ - pr_debug(NAME "load...\n"); - if (n_subbufs < 2) - return -EINVAL; - - dir = debugfs_create_dir(APP_DIR, NULL); - if (!dir) { - pr_err(NAME "Couldn't create relay app directory.\n"); - return -ENOMEM; - } - return 0; -} diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index 579b3b06c90..c88a9c197d2 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -54,73 +54,38 @@ static inline void mmiotrace_iounmap(volatile void __iomem *addr) } #endif /* CONFIG_MMIOTRACE_HOOKS */ -/* in kernel/trace/trace_mmiotrace.c */ -extern int __init init_mmiotrace(void); -extern void enable_mmiotrace(void); -extern void disable_mmiotrace(void); -extern void mmio_trace_record(u32 type, unsigned long addr, unsigned long arg); - -#endif /* __KERNEL__ */ - - -/* - * If you change anything here, you must bump MMIO_VERSION. - * This is the relay data format for user space. - */ -#define MMIO_VERSION 0x04 - -/* mm_io_header.type */ -#define MMIO_OPCODE_MASK 0xff -#define MMIO_OPCODE_SHIFT 0 -#define MMIO_WIDTH_MASK 0xff00 -#define MMIO_WIDTH_SHIFT 8 -#define MMIO_MAGIC (0x6f000000 | (MMIO_VERSION<<16)) -#define MMIO_MAGIC_MASK 0xffff0000 - -enum mm_io_opcode { /* payload type: */ - MMIO_READ = 0x1, /* struct mm_io_rw */ - MMIO_WRITE = 0x2, /* struct mm_io_rw */ - MMIO_PROBE = 0x3, /* struct mm_io_map */ - MMIO_UNPROBE = 0x4, /* struct mm_io_map */ +enum mm_io_opcode { + MMIO_READ = 0x1, /* struct mmiotrace_rw */ + MMIO_WRITE = 0x2, /* struct mmiotrace_rw */ + MMIO_PROBE = 0x3, /* struct mmiotrace_map */ + MMIO_UNPROBE = 0x4, /* struct mmiotrace_map */ MMIO_MARKER = 0x5, /* raw char data */ - MMIO_UNKNOWN_OP = 0x6, /* struct mm_io_rw */ + MMIO_UNKNOWN_OP = 0x6, /* struct mmiotrace_rw */ }; -struct mm_io_header { - __u32 type; /* see MMIO_* macros above */ - __u32 sec; /* timestamp */ - __u32 nsec; - __u32 pid; /* PID of the process, or 0 for kernel core */ - __u16 data_len; /* length of the following payload */ +struct mmiotrace_rw { + unsigned long phys; /* PCI address of register */ + unsigned long value; + unsigned long pc; /* optional program counter */ + int map_id; + unsigned char opcode; /* one of MMIO_{READ,WRITE,UNKNOWN_OP} */ + unsigned char width; /* size of register access in bytes */ }; -struct mm_io_rw { - __u64 address; /* virtual address of register */ - __u64 value; - __u64 pc; /* optional program counter */ +struct mmiotrace_map { + unsigned long phys; /* base address in PCI space */ + unsigned long virt; /* base virtual address */ + unsigned long len; /* mapping size */ + int map_id; + unsigned char opcode; /* MMIO_PROBE or MMIO_UNPROBE */ }; -struct mm_io_map { - __u64 phys; /* base address in PCI space */ - __u64 addr; /* base virtual address */ - __u64 len; /* mapping size */ - __u64 pc; /* optional program counter */ -}; - - -/* - * These structures are used to allow a single relay_write() - * call to write a full packet. - */ - -struct mm_io_header_rw { - struct mm_io_header header; - struct mm_io_rw rw; -} __attribute__((packed)); +/* in kernel/trace/trace_mmiotrace.c */ +extern void enable_mmiotrace(void); +extern void disable_mmiotrace(void); +extern void mmio_trace_rw(struct mmiotrace_rw *rw); +extern void mmio_trace_mapping(struct mmiotrace_map *map); -struct mm_io_header_map { - struct mm_io_header header; - struct mm_io_map map; -} __attribute__((packed)); +#endif /* __KERNEL__ */ #endif /* MMIOTRACE_H */ diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3271916ff03..d14fe49e963 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -831,6 +831,40 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data, trace_function(tr, data, ip, parent_ip, flags); } +#ifdef CONFIG_MMIOTRACE +void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, + struct mmiotrace_rw *rw) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + spin_lock_irqsave(&data->lock, irq_flags); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_MMIO_RW; + entry->mmiorw = *rw; + spin_unlock_irqrestore(&data->lock, irq_flags); + + trace_wake_up(); +} + +void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, + struct mmiotrace_map *map) +{ + struct trace_entry *entry; + unsigned long irq_flags; + + spin_lock_irqsave(&data->lock, irq_flags); + entry = tracing_get_trace_entry(tr, data); + tracing_generic_entry_update(entry, 0); + entry->type = TRACE_MMIO_MAP; + entry->mmiomap = *map; + spin_unlock_irqrestore(&data->lock, irq_flags); + + trace_wake_up(); +} +#endif + void __trace_stack(struct trace_array *tr, struct trace_array_cpu *data, unsigned long flags, diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index c460e85e94e..0ef9ef74c80 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -5,6 +5,7 @@ #include #include #include +#include enum trace_type { __TRACE_FIRST_TYPE = 0, @@ -14,6 +15,8 @@ enum trace_type { TRACE_WAKE, TRACE_STACK, TRACE_SPECIAL, + TRACE_MMIO_RW, + TRACE_MMIO_MAP, __TRACE_LAST_TYPE }; @@ -75,6 +78,8 @@ struct trace_entry { struct ctx_switch_entry ctx; struct special_entry special; struct stack_entry stack; + struct mmiotrace_rw mmiorw; + struct mmiotrace_map mmiomap; }; }; @@ -255,6 +260,15 @@ extern unsigned long ftrace_update_tot_cnt; extern int DYN_FTRACE_TEST_NAME(void); #endif +#ifdef CONFIG_MMIOTRACE +extern void __trace_mmiotrace_rw(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_rw *rw); +extern void __trace_mmiotrace_map(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_map *map); +#endif + #ifdef CONFIG_FTRACE_STARTUP_TEST #ifdef CONFIG_FTRACE extern int trace_selftest_startup_function(struct tracer *trace, diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index e4dd03cc5aa..3a12b1ad0c6 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -11,19 +11,26 @@ #include "trace.h" -extern void -__trace_special(void *__tr, void *__data, - unsigned long arg1, unsigned long arg2, unsigned long arg3); - static struct trace_array *mmio_trace_array; +static void mmio_reset_data(struct trace_array *tr) +{ + int cpu; + + tr->time_start = ftrace_now(tr->cpu); + + for_each_online_cpu(cpu) + tracing_reset(tr->data[cpu]); +} static void mmio_trace_init(struct trace_array *tr) { pr_debug("in %s\n", __func__); mmio_trace_array = tr; - if (tr->ctrl) + if (tr->ctrl) { + mmio_reset_data(tr); enable_mmiotrace(); + } } static void mmio_trace_reset(struct trace_array *tr) @@ -31,15 +38,110 @@ static void mmio_trace_reset(struct trace_array *tr) pr_debug("in %s\n", __func__); if (tr->ctrl) disable_mmiotrace(); + mmio_reset_data(tr); + mmio_trace_array = NULL; } static void mmio_trace_ctrl_update(struct trace_array *tr) { pr_debug("in %s\n", __func__); - if (tr->ctrl) + if (tr->ctrl) { + mmio_reset_data(tr); enable_mmiotrace(); - else + } else { disable_mmiotrace(); + } +} + +/* XXX: This is not called for trace_pipe file! */ +void mmio_print_header(struct trace_iterator *iter) +{ + struct trace_seq *s = &iter->seq; + trace_seq_printf(s, "VERSION broken 20070824\n"); + /* TODO: print /proc/bus/pci/devices contents as PCIDEV lines */ +} + +static int mmio_print_rw(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct mmiotrace_rw *rw = &entry->mmiorw; + struct trace_seq *s = &iter->seq; + unsigned long long t = ns2usecs(entry->t); + unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned secs = (unsigned long)t; + int ret = 1; + + switch (entry->mmiorw.opcode) { + case MMIO_READ: + ret = trace_seq_printf(s, + "R %d %lu.%06lu %d 0x%lx 0x%lx 0x%lx %d\n", + rw->width, secs, usec_rem, rw->map_id, rw->phys, + rw->value, rw->pc, entry->pid); + break; + case MMIO_WRITE: + ret = trace_seq_printf(s, + "W %d %lu.%06lu %d 0x%lx 0x%lx 0x%lx %d\n", + rw->width, secs, usec_rem, rw->map_id, rw->phys, + rw->value, rw->pc, entry->pid); + break; + case MMIO_UNKNOWN_OP: + ret = trace_seq_printf(s, + "UNKNOWN %lu.%06lu %d 0x%lx %02x,%02x,%02x 0x%lx %d\n", + secs, usec_rem, rw->map_id, rw->phys, + (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff, + (rw->value >> 0) & 0xff, rw->pc, entry->pid); + break; + default: + ret = trace_seq_printf(s, "rw what?\n"); + break; + } + if (ret) + return 1; + return 0; +} + +static int mmio_print_map(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct mmiotrace_map *m = &entry->mmiomap; + struct trace_seq *s = &iter->seq; + unsigned long long t = ns2usecs(entry->t); + unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned secs = (unsigned long)t; + int ret = 1; + + switch (entry->mmiorw.opcode) { + case MMIO_PROBE: + ret = trace_seq_printf(s, + "MAP %lu.%06lu %d 0x%lx 0x%lx 0x%lx 0x%lx %d\n", + secs, usec_rem, m->map_id, m->phys, m->virt, m->len, + 0UL, entry->pid); + break; + case MMIO_UNPROBE: + ret = trace_seq_printf(s, + "UNMAP %lu.%06lu %d 0x%lx %d\n", + secs, usec_rem, m->map_id, 0UL, entry->pid); + break; + default: + ret = trace_seq_printf(s, "map what?\n"); + break; + } + if (ret) + return 1; + return 0; +} + +/* return 0 to abort printing without consuming current entry in pipe mode */ +static int mmio_print_line(struct trace_iterator *iter) +{ + switch (iter->ent->type) { + case TRACE_MMIO_RW: + return mmio_print_rw(iter); + case TRACE_MMIO_MAP: + return mmio_print_map(iter); + default: + return 1; /* ignore unknown entries */ + } } static struct tracer mmio_tracer __read_mostly = @@ -47,38 +149,31 @@ static struct tracer mmio_tracer __read_mostly = .name = "mmiotrace", .init = mmio_trace_init, .reset = mmio_trace_reset, + .open = mmio_print_header, .ctrl_update = mmio_trace_ctrl_update, + .print_line = mmio_print_line, }; __init static int init_mmio_trace(void) { - int ret = init_mmiotrace(); - if (ret) - return ret; return register_tracer(&mmio_tracer); } device_initcall(init_mmio_trace); -void mmio_trace_record(u32 type, unsigned long addr, unsigned long arg) +void mmio_trace_rw(struct mmiotrace_rw *rw) { struct trace_array *tr = mmio_trace_array; struct trace_array_cpu *data = tr->data[smp_processor_id()]; + __trace_mmiotrace_rw(tr, data, rw); +} - if (!current || current->pid == 0) { - /* - * XXX: This is a problem. We need to able to record, no - * matter what. tracing_generic_entry_update() would crash. - */ - static unsigned limit; - if (limit++ < 12) - pr_err("Error in %s: no current.\n", __func__); - return; - } - if (!tr || !data) { - static unsigned limit; - if (limit++ < 12) - pr_err("%s: no tr or data\n", __func__); - return; - } - __trace_special(tr, data, type, addr, arg); +void mmio_trace_mapping(struct mmiotrace_map *map) +{ + struct trace_array *tr = mmio_trace_array; + struct trace_array_cpu *data; + + preempt_disable(); + data = tr->data[smp_processor_id()]; + __trace_mmiotrace_map(tr, data, map); + preempt_enable(); } -- cgit v1.2.3-70-g09d2 From 138295373ccf7625fcb0218dfea114837983bc39 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:58 +0200 Subject: ftrace: mmiotrace update, #2 another weekend, another patch. This should apply on top of my previous patch from March 23rd. Summary of changes: - Print PCI device list in output header - work around recursive probe hits on SMP - refactor dis/arm_kmmio_fault_page() and add check for page levels - remove un/reference_kmmio(), the die notifier hook is registered permanently into the list - explicitly check for single stepping in die notifier callback I have tested this version on my UP Athlon64 desktop with Nouveau, and SMP Core 2 Duo laptop with the proprietary nvidia driver. Both systems are 64-bit. One previously unknown bug crept into daylight: the ftrace framework's output routines print the first entry last after buffer has wrapped around. The most important regressions compared to non-ftrace mmiotrace at this time are: - failure of trace_pipe file - illegal lines in output file - unaware of losing data due to buffer full Personally I'd like to see these three solved before submitting to mainline. Other issues may come up once we know when we lose events. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/mmiotrace/kmmio.c | 186 ++++++++++++++--------------------- arch/x86/kernel/mmiotrace/mmio-mod.c | 3 - include/linux/mmiotrace.h | 2 - kernel/trace/trace_mmiotrace.c | 47 ++++++++- 4 files changed, 120 insertions(+), 118 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index efb46793308..cd0d95fe4fe 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -5,15 +5,12 @@ * 2008 Pekka Paalanen */ -#include #include #include #include #include #include -#include #include -#include #include #include #include @@ -22,10 +19,9 @@ #include #include #include -#include #include -#include - +#include +#include #include #define KMMIO_PAGE_HASH_BITS 4 @@ -57,14 +53,9 @@ struct kmmio_context { int active; }; -static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, - void *args); - -static DEFINE_MUTEX(kmmio_init_mutex); static DEFINE_SPINLOCK(kmmio_lock); -/* These are protected by kmmio_lock */ -static int kmmio_initialized; +/* Protected by kmmio_lock */ unsigned int kmmio_count; /* Read-protected by RCU, write-protected by kmmio_lock. */ @@ -79,60 +70,6 @@ static struct list_head *kmmio_page_list(unsigned long page) /* Accessed per-cpu */ static DEFINE_PER_CPU(struct kmmio_context, kmmio_ctx); -/* protected by kmmio_init_mutex */ -static struct notifier_block nb_die = { - .notifier_call = kmmio_die_notifier -}; - -/** - * Makes sure kmmio is initialized and usable. - * This must be called before any other kmmio function defined here. - * May sleep. - */ -void reference_kmmio(void) -{ - mutex_lock(&kmmio_init_mutex); - spin_lock_irq(&kmmio_lock); - if (!kmmio_initialized) { - int i; - for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) - INIT_LIST_HEAD(&kmmio_page_table[i]); - if (register_die_notifier(&nb_die)) - BUG(); - } - kmmio_initialized++; - spin_unlock_irq(&kmmio_lock); - mutex_unlock(&kmmio_init_mutex); -} -EXPORT_SYMBOL_GPL(reference_kmmio); - -/** - * Clean up kmmio after use. This must be called for every call to - * reference_kmmio(). All probes registered after the corresponding - * reference_kmmio() must have been unregistered when calling this. - * May sleep. - */ -void unreference_kmmio(void) -{ - bool unreg = false; - - mutex_lock(&kmmio_init_mutex); - spin_lock_irq(&kmmio_lock); - - if (kmmio_initialized == 1) { - BUG_ON(is_kmmio_active()); - unreg = true; - } - kmmio_initialized--; - BUG_ON(kmmio_initialized < 0); - spin_unlock_irq(&kmmio_lock); - - if (unreg) - unregister_die_notifier(&nb_die); /* calls sync_rcu() */ - mutex_unlock(&kmmio_init_mutex); -} -EXPORT_SYMBOL(unreference_kmmio); - /* * this is basically a dynamic stabbing problem: * Could use the existing prio tree code or @@ -167,58 +104,56 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) return NULL; } -/** Mark the given page as not present. Access to it will trigger a fault. */ -static void arm_kmmio_fault_page(unsigned long page, int *page_level) +static void set_page_present(unsigned long addr, bool present, int *pglevel) { - unsigned long address = page & PAGE_MASK; + pteval_t pteval; + pmdval_t pmdval; int level; - pte_t *pte = lookup_address(address, &level); + pmd_t *pmd; + pte_t *pte = lookup_address(addr, &level); if (!pte) { - pr_err("kmmio: Error in %s: no pte for page 0x%08lx\n", - __func__, page); + pr_err("kmmio: no pte for page 0x%08lx\n", addr); return; } - if (level == PG_LEVEL_2M) { - pmd_t *pmd = (pmd_t *)pte; - set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_PRESENT)); - } else { - /* PG_LEVEL_4K */ - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT)); + if (pglevel) + *pglevel = level; + + switch (level) { + case PG_LEVEL_2M: + pmd = (pmd_t *)pte; + pmdval = pmd_val(*pmd) & ~_PAGE_PRESENT; + if (present) + pmdval |= _PAGE_PRESENT; + set_pmd(pmd, __pmd(pmdval)); + break; + + case PG_LEVEL_4K: + pteval = pte_val(*pte) & ~_PAGE_PRESENT; + if (present) + pteval |= _PAGE_PRESENT; + set_pte_atomic(pte, __pte(pteval)); + break; + + default: + pr_err("kmmio: unexpected page level 0x%x.\n", level); + return; } - if (page_level) - *page_level = level; + __flush_tlb_one(addr); +} - __flush_tlb_one(page); +/** Mark the given page as not present. Access to it will trigger a fault. */ +static void arm_kmmio_fault_page(unsigned long page, int *page_level) +{ + set_page_present(page & PAGE_MASK, false, page_level); } /** Mark the given page as present. */ static void disarm_kmmio_fault_page(unsigned long page, int *page_level) { - unsigned long address = page & PAGE_MASK; - int level; - pte_t *pte = lookup_address(address, &level); - - if (!pte) { - pr_err("kmmio: Error in %s: no pte for page 0x%08lx\n", - __func__, page); - return; - } - - if (level == PG_LEVEL_2M) { - pmd_t *pmd = (pmd_t *)pte; - set_pmd(pmd, __pmd(pmd_val(*pmd) | _PAGE_PRESENT)); - } else { - /* PG_LEVEL_4K */ - set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT)); - } - - if (page_level) - *page_level = level; - - __flush_tlb_one(page); + set_page_present(page & PAGE_MASK, true, page_level); } /* @@ -240,6 +175,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) { struct kmmio_context *ctx; struct kmmio_fault_page *faultpage; + int ret = 0; /* default to fault not handled */ /* * Preemption is now disabled to prevent process switch during @@ -257,21 +193,35 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) /* * Either this page fault is not caused by kmmio, or * another CPU just pulled the kmmio probe from under - * our feet. In the latter case all hell breaks loose. + * our feet. The latter case should not be possible. */ goto no_kmmio; } ctx = &get_cpu_var(kmmio_ctx); if (ctx->active) { + disarm_kmmio_fault_page(faultpage->page, NULL); + if (addr == ctx->addr) { + /* + * On SMP we sometimes get recursive probe hits on the + * same address. Context is already saved, fall out. + */ + pr_debug("kmmio: duplicate probe hit on CPU %d, for " + "address 0x%08lx.\n", + smp_processor_id(), addr); + ret = 1; + goto no_kmmio_ctx; + } /* * Prevent overwriting already in-flight context. - * If this page fault really was due to kmmio trap, - * all hell breaks loose. + * This should not happen, let's hope disarming at least + * prevents a panic. */ pr_emerg("kmmio: recursive probe hit on CPU %d, " "for address 0x%08lx. Ignoring.\n", smp_processor_id(), addr); + pr_emerg("kmmio: previous hit was at 0x%08lx.\n", + ctx->addr); goto no_kmmio_ctx; } ctx->active++; @@ -302,14 +252,14 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) */ put_cpu_var(kmmio_ctx); - return 1; + return 1; /* fault handled */ no_kmmio_ctx: put_cpu_var(kmmio_ctx); no_kmmio: rcu_read_unlock(); preempt_enable_no_resched(); - return 0; /* page fault not handled by kmmio */ + return ret; } /* @@ -322,8 +272,11 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) int ret = 0; struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); - if (!ctx->active) + if (!ctx->active) { + pr_debug("kmmio: spurious debug trap on CPU %d.