From eb4a03780d4c4464ef2ad86d80cca3f3284fe81d Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 18 Jun 2009 12:53:21 -0400 Subject: function-graph: disable when both x86_32 and optimize for size are configured On x86_32, when optimize for size is set, gcc may align the frame pointer and make a copy of the the return address inside the stack frame. The return address that is located in the stack frame may not be the one used to return to the calling function. This will break the function graph tracer. The function graph tracer replaces the return address with a jump to a hook function that can trace the exit of the function. If it only replaces a copy, then the hook will not be called when the function returns. Worse yet, when the parent function returns, the function graph tracer will return back to the location of the child function which will easily crash the kernel with weird results. To see the problem, when i386 is compiled with -Os we get: c106be03: 57 push %edi c106be04: 8d 7c 24 08 lea 0x8(%esp),%edi c106be08: 83 e4 e0 and $0xffffffe0,%esp c106be0b: ff 77 fc pushl 0xfffffffc(%edi) c106be0e: 55 push %ebp c106be0f: 89 e5 mov %esp,%ebp c106be11: 57 push %edi c106be12: 56 push %esi c106be13: 53 push %ebx c106be14: 81 ec 8c 00 00 00 sub $0x8c,%esp c106be1a: e8 f5 57 fb ff call c1021614 When it is compiled with -O2 instead we get: c10896f0: 55 push %ebp c10896f1: 89 e5 mov %esp,%ebp c10896f3: 83 ec 28 sub $0x28,%esp c10896f6: 89 5d f4 mov %ebx,0xfffffff4(%ebp) c10896f9: 89 75 f8 mov %esi,0xfffffff8(%ebp) c10896fc: 89 7d fc mov %edi,0xfffffffc(%ebp) c10896ff: e8 d0 08 fa ff call c1029fd4 The compile with -Os will align the stack pointer then set up the frame pointer (%ebp), and it copies the return address back into the stack frame. The change to the return address in mcount is done to the copy and not the real place holder of the return address. Then compile with -O2 sets up the frame pointer first, this makes the change to the return address by mcount affect where the function will jump on exit. Reported-by: Jake Edge Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 4a13e5a01ce..1eac85253ce 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -121,6 +121,7 @@ config FUNCTION_GRAPH_TRACER bool "Kernel Function Graph Tracer" depends on HAVE_FUNCTION_GRAPH_TRACER depends on FUNCTION_TRACER + depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE default y help Enable the kernel to trace a function at both its return -- cgit v1.2.3-70-g09d2 From 71e308a239c098673570d0b417d42262bb535909 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 18 Jun 2009 12:45:08 -0400 Subject: function-graph: add stack frame test In case gcc does something funny with the stack frames, or the return from function code, we would like to detect that. An arch may implement passing of a variable that is unique to the function and can be saved on entering a function and can be tested when exiting the function. Usually the frame pointer can be used for this purpose. This patch also implements this for x86. Where it passes in the stack frame of the parent function, and will test that frame on exit. There was a case in x86_32 with optimize for size (-Os) where, for a few functions, gcc would align the stack frame and place a copy of the return address into it. The function graph tracer modified the copy and not the actual return address. On return from the funtion, it did not go to the tracer hook, but returned to the parent. This broke the function graph tracer, because the return of the parent (where gcc did not do this funky manipulation) returned to the location that the child function was suppose to. This caused strange kernel crashes. This test detected the problem and pointed out where the issue was. This modifies the parameters of one of the functions that the arch specific code calls, so it includes changes to arch code to accommodate the new prototype. Note, I notice that the parsic arch implements its own push_return_trace. This is now a generic function and the ftrace_push_return_trace should be used instead. This patch does not touch that code. Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Frederic Weisbecker Cc: Helge Deller Cc: Kyle McMartin Signed-off-by: Steven Rostedt --- arch/powerpc/kernel/ftrace.c | 2 +- arch/s390/kernel/ftrace.c | 2 +- arch/x86/Kconfig | 1 + arch/x86/kernel/entry_32.S | 2 ++ arch/x86/kernel/entry_64.S | 2 ++ arch/x86/kernel/ftrace.c | 6 ++++-- include/linux/ftrace.h | 4 +++- kernel/trace/Kconfig | 7 +++++++ kernel/trace/trace_functions_graph.c | 36 ++++++++++++++++++++++++++++++++---- 9 files changed, 53 insertions(+), 9 deletions(-) (limited to 'kernel/trace/Kconfig') diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 2d182f119d1..58d6a610904 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -605,7 +605,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) return; } - if (ftrace_push_return_trace(old, self_addr, &trace.depth) == -EBUSY) { + if (ftrace_push_return_trace(old, self_addr, &trace.depth, 0) == -EBUSY) { *parent = old; return; } diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 82ddfd3a75a..3e298e64f0d 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -190,7 +190,7 @@ unsigned long prepare_ftrace_return(unsigned long ip, unsigned long parent) goto out; if (unlikely(atomic_read(¤t->tracing_graph_pause))) goto out; - if (ftrace_push_return_trace(parent, ip, &trace.depth) == -EBUSY) + if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY) goto out; trace.func = ftrace_mcount_call_adjust(ip) & PSW_ADDR_INSN; /* Only trace if the calling function expects to. */ diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 356d2ec8e2f..fcf12af0742 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -33,6 +33,7 @@ config X86 select HAVE_DYNAMIC_FTRACE select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_GRAPH_TRACER + select HAVE_FUNCTION_GRAPH_FP_TEST select HAVE_FUNCTION_TRACE_MCOUNT_TEST select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE select HAVE_FTRACE_SYSCALLS diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index c929add475c..0d4b28564c1 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1154,6 +1154,7 @@ ENTRY(ftrace_graph_caller) pushl %edx movl 0xc(%esp), %edx lea 0x4(%ebp), %eax + movl (%ebp), %ecx subl $MCOUNT_INSN_SIZE, %edx call prepare_ftrace_return popl %edx @@ -1168,6 +1169,7 @@ return_to_handler: pushl %eax pushl %ecx pushl %edx + movl %ebp, %eax call ftrace_return_to_handler movl %eax, 0xc(%esp) popl %edx diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index de74f0a3e0e..c251be74510 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -135,6 +135,7 @@ ENTRY(ftrace_graph_caller) leaq 8(%rbp), %rdi movq 0x38(%rsp), %rsi + movq (%rbp), %rdx subq $MCOUNT_INSN_SIZE, %rsi call prepare_ftrace_return @@ -150,6 +151,7 @@ GLOBAL(return_to_handler) /* Save the return values */ movq %rax, (%rsp) movq %rdx, 8(%rsp) + movq %rbp, %rdi call ftrace_return_to_handler diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index b79c5533c42..d94e1ea3b9f 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -408,7 +408,8 @@ int ftrace_disable_ftrace_graph_caller(void) * Hook the return address and push it in the stack of return addrs * in current thread info. */ -void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) +void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, + unsigned long frame_pointer) { unsigned long old; int faulted; @@ -453,7 +454,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) return; } - if (ftrace_push_return_trace(old, self_addr, &trace.depth) == -EBUSY) { + if (ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer) == -EBUSY) { *parent = old; return; } diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 39b95c56587..dc3b1328aae 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -362,6 +362,7 @@ struct ftrace_ret_stack { unsigned long func; unsigned long long calltime; unsigned long long subtime; + unsigned long fp; }; /* @@ -372,7 +373,8 @@ struct ftrace_ret_stack { extern void return_to_handler(void); extern int -ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth); +ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, + unsigned long frame_pointer); /* * Sometimes we don't want to trace a function with the function diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 1eac85253ce..b17ed8787de 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -18,6 +18,13 @@ config HAVE_FUNCTION_TRACER config HAVE_FUNCTION_GRAPH_TRACER bool +config HAVE_FUNCTION_GRAPH_FP_TEST + bool + help + An arch may pass in a unique value (frame pointer) to both the + entering and exiting of a function. On exit, the value is compared + and if it does not match, then it will panic the kernel. + config HAVE_FUNCTION_TRACE_MCOUNT_TEST bool help diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 8b592418d8b..d2249abafb5 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -57,7 +57,8 @@ static struct tracer_flags tracer_flags = { /* Add a function return address to the trace stack on thread info.