\n", + smp_processor_id()); goto out; + } if (ctx->probe && ctx->probe->post_handler) ctx->probe->post_handler(ctx->probe, condition, regs); @@ -525,9 +478,22 @@ static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, { struct die_args *arg = args; - if (val == DIE_DEBUG) + if (val == DIE_DEBUG && (arg->err & DR_STEP)) if (post_kmmio_handler(arg->err, arg->regs) == 1) return NOTIFY_STOP; return NOTIFY_DONE; } + +static struct notifier_block nb_die = { + .notifier_call = kmmio_die_notifier +}; + +static int __init init_kmmio(void) +{ + int i; + for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) + INIT_LIST_HEAD(&kmmio_page_table[i]); + return register_die_notifier(&nb_die); +} +fs_initcall(init_kmmio); /* should be before device_initcall() */ diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c index 62abc281a51..8256546d49b 100644 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ b/arch/x86/kernel/mmiotrace/mmio-mod.c @@ -415,8 +415,6 @@ void enable_mmiotrace(void) if (is_enabled()) goto out; - reference_kmmio(); - #if 0 /* XXX: tracing does not support text entries */ marker_file = debugfs_create_file("marker", 0660, dir, NULL, &fops_marker); @@ -448,7 +446,6 @@ void disable_mmiotrace(void) spin_unlock_irq(&trace_lock); clear_trace_list(); /* guarantees: no more kmmio callbacks */ - unreference_kmmio(); if (marker_file) { debugfs_remove(marker_file); marker_file = NULL; diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index c88a9c197d2..dd6b64b160f 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -31,8 +31,6 @@ static inline int is_kmmio_active(void) return kmmio_count; } -extern void reference_kmmio(void); -extern void unreference_kmmio(void); extern int register_kmmio_probe(struct kmmio_probe *p); extern void unregister_kmmio_probe(struct kmmio_probe *p); diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 3a12b1ad0c6..361472b5788 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -8,6 +8,7 @@ #include #include +#include #include "trace.h" @@ -53,12 +54,52 @@ static void mmio_trace_ctrl_update(struct trace_array *tr) } } +static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) +{ + int ret = 0; + int i; + resource_size_t start, end; + const struct pci_driver *drv = pci_dev_driver(dev); + + /* XXX: incomplete checks for trace_seq_printf() return value */ + ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x", + dev->bus->number, dev->devfn, + dev->vendor, dev->device, dev->irq); + /* + * XXX: is pci_resource_to_user() appropriate, since we are + * supposed to interpret the __ioremap() phys_addr argument based on + * these printed values? + */ + for (i = 0; i < 7; i++) { + pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); + ret += trace_seq_printf(s, " %llx", + (unsigned long long)(start | + (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); + } + for (i = 0; i < 7; i++) { + pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); + ret += trace_seq_printf(s, " %llx", + dev->resource[i].start < dev->resource[i].end ? + (unsigned long long)(end - start) + 1 : 0); + } + if (drv) + ret += trace_seq_printf(s, " %s\n", drv->name); + else + ret += trace_seq_printf(s, " \n"); + return ret; +} + /* XXX: This is not called for trace_pipe file! */ -void mmio_print_header(struct trace_iterator *iter) +static void mmio_print_header(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; - trace_seq_printf(s, "VERSION broken 20070824\n"); - /* TODO: print /proc/bus/pci/devices contents as PCIDEV lines */ + struct pci_dev *dev = NULL; + + trace_seq_printf(s, "VERSION 20070824\n"); + + for_each_pci_dev(dev) + mmio_print_pcidev(s, dev); + /* XXX: return value? What if header is very long? */ } static int mmio_print_rw(struct trace_iterator *iter) -- cgit v1.2.3-70-g09d2 From 49023168261a7f9a2fd4a1ca1adbfea922556015 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 21:20:58 +0200 Subject: mmiotrace: cleanup Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/mmiotrace/kmmio.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c index cd0d95fe4fe..3ad27b8504a 100644 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ b/arch/x86/kernel/mmiotrace/kmmio.c @@ -228,7 +228,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) ctx->fpage = faultpage; ctx->probe = get_kmmio_probe(addr); - ctx->saved_flags = (regs->flags & (TF_MASK|IF_MASK)); + ctx->saved_flags = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF)); ctx->addr = addr; if (ctx->probe && ctx->probe->pre_handler) @@ -238,8 +238,8 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) * Enable single-stepping and disable interrupts for the faulting * context. Local interrupts must not get enabled during stepping. */ - regs->flags |= TF_MASK; - regs->flags &= ~IF_MASK; + regs->flags |= X86_EFLAGS_TF; + regs->flags &= ~X86_EFLAGS_IF; /* Now we set present bit in PTE and single step. */ disarm_kmmio_fault_page(ctx->fpage->page, NULL); @@ -283,7 +283,7 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) arm_kmmio_fault_page(ctx->fpage->page, NULL); - regs->flags &= ~TF_MASK; + regs->flags &= ~X86_EFLAGS_TF; regs->flags |= ctx->saved_flags; /* These were acquired in kmmio_handler(). */ @@ -297,7 +297,7 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) * will have TF set, in which case, continue the remaining processing * of do_debug, as if this is not a probe hit. */ - if (!(regs->flags & TF_MASK)) + if (!(regs->flags & X86_EFLAGS_TF)) ret = 1; out: put_cpu_var(kmmio_ctx); -- cgit v1.2.3-70-g09d2 From ff3a3e9ba5e4273a8bc10570adab4a390fb90757 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:59 +0200 Subject: x86 mmiotrace: move files into arch/x86/mm/. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/Makefile | 2 - arch/x86/kernel/mmiotrace/Makefile | 4 - arch/x86/kernel/mmiotrace/kmmio.c | 499 ------------------------------ arch/x86/kernel/mmiotrace/mmio-mod.c | 457 --------------------------- arch/x86/kernel/mmiotrace/pf_in.c | 489 ----------------------------- arch/x86/kernel/mmiotrace/pf_in.h | 39 --- arch/x86/kernel/mmiotrace/testmmiotrace.c | 71 ----- arch/x86/mm/Makefile | 5 + arch/x86/mm/kmmio.c | 499 ++++++++++++++++++++++++++++++ arch/x86/mm/mmio-mod.c | 457 +++++++++++++++++++++++++++ arch/x86/mm/pf_in.c | 489 +++++++++++++++++++++++++++++ arch/x86/mm/pf_in.h | 39 +++ arch/x86/mm/testmmiotrace.c | 71 +++++ 13 files changed, 1560 insertions(+), 1561 deletions(-) delete mode 100644 arch/x86/kernel/mmiotrace/Makefile delete mode 100644 arch/x86/kernel/mmiotrace/kmmio.c delete mode 100644 arch/x86/kernel/mmiotrace/mmio-mod.c delete mode 100644 arch/x86/kernel/mmiotrace/pf_in.c delete mode 100644 arch/x86/kernel/mmiotrace/pf_in.h delete mode 100644 arch/x86/kernel/mmiotrace/testmmiotrace.c create mode 100644 arch/x86/mm/kmmio.c create mode 100644 arch/x86/mm/mmio-mod.c create mode 100644 arch/x86/mm/pf_in.c create mode 100644 arch/x86/mm/pf_in.h create mode 100644 arch/x86/mm/testmmiotrace.c (limited to 'arch') diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index a51ac153685..739d49acd2f 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -79,8 +79,6 @@ obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_VM86) += vm86_32.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o -obj-$(CONFIG_MMIOTRACE) += mmiotrace/ - obj-$(CONFIG_HPET_TIMER) += hpet.o obj-$(CONFIG_K8_NB) += k8.o diff --git a/arch/x86/kernel/mmiotrace/Makefile b/arch/x86/kernel/mmiotrace/Makefile deleted file mode 100644 index dbcd8d50fb8..00000000000 --- a/arch/x86/kernel/mmiotrace/Makefile +++ /dev/null @@ -1,4 +0,0 @@ -obj-$(CONFIG_MMIOTRACE_HOOKS) += kmmio.o -obj-$(CONFIG_MMIOTRACE) += mmiotrace.o -mmiotrace-y := pf_in.o mmio-mod.o -obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o diff --git a/arch/x86/kernel/mmiotrace/kmmio.c b/arch/x86/kernel/mmiotrace/kmmio.c deleted file mode 100644 index 3ad27b8504a..00000000000 --- a/arch/x86/kernel/mmiotrace/kmmio.c +++ /dev/null @@ -1,499 +0,0 @@ -/* Support for MMIO probes. - * Benfit many code from kprobes - * (C) 2002 Louis Zhuang . - * 2007 Alexander Eichner - * 2008 Pekka Paalanen - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#define KMMIO_PAGE_HASH_BITS 4 -#define KMMIO_PAGE_TABLE_SIZE (1 << KMMIO_PAGE_HASH_BITS) - -struct kmmio_fault_page { - struct list_head list; - struct kmmio_fault_page *release_next; - unsigned long page; /* location of the fault page */ - - /* - * Number of times this page has been registered as a part - * of a probe. If zero, page is disarmed and this may be freed. - * Used only by writers (RCU). - */ - int count; -}; - -struct kmmio_delayed_release { - struct rcu_head rcu; - struct kmmio_fault_page *release_list; -}; - -struct kmmio_context { - struct kmmio_fault_page *fpage; - struct kmmio_probe *probe; - unsigned long saved_flags; - unsigned long addr; - int active; -}; - -static DEFINE_SPINLOCK(kmmio_lock); - -/* Protected by kmmio_lock */ -unsigned int kmmio_count; - -/* Read-protected by RCU, write-protected by kmmio_lock. */ -static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE]; -static LIST_HEAD(kmmio_probes); - -static struct list_head *kmmio_page_list(unsigned long page) -{ - return &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)]; -} - -/* Accessed per-cpu */ -static DEFINE_PER_CPU(struct kmmio_context, kmmio_ctx); - -/* - * this is basically a dynamic stabbing problem: - * Could use the existing prio tree code or - * Possible better implementations: - * The Interval Skip List: A Data Structure for Finding All Intervals That - * Overlap a Point (might be simple) - * Space Efficient Dynamic Stabbing with Fast Queries - Mikkel Thorup - */ -/* Get the kmmio at this addr (if any). You must be holding RCU read lock. */ -static struct kmmio_probe *get_kmmio_probe(unsigned long addr) -{ - struct kmmio_probe *p; - list_for_each_entry_rcu(p, &kmmio_probes, list) { - if (addr >= p->addr && addr <= (p->addr + p->len)) - return p; - } - return NULL; -} - -/* You must be holding RCU read lock. */ -static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) -{ - struct list_head *head; - struct kmmio_fault_page *p; - - page &= PAGE_MASK; - head = kmmio_page_list(page); - list_for_each_entry_rcu(p, head, list) { - if (p->page == page) - return p; - } - return NULL; -} - -static void set_page_present(unsigned long addr, bool present, int *pglevel) -{ - pteval_t pteval; - pmdval_t pmdval; - int level; - pmd_t *pmd; - pte_t *pte = lookup_address(addr, &level); - - if (!pte) { - pr_err("kmmio: no pte for page 0x%08lx\n", addr); - return; - } - - if (pglevel) - *pglevel = level; - - switch (level) { - case PG_LEVEL_2M: - pmd = (pmd_t *)pte; - pmdval = pmd_val(*pmd) & ~_PAGE_PRESENT; - if (present) - pmdval |= _PAGE_PRESENT; - set_pmd(pmd, __pmd(pmdval)); - break; - - case PG_LEVEL_4K: - pteval = pte_val(*pte) & ~_PAGE_PRESENT; - if (present) - pteval |= _PAGE_PRESENT; - set_pte_atomic(pte, __pte(pteval)); - break; - - default: - pr_err("kmmio: unexpected page level 0x%x.\n", level); - return; - } - - __flush_tlb_one(addr); -} - -/** Mark the given page as not present. Access to it will trigger a fault. */ -static void arm_kmmio_fault_page(unsigned long page, int *page_level) -{ - set_page_present(page & PAGE_MASK, false, page_level); -} - -/** Mark the given page as present. */ -static void disarm_kmmio_fault_page(unsigned long page, int *page_level) -{ - set_page_present(page & PAGE_MASK, true, page_level); -} - -/* - * This is being called from do_page_fault(). - * - * We may be in an interrupt or a critical section. Also prefecthing may - * trigger a page fault. We may be in the middle of process switch. - * We cannot take any locks, because we could be executing especially - * within a kmmio critical section. - * - * Local interrupts are disabled, so preemption cannot happen. - * Do not enable interrupts, do not sleep, and watch out for other CPUs. - */ -/* - * Interrupts are disabled on entry as trap3 is an interrupt gate - * and they remain disabled thorough out this function. - */ -int kmmio_handler(struct pt_regs *regs, unsigned long addr) -{ - struct kmmio_context *ctx; - struct kmmio_fault_page *faultpage; - int ret = 0; /* default to fault not handled */ - - /* - * Preemption is now disabled to prevent process switch during - * single stepping. We can only handle one active kmmio trace - * per cpu, so ensure that we finish it before something else - * gets to run. We also hold the RCU read lock over single - * stepping to avoid looking up the probe and kmmio_fault_page - * again. - */ - preempt_disable(); - rcu_read_lock(); - - faultpage = get_kmmio_fault_page(addr); - if (!faultpage) { - /* - * Either this page fault is not caused by kmmio, or - * another CPU just pulled the kmmio probe from under - * our feet. The latter case should not be possible. - */ - goto no_kmmio; - } - - ctx = &get_cpu_var(kmmio_ctx); - if (ctx->active) { - disarm_kmmio_fault_page(faultpage->page, NULL); - if (addr == ctx->addr) { - /* - * On SMP we sometimes get recursive probe hits on the - * same address. Context is already saved, fall out. - */ - pr_debug("kmmio: duplicate probe hit on CPU %d, for " - "address 0x%08lx.\n", - smp_processor_id(), addr); - ret = 1; - goto no_kmmio_ctx; - } - /* - * Prevent overwriting already in-flight context. - * This should not happen, let's hope disarming at least - * prevents a panic. - */ - pr_emerg("kmmio: recursive probe hit on CPU %d, " - "for address 0x%08lx. Ignoring.\n", - smp_processor_id(), addr); - pr_emerg("kmmio: previous hit was at 0x%08lx.\n", - ctx->addr); - goto no_kmmio_ctx; - } - ctx->active++; - - ctx->fpage = faultpage; - ctx->probe = get_kmmio_probe(addr); - ctx->saved_flags = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF)); - ctx->addr = addr; - - if (ctx->probe && ctx->probe->pre_handler) - ctx->probe->pre_handler(ctx->probe, regs, addr); - - /* - * Enable single-stepping and disable interrupts for the faulting - * context. Local interrupts must not get enabled during stepping. - */ - regs->flags |= X86_EFLAGS_TF; - regs->flags &= ~X86_EFLAGS_IF; - - /* Now we set present bit in PTE and single step. */ - disarm_kmmio_fault_page(ctx->fpage->page, NULL); - - /* - * If another cpu accesses the same page while we are stepping, - * the access will not be caught. It will simply succeed and the - * only downside is we lose the event. If this becomes a problem, - * the user should drop to single cpu before tracing. - */ - - put_cpu_var(kmmio_ctx); - return 1; /* fault handled */ - -no_kmmio_ctx: - put_cpu_var(kmmio_ctx); -no_kmmio: - rcu_read_unlock(); - preempt_enable_no_resched(); - return ret; -} - -/* - * Interrupts are disabled on entry as trap1 is an interrupt gate - * and they remain disabled thorough out this function. - * This must always get called as the pair to kmmio_handler(). - */ -static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) -{ - int ret = 0; - struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); - - if (!ctx->active) { - pr_debug("kmmio: spurious debug trap on CPU %d.\n", - smp_processor_id()); - goto out; - } - - if (ctx->probe && ctx->probe->post_handler) - ctx->probe->post_handler(ctx->probe, condition, regs); - - arm_kmmio_fault_page(ctx->fpage->page, NULL); - - regs->flags &= ~X86_EFLAGS_TF; - regs->flags |= ctx->saved_flags; - - /* These were acquired in kmmio_handler(). */ - ctx->active--; - BUG_ON(ctx->active); - rcu_read_unlock(); - preempt_enable_no_resched(); - - /* - * if somebody else is singlestepping across a probe point, flags - * will have TF set, in which case, continue the remaining processing - * of do_debug, as if this is not a probe hit. - */ - if (!(regs->flags & X86_EFLAGS_TF)) - ret = 1; -out: - put_cpu_var(kmmio_ctx); - return ret; -} - -/* You must be holding kmmio_lock. */ -static int add_kmmio_fault_page(unsigned long page) -{ - struct kmmio_fault_page *f; - - page &= PAGE_MASK; - f = get_kmmio_fault_page(page); - if (f) { - if (!f->count) - arm_kmmio_fault_page(f->page, NULL); - f->count++; - return 0; - } - - f = kmalloc(sizeof(*f), GFP_ATOMIC); - if (!f) - return -1; - - f->count = 1; - f->page = page; - list_add_rcu(&f->list, kmmio_page_list(f->page)); - - arm_kmmio_fault_page(f->page, NULL); - - return 0; -} - -/* You must be holding kmmio_lock. */ -static void release_kmmio_fault_page(unsigned long page, - struct kmmio_fault_page **release_list) -{ - struct kmmio_fault_page *f; - - page &= PAGE_MASK; - f = get_kmmio_fault_page(page); - if (!f) - return; - - f->count--; - BUG_ON(f->count < 0); - if (!f->count) { - disarm_kmmio_fault_page(f->page, NULL); - f->release_next = *release_list; - *release_list = f; - } -} - -int register_kmmio_probe(struct kmmio_probe *p) -{ - unsigned long flags; - int ret = 0; - unsigned long size = 0; - - spin_lock_irqsave(&kmmio_lock, flags); - if (get_kmmio_probe(p->addr)) { - ret = -EEXIST; - goto out; - } - kmmio_count++; - list_add_rcu(&p->list, &kmmio_probes); - while (size < p->len) { - if (add_kmmio_fault_page(p->addr + size)) - pr_err("kmmio: Unable to set page fault.\n"); - size += PAGE_SIZE; - } -out: - spin_unlock_irqrestore(&kmmio_lock, flags); - /* - * XXX: What should I do here? - * Here was a call to global_flush_tlb(), but it does not exist - * anymore. It seems it's not needed after all. - */ - return ret; -} -EXPORT_SYMBOL(register_kmmio_probe); - -static void rcu_free_kmmio_fault_pages(struct rcu_head *head) -{ - struct kmmio_delayed_release *dr = container_of( - head, - struct kmmio_delayed_release, - rcu); - struct kmmio_fault_page *p = dr->release_list; - while (p) { - struct kmmio_fault_page *next = p->release_next; - BUG_ON(p->count); - kfree(p); - p = next; - } - kfree(dr); -} - -static void remove_kmmio_fault_pages(struct rcu_head *head) -{ - struct kmmio_delayed_release *dr = container_of( - head, - struct kmmio_delayed_release, - rcu); - struct kmmio_fault_page *p = dr->release_list; - struct kmmio_fault_page **prevp = &dr->release_list; - unsigned long flags; - spin_lock_irqsave(&kmmio_lock, flags); - while (p) { - if (!p->count) - list_del_rcu(&p->list); - else - *prevp = p->release_next; - prevp = &p->release_next; - p = p->release_next; - } - spin_unlock_irqrestore(&kmmio_lock, flags); - /* This is the real RCU destroy call. */ - call_rcu(&dr->rcu, rcu_free_kmmio_fault_pages); -} - -/* - * Remove a kmmio probe. You have to synchronize_rcu() before you can be - * sure that the callbacks will not be called anymore. Only after that - * you may actually release your struct kmmio_probe. - * - * Unregistering a kmmio fault page has three steps: - * 1. release_kmmio_fault_page() - * Disarm the page, wait a grace period to let all faults finish. - * 2. remove_kmmio_fault_pages() - * Remove the pages from kmmio_page_table. - * 3. rcu_free_kmmio_fault_pages() - * Actally free the kmmio_fault_page structs as with RCU. - */ -void unregister_kmmio_probe(struct kmmio_probe *p) -{ - unsigned long flags; - unsigned long size = 0; - struct kmmio_fault_page *release_list = NULL; - struct kmmio_delayed_release *drelease; - - spin_lock_irqsave(&kmmio_lock, flags); - while (size < p->len) { - release_kmmio_fault_page(p->addr + size, &release_list); - size += PAGE_SIZE; - } - list_del_rcu(&p->list); - kmmio_count--; - spin_unlock_irqrestore(&kmmio_lock, flags); - - drelease = kmalloc(sizeof(*drelease), GFP_ATOMIC); - if (!drelease) { - pr_crit("kmmio: leaking kmmio_fault_page objects.\n"); - return; - } - drelease->release_list = release_list; - - /* - * This is not really RCU here. We have just disarmed a set of - * pages so that they cannot trigger page faults anymore. However, - * we cannot remove the pages from kmmio_page_table, - * because a probe hit might be in flight on another CPU. The - * pages are collected into a list, and they will be removed from - * kmmio_page_table when it is certain that no probe hit related to - * these pages can be in flight. RCU grace period sounds like a - * good choice. - * - * If we removed the pages too early, kmmio page fault handler might - * not find the respective kmmio_fault_page and determine it's not - * a kmmio fault, when it actually is. This would lead to madness. - */ - call_rcu(&drelease->rcu, remove_kmmio_fault_pages); -} -EXPORT_SYMBOL(unregister_kmmio_probe); - -static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, - void *args) -{ - struct die_args *arg = args; - - if (val == DIE_DEBUG && (arg->err & DR_STEP)) - if (post_kmmio_handler(arg->err, arg->regs) == 1) - return NOTIFY_STOP; - - return NOTIFY_DONE; -} - -static struct notifier_block nb_die = { - .notifier_call = kmmio_die_notifier -}; - -static int __init init_kmmio(void) -{ - int i; - for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) - INIT_LIST_HEAD(&kmmio_page_table[i]); - return register_die_notifier(&nb_die); -} -fs_initcall(init_kmmio); /* should be before device_initcall() */ diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c deleted file mode 100644 index 8256546d49b..00000000000 --- a/arch/x86/kernel/mmiotrace/mmio-mod.c +++ /dev/null @@ -1,457 +0,0 @@ -/* - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * Copyright (C) IBM Corporation, 2005 - * Jeff Muizelaar, 2006, 2007 - * Pekka Paalanen, 2008 - * - * Derived from the read-mod example from relay-examples by Tom Zanussi. - */ -#define DEBUG 1 - -#include -#include -#include -#include -#include -#include -#include -#include -#include /* for ISA_START_ADDRESS */ -#include -#include - -#include "pf_in.h" - -#define NAME "mmiotrace: " - -struct trap_reason { - unsigned long addr; - unsigned long ip; - enum reason_type type; - int active_traces; -}; - -struct remap_trace { - struct list_head list; - struct kmmio_probe probe; - unsigned long phys; - unsigned long id; -}; - -/* Accessed per-cpu. */ -static DEFINE_PER_CPU(struct trap_reason, pf_reason); -static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace); - -#if 0 /* XXX: no way gather this info anymore */ -/* Access to this is not per-cpu. */ -static DEFINE_PER_CPU(atomic_t, dropped); -#endif - -static struct dentry *marker_file; - -static DEFINE_MUTEX(mmiotrace_mutex); -static DEFINE_SPINLOCK(trace_lock); -static atomic_t mmiotrace_enabled; -static LIST_HEAD(trace_list); /* struct remap_trace */ - -/* - * Locking in this file: - * - mmiotrace_mutex enforces enable/disable_mmiotrace() critical sections. - * - mmiotrace_enabled may be modified only when holding mmiotrace_mutex - * and trace_lock. - * - Routines depending on is_enabled() must take trace_lock. - * - trace_list users must hold trace_lock. - * - is_enabled() guarantees that mmio_trace_record is allowed. - * - pre/post callbacks assume the effect of is_enabled() being true. - */ - -/* module parameters */ -static unsigned long filter_offset; -static int nommiotrace; -static int ISA_trace; -static int trace_pc; - -module_param(filter_offset, ulong, 0); -module_param(nommiotrace, bool, 0); -module_param(ISA_trace, bool, 0); -module_param(trace_pc, bool, 0); - -MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); -MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); -MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); -MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); - -static bool is_enabled(void) -{ - return atomic_read(&mmiotrace_enabled); -} - -#if 0 /* XXX: needs rewrite */ -/* - * Write callback for the debugfs entry: - * Read a marker and write it to the mmio trace log - */ -static ssize_t write_marker(struct file *file, const char __user *buffer, - size_t count, loff_t *ppos) -{ - char *event = NULL; - struct mm_io_header *headp; - ssize_t len = (count > 65535) ? 