*/ int -ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth) +ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, + unsigned long frame_pointer) { unsigned long long calltime; int index; @@ -85,6 +86,7 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth) current->ret_stack[index].func = func; current->ret_stack[index].calltime = calltime; current->ret_stack[index].subtime = 0; + current->ret_stack[index].fp = frame_pointer; *depth = index; return 0; @@ -92,7 +94,8 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth) /* Retrieve a function return address to the trace stack on thread info.*/ static void -ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) +ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, + unsigned long frame_pointer) { int index; @@ -106,6 +109,31 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) return; } +#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST + /* + * The arch may choose to record the frame pointer used + * and check it here to make sure that it is what we expect it + * to be. If gcc does not set the place holder of the return + * address in the frame pointer, and does a copy instead, then + * the function graph trace will fail. This test detects this + * case. + * + * Currently, x86_32 with optimize for size (-Os) makes the latest + * gcc do the above. + */ + if (unlikely(current->ret_stack[index].fp != frame_pointer)) { + ftrace_graph_stop(); + WARN(1, "Bad frame pointer: expected %lx, received %lx\n" + " from func %pF return to %lx\n", + current->ret_stack[index].fp, + frame_pointer, + (void *)current->ret_stack[index].func, + current->ret_stack[index].ret); + *ret = (unsigned long)panic; + return; + } +#endif + *ret = current->ret_stack[index].ret; trace->func = current->ret_stack[index].func; trace->calltime = current->ret_stack[index].calltime; @@ -117,12 +145,12 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret) * Send the trace to the ring-buffer. * @return the original return address. */ -unsigned long ftrace_return_to_handler(void) +unsigned long ftrace_return_to_handler(unsigned long frame_pointer) { struct ftrace_graph_ret trace; unsigned long ret; - ftrace_pop_return_trace(&trace, &ret); + ftrace_pop_return_trace(&trace, &ret, frame_pointer); trace.rettime = trace_clock_local(); ftrace_graph_return(&trace); barrier(); -- cgit v1.2.3-70-g09d2 From 238a24f626628cb16a3015f332d649f08246ca89 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 29 Jun 2009 15:55:10 +0800 Subject: tracing/fastboot: Document the need of initcall_debug To use boot tracer, one should pass initcall_debug as well as ftrace=initcall to the command line. Signed-off-by: Li Zefan Cc: Frederic Weisbecker Cc: Steven Rostedt LKML-Reference: <4A48735E.9050002@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/Kconfig | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 1551f47e766..019f380fd76 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -226,13 +226,13 @@ config BOOT_TRACER the timings of the initcalls and traces key events and the identity of tasks that can cause boot delays, such as context-switches. - Its aim is to be parsed by the /scripts/bootgraph.pl tool to + Its aim is to be parsed by the scripts/bootgraph.pl tool to produce pretty graphics about boot inefficiencies, giving a visual representation of the delays during initcalls - but the raw /debug/tracing/trace text output is readable too. - You must pass in ftrace=initcall to the kernel command line - to enable this on bootup. + You must pass in initcall_debug and ftrace=initcall to the kernel + command line to enable this on bootup. config TRACE_BRANCH_PROFILING bool -- cgit v1.2.3-70-g09d2 From 667000011927b4fcc359beac4a2447889db6d349 Mon Sep 17 00:00:00 2001 From: Josh Stone Date: Mon, 24 Aug 2009 14:43:11 -0700 Subject: tracing: Rename FTRACE_SYSCALLS for tracepoints s/HAVE_FTRACE_SYSCALLS/HAVE_SYSCALL_TRACEPOINTS/g s/TIF_SYSCALL_FTRACE/TIF_SYSCALL_TRACEPOINT/g The syscall enter/exit tracing is no longer specific to just ftrace, so they now have names that reflect their tie to tracepoints instead. Signed-off-by: Josh Stone Cc: Jason Baron Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Li Zefan Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Mathieu Desnoyers Cc: Jiaying Zhang Cc: Martin Bligh Cc: Lai Jiangshan Cc: Paul Mundt Cc: Martin