65535 : count; - - event = kzalloc(sizeof(*headp) + len, GFP_KERNEL); - if (!event) - return -ENOMEM; - - headp = (struct mm_io_header *)event; - headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT); - headp->data_len = len; - - if (copy_from_user(event + sizeof(*headp), buffer, len)) { - kfree(event); - return -EFAULT; - } - - spin_lock_irq(&trace_lock); -#if 0 /* XXX: convert this to use tracing */ - if (is_enabled()) - relay_write(chan, event, sizeof(*headp) + len); - else -#endif - len = -EINVAL; - spin_unlock_irq(&trace_lock); - kfree(event); - return len; -} -#endif - -static void print_pte(unsigned long address) -{ - int level; - pte_t *pte = lookup_address(address, &level); - - if (!pte) { - pr_err(NAME "Error in %s: no pte for page 0x%08lx\n", - __func__, address); - return; - } - - if (level == PG_LEVEL_2M) { - pr_emerg(NAME "4MB pages are not currently supported: " - "0x%08lx\n", address); - BUG(); - } - pr_info(NAME "pte for 0x%lx: 0x%lx 0x%lx\n", address, pte_val(*pte), - pte_val(*pte) & _PAGE_PRESENT); -} - -/* - * For some reason the pre/post pairs have been called in an - * unmatched order. Report and die. - */ -static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) -{ - const struct trap_reason *my_reason = &get_cpu_var(pf_reason); - pr_emerg(NAME "unexpected fault for address: 0x%08lx, " - "last fault for address: 0x%08lx\n", - addr, my_reason->addr); - print_pte(addr); - print_symbol(KERN_EMERG "faulting IP is at %s\n", regs->ip); - print_symbol(KERN_EMERG "last faulting IP was at %s\n", my_reason->ip); -#ifdef __i386__ - pr_emerg("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", - regs->ax, regs->bx, regs->cx, regs->dx); - pr_emerg("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", - regs->si, regs->di, regs->bp, regs->sp); -#else - pr_emerg("rax: %016lx rcx: %016lx rdx: %016lx\n", - regs->ax, regs->cx, regs->dx); - pr_emerg("rsi: %016lx rdi: %016lx rbp: %016lx rsp: %016lx\n", - regs->si, regs->di, regs->bp, regs->sp); -#endif - put_cpu_var(pf_reason); - BUG(); -} - -static void pre(struct kmmio_probe *p, struct pt_regs *regs, - unsigned long addr) -{ - struct trap_reason *my_reason = &get_cpu_var(pf_reason); - struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); - const unsigned long instptr = instruction_pointer(regs); - const enum reason_type type = get_ins_type(instptr); - struct remap_trace *trace = p->user_data; - - /* it doesn't make sense to have more than one active trace per cpu */ - if (my_reason->active_traces) - die_kmmio_nesting_error(regs, addr); - else - my_reason->active_traces++; - - my_reason->type = type; - my_reason->addr = addr; - my_reason->ip = instptr; - - my_trace->phys = addr - trace->probe.addr + trace->phys; - my_trace->map_id = trace->id; - - /* - * Only record the program counter when requested. - * It may taint clean-room reverse engineering. - */ - if (trace_pc) - my_trace->pc = instptr; - else - my_trace->pc = 0; - - /* - * XXX: the timestamp recorded will be *after* the tracing has been - * done, not at the time we hit the instruction. SMP implications - * on event ordering? - */ - - switch (type) { - case REG_READ: - my_trace->opcode = MMIO_READ; - my_trace->width = get_ins_mem_width(instptr); - break; - case REG_WRITE: - my_trace->opcode = MMIO_WRITE; - my_trace->width = get_ins_mem_width(instptr); - my_trace->value = get_ins_reg_val(instptr, regs); - break; - case IMM_WRITE: - my_trace->opcode = MMIO_WRITE; - my_trace->width = get_ins_mem_width(instptr); - my_trace->value = get_ins_imm_val(instptr); - break; - default: - { - unsigned char *ip = (unsigned char *)instptr; - my_trace->opcode = MMIO_UNKNOWN_OP; - my_trace->width = 0; - my_trace->value = (*ip) << 16 | *(ip + 1) << 8 | - *(ip + 2); - } - } - put_cpu_var(cpu_trace); - put_cpu_var(pf_reason); -} - -static void post(struct kmmio_probe *p, unsigned long condition, - struct pt_regs *regs) -{ - struct trap_reason *my_reason = &get_cpu_var(pf_reason); - struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); - - /* this should always return the active_trace count to 0 */ - my_reason->active_traces--; - if (my_reason->active_traces) { - pr_emerg(NAME "unexpected post handler"); - BUG(); - } - - switch (my_reason->type) { - case REG_READ: - my_trace->value = get_ins_reg_val(my_reason->ip, regs); - break; - default: - break; - } - - mmio_trace_rw(my_trace); - put_cpu_var(cpu_trace); - put_cpu_var(pf_reason); -} - -static void ioremap_trace_core(unsigned long offset, unsigned long size, - void __iomem *addr) -{ - static atomic_t next_id; - struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); - struct mmiotrace_map map = { - .phys = offset, - .virt = (unsigned long)addr, - .len = size, - .opcode = MMIO_PROBE - }; - - if (!trace) { - pr_err(NAME "kmalloc failed in ioremap\n"); - return; - } - - *trace = (struct remap_trace) { - .probe = { - .addr = (unsigned long)addr, - .len = size, - .pre_handler = pre, - .post_handler = post, - .user_data = trace - }, - .phys = offset, - .id = atomic_inc_return(&next_id) - }; - map.map_id = trace->id; - - spin_lock_irq(&trace_lock); - if (!is_enabled()) - goto not_enabled; - - mmio_trace_mapping(&map); - list_add_tail(&trace->list, &trace_list); - if (!nommiotrace) - register_kmmio_probe(&trace->probe); - -not_enabled: - spin_unlock_irq(&trace_lock); -} - -void -mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) -{ - if (!is_enabled()) /* recheck and proper locking in *_core() */ - return; - - pr_debug(NAME "ioremap_*(0x%lx, 0x%lx) = %p\n", offset, size, addr); - if ((filter_offset) && (offset != filter_offset)) - return; - ioremap_trace_core(offset, size, addr); -} - -static void iounmap_trace_core(volatile void __iomem *addr) -{ - struct mmiotrace_map map = { - .phys = 0, - .virt = (unsigned long)addr, - .len = 0, - .opcode = MMIO_UNPROBE - }; - struct remap_trace *trace; - struct remap_trace *tmp; - struct remap_trace *found_trace = NULL; - - pr_debug(NAME "Unmapping %p.\n", addr); - - spin_lock_irq(&trace_lock); - if (!is_enabled()) - goto not_enabled; - - list_for_each_entry_safe(trace, tmp, &trace_list, list) { - if ((unsigned long)addr == trace->probe.addr) { - if (!nommiotrace) - unregister_kmmio_probe(&trace->probe); - list_del(&trace->list); - found_trace = trace; - break; - } - } - map.map_id = (found_trace) ? found_trace->id : -1; - mmio_trace_mapping(&map); - -not_enabled: - spin_unlock_irq(&trace_lock); - if (found_trace) { - synchronize_rcu(); /* unregister_kmmio_probe() requirement */ - kfree(found_trace); - } -} - -void mmiotrace_iounmap(volatile void __iomem *addr) -{ - might_sleep(); - if (is_enabled()) /* recheck and proper locking in *_core() */ - iounmap_trace_core(addr); -} - -static void clear_trace_list(void) -{ - struct remap_trace *trace; - struct remap_trace *tmp; - - /* - * No locking required, because the caller ensures we are in a - * critical section via mutex, and is_enabled() is false, - * i.e. nothing can traverse or modify this list. - * Caller also ensures is_enabled() cannot change. - */ - list_for_each_entry(trace, &trace_list, list) { - pr_notice(NAME "purging non-iounmapped " - "trace @0x%08lx, size 0x%lx.\n", - trace->probe.addr, trace->probe.len); - if (!nommiotrace) - unregister_kmmio_probe(&trace->probe); - } - synchronize_rcu(); /* unregister_kmmio_probe() requirement */ - - list_for_each_entry_safe(trace, tmp, &trace_list, list) { - list_del(&trace->list); - kfree(trace); - } -} - -#if 0 /* XXX: out of order */ -static struct file_operations fops_marker = { - .owner = THIS_MODULE, - .write = write_marker -}; -#endif - -void enable_mmiotrace(void) -{ - mutex_lock(&mmiotrace_mutex); - if (is_enabled()) - goto out; - -#if 0 /* XXX: tracing does not support text entries */ - marker_file = debugfs_create_file("marker", 0660, dir, NULL, - &fops_marker); - if (!marker_file) - pr_err(NAME "marker file creation failed.\n"); -#endif - - if (nommiotrace) - pr_info(NAME "MMIO tracing disabled.\n"); - if (ISA_trace) - pr_warning(NAME "Warning! low ISA range will be traced.\n"); - spin_lock_irq(&trace_lock); - atomic_inc(&mmiotrace_enabled); - spin_unlock_irq(&trace_lock); - pr_info(NAME "enabled.\n"); -out: - mutex_unlock(&mmiotrace_mutex); -} - -void disable_mmiotrace(void) -{ - mutex_lock(&mmiotrace_mutex); - if (!is_enabled()) - goto out; - - spin_lock_irq(&trace_lock); - atomic_dec(&mmiotrace_enabled); - BUG_ON(is_enabled()); - spin_unlock_irq(&trace_lock); - - clear_trace_list(); /* guarantees: no more kmmio callbacks */ - if (marker_file) { - debugfs_remove(marker_file); - marker_file = NULL; - } - - pr_info(NAME "disabled.\n"); -out: - mutex_unlock(&mmiotrace_mutex); -} diff --git a/arch/x86/kernel/mmiotrace/pf_in.c b/arch/x86/kernel/mmiotrace/pf_in.c deleted file mode 100644 index efa1911e20c..00000000000 --- a/arch/x86/kernel/mmiotrace/pf_in.c +++ /dev/null @@ -1,489 +0,0 @@ -/* - * Fault Injection Test harness (FI) - * Copyright (C) Intel Crop. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, - * USA. - * - */ - -/* Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp - * Copyright by Intel Crop., 2002 - * Louis Zhuang (louis.zhuang@intel.com) - * - * Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007 - */ - -#include -#include /* struct pt_regs */ -#include "pf_in.h" - -#ifdef __i386__ -/* IA32 Manual 3, 2-1 */ -static unsigned char prefix_codes[] = { - 0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64, - 0x65, 0x2E, 0x3E, 0x66, 0x67 -}; -/* IA32 Manual 3, 3-432*/ -static unsigned int reg_rop[] = { - 0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F -}; -static unsigned int reg_wop[] = { 0x88, 0x89 }; -static unsigned int imm_wop[] = { 0xC6, 0xC7 }; -/* IA32 Manual 3, 3-432*/ -static unsigned int rw8[] = { 0x88, 0x8A, 0xC6 }; -static unsigned int rw32[] = { - 0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F -}; -static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F }; -static unsigned int mw16[] = { 0xB70F, 0xBF0F }; -static unsigned int mw32[] = { 0x89, 0x8B, 0xC7 }; -static unsigned int mw64[] = {}; -#else /* not __i386__ */ -static unsigned char prefix_codes[] = { - 0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36, - 0xF0, 0xF3, 0xF2, - /* REX Prefixes */ - 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, - 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f -}; -/* AMD64 Manual 3, Appendix A*/ -static unsigned int reg_rop[] = { - 0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F -}; -static unsigned int reg_wop[] = { 0x88, 0x89 }; -static unsigned int imm_wop[] = { 0xC6, 0xC7 }; -static unsigned int rw8[] = { 0xC6, 0x88, 0x8A }; -static unsigned int rw32[] = { - 0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F -}; -/* 8 bit only */ -static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F }; -/* 16 bit only */ -static unsigned int mw16[] = { 0xB70F, 0xBF0F }; -/* 16 or 32 bit */ -static unsigned int mw32[] = { 0xC7 }; -/* 16, 32 or 64 bit */ -static unsigned int mw64[] = { 0x89, 0x8B }; -#endif /* not __i386__ */ - -static int skip_prefix(unsigned char *addr, int *shorted, int *enlarged, - int *rexr) -{ - int i; - unsigned char *p = addr; - *shorted = 0; - *enlarged = 0; - *rexr = 0; - -restart: - for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) { - if (*p == prefix_codes[i]) { - if (*p == 0x66) - *shorted = 1; -#ifdef __amd64__ - if ((*p & 0xf8) == 0x48) - *enlarged = 1; - if ((*p & 0xf4) == 0x44) - *rexr = 1; -#endif - p++; - goto restart; - } - } - - return (p - addr); -} - -static int get_opcode(unsigned char *addr, unsigned int *opcode) -{ - int len; - - if (*addr == 0x0F) { - /* 0x0F is extension instruction */ - *opcode = *(unsigned short *)addr; - len = 2; - } else { - *opcode = *addr; - len = 1; - } - - return len; -} - -#define CHECK_OP_TYPE(opcode, array, type) \ - for (i = 0; i < ARRAY_SIZE(array); i++) { \ - if (array[i] == opcode) { \ - rv = type; \ - goto exit; \ - } \ - } - -enum reason_type get_ins_type(unsigned long ins_addr) -{ - unsigned int opcode; - unsigned char *p; - int shorted, enlarged, rexr; - int i; - enum reason_type rv = OTHERS; - - p = (unsigned char *)ins_addr; - p += skip_prefix(p, &shorted, &enlarged, &rexr); - p += get_opcode(p, &opcode); - - CHECK_OP_TYPE(opcode, reg_rop, REG_READ); - CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE); - CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE); - -exit: - return rv; -} -#undef CHECK_OP_TYPE - -static unsigned int get_ins_reg_width(unsigned long ins_addr) -{ - unsigned int opcode; - unsigned char *p; - int i, shorted, enlarged, rexr; - - p = (unsigned char *)ins_addr; - p += skip_prefix(p, &shorted, &enlarged, &rexr); - p += get_opcode(p, &opcode); - - for (i = 0; i < ARRAY_SIZE(rw8); i++) - if (rw8[i] == opcode) - return 1; - - for (i = 0; i < ARRAY_SIZE(rw32); i++) - if (rw32[i] == opcode) - return (shorted ? 2 : (enlarged ? 8 : 4)); - - printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode); - return 0; -} - -unsigned int get_ins_mem_width(unsigned long ins_addr) -{ - unsigned int opcode; - unsigned char *p; - int i, shorted, enlarged, rexr; - - p = (unsigned char *)ins_addr; - p += skip_prefix(p, &shorted, &enlarged, &rexr); - p += get_opcode(p, &opcode); - - for (i = 0; i < ARRAY_SIZE(mw8); i++) - if (mw8[i] == opcode) - return 1; - - for (i = 0; i < ARRAY_SIZE(mw16); i++) - if (mw16[i] == opcode) - return 2; - - for (i = 0; i < ARRAY_SIZE(mw32); i++) - if (mw32[i] == opcode) - return shorted ? 2 : 4; - - for (i = 0; i < ARRAY_SIZE(mw64); i++) - if (mw64[i] == opcode) - return shorted ? 2 : (enlarged ? 8 : 4); - - printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode); - return 0; -} - -/* - * Define register ident in mod/rm byte. - * Note: these are NOT the same as in ptrace-abi.h. - */ -enum { - arg_AL = 0, - arg_CL = 1, - arg_DL = 2, - arg_BL = 3, - arg_AH = 4, - arg_CH = 5, - arg_DH = 6, - arg_BH = 7, - - arg_AX = 0, - arg_CX = 1, - arg_DX = 2, - arg_BX = 3, - arg_SP = 4, - arg_BP = 5, - arg_SI = 6, - arg_DI = 7, -#ifdef __amd64__ - arg_R8 = 8, - arg_R9 = 9, - arg_R10 = 10, - arg_R11 = 11, - arg_R12 = 12, - arg_R13 = 13, - arg_R14 = 14, - arg_R15 = 15 -#endif -}; - -static unsigned char *get_reg_w8(int no, struct pt_regs *regs) -{ - unsigned char *rv = NULL; - - switch (no) { - case arg_AL: - rv = (unsigned char *)®s->ax; - break; - case arg_BL: - rv = (unsigned char *)®s->bx; - break; - case arg_CL: - rv = (unsigned char *)®s->cx; - break; - case arg_DL: - rv = (unsigned char *)®s->dx; - break; - case arg_AH: - rv = 1 + (unsigned char *)®s->ax; - break; - case arg_BH: - rv = 1 + (unsigned char *)®s->bx; - break; - case arg_CH: - rv = 1 + (unsigned char *)®s->cx; - break; - case arg_DH: - rv = 1 + (unsigned char *)®s->dx; - break; -#ifdef __amd64__ - case arg_R8: - rv = (unsigned char *)®s->r8; - break; - case arg_R9: - rv = (unsigned char *)®s->r9; - break; - case arg_R10: - rv = (unsigned char *)®s->r10; - break; - case arg_R11: - rv = (unsigned char *)®s->r11; - break; - case arg_R12: - rv = (unsigned char *)®s->r12; - break; - case arg_R13: - rv = (unsigned char *)®s->r13; - break; - case arg_R14: - rv = (unsigned char *)®s->r14; - break; - case arg_R15: - rv = (unsigned char *)®s->r15; - break; -#endif - default: - printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no); - break; - } - return rv; -} - -static unsigned long *get_reg_w32(int no, struct pt_regs *regs) -{ - unsigned long *rv = NULL; - - switch (no) { - case arg_AX: - rv = ®s->ax; - break; - case arg_BX: - rv = ®s->bx; - break; - case arg_CX: - rv = ®s->cx; - break; - case arg_DX: - rv = ®s->dx; - break; - case arg_SP: - rv = ®s->sp; - break; - case arg_BP: - rv = ®s->bp; - break; - case arg_SI: - rv = ®s->si; - break; - case arg_DI: - rv = ®s->di; - break; -#ifdef __amd64__ - case arg_R8: - rv = ®s->r8; - break; - case arg_R9: - rv = ®s->r9; - break; - case arg_R10: - rv = ®s->r10; - break; - case arg_R11: - rv = ®s->r11; - break; - case arg_R12: - rv = ®s->r12; - break; - case arg_R13: - rv = ®s->r13; - break; - case arg_R14: - rv = ®s->r14; - break; - case arg_R15: - rv = ®s->r15; - break; -#endif - default: - printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no); - } - - return rv; -} - -unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs) -{ - unsigned int opcode; - unsigned char mod_rm; - int reg; - unsigned char *p; - int i, shorted, enlarged, rexr; - unsigned long rv; - - p = (unsigned char *)ins_addr; - p += skip_prefix(p, &shorted, &enlarged, &rexr); - p += get_opcode(p, &opcode); - for (i = 0; i < ARRAY_SIZE(reg_rop); i++) - if (reg_rop[i] == opcode) { - rv = REG_READ; - goto do_work; - } - - for (i = 0; i < ARRAY_SIZE(reg_wop); i++) - if (reg_wop[i] == opcode) { - rv = REG_WRITE; - goto do_work; - } - - printk(KERN_ERR "mmiotrace: Not a register instruction, opcode " - "0x%02x\n", opcode); - goto err; - -do_work: - mod_rm = *p; - reg = ((mod_rm >> 3) & 0x7) | (rexr << 3); - switch (get_ins_reg_width(ins_addr)) { - case 1: - return *get_reg_w8(reg, regs); - - case 2: - return *(unsigned short *)get_reg_w32(reg, regs); - - case 4: - return *(unsigned int *)get_reg_w32(reg, regs); - -#ifdef __amd64__ - case 8: - return *(unsigned long *)get_reg_w32(reg, regs); -#endif - - default: - printk(KERN_ERR "mmiotrace: Error width# %d\n", reg); - } - -err: - return 0; -} - -unsigned long get_ins_imm_val(unsigned long ins_addr) -{ - unsigned int opcode; - unsigned char mod_rm; - unsigned char mod; - unsigned char *p; - int i, shorted, enlarged, rexr; - unsigned long rv; - - p = (unsigned char *)ins_addr; - p += skip_prefix(p, &shorted, &enlarged, &rexr); - p += get_opcode(p, &opcode); - for (i = 0; i < ARRAY_SIZE(imm_wop); i++) - if (imm_wop[i] == opcode) { - rv = IMM_WRITE; - goto do_work; - } - - printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode " - "0x%02x\n", opcode); - goto err; - -do_work: - mod_rm = *p; - mod = mod_rm >> 6; - p++; - switch (mod) { - case 0: - /* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2) */ - /* AMD64: XXX Check for address size prefix? */ - if ((mod_rm & 0x7) == 0x5) - p += 4; - break; - - case 1: - p += 1; - break; - - case 2: - p += 4; - break; - - case 3: - default: - printk(KERN_ERR "mmiotrace: not a memory access instruction " - "at 0x%lx, rm_mod=0x%02x\n", - ins_addr, mod_rm); - } - - switch (get_ins_reg_width(ins_addr)) { - case 1: - return *(unsigned char *)p; - - case 2: - return *(unsigned short *)p; - - case 4: - return *(unsigned int *)p; - -#ifdef __amd64__ - case 8: - return *(unsigned long *)p; -#endif - - default: - printk(KERN_ERR "mmiotrace: Error: width.\n"); - } - -err: - return 0; -} diff --git a/arch/x86/kernel/mmiotrace/pf_in.h b/arch/x86/kernel/mmiotrace/pf_in.h deleted file mode 100644 index e05341a51a2..00000000000 --- a/arch/x86/kernel/mmiotrace/pf_in.h +++ /dev/null @@ -1,39 +0,0 @@ -/* - * Fault Injection Test harness (FI) - * Copyright (C) Intel Crop. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version 2 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, - * USA. - * - */ - -#ifndef __PF_H_ -#define __PF_H_ - -enum reason_type { - NOT_ME, /* page fault is not in regions */ - NOTHING, /* access others point in regions */ - REG_READ, /* read from addr to reg */ - REG_WRITE, /* write from reg to addr */ - IMM_WRITE, /* write from imm to addr */ - OTHERS /* Other instructions can not intercept */ -}; - -enum reason_type get_ins_type(unsigned long ins_addr); -unsigned int get_ins_mem_width(unsigned long ins_addr); -unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs); -unsigned long get_ins_imm_val(unsigned long ins_addr); - -#endif /* __PF_H_ */ diff --git a/arch/x86/kernel/mmiotrace/testmmiotrace.c b/arch/x86/kernel/mmiotrace/testmmiotrace.c deleted file mode 100644 index cfa60b227c8..00000000000 --- a/arch/x86/kernel/mmiotrace/testmmiotrace.c +++ /dev/null @@ -1,71 +0,0 @@ -/* - * Written by Pekka Paalanen, 2008 - */ -#include -#include - -#define MODULE_NAME "testmmiotrace" - -static unsigned long mmio_address; -module_param(mmio_address, ulong, 0); -MODULE_PARM_DESC(mmio_address, "Start address of the mapping of 16 kB."); - -static void do_write_test(void __iomem *p) -{ - unsigned int i; - for (i = 0; i < 256; i++) - iowrite8(i, p + i); - for (i = 1024; i < (5 * 1024); i += 2) - iowrite16(i * 12 + 7, p + i); - for (i = (5 * 1024); i < (16 * 1024); i += 4) - iowrite32(i * 212371 + 13, p + i); -} - -static void do_read_test(void __iomem *p) -{ - unsigned int i; - for (i = 0; i < 256; i++) - ioread8(p + i); - for (i = 1024; i < (5 * 1024); i += 2) - ioread16(p + i); - for (i = (5 * 1024); i < (16 * 1024); i += 4) - ioread32(p + i); -} - -static void do_test(void) -{ - void __iomem *p = ioremap_nocache(mmio_address, 0x4000); - if (!p) { - pr_err(MODULE_NAME ": could not ioremap, aborting.\n"); - return; - } - do_write_test(p); - do_read_test(p); - iounmap(p); -} - -static int __init init(void) -{ - if (mmio_address == 0) { - pr_err(MODULE_NAME ": you have to use the module argument " - "mmio_address.\n"); - pr_err(MODULE_NAME ": DO NOT LOAD THIS MODULE UNLESS" - " YOU REALLY KNOW WHAT YOU ARE DOING!\n"); - return -ENXIO; - } - - pr_warning(MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx " - "in PCI address space, and writing " - "rubbish in there.\n", mmio_address); - do_test(); - return 0; -} - -static void __exit cleanup(void) -{ - pr_debug(MODULE_NAME ": unloaded.\n"); -} - -module_init(init); -module_exit(cleanup); -MODULE_LICENSE("GPL"); diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index b7b3e4c7cfc..07dab503c9e 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -8,6 +8,11 @@ obj-$(CONFIG_X86_PTDUMP) += dump_pagetables.o obj-$(CONFIG_HIGHMEM) += highmem_32.o +obj-$(CONFIG_MMIOTRACE_HOOKS) += kmmio.o +obj-$(CONFIG_MMIOTRACE) += mmiotrace.o +mmiotrace-y := pf_in.o mmio-mod.o +obj-$(CONFIG_MMIOTRACE_TEST) += testmmiotrace.o + ifeq ($(CONFIG_X86_32),y) obj-$(CONFIG_NUMA) += discontig_32.o else diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c new file mode 100644 index 00000000000..3ad27b8504a --- /dev/null +++ b/arch/x86/mm/kmmio.c @@ -0,0 +1,499 @@ +/* Support for MMIO probes. + * Benfit many code from kprobes + * (C) 2002 Louis Zhuang . + * 2007 Alexander Eichner + * 2008 Pekka Paalanen + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define KMMIO_PAGE_HASH_BITS 4 +#define KMMIO_PAGE_TABLE_SIZE (1 << KMMIO_PAGE_HASH_BITS) + +struct kmmio_fault_page { + struct list_head list; + struct kmmio_fault_page *release_next; + unsigned long page; /* location of the fault page */ + + /* + * Number of times this page has been registered as a part + * of a probe. If zero, page is disarmed and this may be freed. + * Used only by writers (RCU). + */ + int count; +}; + +struct kmmio_delayed_release { + struct rcu_head rcu; + struct kmmio_fault_page *release_list; +}; + +struct kmmio_context { + struct kmmio_fault_page *fpage; + struct kmmio_probe *probe; + unsigned long saved_flags; + unsigned long addr; + int active; +}; + +static DEFINE_SPINLOCK(kmmio_lock); + +/* Protected by kmmio_lock */ +unsigned int kmmio_count; + +/* Read-protected by RCU, write-protected by kmmio_lock. */ +static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE]; +static LIST_HEAD(kmmio_probes); + +static struct list_head *kmmio_page_list(unsigned long page) +{ + return &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)]; +} + +/* Accessed per-cpu */ +static DEFINE_PER_CPU(struct kmmio_context, kmmio_ctx); + +/* + * this is basically a dynamic stabbing problem: + * Could use the existing prio tree code or + * Possible better implementations: + * The Interval Skip List: A Data Structure for Finding All Intervals That + * Overlap a Point (might be simple) + * Space Efficient Dynamic Stabbing with Fast Queries - Mikkel Thorup + */ +/* Get the kmmio at this addr (if any). You must be holding RCU read lock. */ +static struct kmmio_probe *get_kmmio_probe(unsigned long addr) +{ + struct kmmio_probe *p; + list_for_each_entry_rcu(p, &kmmio_probes, list) { + if (addr >= p->addr && addr <= (p->addr + p->len)) + return p; + } + return NULL; +} + +/* You must be holding RCU read lock. */ +static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) +{ + struct list_head *head; + struct kmmio_fault_page *p; + + page &= PAGE_MASK; + head = kmmio_page_list(page); + list_for_each_entry_rcu(p, head, list) { + if (p->page == page) + return p; + } + return NULL; +} + +static void set_page_present(unsigned long addr, bool present, int *pglevel) +{ + pteval_t pteval; + pmdval_t pmdval; + int level; + pmd_t *pmd; + pte_t *pte = lookup_address(addr, &level); + + if (!pte) { + pr_err("kmmio: no pte for page 0x%08lx\n", addr); + return; + } + + if (pglevel) + *pglevel = level; + + switch (level) { + case PG_LEVEL_2M: + pmd = (pmd_t *)pte; + pmdval = pmd_val(*pmd) & ~_PAGE_PRESENT; + if (present) + pmdval |= _PAGE_PRESENT; + set_pmd(pmd, __pmd(pmdval)); + break; + + case PG_LEVEL_4K: + pteval = pte_val(*pte) & ~_PAGE_PRESENT; + if (present) + pteval |= _PAGE_PRESENT; + set_pte_atomic(pte, __pte(pteval)); + break; + + default: + pr_err("kmmio: unexpected page level 0x%x.\n", level); + return; + } + + __flush_tlb_one(addr); +} + +/** Mark the given page as not present. Access to it will trigger a fault. */ +static void arm_kmmio_fault_page(unsigned long page, int *page_level) +{ + set_page_present(page & PAGE_MASK, false, page_level); +} + +/** Mark the given page as present. */ +static void disarm_kmmio_fault_page(unsigned long page, int *page_level) +{ + set_page_present(page & PAGE_MASK, true, page_level); +} + +/* + * This is being called from do_page_fault(). + * + * We may be in an interrupt or a critical section. Also prefecthing may + * trigger a page fault. We may be in the middle of process switch. + * We cannot take any locks, because we could be executing especially + * within a kmmio critical section. + * + * Local interrupts are disabled, so preemption cannot happen. + * Do not enable interrupts, do not sleep, and watch out for other CPUs. + */ +/* + * Interrupts are disabled on entry as trap3 is an interrupt gate + * and they remain disabled thorough out this function. + */ +int kmmio_handler(struct pt_regs *regs, unsigned long addr) +{ + struct kmmio_context *ctx; + struct kmmio_fault_page *faultpage; + int ret = 0; /* default to fault not handled */ + + /* + * Preemption is now disabled to prevent process switch during + * single stepping. We can only handle one active kmmio trace + * per cpu, so ensure that we finish it before something else + * gets to run. We also hold the RCU read lock over single + * stepping to avoid looking up the probe and kmmio_fault_page + * again. + */ + preempt_disable(); + rcu_read_lock(); + + faultpage = get_kmmio_fault_page(addr); + if (!faultpage) { + /* + * Either this page fault is not caused by kmmio, or + * another CPU just pulled the kmmio probe from under + * our feet. The latter case should not be possible. + */ + goto no_kmmio; + } + + ctx = &get_cpu_var(kmmio_ctx); + if (ctx->active) { + disarm_kmmio_fault_page(faultpage->page, NULL); + if (addr == ctx->addr) { + /* + * On SMP we sometimes get recursive probe hits on the + * same address. Context is already saved, fall out. + */ + pr_debug("kmmio: duplicate probe hit on CPU %d, for " + "address 0x%08lx.\n", + smp_processor_id(), addr); + ret = 1; + goto no_kmmio_ctx; + } + /* + * Prevent overwriting already in-flight context. + * This should not happen, let's hope disarming at least + * prevents a panic. + */ + pr_emerg("kmmio: recursive probe hit on CPU %d, " + "for address 0x%08lx. Ignoring.\n", + smp_processor_id(), addr); + pr_emerg("kmmio: previous hit was at 0x%08lx.\n", + ctx->addr); + goto no_kmmio_ctx; + } + ctx->active++; + + ctx->fpage = faultpage; + ctx->probe = get_kmmio_probe(addr); + ctx->saved_flags = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF)); + ctx->addr = addr; + + if (ctx->probe && ctx->probe->pre_handler) + ctx->probe->pre_handler(ctx->probe, regs, addr); + + /* + * Enable single-stepping and disable interrupts for the faulting + * context. Local interrupts must not get enabled during stepping. + */ + regs->flags |= X86_EFLAGS_TF; + regs->flags &= ~X86_EFLAGS_IF; + + /* Now we set present bit in PTE and single step. */ + disarm_kmmio_fault_page(ctx->fpage->page, NULL); + + /* + * If another cpu accesses the same page while we are stepping, + * the access will not be caught. It will simply succeed and the + * only downside is we lose the event. If this becomes a problem, + * the user should drop to single cpu before tracing. + */ + + put_cpu_var(kmmio_ctx); + return 1; /* fault handled */ + +no_kmmio_ctx: + put_cpu_var(kmmio_ctx); +no_kmmio: + rcu_read_unlock(); + preempt_enable_no_resched(); + return ret; +} + +/* + * Interrupts are disabled on entry as trap1 is an interrupt gate + * and they remain disabled thorough out this function. + * This must always get called as the pair to kmmio_handler(). + */ +static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) +{ + int ret = 0; + struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); + + if (!ctx->active) { + pr_debug("kmmio: spurious debug trap on CPU %d.\n", + smp_processor_id()); + goto out; + } + + if (ctx->probe && ctx->probe->post_handler) + ctx->probe->post_handler(ctx->probe, condition, regs); + + arm_kmmio_fault_page(ctx->fpage->page, NULL); + + regs->flags &= ~X86_EFLAGS_TF; + regs->flags |= ctx->saved_flags; + + /* These were acquired in kmmio_handler(). */ + ctx->active--; + BUG_ON(ctx->active); + rcu_read_unlock(); + preempt_enable_no_resched(); + + /* + * if somebody else is singlestepping across a probe point, flags + * will have TF set, in which case, continue the remaining processing + * of do_debug, as if this is not a probe hit. + */ + if (!(regs->flags & X86_EFLAGS_TF)) + ret = 1; +out: + put_cpu_var(kmmio_ctx); + return ret; +} + +/* You must be holding kmmio_lock. */ +static int add_kmmio_fault_page(unsigned long page) +{ + struct kmmio_fault_page *f; + + page &= PAGE_MASK; + f = get_kmmio_fault_page(page); + if (f) { + if (!f->count) + arm_kmmio_fault_page(f->page, NULL); + f->count++; + return 0; + } + + f = kmalloc(sizeof(*f), GFP_ATOMIC); + if (!f) + return -1; + + f->count = 1; + f->page = page; + list_add_rcu(&f->list, kmmio_page_list(f->page)); + + arm_kmmio_fault_page(f->page, NULL); + + return 0; +} + +/* You must be holding kmmio_lock. */ +static void release_kmmio_fault_page(unsigned long page, + struct kmmio_fault_page **release_list) +{ + struct kmmio_fault_page *f; + + page &= PAGE_MASK; + f = get_kmmio_fault_page(page); + if (!f) + return; + + f->count--; + BUG_ON(f->count < 0); + if (!f->count) { + disarm_kmmio_fault_page(f->page, NULL); + f->release_next = *release_list; + *release_list = f; + } +} + +int register_kmmio_probe(struct kmmio_probe *p) +{ + unsigned long flags; + int ret = 0; + unsigned long size = 0; + + spin_lock_irqsave(&kmmio_lock, flags); + if (get_kmmio_probe(p->addr)) { + ret = -EEXIST; + goto out; + } + kmmio_count++; + list_add_rcu(&p->list, &kmmio_probes); + while (size < p->len) { + if (add_kmmio_fault_page(p->addr + size)) + pr_err("kmmio: Unable to set page fault.\n"); + size += PAGE_SIZE; + } +out: + spin_unlock_irqrestore(&kmmio_lock, flags); + /* + * XXX: What should I do here? + * Here was a call to global_flush_tlb(), but it does not exist + * anymore. It seems it's not needed after all. + */ + return ret; +} +EXPORT_SYMBOL(register_kmmio_probe); + +static void rcu_free_kmmio_fault_pages(struct rcu_head *head) +{ + struct kmmio_delayed_release *dr = container_of( + head, + struct kmmio_delayed_release, + rcu); + struct kmmio_fault_page *p = dr->release_list; + while (p) { + struct kmmio_fault_page *next = p->release_next; + BUG_ON(p->count); + kfree(p); + p = next; + } + kfree(dr); +} + +static void remove_kmmio_fault_pages(struct rcu_head *head) +{ + struct kmmio_delayed_release *dr = container_of( + head, + struct kmmio_delayed_release, + rcu); + struct kmmio_fault_page *p = dr->release_list; + struct kmmio_fault_page **prevp = &dr->release_list; + unsigned long flags; + spin_lock_irqsave(&kmmio_lock, flags); + while (p) { + if (!p->count) + list_del_rcu(&p->list); + else + *prevp = p->release_next; + prevp = &p->release_next; + p = p->release_next; + } + spin_unlock_irqrestore(&kmmio_lock, flags); + /* This is the real RCU destroy call. */ + call_rcu(&dr->rcu, rcu_free_kmmio_fault_pages); +} + +/* + * Remove a kmmio probe. You have to synchronize_rcu() before you can be + * sure that the callbacks will not be called anymore. Only after that + * you may actually release your struct kmmio_probe. + * + * Unregistering a kmmio fault page has three steps: + * 1. release_kmmio_fault_page() + * Disarm the page, wait a grace period to let all faults finish. + * 2. remove_kmmio_fault_pages() + * Remove the pages from kmmio_page_table. + * 3. rcu_free_kmmio_fault_pages() + * Actally free the kmmio_fault_page structs as with RCU. + */ +void unregister_kmmio_probe(struct kmmio_probe *p) +{ + unsigned long flags; + unsigned long size = 0; + struct kmmio_fault_page *release_list = NULL; + struct kmmio_delayed_release *drelease; + + spin_lock_irqsave(&kmmio_lock, flags); + while (size < p->len) { + release_kmmio_fault_page(p->addr + size, &release_list); + size += PAGE_SIZE; + } + list_del_rcu(&p->list); + kmmio_count--; + spin_unlock_irqrestore(&kmmio_lock, flags); + + drelease = kmalloc(sizeof(*drelease), GFP_ATOMIC); + if (!drelease) { + pr_crit("kmmio: leaking kmmio_fault_page objects.\n"); + return; + } + drelease->release_list = release_list; + + /* + * This is not really RCU here. We have just disarmed a set of + * pages so that they cannot trigger page faults anymore. However, + * we cannot remove the pages from kmmio_page_table, + * because a probe hit might be in flight on another CPU. The + * pages are collected into a list, and they will be removed from + * kmmio_page_table when it is certain that no probe hit related to + * these pages can be in flight. RCU grace period sounds like a + * good choice. + * + * If we removed the pages too early, kmmio page fault handler might + * not find the respective kmmio_fault_page and determine it's not + * a kmmio fault, when it actually is. This would lead to madness. + */ + call_rcu(&drelease->rcu, remove_kmmio_fault_pages); +} +EXPORT_SYMBOL(unregister_kmmio_probe); + +static int kmmio_die_notifier(struct notifier_block *nb, unsigned long val, + void *args) +{ + struct die_args *arg = args; + + if (val == DIE_DEBUG && (arg->err & DR_STEP)) + if (post_kmmio_handler(arg->err, arg->regs) == 1) + return NOTIFY_STOP; + + return NOTIFY_DONE; +} + +static struct notifier_block nb_die = { + .notifier_call = kmmio_die_notifier +}; + +static int __init init_kmmio(void) +{ + int i; + for (i = 0; i < KMMIO_PAGE_TABLE_SIZE; i++) + INIT_LIST_HEAD(&kmmio_page_table[i]); + return register_die_notifier(&nb_die); +} +fs_initcall(init_kmmio); /* should be before device_initcall() */ diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c new file mode 100644 index 00000000000..8256546d49b --- /dev/null +++ b/arch/x86/mm/mmio-mod.c @@ -0,0 +1,457 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright (C) IBM Corporation, 2005 + * Jeff Muizelaar, 2006, 2007 + * Pekka Paalanen, 2008 + * + * Derived from the read-mod example from relay-examples by Tom Zanussi. + */ +#define DEBUG 1 + +#include +#include +#include +#include +#include +#include +#include +#include +#include /* for ISA_START_ADDRESS */ +#include +#include + +#include "pf_in.h" + +#define NAME "mmiotrace: " + +struct trap_reason { + unsigned long addr; + unsigned long ip; + enum reason_type type; + int active_traces; +}; + +struct remap_trace { + struct list_head list; + struct kmmio_probe probe; + unsigned long phys; + unsigned long id; +}; + +/* Accessed per-cpu. */ +static DEFINE_PER_CPU(struct trap_reason, pf_reason); +static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace); + +#if 0 /* XXX: no way gather this info anymore */ +/* Access to this is not per-cpu. */ +static DEFINE_PER_CPU(atomic_t, dropped); +#endif + +static struct dentry *marker_file; + +static DEFINE_MUTEX(mmiotrace_mutex); +static DEFINE_SPINLOCK(trace_lock); +static atomic_t mmiotrace_enabled; +static LIST_HEAD(trace_list); /* struct remap_trace */ + +/* + * Locking in this file: + * - mmiotrace_mutex enforces enable/disable_mmiotrace() critical sections. + * - mmiotrace_enabled may be modified only when holding mmiotrace_mutex + * and trace_lock. + * - Routines depending on is_enabled() must take trace_lock. + * - trace_list users must hold trace_lock. + * - is_enabled() guarantees that mmio_trace_record is allowed. + * - pre/post callbacks assume the effect of is_enabled() being true. + */ + +/* module parameters */ +static unsigned long filter_offset; +static int nommiotrace; +static int ISA_trace; +static int trace_pc; + +module_param(filter_offset, ulong, 0); +module_param(nommiotrace, bool, 0); +module_param(ISA_trace, bool, 0); +module_param(trace_pc, bool, 0); + +MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); +MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); +MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); +MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); + +static bool is_enabled(void) +{ + return atomic_read(&mmiotrace_enabled); +} + +#if 0 /* XXX: needs rewrite */ +/* + * Write callback for the debugfs entry: + * Read a marker and write it to the mmio trace log + */ +static ssize_t write_marker(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + char *event = NULL; + struct mm_io_header *headp; + ssize_t len = (count > 65535) ? 65535 : count; + + event = kzalloc(sizeof(*headp) + len, GFP_KERNEL); + if (!event) + return -ENOMEM; + + headp = (struct mm_io_header *)event; + headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT); + headp->data_len = len; + + if (copy_from_user(event + sizeof(*headp), buffer, len)) { + kfree(event); + return -EFAULT; + } + + spin_lock_irq(&trace_lock); +#if 0 /* XXX: convert this to use tracing */ + if (is_enabled()) + relay_write(chan, event, sizeof(*headp) + len); + else +#endif + len = -EINVAL; + spin_unlock_irq(&trace_lock); + kfree(event); + return len; +} +#endif + +static void print_pte(unsigned long address) +{ + int level; + pte_t *pte = lookup_address(address, &level); + + if (!pte) { + pr_err(NAME "Error in %s: no pte for page 0x%08lx\n", + __func__, address); + return; + } + + if (level == PG_LEVEL_2M) { + pr_emerg(NAME "4MB pages are not currently supported: " + "0x%08lx\n", address); + BUG(); + } + pr_info(NAME "pte for 0x%lx: 0x%lx 0x%lx\n", address, pte_val(*pte), + pte_val(*pte) & _PAGE_PRESENT); +} + +/* + * For some reason the pre/post pairs have been called in an + * unmatched order. Report and die. + */ +static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr) +{ + const struct trap_reason *my_reason = &get_cpu_var(pf_reason); + pr_emerg(NAME "unexpected fault for address: 0x%08lx, " + "last fault for address: 0x%08lx\n", + addr, my_reason->addr); + print_pte(addr); + print_symbol(KERN_EMERG "faulting IP is at %s\n", regs->ip); + print_symbol(KERN_EMERG "last faulting IP was at %s\n", my_reason->ip); +#ifdef __i386__ + pr_emerg("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n", + regs->ax, regs->bx, regs->cx, regs->dx); + pr_emerg("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n", + regs->si, regs->di, regs->bp, regs->sp); +#else + pr_emerg("rax: %016lx rcx: %016lx rdx: %016lx\n", + regs->ax, regs->cx, regs->dx); + pr_emerg("rsi: %016lx rdi: %016lx rbp: %016lx rsp: %016lx\n", + regs->si, regs->di, regs->bp, regs->sp); +#endif + put_cpu_var(pf_reason); + BUG(); +} + +static void pre(struct kmmio_probe *p, struct pt_regs *regs, + unsigned long addr) +{ + struct trap_reason *my_reason = &get_cpu_var(pf_reason); + struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); + const unsigned long instptr = instruction_pointer(regs); + const enum reason_type type = get_ins_type(instptr); + struct remap_trace *trace = p->user_data; + + /* it doesn't make sense to have more than one active trace per cpu */ + if (my_reason->active_traces) + die_kmmio_nesting_error(regs, addr); + else + my_reason->active_traces++; + + my_reason->type = type; + my_reason->addr = addr; + my_reason->ip = instptr; + + my_trace->phys = addr - trace->probe.addr + trace->phys; + my_trace->map_id = trace->id; + + /* + * Only record the program counter when requested. + * It may taint clean-room reverse engineering. + */ + if (trace_pc) + my_trace->pc = instptr; + else + my_trace->pc = 0; + + /* + * XXX: the timestamp recorded will be *after* the tracing has been + * done, not at the time we hit the instruction. SMP implications + * on event ordering? + */ + + switch (type) { + case REG_READ: + my_trace->opcode = MMIO_READ; + my_trace->width = get_ins_mem_width(instptr); + break; + case REG_WRITE: + my_trace->opcode = MMIO_WRITE; + my_trace->width = get_ins_mem_width(instptr); + my_trace->value = get_ins_reg_val(instptr, regs); + break; + case IMM_WRITE: + my_trace->opcode = MMIO_WRITE; + my_trace->width = get_ins_mem_width(instptr); + my_trace->value = get_ins_imm_val(instptr); + break; + default: + { + unsigned char *ip = (unsigned char *)instptr; + my_trace->opcode = MMIO_UNKNOWN_OP; + my_trace->width = 0; + my_trace->value = (*ip) << 16 | *(ip + 1) << 8 | + *(ip + 2); + } + } + put_cpu_var(cpu_trace); + put_cpu_var(pf_reason); +} + +static void post(struct kmmio_probe *p, unsigned long condition, + struct pt_regs *regs) +{ + struct trap_reason *my_reason = &get_cpu_var(pf_reason); + struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); + + /* this should always return the active_trace count to 0 */ + my_reason->active_traces--; + if (my_reason->active_traces) { + pr_emerg(NAME "unexpected post handler"); + BUG(); + } + + switch (my_reason->type) { + case REG_READ: + my_trace->value = get_ins_reg_val(my_reason->ip, regs); + break; + default: + break; + } + + mmio_trace_rw(my_trace); + put_cpu_var(cpu_trace); + put_cpu_var(pf_reason); +} + +static void ioremap_trace_core(unsigned long offset, unsigned long size, + void __iomem *addr) +{ + static atomic_t next_id; + struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); + struct mmiotrace_map map = { + .phys = offset, + .virt = (unsigned long)addr, + .len = size, + .opcode = MMIO_PROBE + }; + + if (!trace) { + pr_err(NAME "kmalloc failed in ioremap\n"); + return; + } + + *trace = (struct remap_trace) { + .probe = { + .addr = (unsigned long)addr, + .len = size, + .pre_handler = pre, + .post_handler = post, + .user_data = trace + }, + .phys = offset, + .id = atomic_inc_return(&next_id) + }; + map.map_id = trace->id; + + spin_lock_irq(&trace_lock); + if (!is_enabled()) + goto not_enabled; + + mmio_trace_mapping(&map); + list_add_tail(&trace->list, &trace_list); + if (!nommiotrace) + register_kmmio_probe(&trace->probe); + +not_enabled: + spin_unlock_irq(&trace_lock); +} + +void +mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) +{ + if (!is_enabled()) /* recheck and proper locking in *_core() */ + return; + + pr_debug(NAME "ioremap_*(0x%lx, 0x%lx) = %p\n", offset, size, addr); + if ((filter_offset) && (offset != filter_offset)) + return; + ioremap_trace_core(offset, size, addr); +} + +static void iounmap_trace_core(volatile void __iomem *addr) +{ + struct mmiotrace_map map = { + .phys = 0, + .virt = (unsigned long)addr, + .len = 0, + .opcode = MMIO_UNPROBE + }; + struct remap_trace *trace; + struct remap_trace *tmp; + struct remap_trace *found_trace = NULL; + + pr_debug(NAME "Unmapping %p.\n", addr); + + spin_lock_irq(&trace_lock); + if (!is_enabled()) + goto not_enabled; + + list_for_each_entry_safe(trace, tmp, &trace_list, list) { + if ((unsigned long)addr == trace->probe.addr) { + if (!nommiotrace) + unregister_kmmio_probe(&trace->probe); + list_del(&trace->list); + found_trace = trace; + break; + } + } + map.map_id = (found_trace) ? found_trace->id : -1; + mmio_trace_mapping(&map); + +not_enabled: + spin_unlock_irq(&trace_lock); + if (found_trace) { + synchronize_rcu(); /* unregister_kmmio_probe() requirement */ + kfree(found_trace); + } +} + +void mmiotrace_iounmap(volatile void __iomem *addr) +{ + might_sleep(); + if (is_enabled()) /* recheck and proper locking in *_core() */ + iounmap_trace_core(addr); +} + +static void clear_trace_list(void) +{ + struct remap_trace *trace; + struct remap_trace *tmp; + + /* + * No locking required, because the caller ensures we are in a + * critical section via mutex, and is_enabled() is false, + * i.e. nothing can traverse or modify this list. + * Caller also ensures is_enabled() cannot change. + */ + list_for_each_entry(trace, &trace_list, list) { + pr_notice(NAME "purging non-iounmapped " + "trace @0x%08lx, size 0x%lx.\n", + trace->probe.addr, trace->probe.len); + if (!nommiotrace) + unregister_kmmio_probe(&trace->probe); + } + synchronize_rcu(); /* unregister_kmmio_probe() requirement */ + + list_for_each_entry_safe(trace, tmp, &trace_list, list) { + list_del(&trace->list); + kfree(trace); + } +} + +#if 0 /* XXX: out of order */ +static struct file_operations fops_marker = { + .owner = THIS_MODULE, + .write = write_marker +}; +#endif + +void enable_mmiotrace(void) +{ + mutex_lock(&mmiotrace_mutex); + if (is_enabled()) + goto out; + +#if 0 /* XXX: tracing does not support text entries */ + marker_file = debugfs_create_file("marker", 0660, dir, NULL, + &fops_marker); + if (!marker_file) + pr_err(NAME "marker file creation failed.\n"); +#endif + + if (nommiotrace) + pr_info(NAME "MMIO tracing disabled.\n"); + if (ISA_trace) + pr_warning(NAME "Warning! low ISA range will be traced.\n"); + spin_lock_irq(&trace_lock); + atomic_inc(&mmiotrace_enabled); + spin_unlock_irq(&trace_lock); + pr_info(NAME "enabled.\n"); +out: + mutex_unlock(&mmiotrace_mutex); +} + +void disable_mmiotrace(void) +{ + mutex_lock(&mmiotrace_mutex); + if (!is_enabled()) + goto out; + + spin_lock_irq(&trace_lock); + atomic_dec(&mmiotrace_enabled); + BUG_ON(is_enabled()); + spin_unlock_irq(&trace_lock); + + clear_trace_list(); /* guarantees: no more kmmio callbacks */ + if (marker_file) { + debugfs_remove(marker_file); + marker_file = NULL; + } + + pr_info(NAME "disabled.\n"); +out: + mutex_unlock(&mmiotrace_mutex); +} diff --git a/arch/x86/mm/pf_in.c b/arch/x86/mm/pf_in.c new file mode 100644 index 00000000000..efa1911e20c --- /dev/null +++ b/arch/x86/mm/pf_in.c @@ -0,0 +1,489 @@ +/* + * Fault Injection Test harness (FI) + * Copyright (C) Intel Crop. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + * USA. + * + */ + +/* Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp + * Copyright by Intel Crop., 2002 + * Louis Zhuang (louis.zhuang@intel.com) + * + * Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007 + */ + +#include +#include /* struct pt_regs */ +#include "pf_in.h" + +#ifdef __i386__ +/* IA32 Manual 3, 2-1 */ +static unsigned char prefix_codes[] = { + 0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64, + 0x65, 0x2E, 0x3E, 0x66, 0x67 +}; +/* IA32 Manual 3, 3-432*/ +static unsigned int reg_rop[] = { + 0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +static unsigned int reg_wop[] = { 0x88, 0x89 }; +static unsigned int imm_wop[] = { 0xC6, 0xC7 }; +/* IA32 Manual 3, 3-432*/ +static unsigned int rw8[] = { 0x88, 0x8A, 0xC6 }; +static unsigned int rw32[] = { + 0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F }; +static unsigned int mw16[] = { 0xB70F, 0xBF0F }; +static unsigned int mw32[] = { 0x89, 0x8B, 0xC7 }; +static unsigned int mw64[] = {}; +#else /* not __i386__ */ +static unsigned char prefix_codes[] = { + 0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36, + 0xF0, 0xF3, 0xF2, + /* REX Prefixes */ + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, + 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f +}; +/* AMD64 Manual 3, Appendix A*/ +static unsigned int reg_rop[] = { + 0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +static unsigned int reg_wop[] = { 0x88, 0x89 }; +static unsigned int imm_wop[] = { 0xC6, 0xC7 }; +static unsigned int rw8[] = { 0xC6, 0x88, 0x8A }; +static unsigned int rw32[] = { + 0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F +}; +/* 8 bit only */ +static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F }; +/* 16 bit only */ +static unsigned int mw16[] = { 0xB70F, 0xBF0F }; +/* 16 or 32 bit */ +static unsigned int mw32[] = { 0xC7 }; +/* 16, 32 or 64 bit */ +static unsigned int mw64[] = { 0x89, 0x8B }; +#endif /* not __i386__ */ + +static int skip_prefix(unsigned char *addr, int *shorted, int *enlarged, + int *rexr) +{ + int i; + unsigned char *p = addr; + *shorted = 0; + *enlarged = 0; + *rexr = 0; + +restart: + for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) { + if (*p == prefix_codes[i]) { + if (*p == 0x66) + *shorted = 1; +#ifdef __amd64__ + if ((*p & 0xf8) == 0x48) + *enlarged = 1; + if ((*p & 0xf4) == 0x44) + *rexr = 1; +#endif + p++; + goto restart; + } + } + + return (p - addr); +} + +static int get_opcode(unsigned char *addr, unsigned int *opcode) +{ + int len; + + if (*addr == 0x0F) { + /* 0x0F is extension instruction */ + *opcode = *(unsigned short *)addr; + len = 2; + } else { + *opcode = *addr; + len = 1; + } + + return len; +} + +#define CHECK_OP_TYPE(opcode, array, type) \ + for (i = 0; i < ARRAY_SIZE(array); i++) { \ + if (array[i] == opcode) { \ + rv = type; \ + goto exit; \ + } \ + } + +enum reason_type get_ins_type(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char *p; + int shorted, enlarged, rexr; + int i; + enum reason_type rv = OTHERS; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + + CHECK_OP_TYPE(opcode, reg_rop, REG_READ); + CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE); + CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE); + +exit: + return rv; +} +#undef CHECK_OP_TYPE + +static unsigned int get_ins_reg_width(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char *p; + int i, shorted, enlarged, rexr; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + + for (i = 0; i < ARRAY_SIZE(rw8); i++) + if (rw8[i] == opcode) + return 1; + + for (i = 0; i < ARRAY_SIZE(rw32); i++) + if (rw32[i] == opcode) + return (shorted ? 2 : (enlarged ? 8 : 4)); + + printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode); + return 0; +} + +unsigned int get_ins_mem_width(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char *p; + int i, shorted, enlarged, rexr; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + + for (i = 0; i < ARRAY_SIZE(mw8); i++) + if (mw8[i] == opcode) + return 1; + + for (i = 0; i < ARRAY_SIZE(mw16); i++) + if (mw16[i] == opcode) + return 2; + + for (i = 0; i < ARRAY_SIZE(mw32); i++) + if (mw32[i] == opcode) + return shorted ? 2 : 4; + + for (i = 0; i < ARRAY_SIZE(mw64); i++) + if (mw64[i] == opcode) + return shorted ? 2 : (enlarged ? 8 : 4); + + printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode); + return 0; +} + +/* + * Define register ident in mod/rm byte. + * Note: these are NOT the same as in ptrace-abi.h. + */ +enum { + arg_AL = 0, + arg_CL = 1, + arg_DL = 2, + arg_BL = 3, + arg_AH = 4, + arg_CH = 5, + arg_DH = 6, + arg_BH = 7, + + arg_AX = 0, + arg_CX = 1, + arg_DX = 2, + arg_BX = 3, + arg_SP = 4, + arg_BP = 5, + arg_SI = 6, + arg_DI = 7, +#ifdef __amd64__ + arg_R8 = 8, + arg_R9 = 9, + arg_R10 = 10, + arg_R11 = 11, + arg_R12 = 12, + arg_R13 = 13, + arg_R14 = 14, + arg_R15 = 15 +#endif +}; + +static unsigned char *get_reg_w8(int no, struct pt_regs *regs) +{ + unsigned char *rv = NULL; + + switch (no) { + case arg_AL: + rv = (unsigned char *)®s->ax; + break; + case arg_BL: + rv = (unsigned char *)®s->bx; + break; + case arg_CL: + rv = (unsigned char *)®s->cx; + break; + case arg_DL: + rv = (unsigned char *)®s->dx; + break; + case arg_AH: + rv = 1 + (unsigned char *)®s->ax; + break; + case arg_BH: + rv = 1 + (unsigned char *)®s->bx; + break; + case arg_CH: + rv = 1 + (unsigned char *)®s->cx; + break; + case arg_DH: + rv = 1 + (unsigned char *)®s->dx; + break; +#ifdef __amd64__ + case arg_R8: + rv = (unsigned char *)®s->r8; + break; + case arg_R9: + rv = (unsigned char *)®s->r9; + break; + case arg_R10: + rv = (unsigned char *)®s->r10; + break; + case arg_R11: + rv = (unsigned char *)®s->r11; + break; + case arg_R12: + rv = (unsigned char *)®s->r12; + break; + case arg_R13: + rv = (unsigned char *)®s->r13; + break; + case arg_R14: + rv = (unsigned char *)®s->r14; + break; + case arg_R15: + rv = (unsigned char *)®s->r15; + break; +#endif + default: + printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no); + break; + } + return rv; +} + +static unsigned long *get_reg_w32(int no, struct pt_regs *regs) +{ + unsigned long *rv = NULL; + + switch (no) { + case arg_AX: + rv = ®s->ax; + break; + case arg_BX: + rv = ®s->bx; + break; + case arg_CX: + rv = ®s->cx; + break; + case arg_DX: + rv = ®s->dx; + break; + case arg_SP: + rv = ®s->sp; + break; + case arg_BP: + rv = ®s->bp; + break; + case arg_SI: + rv = ®s->si; + break; + case arg_DI: + rv = ®s->di; + break; +#ifdef __amd64__ + case arg_R8: + rv = ®s->r8; + break; + case arg_R9: + rv = ®s->r9; + break; + case arg_R10: + rv = ®s->r10; + break; + case arg_R11: + rv = ®s->r11; + break; + case arg_R12: + rv = ®s->r12; + break; + case arg_R13: + rv = ®s->r13; + break; + case arg_R14: + rv = ®s->r14; + break; + case arg_R15: + rv = ®s->r15; + break; +#endif + default: + printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no); + } + + return rv; +} + +unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs) +{ + unsigned int opcode; + unsigned char mod_rm; + int reg; + unsigned char *p; + int i, shorted, enlarged, rexr; + unsigned long rv; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + for (i = 0; i < ARRAY_SIZE(reg_rop); i++) + if (reg_rop[i] == opcode) { + rv = REG_READ; + goto do_work; + } + + for (i = 0; i < ARRAY_SIZE(reg_wop); i++) + if (reg_wop[i] == opcode) { + rv = REG_WRITE; + goto do_work; + } + + printk(KERN_ERR "mmiotrace: Not a register instruction, opcode " + "0x%02x\n", opcode); + goto err; + +do_work: + mod_rm = *p; + reg = ((mod_rm >> 3) & 0x7) | (rexr << 3); + switch (get_ins_reg_width(ins_addr)) { + case 1: + return *get_reg_w8(reg, regs); + + case 2: + return *(unsigned short *)get_reg_w32(reg, regs); + + case 4: + return *(unsigned int *)get_reg_w32(reg, regs); + +#ifdef __amd64__ + case 8: + return *(unsigned long *)get_reg_w32(reg, regs); +#endif + + default: + printk(KERN_ERR "mmiotrace: Error width# %d\n", reg); + } + +err: + return 0; +} + +unsigned long get_ins_imm_val(unsigned long ins_addr) +{ + unsigned int opcode; + unsigned char mod_rm; + unsigned char mod; + unsigned char *p; + int i, shorted, enlarged, rexr; + unsigned long rv; + + p = (unsigned char *)ins_addr; + p += skip_prefix(p, &shorted, &enlarged, &rexr); + p += get_opcode(p, &opcode); + for (i = 0; i < ARRAY_SIZE(imm_wop); i++) + if (imm_wop[i] == opcode) { + rv = IMM_WRITE; + goto do_work; + } + + printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode " + "0x%02x\n", opcode); + goto err; + +do_work: + mod_rm = *p; + mod = mod_rm >> 6; + p++; + switch (mod) { + case 0: + /* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2) */ + /* AMD64: XXX Check for address size prefix? */ + if ((mod_rm & 0x7) == 0x5) + p += 4; + break; + + case 1: + p += 1; + break; + + case 2: + p += 4; + break; + + case 3: + default: + printk(KERN_ERR "mmiotrace: not a memory access instruction " + "at 0x%lx, rm_mod=0x%02x\n", + ins_addr, mod_rm); + } + + switch (get_ins_reg_width(ins_addr)) { + case 1: + return *(unsigned char *)p; + + case 2: + return *(unsigned short *)p; + + case 4: + return *(unsigned int *)p; + +#ifdef __amd64__ + case 8: + return *(unsigned long *)p; +#endif + + default: + printk(KERN_ERR "mmiotrace: Error: width.\n"); + } + +err: + return 0; +} diff --git a/arch/x86/mm/pf_in.h b/arch/x86/mm/pf_in.h new file mode 100644 index 00000000000..e05341a51a2 --- /dev/null +++ b/arch/x86/mm/pf_in.h @@ -0,0 +1,39 @@ +/* + * Fault Injection Test harness (FI) + * Copyright (C) Intel Crop. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + * USA. + * + */ + +#ifndef __PF_H_ +#define __PF_H_ + +enum reason_type { + NOT_ME, /* page fault is not in regions */ + NOTHING, /* access others point in regions */ + REG_READ, /* read from addr to reg */ + REG_WRITE, /* write from reg to addr */ + IMM_WRITE, /* write from imm to addr */ + OTHERS /* Other instructions can not intercept */ +}; + +enum reason_type get_ins_type(unsigned long ins_addr); +unsigned int get_ins_mem_width(unsigned long ins_addr); +unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs); +unsigned long get_ins_imm_val(unsigned long ins_addr); + +#endif /* __PF_H_ */ diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c new file mode 100644 index 00000000000..cfa60b227c8 --- /dev/null +++ b/arch/x86/mm/testmmiotrace.c @@ -0,0 +1,71 @@ +/* + * Written by Pekka Paalanen, 2008 + */ +#include +#include + +#define MODULE_NAME "testmmiotrace" + +static unsigned long mmio_address; +module_param(mmio_address, ulong, 0); +MODULE_PARM_DESC(mmio_address, "Start address of the mapping of 16 kB."); + +static void do_write_test(void __iomem *p) +{ + unsigned int i; + for (i = 0; i < 256; i++) + iowrite8(i, p + i); + for (i = 1024; i < (5 * 1024); i += 2) + iowrite16(i * 12 + 7, p + i); + for (i = (5 * 1024); i < (16 * 1024); i += 4) + iowrite32(i * 212371 + 13, p + i); +} + +static void do_read_test(void __iomem *p) +{ + unsigned int i; + for (i = 0; i < 256; i++) + ioread8(p + i); + for (i = 1024; i < (5 * 1024); i += 2) + ioread16(p + i); + for (i = (5 * 1024); i < (16 * 1024); i += 4) + ioread32(p + i); +} + +static void do_test(void) +{ + void __iomem *p = ioremap_nocache(mmio_address, 0x4000); + if (!p) { + pr_err(MODULE_NAME ": could not ioremap, aborting.\n"); + return; + } + do_write_test(p); + do_read_test(p); + iounmap(p); +} + +static int __init init(void) +{ + if (mmio_address == 0) { + pr_err(MODULE_NAME ": you have to use the module argument " + "mmio_address.\n"); + pr_err(MODULE_NAME ": DO NOT LOAD THIS MODULE UNLESS" + " YOU REALLY KNOW WHAT YOU ARE DOING!\n"); + return -ENXIO; + } + + pr_warning(MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx " + "in PCI address space, and writing " + "rubbish in there.\n", mmio_address); + do_test(); + return 0; +} + +static void __exit cleanup(void) +{ + pr_debug(MODULE_NAME ": unloaded.\n"); +} + +module_init(init); +module_exit(cleanup); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-70-g09d2 From e4b37ee68609037ffcaa2fcfae47cd31a605bb9e Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:59 +0200 Subject: x86 mmiotrace: remove ISA_trace parameter. This had become a no-op. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/mmio-mod.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index 8256546d49b..ab2bb776d31 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -81,17 +81,14 @@ static LIST_HEAD(trace_list); /* struct remap_trace */ /* module parameters */ static unsigned long filter_offset; static int nommiotrace; -static int ISA_trace; static int trace_pc; module_param(filter_offset, ulong, 0); module_param(nommiotrace, bool, 0); -module_param(ISA_trace, bool, 0); module_param(trace_pc, bool, 0); MODULE_PARM_DESC(filter_offset, "Start address of traced mappings."); MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing."); -MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range."); MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions."); static bool is_enabled(void) @@ -424,8 +421,6 @@ void enable_mmiotrace(void) if (nommiotrace) pr_info(NAME "MMIO tracing disabled.\n"); - if (ISA_trace) - pr_warning(NAME "Warning! low ISA range will be traced.