Schwidefsky Cc: Heiko Carstens LKML-Reference: <1251150194-1713-2-git-send-email-jistone@redhat.com> Signed-off-by: Frederic Weisbecker --- arch/s390/Kconfig | 2 +- arch/s390/defconfig | 2 +- arch/s390/include/asm/thread_info.h | 4 ++-- arch/s390/kernel/entry.S | 2 +- arch/s390/kernel/entry64.S | 2 +- arch/s390/kernel/ptrace.c | 4 ++-- arch/x86/Kconfig | 2 +- arch/x86/configs/i386_defconfig | 2 +- arch/x86/configs/x86_64_defconfig | 2 +- arch/x86/include/asm/thread_info.h | 13 +++++++------ arch/x86/kernel/ptrace.c | 4 ++-- kernel/trace/Kconfig | 4 ++-- kernel/tracepoint.c | 4 ++-- 13 files changed, 24 insertions(+), 23 deletions(-) (limited to 'kernel/trace/Kconfig') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 2ae5d72f47e..7238ef4c7a6 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -84,7 +84,7 @@ config S390 select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_TRACE_MCOUNT_TEST select HAVE_FTRACE_MCOUNT_RECORD - select HAVE_FTRACE_SYSCALLS + select HAVE_SYSCALL_TRACEPOINTS select HAVE_DYNAMIC_FTRACE select HAVE_FUNCTION_GRAPH_TRACER select HAVE_DEFAULT_NO_SPIN_MUTEXES diff --git a/arch/s390/defconfig b/arch/s390/defconfig index fcba206529f..4e91a2573cc 100644 --- a/arch/s390/defconfig +++ b/arch/s390/defconfig @@ -900,7 +900,7 @@ CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y CONFIG_HAVE_DYNAMIC_FTRACE=y CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y -CONFIG_HAVE_FTRACE_SYSCALLS=y +CONFIG_HAVE_SYSCALL_TRACEPOINTS=y CONFIG_TRACING_SUPPORT=y CONFIG_FTRACE=y # CONFIG_FUNCTION_TRACER is not set diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index ba1cab9fc1f..07eb61b2fb3 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -92,7 +92,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SYSCALL_TRACE 8 /* syscall trace active */ #define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */ #define TIF_SECCOMP 10 /* secure computing */ -#define TIF_SYSCALL_FTRACE 11 /* ftrace syscall instrumentation */ +#define TIF_SYSCALL_TRACEPOINT 11 /* syscall tracepoint instrumentation */ #define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */ #define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */ @@ -111,7 +111,7 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_SYSCALL_TRACE (1<>8 | _TIF_SYSCALL_AUDIT>>8 | \ - _TIF_SECCOMP>>8 | _TIF_SYSCALL_FTRACE>>8) + _TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8) STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER STACK_SIZE = 1 << STACK_SHIFT diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index f6618e9e15e..3ceb53c9c49 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -57,7 +57,7 @@ _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ _TIF_MCCK_PENDING) _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \ - _TIF_SECCOMP>>8 | _TIF_SYSCALL_FTRACE>>8) + _TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8) #define BASED(name) name-system_call(%r13) diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index c5e87d891ca..9d3dcfa79ea 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -664,7 +664,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) ret = -1; } - if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE))) + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_syscall_enter(regs, regs->gprs[2]); if (unlikely(current->audit_context)) @@ -682,7 +682,7 @@ asmlinkage void do_syscall_trace_exit(struct pt_regs *regs) audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]); - if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE))) + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_syscall_exit(regs, regs->gprs[2]); if (test_thread_flag(TIF_SYSCALL_TRACE)) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 738bdc6b0f8..d59cbf758f3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -37,7 +37,7 @@ config X86 select HAVE_FUNCTION_GRAPH_FP_TEST select HAVE_FUNCTION_TRACE_MCOUNT_TEST select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE - select HAVE_FTRACE_SYSCALLS + select HAVE_SYSCALL_TRACEPOINTS select HAVE_KVM select HAVE_ARCH_KGDB select HAVE_ARCH_TRACEHOOK diff --git a/arch/x86/configs/i386_defconfig b/arch/x86/configs/i386_defconfig index edb992ebef9..d28fad19654 100644 --- a/arch/x86/configs/i386_defconfig +++ b/arch/x86/configs/i386_defconfig @@ -2355,7 +2355,7 @@ CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y CONFIG_HAVE_DYNAMIC_FTRACE=y CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y CONFIG_HAVE_HW_BRANCH_TRACER=y -CONFIG_HAVE_FTRACE_SYSCALLS=y +CONFIG_HAVE_SYSCALL_TRACEPOINTS=y CONFIG_RING_BUFFER=y CONFIG_TRACING=y CONFIG_TRACING_SUPPORT=y diff --git a/arch/x86/configs/x86_64_defconfig b/arch/x86/configs/x86_64_defconfig index cee1dd2e69b..6c86acd847a 100644 --- a/arch/x86/configs/x86_64_defconfig +++ b/arch/x86/configs/x86_64_defconfig @@ -2329,7 +2329,7 @@ CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y CONFIG_HAVE_DYNAMIC_FTRACE=y CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y CONFIG_HAVE_HW_BRANCH_TRACER=y -CONFIG_HAVE_FTRACE_SYSCALLS=y +CONFIG_HAVE_SYSCALL_TRACEPOINTS=y CONFIG_RING_BUFFER=y CONFIG_TRACING=y CONFIG_TRACING_SUPPORT=y diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index fad7d40b75f..6f7786aea4f 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -95,7 +95,7 @@ struct thread_info { #define TIF_DEBUGCTLMSR 25 /* uses thread_struct.debugctlmsr */ #define TIF_DS_AREA_MSR 26 /* uses thread_struct.ds_area_msr */ #define TIF_LAZY_MMU_UPDATES 27 /* task is updating the mmu lazily */ -#define TIF_SYSCALL_FTRACE 28 /* for ftrace syscall instrumentation */ +#define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) @@ -118,17 +118,17 @@ struct thread_info { #define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR) #define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR) #define _TIF_LAZY_MMU_UPDATES (1 << TIF_LAZY_MMU_UPDATES) -#define _TIF_SYSCALL_FTRACE (1 << TIF_SYSCALL_FTRACE) +#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) /* work to do in syscall_trace_enter() */ #define _TIF_WORK_SYSCALL_ENTRY \ - (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_FTRACE | \ - _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | _TIF_SINGLESTEP) + (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \ + _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT) /* work to do in syscall_trace_leave() */ #define _TIF_WORK_SYSCALL_EXIT \ (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \ - _TIF_SYSCALL_FTRACE) + _TIF_SYSCALL_TRACEPOINT) /* work to do on interrupt/exception return */ #define _TIF_WORK_MASK \ @@ -137,7 +137,8 @@ struct thread_info { _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU)) /* work to do on any return to user space */ -#define _TIF_ALLWORK_MASK ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_FTRACE) +#define _TIF_ALLWORK_MASK \ + ((0x0000FFFF & ~_TIF_SECCOMP) | _TIF_SYSCALL_TRACEPOINT) /* Only used for 64 bit */ #define _TIF_DO_NOTIFY_MASK \ diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 34dd6f15185..a909afef44f 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -1500,7 +1500,7 @@ asmregparm long syscall_trace_enter(struct pt_regs *regs) tracehook_report_syscall_entry(regs)) ret = -1L; - if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE))) + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_syscall_enter(regs, regs->orig_ax); if (unlikely(current->audit_context)) { @@ -1526,7 +1526,7 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs) if (unlikely(current->audit_context)) audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax); - if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE))) + if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) trace_syscall_exit(regs, regs->ax); if (test_thread_flag(TIF_SYSCALL_TRACE)) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 019f380fd76..06be85a7ef8 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -41,7 +41,7 @@ config HAVE_FTRACE_MCOUNT_RECORD config HAVE_HW_BRANCH_TRACER bool -config HAVE_FTRACE_SYSCALLS +config HAVE_SYSCALL_TRACEPOINTS bool config TRACER_MAX_TRACE @@ -211,7 +211,7 @@ config ENABLE_DEFAULT_TRACERS config FTRACE_SYSCALLS bool "Trace syscalls" - depends on HAVE_FTRACE_SYSCALLS + depends on HAVE_SYSCALL_TRACEPOINTS select GENERIC_TRACER select KALLSYMS help diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 06f165a4408..be86b9a01a0 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -590,7 +590,7 @@ void syscall_regfunc(void) if (!sys_tracepoint_refcount) { read_lock_irqsave(&tasklist_lock, flags); do_each_thread(g, t) { - set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE); + set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); } while_each_thread(g, t); read_unlock_irqrestore(&tasklist_lock, flags); } @@ -608,7 +608,7 @@ void syscall_unregfunc(void) if (!sys_tracepoint_refcount) { read_lock_irqsave(&tasklist_lock, flags); do_each_thread(g, t) { - clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE); + clear_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); } while_each_thread(g, t); read_unlock_irqrestore(&tasklist_lock, flags); } -- cgit v1.2.3-70-g09d2 From c0729be99cb2b9d9749256254f1c40a801835896 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 26 Aug 2009 22:23:52 -0400 Subject: tracing: remove legacy select of MARKERS by context switch tracing The context switch tracer was made before tracepoints were mature, and the original version used markers. This is no longer true and this patch removes the select. Reported-by: Thomas Gleixner Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 06be85a7ef8..163fbfc2f39 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -60,7 +60,6 @@ config EVENT_TRACING bool config CONTEXT_SWITCH_TRACER - select MARKERS bool # All tracer options should select GENERIC_TRACER. For those options that are -- cgit v1.2.3-70-g09d2 From 85bac32c4a52c592b857f2c360cc5ec93a097d70 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 4 Sep 2009 14:24:40 -0400 Subject: ring-buffer: only enable ring_buffer_swap_cpu when needed Since the ability to swap the cpu buffers adds a small overhead to the recording of a trace, we only want to add it when needed. Only the irqsoff and preemptoff tracers use this feature, and both are not recommended for production kernels. This patch disables its use when neither irqsoff nor preemptoff is configured. Signed-off-by: Steven Rostedt --- include/linux/ring_buffer.h | 9 +++++++++ kernel/trace/Kconfig | 8 ++++++++ kernel/trace/ring_buffer.c | 4 ++++ 3 files changed, 21 insertions(+) (limited to 'kernel/trace/Kconfig') diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index e061b4ecdc3..5fcc31ed577 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -140,8 +140,17 @@ unsigned long ring_buffer_size(struct ring_buffer *buffer); void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu); void ring_buffer_reset(struct ring_buffer *buffer); +#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, struct ring_buffer *buffer_b, int cpu); +#else +static inline int +ring_buffer_swap_cpu(struct ring_buffer *buffer_a, + struct ring_buffer *buffer_b, int cpu) +{ + return -ENODEV; +} +#endif int ring_buffer_empty(struct ring_buffer *buffer); int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu); diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 163fbfc2f39..1ea0d1234f4 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -62,6 +62,12 @@ config EVENT_TRACING config CONTEXT_SWITCH_TRACER bool +config RING_BUFFER_ALLOW_SWAP + bool + help + Allow the use of ring_buffer_swap_cpu. + Adds a very slight overhead to tracing when enabled. + # All tracer options should select GENERIC_TRACER. For those options that are # enabled by all tracers (context switch and event tracer) they select TRACING. # This allows those options to appear when no other tracer is selected. But the @@ -146,6 +152,7 @@ config IRQSOFF_TRACER select TRACE_IRQFLAGS select GENERIC_TRACER select TRACER_MAX_TRACE + select RING_BUFFER_ALLOW_SWAP help This option measures the time spent in irqs-off critical sections, with microsecond accuracy. @@ -167,6 +174,7 @@ config PREEMPT_TRACER depends on PREEMPT select GENERIC_TRACER select TRACER_MAX_TRACE + select RING_BUFFER_ALLOW_SWAP help This option measures the time spent in preemption off critical sections, with microsecond accuracy. diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 1766c0e8db5..454e74e718c 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2084,6 +2084,7 @@ rb_reserve_next_event(struct ring_buffer *buffer, rb_start_commit(cpu_buffer); +#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP /* * Due to the ability to swap a cpu buffer from a buffer * it is possible it was swapped before we committed. @@ -2096,6 +2097,7 @@ rb_reserve_next_event(struct ring_buffer *buffer, local_dec(&cpu_buffer->commits); return NULL; } +#endif length = rb_calculate_event_length(length); again: @@ -3498,6 +3500,7 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu) } EXPORT_SYMBOL_GPL(ring_buffer_empty_cpu); +#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP /** * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers * @buffer_a: One buffer to swap with @@ -3573,6 +3576,7 @@ out: return ret; } EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu); +#endif /* CONFIG_RING_BUFFER_ALLOW_SWAP */ /** * ring_buffer_alloc_read_page - allocate a page to read from buffer -- cgit v1.2.3-70-g09d2