\n"); spin_lock_irq(&trace_lock); atomic_inc(&mmiotrace_enabled); spin_unlock_irq(&trace_lock); -- cgit v1.2.3-70-g09d2 From c6c67c1afcce71335b18ed8769b1165c468bfb03 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:20:59 +0200 Subject: mmiotrace: add user documentation Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- Documentation/tracers/mmiotrace.txt | 153 ++++++++++++++++++++++++++++++++++++ arch/x86/Kconfig.debug | 8 +- 2 files changed, 156 insertions(+), 5 deletions(-) create mode 100644 Documentation/tracers/mmiotrace.txt (limited to 'arch') diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/tracers/mmiotrace.txt new file mode 100644 index 00000000000..84246f70387 --- /dev/null +++ b/Documentation/tracers/mmiotrace.txt @@ -0,0 +1,153 @@ + In-kernel memory-mapped I/O tracing + + +Home page and links to optional user space tools: + + http://nouveau.freedesktop.org/wiki/MmioTrace + +MMIO tracing was originally developed by Intel around 2003 for their Fault +Injection Test Harness. In Dec 2006 - Jan 2007, using the code from Intel, +Jeff Muizelaar created a tool for tracing MMIO accesses with the Nouveau +project in mind. Since then many people have contributed. + +Mmiotrace was built for reverse engineering any memory-mapped IO device with +the Nouveau project as the first real user. Only x86 and x86_64 architectures +are supported. + +Out-of-tree mmiotrace was originally modified for mainline inclusion and +ftrace framework by Pekka Paalanen . + + +Preparation +----------- + +Mmiotrace feature is compiled in by the CONFIG_MMIOTRACE option. Tracing is +disabled by default, so it is safe to have this set to yes. SMP systems are +supported, but tracing is unreliable and may miss events if more than one CPU +is on-line, therefore mmiotrace takes all but one CPU off-line during run-time +activation [not implemented]. + + +Usage Quick Reference +--------------------- + +$ mount -t debugfs debugfs /debug +$ echo mmiotrace > /debug/tracing/current_tracer +$ cat /debug/tracing/trace_pipe > mydump.txt & +Start X or whatever. +$ echo "X is up" > /debug/tracing/marker +$ echo none > /debug/tracing/current_tracer +Check kernel log. + + +Usage +----- + +Make sure debugfs is mounted to /debug. If not, (requires root privileges) +$ mount -t debugfs debugfs /debug + +Check that the driver you are about to trace is not loaded. + +Activate mmiotrace (requires root privileges): +$ echo mmiotrace > /debug/tracing/current_tracer + +Start storing the trace: +$ cat /debug/tracing/trace_pipe > mydump.txt & +The 'cat' process should stay running (sleeping) in the background. + +Load the driver you want to trace and use it. Mmiotrace will only catch MMIO +accesses to areas that are ioremapped while mmiotrace is active. + +[Unimplemented feature:] +During tracing you can place comments (markers) into the trace by +$ echo "X is up" > /debug/tracing/marker +This makes it easier to see which part of the (huge) trace corresponds to +which action. It is recommended to place descriptive markers about what you +do. + +Shut down mmiotrace (requires root privileges): +$ echo none > /debug/tracing/current_tracer +The 'cat' process exits. If it does not, kill it by 'fg' and pressing ctrl+c. + +[This feature is not implemented yet!] +Check your kernel log. If there are messages about mmiotrace losing events, +this is due to buffer overrun, and the trace is incomplete. You should enlarge +the buffers and try again. [How?] + +If you are doing a trace for a driver project, e.g. Nouveau, you should also +do the following before sending your results: +$ lspci -vvv > lspci.txt +$ dmesg > dmesg.txt +$ tar zcf pciid-nick-mmiotrace.tar.gz mydump.txt lspci.txt dmesg.txt +and then send the .tar.gz file. The trace compresses considerably. Replace +"pciid" and "nick" with the PCI ID or model name of your piece of hardware +under investigation and your nick name. + + +How Mmiotrace Works +------------------- + +Access to hardware IO-memory is gained by mapping addresses from PCI bus by +calling one of the ioremap_*() functions. Mmiotrace is hooked into the +__ioremap() function and gets called whenever a mapping is created. Mapping is +an event that is recorded into the trace log. Note, that ISA range mappings +are not caught, since the mapping always exists and is returned directly. + +MMIO accesses are recorded via page faults. Just before __ioremap() returns, +the mapped pages are marked as not present. Any access to the pages causes a +fault. The page fault handler calls mmiotrace to handle the fault. Mmiotrace +marks the page present, sets TF flag to achieve single stepping and exits the +fault handler. The instruction that faulted is executed and debug trap is +entered. Here mmiotrace again marks the page as not present. The instruction +is decoded to get the type of operation (read/write), data width and the value +read or written. These are stored to the trace log. + +Setting the page present in the page fault handler has a race condition on SMP +machines. During the single stepping other CPUs may run freely on that page +and events can be missed without a notice. Re-enabling other CPUs during +tracing is discouraged. + + +Trace Log Format +---------------- + +The raw log is text and easily filtered with e.g. grep and awk. One record is +one line in the log. A record starts with a keyword, followed by keyword +dependant arguments. Arguments are separated by a space, or continue until the +end of line. The format for version 20070824 is as follows: + +Explanation Keyword Space separated arguments +--------------------------------------------------------------------------- + +read event R width, timestamp, map id, physical, value, PC, PID +write event W width, timestamp, map id, physical, value, PC, PID +ioremap event MAP timestamp, map id, physical, virtual, length, PC, PID +iounmap event UNMAP timestamp, map id, PC, PID +marker MARK timestamp, text +version VERSION the string "20070824" +info for reader LSPCI one line from lspci -v +PCI address map PCIDEV space separated /proc/bus/pci/devices data +unk. opcode UNKNOWN timestamp, map id, physical, data, PC, PID + +Timestamp is in seconds with decimals. Physical is a PCI bus address, virtual +is a kernel virtual address. Width is the data width in bytes and value is the +data value. Map id is an arbitrary id number identifying the mapping that was +used in an operation. PC is the program counter and PID is process id. PC is +zero if it is not recorded. PID is always zero as tracing MMIO accesses +originating in user space memory is not yet supported. + +For instance, the following awk filter will pass all 32-bit writes that target +physical addresses in the range [0xfb73ce40, 0xfb800000[ + +$ awk '/W 4 / { adr=strtonum($5); if (adr >= 0xfb73ce40 && +adr < 0xfb800000) print; }' + + +Tools for Developers +-------------------- + +The user space tools include utilities for: +- replacing numeric addresses and values with hardware register names +- replaying MMIO logs, i.e., re-executing the recorded writes + + diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 1d6de0d67f9..b28ace2be1a 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -180,12 +180,10 @@ config MMIOTRACE help Mmiotrace traces Memory Mapped I/O access and is meant for debugging and reverse engineering. It is called from the ioremap - implementation and works via page faults. A user space program is - required to collect the MMIO data from debugfs files. - Tracing is disabled by default and can be enabled from a debugfs - file. + implementation and works via page faults. Tracing is disabled by + default and can be enabled run-time. - See http://nouveau.freedesktop.org/wiki/MmioTrace + See Documentation/tracers/mmiotrace.txt. If you are not helping to develop drivers, say N. config MMIOTRACE_TEST -- cgit v1.2.3-70-g09d2 From 0663bb6cd9a457fbd8ca95c627bb762d07321a39 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 12 May 2008 21:20:59 +0200 Subject: mmiotrace: fix printk format Fix gcc printk format warnings: next-20080415/arch/x86/mm/mmio-mod.c: In function 'print_pte': next-20080415/arch/x86/mm/mmio-mod.c:154: warning: format '%lx' expects type 'long unsigned int', but argument 3 has type 'pteval_t' next-20080415/arch/x86/mm/mmio-mod.c:154: warning: format '%lx' expects type 'long unsigned int', but argument 4 has type 'pteval_t' next-20080415/arch/x86/mm/mmio-mod.c: At top level: next-20080415/arch/x86/mm/mmio-mod.c:403: warning: 'downed_cpus' defined but not used Signed-off-by: Randy Dunlap Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/mmio-mod.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index ab2bb776d31..6d6cac84c04 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -150,8 +150,9 @@ static void print_pte(unsigned long address) "0x%08lx\n", address); BUG(); } - pr_info(NAME "pte for 0x%lx: 0x%lx 0x%lx\n", address, pte_val(*pte), - pte_val(*pte) & _PAGE_PRESENT); + pr_info(NAME "pte for 0x%lx: 0x%llx 0x%llx\n", address, + (unsigned long long)pte_val(*pte), + (unsigned long long)pte_val(*pte) & _PAGE_PRESENT); } /* -- cgit v1.2.3-70-g09d2 From 37b3619257d3190f47f233d7ed626d4b9916462c Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 12 May 2008 21:20:59 +0200 Subject: x86/mmiotrace: uses/depends on PCI Don't try to build mmiotrace when CONFIG_PCI=n. next-20080416/kernel/trace/trace_mmiotrace.c: In function 'mmio_print_pcidev': next-20080416/kernel/trace/trace_mmiotrace.c:62: error: implicit declaration of function 'pci_dev_driver' Signed-off-by: Randy Dunlap Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig.debug | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index b28ace2be1a..1e53df0ba08 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -173,7 +173,7 @@ config MMIOTRACE_HOOKS config MMIOTRACE bool "Memory mapped IO tracing" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL && PCI select TRACING select MMIOTRACE_HOOKS default y @@ -181,7 +181,7 @@ config MMIOTRACE Mmiotrace traces Memory Mapped I/O access and is meant for debugging and reverse engineering. It is called from the ioremap implementation and works via page faults. Tracing is disabled by - default and can be enabled run-time. + default and can be enabled at run-time. See Documentation/tracers/mmiotrace.txt. If you are not helping to develop drivers, say N. -- cgit v1.2.3-70-g09d2 From 7423d1115f18627666d475fccc7c62394406ff8c Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:02 +0200 Subject: x86 mmiotrace: dynamically disable non-boot CPUs From 8979ee55cb6a429c4edd72ebec2244b849f6a79a Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Sat, 12 Apr 2008 00:18:57 +0300 Mmiotrace is not reliable with multiple CPUs and may miss events. Drop to single CPU when mmiotrace is activated. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- arch/x86/mm/mmio-mod.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'arch') diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index 6d6cac84c04..1f77d853203 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -32,6 +32,7 @@ #include /* for ISA_START_ADDRESS */ #include #include +#include #include "pf_in.h" @@ -400,6 +401,64 @@ static void clear_trace_list(void) } } +#ifdef CONFIG_HOTPLUG_CPU +static cpumask_t downed_cpus; + +static void enter_uniprocessor(void) +{ + int cpu; + int err; + + get_online_cpus(); + downed_cpus = cpu_online_map; + cpu_clear(first_cpu(cpu_online_map), downed_cpus); + if (num_online_cpus() > 1) + pr_notice(NAME "Disabling non-boot CPUs...\n"); + put_online_cpus(); + + for_each_cpu_mask(cpu, downed_cpus) { + err = cpu_down(cpu); + if (!err) { + pr_info(NAME "CPU%d is down.\n", cpu); + } else { + pr_err(NAME "Error taking CPU%d down: %d\n", cpu, err); + } + } + if (num_online_cpus() > 1) + pr_warning(NAME "multiple CPUs still online, " + "may miss events.\n"); +} + +static void leave_uniprocessor(void) +{ + int cpu; + int err; + + if (cpus_weight(downed_cpus) == 0) + return; + pr_notice(NAME "Re-enabling CPUs...\n"); + for_each_cpu_mask(cpu, downed_cpus) { + err = cpu_up(cpu); + if (!err) + pr_info(NAME "enabled CPU%d.\n", cpu); + else + pr_err(NAME "cannot re-enable CPU%d: %d\n", cpu, err); + } +} + +#else /* !CONFIG_HOTPLUG_CPU */ +static void enter_uniprocessor(void) +{ + if (num_online_cpus() > 1) + pr_warning(NAME "multiple CPUs are online, may miss events. " + "Suggest booting with maxcpus=1 kernel argument.\n"); +} + +static void leave_uniprocessor(void) +{ +} +#endif + #if 0 /* XXX: out of order */ static struct file_operations fops_marker = { .owner = THIS_MODULE, @@ -422,6 +481,7 @@ void enable_mmiotrace(void) if (nommiotrace) pr_info(NAME "MMIO tracing disabled.\n"); + enter_uniprocessor(); spin_lock_irq(&trace_lock); atomic_inc(&mmiotrace_enabled); spin_unlock_irq(&trace_lock); @@ -442,6 +502,7 @@ void disable_mmiotrace(void) spin_unlock_irq(&trace_lock); clear_trace_list(); /* guarantees: no more kmmio callbacks */ + leave_uniprocessor(); if (marker_file) { debugfs_remove(marker_file); marker_file = NULL; -- cgit v1.2.3-70-g09d2 From 970e6fa03885f32cc43e42cb08c73a5f54cd8bd9 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:03 +0200 Subject: mmiotrace: code style cleanups From c2da03771e29159627c5c7b9509ec70bce9f91ee Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 28 Apr 2008 21:25:22 +0300 Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- arch/x86/mm/kmmio.c | 4 ++-- arch/x86/mm/mmio-mod.c | 7 +++---- arch/x86/mm/testmmiotrace.c | 2 +- include/linux/mmiotrace.h | 6 +----- 4 files changed, 7 insertions(+), 12 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 3ad27b8504a..6a92d9111b6 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -17,10 +17,10 @@ #include #include #include -#include +#include #include #include -#include +#include #include #include diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index 1f77d853203..a8d2a0019da 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -24,7 +24,7 @@ #include #include #include -#include +#include #include #include #include @@ -418,11 +418,10 @@ static void enter_uniprocessor(void) for_each_cpu_mask(cpu, downed_cpus) { err = cpu_down(cpu); - if (!err) { + if (!err) pr_info(NAME "CPU%d is down.\n", cpu); - } else { + else pr_err(NAME "Error taking CPU%d down: %d\n", cpu, err); - } } if (num_online_cpus() > 1) pr_warning(NAME "multiple CPUs still online, " diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c index cfa60b227c8..d877c5b423e 100644 --- a/arch/x86/mm/testmmiotrace.c +++ b/arch/x86/mm/testmmiotrace.c @@ -2,7 +2,7 @@ * Written by Pekka Paalanen, 2008 */ #include -#include +#include #define MODULE_NAME "testmmiotrace" diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index dd6b64b160f..de8e91258da 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -1,9 +1,7 @@ #ifndef MMIOTRACE_H #define MMIOTRACE_H -#include - -#ifdef __KERNEL__ +#include #include @@ -84,6 +82,4 @@ extern void disable_mmiotrace(void); extern void mmio_trace_rw(struct mmiotrace_rw *rw); extern void mmio_trace_mapping(struct mmiotrace_map *map); -#endif /* __KERNEL__ */ - #endif /* MMIOTRACE_H */ -- cgit v1.2.3-70-g09d2 From 87e547fe41a8b57d6d80afc67a0031fbe477eb0d Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:03 +0200 Subject: x86 mmiotrace: fix page-unaligned ioremaps mmiotrace_ioremap() expects to receive the original unaligned map phys address and size. Also fix {un,}register_kmmio_probe() to deal properly with unaligned size. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- arch/x86/mm/ioremap.c | 4 +++- arch/x86/mm/kmmio.c | 13 +++++++++++-- arch/x86/mm/mmio-mod.c | 1 + 3 files changed, 15 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 8927c878544..a7c80a6e862 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -123,6 +123,8 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, { unsigned long pfn, offset, vaddr; resource_size_t last_addr; + const resource_size_t unaligned_phys_addr = phys_addr; + const unsigned long unaligned_size = size; struct vm_struct *area; unsigned long new_prot_val; pgprot_t prot; @@ -236,7 +238,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, } ret_addr = (void __iomem *) (vaddr + offset); - mmiotrace_ioremap(phys_addr, size, ret_addr); + mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr); return ret_addr; } diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 6a92d9111b6..93b1797666c 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -351,11 +351,19 @@ static void release_kmmio_fault_page(unsigned long page, } } +/* + * With page-unaligned ioremaps, one or two armed pages may contain + * addresses from outside the intended mapping. Events for these addresses + * are currently silently dropped. The events may result only from programming + * mistakes by accessing addresses before the beginning or past the end of a + * mapping. + */ int register_kmmio_probe(struct kmmio_probe *p) { unsigned long flags; int ret = 0; unsigned long size = 0; + const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK); spin_lock_irqsave(&kmmio_lock, flags); if (get_kmmio_probe(p->addr)) { @@ -364,7 +372,7 @@ int register_kmmio_probe(struct kmmio_probe *p) } kmmio_count++; list_add_rcu(&p->list, &kmmio_probes); - while (size < p->len) { + while (size < size_lim) { if (add_kmmio_fault_page(p->addr + size)) pr_err("kmmio: Unable to set page fault.\n"); size += PAGE_SIZE; @@ -436,11 +444,12 @@ void unregister_kmmio_probe(struct kmmio_probe *p) { unsigned long flags; unsigned long size = 0; + const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK); struct kmmio_fault_page *release_list = NULL; struct kmmio_delayed_release *drelease; spin_lock_irqsave(&kmmio_lock, flags); - while (size < p->len) { + while (size < size_lim) { release_kmmio_fault_page(p->addr + size, &release_list); size += PAGE_SIZE; } diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index a8d2a0019da..278998c1998 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -280,6 +280,7 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size, { static atomic_t next_id; struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL); + /* These are page-unaligned. */ struct mmiotrace_map map = { .phys = offset, .virt = (unsigned long)addr, -- cgit v1.2.3-70-g09d2 From dee310d0adf41019aca476052ac3085ff286d9be Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:03 +0200 Subject: x86 mmiotrace: use resource_size_t for phys addresses Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- arch/x86/mm/mmio-mod.c | 11 ++++++----- include/linux/mmiotrace.h | 14 +++++++------- kernel/trace/trace_mmiotrace.c | 20 ++++++++++++-------- 3 files changed, 25 insertions(+), 20 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index 278998c1998..3b04a012612 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -48,7 +48,7 @@ struct trap_reason { struct remap_trace { struct list_head list; struct kmmio_probe probe; - unsigned long phys; + resource_size_t phys; unsigned long id; }; @@ -275,7 +275,7 @@ static void post(struct kmmio_probe *p, unsigned long condition, put_cpu_var(pf_reason); } -static void ioremap_trace_core(unsigned long offset, unsigned long size, +static void ioremap_trace_core(resource_size_t offset, unsigned long size, void __iomem *addr) { static atomic_t next_id; @@ -319,13 +319,14 @@ not_enabled: spin_unlock_irq(&trace_lock); } -void -mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) +void mmiotrace_ioremap(resource_size_t offset, unsigned long size, + void __iomem *addr) { if (!is_enabled()) /* recheck and proper locking in *_core() */ return; - pr_debug(NAME "ioremap_*(0x%lx, 0x%lx) = %p\n", offset, size, addr); + pr_debug(NAME "ioremap_*(0x%llx, 0x%lx) = %p\n", + (unsigned long long)offset, size, addr); if ((filter_offset) && (offset != filter_offset)) return; ioremap_trace_core(offset, size, addr); diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index de8e91258da..5cbbc374e94 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -2,7 +2,6 @@ #define MMIOTRACE_H #include - #include struct kmmio_probe; @@ -37,14 +36,15 @@ extern int kmmio_handler(struct pt_regs *regs, unsigned long addr); /* Called from ioremap.c */ #ifdef CONFIG_MMIOTRACE -extern void -mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr); +extern void mmiotrace_ioremap(resource_size_t offset, unsigned long size, + void __iomem *addr); extern void mmiotrace_iounmap(volatile void __iomem *addr); #else -static inline void -mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr) +static inline void mmiotrace_ioremap(resource_size_t offset, + unsigned long size, void __iomem *addr) { } + static inline void mmiotrace_iounmap(volatile void __iomem *addr) { } @@ -60,7 +60,7 @@ enum mm_io_opcode { }; struct mmiotrace_rw { - unsigned long phys; /* PCI address of register */ + resource_size_t phys; /* PCI address of register */ unsigned long value; unsigned long pc; /* optional program counter */ int map_id; @@ -69,7 +69,7 @@ struct mmiotrace_rw { }; struct mmiotrace_map { - unsigned long phys; /* base address in PCI space */ + resource_size_t phys; /* base address in PCI space */ unsigned long virt; /* base virtual address */ unsigned long len; /* mapping size */ int map_id; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index 3c1dacdc2d8..b13dc19dcbb 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -184,20 +184,23 @@ static int mmio_print_rw(struct trace_iterator *iter) switch (entry->mmiorw.opcode) { case MMIO_READ: ret = trace_seq_printf(s, - "R %d %lu.%06lu %d 0x%lx 0x%lx 0x%lx %d\n", - rw->width, secs, usec_rem, rw->map_id, rw->phys, + "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", + rw->width, secs, usec_rem, rw->map_id, + (unsigned long long)rw->phys, rw->value, rw->pc, 0); break; case MMIO_WRITE: ret = trace_seq_printf(s, - "W %d %lu.%06lu %d 0x%lx 0x%lx 0x%lx %d\n", - rw->width, secs, usec_rem, rw->map_id, rw->phys, + "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", + rw->width, secs, usec_rem, rw->map_id, + (unsigned long long)rw->phys, rw->value, rw->pc, 0); break; case MMIO_UNKNOWN_OP: ret = trace_seq_printf(s, - "UNKNOWN %lu.%06lu %d 0x%lx %02x,%02x,%02x 0x%lx %d\n", - secs, usec_rem, rw->map_id, rw->phys, + "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 0x%lx %d\n", + secs, usec_rem, rw->map_id, + (unsigned long long)rw->phys, (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff, (rw->value >> 0) & 0xff, rw->pc, 0); break; @@ -223,8 +226,9 @@ static int mmio_print_map(struct trace_iterator *iter) switch (entry->mmiorw.opcode) { case MMIO_PROBE: ret = trace_seq_printf(s, - "MAP %lu.%06lu %d 0x%lx 0x%lx 0x%lx 0x%lx %d\n", - secs, usec_rem, m->map_id, m->phys, m->virt, m->len, + "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", + secs, usec_rem, m->map_id, + (unsigned long long)m->phys, m->virt, m->len, 0UL, 0); break; case MMIO_UNPROBE: -- cgit v1.2.3-70-g09d2 From a50445d76c22a34ae149704ea5adaef171c8acb7 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:03 +0200 Subject: mmiotrace: rename kmmio_probe::user_data to :private. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- arch/x86/mm/mmio-mod.c | 4 ++-- include/linux/mmiotrace.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index 3b04a012612..ed0e0e90b3e 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -191,7 +191,7 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs, struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace); const unsigned long instptr = instruction_pointer(regs); const enum reason_type type = get_ins_type(instptr); - struct remap_trace *trace = p->user_data; + struct remap_trace *trace = p->private; /* it doesn't make sense to have more than one active trace per cpu */ if (my_reason->active_traces) @@ -299,7 +299,7 @@ static void ioremap_trace_core(resource_size_t offset, unsigned long size, .len = size, .pre_handler = pre, .post_handler = post, - .user_data = trace + .private = trace }, .phys = offset, .id = atomic_inc_return(&next_id) diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h index 5cbbc374e94..61d19e1b7a0 100644 --- a/include/linux/mmiotrace.h +++ b/include/linux/mmiotrace.h @@ -18,7 +18,7 @@ struct kmmio_probe { unsigned long len; /* length of the probe region */ kmmio_pre_handler_t pre_handler; /* Called before addr is executed. */ kmmio_post_handler_t post_handler; /* Called after addr is executed */ - void *user_data; + void *private; }; /* kmmio is active by some kmmio_probes? */ -- cgit v1.2.3-70-g09d2 From 790e2a290b499b0400254e6870ec27969065d122 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 12 May 2008 21:21:14 +0200 Subject: x86 mmiotrace: page level is unsigned Fixes some sparse warnings. Signed-off-by: Pekka Paalanen Signed-off-by: Ingo Molnar --- arch/x86/mm/kmmio.c | 13 +++++++------ arch/x86/mm/mmio-mod.c | 2 +- 2 files changed, 8 insertions(+), 7 deletions(-) (limited to 'arch') diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 93b1797666c..b65871e6bba 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -104,11 +104,12 @@ static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page) return NULL; } -static void set_page_present(unsigned long addr, bool present, int *pglevel) +static void set_page_present(unsigned long addr, bool present, + unsigned int *pglevel) { pteval_t pteval; pmdval_t pmdval; - int level; + unsigned int level; pmd_t *pmd; pte_t *pte = lookup_address(addr, &level); @@ -145,15 +146,15 @@ static void set_page_present(unsigned long addr, bool present, int *pglevel) } /** Mark the given page as not present. Access to it will trigger a fault. */ -static void arm_kmmio_fault_page(unsigned long page, int *page_level) +static void arm_kmmio_fault_page(unsigned long page, unsigned int *pglevel) { - set_page_present(page & PAGE_MASK, false, page_level); + set_page_present(page & PAGE_MASK, false, pglevel); } /** Mark the given page as present. */ -static void disarm_kmmio_fault_page(unsigned long page, int *page_level) +static void disarm_kmmio_fault_page(unsigned long page, unsigned int *pglevel) { - set_page_present(page & PAGE_MASK, true, page_level); + set_page_present(page & PAGE_MASK, true, pglevel); } /* diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index ed0e0e90b3e..e7397e108be 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -137,7 +137,7 @@ static ssize_t write_marker(struct file *file, const char __user *buffer, static void print_pte(unsigned long address) { - int level; + unsigned int level; pte_t *pte = lookup_address(address, &level); if (!pte) { -- cgit v1.2.3-70-g09d2 From 668a6c3654560aef8741642478973e205a4f02bf Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 19 May 2008 13:35:24 +0200 Subject: - fix mmioftrace + rcu merge interaction Signed-off-by: Thomas Gleixner --- arch/x86/mm/kmmio.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index b65871e6bba..93d82038af4 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -6,6 +6,7 @@ */ #include +#include #include #include #include -- cgit v1.2.3-70-g09d2 From ccbfac2923c9febaeaf07a50054027a92b502718 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 22 May 2008 14:31:07 -0400 Subject: ftrace: powerpc clean ups This patch cleans up the ftrace code in PowerPC based on the comments from Michael Ellerman. Signed-off-by: Steven Rostedt Cc: Michael Ellerman Cc: proski@gnu.org Cc: a.p.zijlstra@chello.nl Cc: Pekka Paalanen Cc: Steven Rostedt Cc: linuxppc-dev@ozlabs.org Cc: Soeren Sandmann Pedersen Cc: paulus@samba.org Signed-off-by: Thomas Gleixner --- arch/powerpc/kernel/entry_32.S | 11 ++--------- arch/powerpc/kernel/ftrace.c | 8 +++++++- arch/powerpc/kernel/ppc_ksyms.c | 5 +++++ arch/powerpc/kernel/setup_32.c | 5 ----- arch/powerpc/kernel/setup_64.c | 5 ----- include/asm-powerpc/ftrace.h | 6 ++++++ 6 files changed, 20 insertions(+), 20 deletions(-) create mode 100644 include/asm-powerpc/ftrace.h (limited to 'arch') diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 0e6221889ca..3b1dd29d9f9 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1129,18 +1129,11 @@ _GLOBAL(_mcount) stw r5, 8(r1) LOAD_REG_ADDR(r5, ftrace_trace_function) -#if 0 - mtctr r3 - mr r1, r5 - bctrl -#endif lwz r5,0(r5) -#if 1 + mtctr r5 bctrl -#else - bl ftrace_stub -#endif + nop lwz r6, 8(r1) diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 5a4993fefa4..69ed4122346 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -51,10 +51,16 @@ notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) { static unsigned int op; + /* + * It would be nice to just use create_function_call, but that will + * update the code itself. Here we need to just return the + * instruction that is going to be modified, without modifying the + * code. + */ addr = GET_ADDR(addr); /* Set to "bl addr" */ - op = 0x48000001 | (ftrace_calc_offset(ip, addr) & 0x03fffffe); + op = 0x48000001 | (ftrace_calc_offset(ip, addr) & 0x03fffffc); /* * No locking needed, this must be called via kstop_machine diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index cf6b5a7d8b3..4300db52662 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -43,6 +43,7 @@ #include #include #include +#include #ifdef CONFIG_PPC32 extern void transfer_to_handler(void); @@ -68,6 +69,10 @@ EXPORT_SYMBOL(single_step_exception); EXPORT_SYMBOL(sys_sigreturn); #endif +#ifdef CONFIG_FTRACE +EXPORT_SYMBOL(_mcount); +#endif + EXPORT_SYMBOL(strcpy); EXPORT_SYMBOL(strncpy); EXPORT_SYMBOL(strcat); diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c index 22f8e2bacd3..19e8fcb9cea 100644 --- a/arch/powerpc/kernel/setup_32.c +++ b/arch/powerpc/kernel/setup_32.c @@ -47,11 +47,6 @@ #include #endif -#ifdef CONFIG_FTRACE -extern void _mcount(void); -EXPORT_SYMBOL(_mcount); -#endif - extern void bootx_init(unsigned long r4, unsigned long phys); int boot_cpuid; diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 277bf18cbbc..098fd96a394 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -85,11 +85,6 @@ struct ppc64_caches ppc64_caches = { }; EXPORT_SYMBOL_GPL(ppc64_caches); -#ifdef CONFIG_FTRACE -extern void _mcount(void); -EXPORT_SYMBOL(_mcount); -#endif - /* * These are used in binfmt_elf.c to put aux entries on the stack * for each elf executable being started. diff --git a/include/asm-powerpc/ftrace.h b/include/asm-powerpc/ftrace.h new file mode 100644 index 00000000000..b1bfa704b6e --- /dev/null +++ b/include/asm-powerpc/ftrace.h @@ -0,0 +1,6 @@ +#ifndef _ASM_POWERPC_FTRACE +#define _ASM_POWERPC_FTRACE + +extern void _mcount(void); + +#endif -- cgit v1.2.3-70-g09d2 From 014c257cce65e9d1cd2d28ec1c89a37c536b151d Mon Sep 17 00:00:00 2001 From: Abhishek Sagar Date: Sat, 31 May 2008 14:23:50 +0530 Subject: ftrace: core support for ARM Core ftrace support for the ARM architecture, which includes support for dynamic function tracing. Signed-off-by: Abhishek Sagar Signed-off-by: Ingo Molnar --- arch/arm/Kconfig | 2 + arch/arm/boot/compressed/Makefile | 6 ++ arch/arm/kernel/Makefile | 5 ++ arch/arm/kernel/armksyms.c | 5 ++ arch/arm/kernel/entry-common.S | 47 ++++++++++++++ arch/arm/kernel/ftrace.c | 128 ++++++++++++++++++++++++++++++++++++++ 6 files changed, 193 insertions(+) create mode 100644 arch/arm/kernel/ftrace.c (limited to 'arch') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b786e68914d..3845e5c8a34 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -14,6 +14,8 @@ config ARM select HAVE_OPROFILE select HAVE_KPROBES if (!XIP_KERNEL) select HAVE_KRETPROBES if (HAVE_KPROBES) + select HAVE_FTRACE if (!XIP_KERNEL) + select HAVE_DYNAMIC_FTRACE if (HAVE_FTRACE) help The ARM series is a line of low-power-consumption RISC chip designs licensed by ARM Ltd and targeted at embedded applications and diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index de9d9ee5095..95baac4939e 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -69,6 +69,12 @@ SEDFLAGS = s/TEXT_START/$(ZTEXTADDR)/;s/BSS_START/$(ZBSSADDR)/ targets := vmlinux vmlinux.lds piggy.gz piggy.o font.o font.c \ head.o misc.o $(OBJS) + +ifeq ($(CONFIG_FTRACE),y) +ORIG_CFLAGS := $(KBUILD_CFLAGS) +KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS)) +endif + EXTRA_CFLAGS := -fpic -fno-builtin EXTRA_AFLAGS := diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index ad455ff5aeb..eb9092ca800 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -4,6 +4,10 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) +ifdef CONFIG_DYNAMIC_FTRACE +CFLAGS_REMOVE_ftrace.o = -pg +endif + # Object file lists. obj-y := compat.o entry-armv.o entry-common.o irq.o \ @@ -18,6 +22,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o obj-$(CONFIG_ISA_DMA) += dma-isa.o obj-$(CONFIG_PCI) += bios32.o isa.o obj-$(CONFIG_SMP) += smp.o +obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_KPROBES) += kprobes.o kprobes-decode.o obj-$(CONFIG_ATAGS_PROC) += atags.o diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 688b7b1ee41..3b132215cbf 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -48,6 +48,11 @@ extern void __aeabi_ulcmp(void); extern void fpundefinstr(void); extern void fp_enter(void); +#ifdef CONFIG_FTRACE +extern void mcount(void); +EXPORT_SYMBOL(mcount); +#endif + /* * This has a special calling convention; it doesn't * modify any of the usual registers, except for LR. diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 597ed00a08d..8f79a4789ed 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -99,6 +99,53 @@ ENTRY(ret_from_fork) #undef CALL #define CALL(x) .long x +#ifdef CONFIG_FTRACE +#ifdef CONFIG_DYNAMIC_FTRACE +ENTRY(mcount) + stmdb sp!, {r0-r3, lr} + mov r0, lr + + .globl mcount_call +mcount_call: + bl ftrace_stub + ldmia sp!, {r0-r3, pc} + +ENTRY(ftrace_caller) + stmdb sp!, {r0-r3, lr} + ldr r1, [fp, #-4] + mov r0, lr + + .globl ftrace_call +ftrace_call: + bl ftrace_stub + ldmia sp!, {r0-r3, pc} + +#else + +ENTRY(mcount) + stmdb sp!, {r0-r3, lr} + ldr r0, =ftrace_trace_function + ldr r2, [r0] + adr r0, ftrace_stub + cmp r0, r2 + bne trace + ldmia sp!, {r0-r3, pc} + +trace: + ldr r1, [fp, #-4] + mov r0, lr + mov lr, pc + mov pc, r2 + ldmia sp!, {r0-r3, pc} + +#endif /* CONFIG_DYNAMIC_FTRACE */ + + .globl ftrace_stub +ftrace_stub: + mov pc, lr + +#endif /* CONFIG_FTRACE */ + /*============================================================================= * SWI handler *----------------------------------------------------------------------------- diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c new file mode 100644 index 00000000000..f4cb4cc3fa0 --- /dev/null +++ b/arch/arm/kernel/ftrace.c @@ -0,0 +1,128 @@ +/* + * Dynamic function tracing support. + * + * Copyright (C) 2008 Abhishek Sagar + * + * For licencing details, see COPYING. + * + * Defines low-level handling of mcount calls when the kernel + * is compiled with the -pg flag. When using dynamic ftrace, the + * mcount call-sites get patched lazily with NOP till they are + * enabled. All code mutation routines here take effect atomically. + */ + +#include +#include + +#define INSN_SIZE 4 +#define PC_OFFSET 8 +#define BL_OPCODE 0xeb000000 +#define BL_OFFSET_MASK 0x00ffffff + +static unsigned long bl_insn; +static const unsigned long NOP = 0xe1a00000; /* mov r0, r0 */ + +/* return true if mcount call site is already patched/no-op'ed */ +int ftrace_ip_converted(unsigned long pc) +{ + unsigned long save; + + pc -= INSN_SIZE; + save = *(unsigned long *)pc; + return save == NOP; +} + +unsigned char *ftrace_nop_replace(void) +{ + return (char *)&NOP; +} + +/* construct a branch (BL) instruction to addr */ +unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr) +{ + long offset; + + offset = (long)addr - (long)(pc - INSN_SIZE + PC_OFFSET); + if (unlikely(offset < -33554432 || offset > 33554428)) { + /* Can't generate branches that far (from ARM ARM). Ftrace + * doesn't generate branches outside of core kernel text. + */ + WARN_ON_ONCE(1); + return NULL; + } + offset = (offset >> 2) & BL_OFFSET_MASK; + bl_insn = BL_OPCODE | offset; + return (unsigned char *)&bl_insn; +} + +int ftrace_modify_code(unsigned long pc, unsigned char *old_code, + unsigned char *new_code) +{ + unsigned long err = 0, replaced = 0, old, new; + + old = *(unsigned long *)old_code; + new = *(unsigned long *)new_code; + pc -= INSN_SIZE; + + __asm__ __volatile__ ( + "1: ldr %1, [%2] \n" + " cmp %1, %4 \n" + "2: streq %3, [%2] \n" + " cmpne %1, %3 \n" + " movne %0, #2 \n" + "3:\n" + + ".section .fixup, \"ax\"\n" + "4: mov %0, #1 \n" + " b 3b \n" + ".previous\n" + + ".section __ex_table, \"a\"\n" + " .long 1b, 4b \n" + " .long 2b, 4b \n" + ".previous\n" + + : "=r"(err), "=r"(replaced) + : "r"(pc), "r"(new), "r"(old), "0"(err), "1"(replaced) + : "memory"); + + if (!err && (replaced == old)) + flush_icache_range(pc, pc + INSN_SIZE); + + return err; +} + +int ftrace_update_ftrace_func(ftrace_func_t func) +{ + int ret; + unsigned long pc, old; + unsigned char *new; + + pc = (unsigned long)&ftrace_call; + pc += INSN_SIZE; + memcpy(&old, &ftrace_call, INSN_SIZE); + new = ftrace_call_replace(pc, (unsigned long)func); + ret = ftrace_modify_code(pc, (unsigned char *)&old, new); + return ret; +} + +int ftrace_mcount_set(unsigned long *data) +{ + unsigned long pc, old; + unsigned long *addr = data; + unsigned char *new; + + pc = (unsigned long)&mcount_call; + pc += INSN_SIZE; + memcpy(&old, &mcount_call, INSN_SIZE); + new = ftrace_call_replace(pc, *addr); + *addr = ftrace_modify_code(pc, (unsigned char *)&old, new); + return 0; +} + +/* run from kstop_machine */ +int __init ftrace_dyn_arch_init(void *data) +{ + ftrace_mcount_set(data); + return 0; +} -- cgit v1.2.3-70-g09d2 From e0773410247f1e5fc6f7c52a4c5f3c6c9873d527 Mon Sep 17 00:00:00 2001 From: Abhishek Sagar Date: Sat, 31 May 2008 14:24:02 +0530 Subject: ftrace: export kretprobe_trampoline for function tracer Follow suit from kprobe implementations on other archs and make kretprobe_trampoline non-static. Ftrace implmentation (more specifically, kernel/trace/trace.c) requires access to it (see-> http://kerneltrap.org/mailarchive/linux-kernel/2008/5/27/1955234). Signed-off-by: Abhishek Sagar Signed-off-by: Ingo Molnar --- arch/arm/kernel/kprobes.c | 2 +- include/asm-arm/kprobes.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm/kernel/kprobes.c b/arch/arm/kernel/kprobes.c index 5593dd20721..5ee39e10c8d 100644 --- a/arch/arm/kernel/kprobes.c +++ b/arch/arm/kernel/kprobes.c @@ -274,7 +274,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, * for kretprobe handlers which should normally be interested in r0 only * anyway. */ -static void __attribute__((naked)) __kprobes kretprobe_trampoline(void) +void __naked __kprobes kretprobe_trampoline(void) { __asm__ __volatile__ ( "stmdb sp!, {r0 - r11} \n\t" diff --git a/include/asm-arm/kprobes.h b/include/asm-arm/kprobes.h index c042194d3ab..b1a37876942 100644 --- a/include/asm-arm/kprobes.h +++ b/include/asm-arm/kprobes.h @@ -59,6 +59,7 @@ struct kprobe_ctlblk { }; void arch_remove_kprobe(struct kprobe *); +void kretprobe_trampoline(void); int kprobe_trap_handler(struct pt_regs *regs, unsigned int instr); int kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr); -- cgit v1.2.3-70-g09d2 From 1d74f2a0f64b4091e5e91b55ac1b17dff93f4b59 Mon Sep 17 00:00:00 2001 From: Abhishek Sagar Date: Sun, 1 Jun 2008 21:47:42 +0530 Subject: ftrace: remove ftrace_ip_converted() Remove the unneeded function ftrace_ip_converted(). Signed-off-by: Abhishek Sagar Signed-off-by: Ingo Molnar --- arch/arm/kernel/ftrace.c | 10 ---------- arch/powerpc/kernel/ftrace.c | 10 ---------- arch/sparc64/kernel/ftrace.c | 7 ------- arch/x86/kernel/ftrace.c | 10 ---------- kernel/trace/ftrace.c | 7 ------- 5 files changed, 44 deletions(-) (limited to 'arch') diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index f4cb4cc3fa0..22f3d6e309f 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -22,16 +22,6 @@ static unsigned long bl_insn; static const unsigned long NOP = 0xe1a00000; /* mov r0, r0 */ -/* return true if mcount call site is already patched/no-op'ed */ -int ftrace_ip_converted(unsigned long pc) -{ - unsigned long save; - - pc -= INSN_SIZE; - save = *(unsigned long *)pc; - return save == NOP; -} - unsigned char *ftrace_nop_replace(void) { return (char *)&NOP; diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 69ed4122346..e12c593ab9c 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -27,16 +27,6 @@ static unsigned int ftrace_nop = 0x60000000; # define GET_ADDR(addr) *(unsigned long *)addr #endif -notrace int ftrace_ip_converted(unsigned long ip) -{ - unsigned int save; - - ip -= CALL_BACK; - save = *(unsigned int *)ip; - - return save == ftrace_nop; -} - static unsigned int notrace ftrace_calc_offset(long ip, long addr) { return (int)((addr + CALL_BACK) - ip); diff --git a/arch/sparc64/kernel/ftrace.c b/arch/sparc64/kernel/ftrace.c index f449e6df6c4..c17373195b1 100644 --- a/arch/sparc64/kernel/ftrace.c +++ b/arch/sparc64/kernel/ftrace.c @@ -7,13 +7,6 @@ static const u32 ftrace_nop = 0x01000000; -notrace int ftrace_ip_converted(unsigned long ip) -{ - u32 insn = *(u32 *) ip; - - return (insn == ftrace_nop); -} - notrace unsigned char *ftrace_nop_replace(void) { return (char *)&ftrace_nop; diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 498608c015f..bc5cf8d4674 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -31,16 +31,6 @@ union ftrace_code_union { } __attribute__((packed)); }; -notrace int ftrace_ip_converted(unsigned long ip) -{ - unsigned long save; - - ip -= CALL_BACK; - save = *(long *)ip; - - return save == *ftrace_nop; -} - static int notrace ftrace_calc_offset(long ip, long addr) { return (int)(addr - ip); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ec54cb7d69d..a8929e4c77c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -306,13 +306,6 @@ ftrace_record_ip(unsigned long ip) if (ftrace_ip_in_hash(ip, key)) goto out_unlock; - /* - * There's a slight race that the ftraced will update the - * hash and reset here. If it is already converted, skip it. - */ - if (ftrace_ip_converted(ip)) - goto out_unlock; - node = ftrace_alloc_dyn_node(ip); if (!node) goto out_unlock; -- cgit v1.2.3-70-g09d2 From ee4311adf105f4d740f52e3948acc1d81598afcc Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 17 Jun 2008 17:43:02 +0200 Subject: ftrace: build fix with gcc 4.3 fix: arch/x86/kernel/ftrace.c: Assembler messages: arch/x86/kernel/ftrace.c:82: Error: bad register name `%sil' make[1]: *** [arch/x86/kernel/ftrace.o] Error 1 Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index bc5cf8d4674..55828149e01 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -88,7 +88,7 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, ".previous\n" _ASM_EXTABLE(1b, 3b) : "=r"(faulted), "=a"(replaced) - : "r"(ip), "r"(new), "r"(newch), + : "r"(ip), "r"(new), "c"(newch), "0"(faulted), "a"(old) : "memory"); sync_core(); -- cgit v1.2.3-70-g09d2 From 395a59d0f8e86bb39cd700c3d185d30c670bb958 Mon Sep 17 00:00:00 2001 From: Abhishek Sagar Date: Sat, 21 Jun 2008 23:47:27 +0530 Subject: ftrace: store mcount address in rec->ip Record the address of the mcount call-site. Currently all archs except sparc64 record the address of the instruction following the mcount call-site. Some general cleanups are entailed. Storing mcount addresses in rec->ip enables looking them up in the kprobe hash table later on to check if they're kprobe'd. Signed-off-by: Abhishek Sagar Cc: davem@davemloft.net Cc: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/arm/kernel/armksyms.c | 10 +++++----- arch/arm/kernel/entry-common.S | 4 ++++ arch/arm/kernel/ftrace.c | 16 +++++++--------- arch/powerpc/kernel/entry_32.S | 4 ++++ arch/powerpc/kernel/entry_64.S | 5 ++++- arch/powerpc/kernel/ftrace.c | 21 +++++++-------------- arch/sparc64/kernel/ftrace.c | 10 ++++++---- arch/sparc64/kernel/sparc64_ksyms.c | 2 +- arch/x86/kernel/entry_32.S | 4 ++++ arch/x86/kernel/entry_64.S | 4 ++++ arch/x86/kernel/ftrace.c | 26 +++++++++----------------- arch/x86/kernel/i386_ksyms_32.c | 2 +- arch/x86/kernel/x8664_ksyms_64.c | 2 +- include/asm-arm/ftrace.h | 14 ++++++++++++++ include/asm-powerpc/ftrace.h | 8 ++++++++ include/asm-sparc64/ftrace.h | 14 ++++++++++++++ include/asm-x86/ftrace.h | 14 ++++++++++++++ include/linux/ftrace.h | 3 +-- kernel/trace/ftrace.c | 3 ++- 19 files changed, 110 insertions(+), 56 deletions(-) create mode 100644 include/asm-arm/ftrace.h create mode 100644 include/asm-sparc64/ftrace.h create mode 100644 include/asm-x86/ftrace.h (limited to 'arch') diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 3b132215cbf..cc7b246e965 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -18,6 +18,7 @@ #include #include #include +#include /* * libgcc functions - functions that are used internally by the @@ -48,11 +49,6 @@ extern void __aeabi_ulcmp(void); extern void fpundefinstr(void); extern void fp_enter(void); -#ifdef CONFIG_FTRACE -extern void mcount(void); -EXPORT_SYMBOL(mcount); -#endif - /* * This has a special calling convention; it doesn't * modify any of the usual registers, except for LR. @@ -186,3 +182,7 @@ EXPORT_SYMBOL(_find_next_bit_be); #endif EXPORT_SYMBOL(copy_page); + +#ifdef CONFIG_FTRACE +EXPORT_SYMBOL(mcount); +#endif diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 8f79a4789ed..84694e88b42 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -9,6 +9,7 @@ */ #include +#include #include #include "entry-header.S" @@ -104,6 +105,7 @@ ENTRY(ret_from_fork) ENTRY(mcount) stmdb sp!, {r0-r3, lr} mov r0, lr + sub r0, r0, #MCOUNT_INSN_SIZE .globl mcount_call mcount_call: @@ -114,6 +116,7 @@ ENTRY(ftrace_caller) stmdb sp!, {r0-r3, lr} ldr r1, [fp, #-4] mov r0, lr + sub r0, r0, #MCOUNT_INSN_SIZE .globl ftrace_call ftrace_call: @@ -134,6 +137,7 @@ ENTRY(mcount) trace: ldr r1, [fp, #-4] mov r0, lr + sub r0, r0, #MCOUNT_INSN_SIZE mov lr, pc mov pc, r2 ldmia sp!, {r0-r3, pc} diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 22f3d6e309f..76d50e6091b 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -12,9 +12,10 @@ */ #include + #include +#include -#define INSN_SIZE 4 #define PC_OFFSET 8 #define BL_OPCODE 0xeb000000 #define BL_OFFSET_MASK 0x00ffffff @@ -32,10 +33,10 @@ unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr) { long offset; - offset = (long)addr - (long)(pc - INSN_SIZE + PC_OFFSET); + offset = (long)addr - (long)(pc + PC_OFFSET); if (unlikely(offset < -33554432 || offset > 33554428)) { /* Can't generate branches that far (from ARM ARM). Ftrace - * doesn't generate branches outside of core kernel text. + * doesn't generate branches outside of kernel text. */ WARN_ON_ONCE(1); return NULL; @@ -52,7 +53,6 @@ int ftrace_modify_code(unsigned long pc, unsigned char *old_code, old = *(unsigned long *)old_code; new = *(unsigned long *)new_code; - pc -= INSN_SIZE; __asm__ __volatile__ ( "1: ldr %1, [%2] \n" @@ -77,7 +77,7 @@ int ftrace_modify_code(unsigned long pc, unsigned char *old_code, : "memory"); if (!err && (replaced == old)) - flush_icache_range(pc, pc + INSN_SIZE); + flush_icache_range(pc, pc + MCOUNT_INSN_SIZE); return err; } @@ -89,8 +89,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func) unsigned char *new; pc = (unsigned long)&ftrace_call; - pc += INSN_SIZE; - memcpy(&old, &ftrace_call, INSN_SIZE); + memcpy(&old, &ftrace_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(pc, (unsigned long)func); ret = ftrace_modify_code(pc, (unsigned char *)&old, new); return ret; @@ -103,8 +102,7 @@ int ftrace_mcount_set(unsigned long *data) unsigned char *new; pc = (unsigned long)&mcount_call; - pc += INSN_SIZE; - memcpy(&old, &mcount_call, INSN_SIZE); + memcpy(&old, &mcount_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(pc, *addr); *addr = ftrace_modify_code(pc, (unsigned char *)&old, new); return 0; diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 3b1dd29d9f9..7231a708af0 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -30,6 +30,7 @@ #include #include #include +#include #undef SHOW_SYSCALLS #undef SHOW_SYSCALLS_TASK @@ -1053,6 +1054,7 @@ _GLOBAL(_mcount) stw r10,40(r1) stw r3, 44(r1) stw r5, 8(r1) + subi r3, r3, MCOUNT_INSN_SIZE .globl mcount_call mcount_call: bl ftrace_stub @@ -1090,6 +1092,7 @@ _GLOBAL(ftrace_caller) stw r10,40(r1) stw r3, 44(r1) stw r5, 8(r1) + subi r3, r3, MCOUNT_INSN_SIZE .globl ftrace_call ftrace_call: bl ftrace_stub @@ -1128,6 +1131,7 @@ _GLOBAL(_mcount) stw r3, 44(r1) stw r5, 8(r1) + subi r3, r3, MCOUNT_INSN_SIZE LOAD_REG_ADDR(r5, ftrace_trace_function) lwz r5,0(r5) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 2c4d9e056ea..2f511a969d2 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -31,6 +31,7 @@ #include #include #include +#include /* * System calls. @@ -879,6 +880,7 @@ _GLOBAL(_mcount) mflr r3 stdu r1, -112(r1) std r3, 128(r1) + subi r3, r3, MCOUNT_INSN_SIZE .globl mcount_call mcount_call: bl ftrace_stub @@ -895,6 +897,7 @@ _GLOBAL(ftrace_caller) stdu r1, -112(r1) std r3, 128(r1) ld r4, 16(r11) + subi r3, r3, MCOUNT_INSN_SIZE .globl ftrace_call ftrace_call: bl ftrace_stub @@ -916,7 +919,7 @@ _GLOBAL(_mcount) std r3, 128(r1) ld r4, 16(r11) - + subi r3, r3, MCOUNT_INSN_SIZE LOAD_REG_ADDR(r5,ftrace_trace_function) ld r5,0(r5) ld r5,0(r5) diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index e12c593ab9c..3855ceb937b 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -15,8 +15,8 @@ #include #include +#include -#define CALL_BACK 4 static unsigned int ftrace_nop = 0x60000000; @@ -27,9 +27,10 @@ static unsigned int ftrace_nop = 0x60000000; # define GET_ADDR(addr) *(unsigned long *)addr #endif + static unsigned int notrace ftrace_calc_offset(long ip, long addr) { - return (int)((addr + CALL_BACK) - ip); + return (int)(addr - ip); } notrace unsigned char *ftrace_nop_replace(void) @@ -76,9 +77,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned new = *(unsigned *)new_code; int faulted = 0; - /* move the IP back to the start of the call */ - ip -= CALL_BACK; - /* * Note: Due to modules and __init, code can * disappear and change, we need to protect against faulting @@ -118,12 +116,10 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, notrace int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned long ip = (unsigned long)(&ftrace_call); - unsigned char old[4], *new; + unsigned char old[MCOUNT_INSN_SIZE], *new; int ret; - ip += CALL_BACK; - - memcpy(old, &ftrace_call, 4); + memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, (unsigned long)func); ret = ftrace_modify_code(ip, old, new); @@ -134,16 +130,13 @@ notrace int ftrace_mcount_set(unsigned long *data) { unsigned long ip = (long)(&mcount_call); unsigned long *addr = data; - unsigned char old[4], *new; - - /* ip is at the location, but modify code will subtact this */ - ip += CALL_BACK; + unsigned char old[MCOUNT_INSN_SIZE], *new; /* * Replace the mcount stub with a pointer to the * ip recorder function. */ - memcpy(old, &mcount_call, 4); + memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, *addr); *addr = ftrace_modify_code(ip, old, new); diff --git a/arch/sparc64/kernel/ftrace.c b/arch/sparc64/kernel/ftrace.c index c17373195b1..4298d0aee71 100644 --- a/arch/sparc64/kernel/ftrace.c +++ b/arch/sparc64/kernel/ftrace.c @@ -5,6 +5,8 @@ #include #include +#include + static const u32 ftrace_nop = 0x01000000; notrace unsigned char *ftrace_nop_replace(void) @@ -60,9 +62,9 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, notrace int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned long ip = (unsigned long)(&ftrace_call); - unsigned char old[4], *new; + unsigned char old[MCOUNT_INSN_SIZE], *new; - memcpy(old, &ftrace_call, 4); + memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, (unsigned long)func); return ftrace_modify_code(ip, old, new); } @@ -71,13 +73,13 @@ notrace int ftrace_mcount_set(unsigned long *data) { unsigned long ip = (long)(&mcount_call); unsigned long *addr = data; - unsigned char old[4], *new; + unsigned char old[MCOUNT_INSN_SIZE], *new; /* * Replace the mcount stub with a pointer to the * ip recorder function. */ - memcpy(old, &mcount_call, 4); + memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, *addr); *addr = ftrace_modify_code(ip, old, new); diff --git a/arch/sparc64/kernel/sparc64_ksyms.c b/arch/sparc64/kernel/sparc64_ksyms.c index 8ac0b99f2c5..b80d982a29c 100644 --- a/arch/sparc64/kernel/sparc64_ksyms.c +++ b/arch/sparc64/kernel/sparc64_ksyms.c @@ -53,6 +53,7 @@ #include #include #include +#include struct poll { int fd; @@ -112,7 +113,6 @@ EXPORT_SYMBOL(smp_call_function); #endif /* CONFIG_SMP */ #if defined(CONFIG_MCOUNT) -extern void _mcount(void); EXPORT_SYMBOL(_mcount); #endif diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 04ea83ccb97..95e6bbe3665 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -51,6 +51,7 @@ #include #include #include +#include #include "irq_vectors.h" /* @@ -1118,6 +1119,7 @@ ENTRY(mcount) pushl %ecx pushl %edx movl 0xc(%esp), %eax + subl $MCOUNT_INSN_SIZE, %eax .globl mcount_call mcount_call: @@ -1136,6 +1138,7 @@ ENTRY(ftrace_caller) pushl %edx movl 0xc(%esp), %eax movl 0x4(%ebp), %edx + subl $MCOUNT_INSN_SIZE, %eax .globl ftrace_call ftrace_call: @@ -1166,6 +1169,7 @@ trace: pushl %edx movl 0xc(%esp), %eax movl 0x4(%ebp), %edx + subl $MCOUNT_INSN_SIZE, %eax call *ftrace_trace_function diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index fe25e5febca..b0f7308f78a 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -51,6 +51,7 @@ #include #include #include +#include .code64 @@ -68,6 +69,7 @@ ENTRY(mcount) movq %r9, 48(%rsp) movq 0x38(%rsp), %rdi + subq $MCOUNT_INSN_SIZE, %rdi .globl mcount_call mcount_call: @@ -99,6 +101,7 @@ ENTRY(ftrace_caller) movq 0x38(%rsp), %rdi movq 8(%rbp), %rsi + subq $MCOUNT_INSN_SIZE, %rdi .globl ftrace_call ftrace_call: @@ -139,6 +142,7 @@ trace: movq 0x38(%rsp), %rdi movq 8(%rbp), %rsi + subq $MCOUNT_INSN_SIZE, %rdi call *ftrace_trace_function diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 55828149e01..ab115cd15fd 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -17,20 +17,21 @@ #include #include +#include -#define CALL_BACK 5 /* Long is fine, even if it is only 4 bytes ;-) */ static long *ftrace_nop; union ftrace_code_union { - char code[5]; + char code[MCOUNT_INSN_SIZE]; struct { char e8; int offset; } __attribute__((packed)); }; + static int notrace ftrace_calc_offset(long ip, long addr) { return (int)(addr - ip); @@ -46,7 +47,7 @@ notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) static union ftrace_code_union calc; calc.e8 = 0xe8; - calc.offset = ftrace_calc_offset(ip, addr); + calc.offset = ftrace_calc_offset(ip + MCOUNT_INSN_SIZE, addr); /* * No locking needed, this must be called via kstop_machine @@ -65,9 +66,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char newch = new_code[4]; int faulted = 0; - /* move the IP back to the start of the call */ - ip -= CALL_BACK; - /* * Note: Due to modules and __init, code can * disappear and change, we need to protect against faulting @@ -102,12 +100,10 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, notrace int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned long ip = (unsigned long)(&ftrace_call); - unsigned char old[5], *new; + unsigned char old[MCOUNT_INSN_SIZE], *new; int ret; - ip += CALL_BACK; - - memcpy(old, &ftrace_call, 5); + memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, (unsigned long)func); ret = ftrace_modify_code(ip, old, new); @@ -118,16 +114,13 @@ notrace int ftrace_mcount_set(unsigned long *data) { unsigned long ip = (long)(&mcount_call); unsigned long *addr = data; - unsigned char old[5], *new; - - /* ip is at the location, but modify code will subtact this */ - ip += CALL_BACK; + unsigned char old[MCOUNT_INSN_SIZE], *new; /* * Replace the mcount stub with a pointer to the * ip recorder function. */ - memcpy(old, &mcount_call, 5); + memcpy(old, &mcount_call, MCOUNT_INSN_SIZE); new = ftrace_call_replace(ip, *addr); *addr = ftrace_modify_code(ip, old, new); @@ -142,8 +135,7 @@ int __init ftrace_dyn_arch_init(void *data) ftrace_mcount_set(data); - ftrace_nop = (unsigned long *)noptable[CALL_BACK]; + ftrace_nop = (unsigned long *)noptable[MCOUNT_INSN_SIZE]; return 0; } - diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c index 29999dbb754..dd7ebee446a 100644 --- a/arch/x86/kernel/i386_ksyms_32.c +++ b/arch/x86/kernel/i386_ksyms_32.c @@ -1,9 +1,9 @@ -#include #include #include #include #include +#include #ifdef CONFIG_FTRACE /* mcount is defined in assembly */ diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index 122885bc5f3..16ff4bf418d 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -1,7 +1,6 @@ /* Exports for assembly files. All C exports should go in the respective C files. */ -#include #include #include @@ -11,6 +10,7 @@ #include #include #include +#include #ifdef CONFIG_FTRACE /* mcount is defined in assembly */ diff --git a/include/asm-arm/ftrace.h b/include/asm-arm/ftrace.h new file mode 100644 index 00000000000..584ef9a8e5a --- /dev/null +++ b/include/asm-arm/ftrace.h @@ -0,0 +1,14 @@ +#ifndef _ASM_ARM_FTRACE +#define _ASM_ARM_FTRACE + +#ifdef CONFIG_FTRACE +#define MCOUNT_ADDR ((long)(mcount)) +#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ + +#ifndef __ASSEMBLY__ +extern void mcount(void); +#endif + +#endif + +#endif /* _ASM_ARM_FTRACE */ diff --git a/include/asm-powerpc/ftrace.h b/include/asm-powerpc/ftrace.h index b1bfa704b6e..de921326cca 100644 --- a/include/asm-powerpc/ftrace.h +++ b/include/asm-powerpc/ftrace.h @@ -1,6 +1,14 @@ #ifndef _ASM_POWERPC_FTRACE #define _ASM_POWERPC_FTRACE +#ifdef CONFIG_FTRACE +#define MCOUNT_ADDR ((long)(_mcount)) +#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ + +#ifndef __ASSEMBLY__ extern void _mcount(void); +#endif #endif + +#endif /* _ASM_POWERPC_FTRACE */ diff --git a/include/asm-sparc64/ftrace.h b/include/asm-sparc64/ftrace.h new file mode 100644 index 00000000000..f76a40a338b --- /dev/null +++ b/include/asm-sparc64/ftrace.h @@ -0,0 +1,14 @@ +#ifndef _ASM_SPARC64_FTRACE +#define _ASM_SPARC64_FTRACE + +#ifdef CONFIG_FTRACE +#define MCOUNT_ADDR ((long)(_mcount)) +#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ + +#ifndef __ASSEMBLY__ +extern void _mcount(void); +#endif + +#endif + +#endif /* _ASM_SPARC64_FTRACE */ diff --git a/include/asm-x86/ftrace.h b/include/asm-x86/ftrace.h new file mode 100644 index 00000000000..c184441133f --- /dev/null +++ b/include/asm-x86/ftrace.h @@ -0,0 +1,14 @@ +#ifndef _ASM_X86_FTRACE +#define _ASM_SPARC64_FTRACE + +#ifdef CONFIG_FTRACE +#define MCOUNT_ADDR ((long)(mcount)) +#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */ + +#ifndef __ASSEMBLY__ +extern void mcount(void); +#endif + +#endif /* CONFIG_FTRACE */ + +#endif /* _ASM_X86_FTRACE */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 20e14d0093c..366098d591d 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -31,7 +31,6 @@ int unregister_ftrace_function(struct ftrace_ops *ops); void clear_ftrace_function(void); extern void ftrace_stub(unsigned long a0, unsigned long a1); -extern void mcount(void); #else /* !CONFIG_FTRACE */ # define register_ftrace_function(ops) do { } while (0) @@ -54,7 +53,7 @@ enum { struct dyn_ftrace { struct hlist_node node; - unsigned long ip; + unsigned long ip; /* address of mcount call-site */ unsigned long flags; }; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0d5bcf69952..f1e9e5c74e6 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -27,6 +27,8 @@ #include #include +#include + #include "trace.h" /* ftrace_enabled is a method to turn ftrace on or off */ @@ -329,7 +331,6 @@ ftrace_record_ip(unsigned long ip) } #define FTRACE_ADDR ((long)(ftrace_caller)) -#define MCOUNT_ADDR ((long)(mcount)) static int __ftrace_replace_code(struct dyn_ftrace *rec, -- cgit v1.2.3-70-g09d2 From 760378e1497841246ea7e42abad617d8a8ac0bcc Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 1 Jul 2008 17:35:06 +0200 Subject: fix "ftrace: store mcount address in rec->ip" Alexander Beregalov reported this build failure: $ make CROSS_COMPILE=sparc64-unknown-linux-gnu- image modules && sudo make modules_install CHK include/linux/version.h CHK include/linux/utsrelease.h CALL scripts/checksyscalls.sh CHK include/linux/compile.h dnsdomainname: Unknown host CC arch/sparc64/kernel/sparc64_ksyms.o arch/sparc64/kernel/sparc64_ksyms.c:116: error: '_mcount' undeclared here (not in a function) cc1: warnings being treated as errors arch/sparc64/kernel/sparc64_ksyms.c:116: error: type defaults to 'int' in declaration of '_mcount' And bisected it back to: | commit 395a59d0f8e86bb39cd700c3d185d30c670bb958 | Author: Abhishek Sagar | Date: Sat Jun 21 23:47:27 2008 +0530 | | ftrace: store mcount address in rec->ip the mcount prototype is only available under CONFIG_FTRACE, extend it to CONFIG_MCOUNT as well. Reported-and-bisected-by: Alexander Beregalov Signed-off-by: Ingo Molnar --- arch/sparc64/kernel/sparc64_ksyms.c | 2 +- include/asm-sparc64/ftrace.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/sparc64/kernel/sparc64_ksyms.c b/arch/sparc64/kernel/sparc64_ksyms.c index b80d982a29c..49d3ea50c24 100644 --- a/arch/sparc64/kernel/sparc64_ksyms.c +++ b/arch/sparc64/kernel/sparc64_ksyms.c @@ -112,7 +112,7 @@ EXPORT_SYMBOL(__write_trylock); EXPORT_SYMBOL(smp_call_function); #endif /* CONFIG_SMP */ -#if defined(CONFIG_MCOUNT) +#ifdef CONFIG_MCOUNT EXPORT_SYMBOL(_mcount); #endif diff --git a/include/asm-sparc64/ftrace.h b/include/asm-sparc64/ftrace.h index f76a40a338b..d27716cd38c 100644 --- a/include/asm-sparc64/ftrace.h +++ b/include/asm-sparc64/ftrace.h @@ -1,7 +1,7 @@ #ifndef _ASM_SPARC64_FTRACE #define _ASM_SPARC64_FTRACE -#ifdef CONFIG_FTRACE +#ifdef CONFIG_MCOUNT #define MCOUNT_ADDR ((long)(_mcount)) #define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ -- cgit v1.2.3-70-g09d2