summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorSteven Rostedt <srostedt@redhat.com>2009-02-09 21:10:27 -0800
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-02-23 10:48:53 +1100
commit6794c78243bfda020ab184d6d578944f8e90d26c (patch)
treee697b43e4b757723ed9798c9666b759d9e29ca12
parent17be5b3ddf71d980f67fc826e49b00cd2afd724d (diff)
powerpc64: port of the function graph tracer
This is a port of the function graph tracer that was written by Frederic Weisbecker for the x86. This only works for PPC64 at the moment and only for static tracing. PPC32 and dynamic function graph tracing support will come later. The trace produces a visual calling of functions: # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) 2.224 us | } 0) ! 271.024 us | } 0) ! 320.080 us | } 0) ! 324.656 us | } 0) ! 329.136 us | } 0) | .put_prev_task_fair() { 0) | .update_curr() { 0) 2.240 us | .update_min_vruntime(); 0) 6.512 us | } 0) 2.528 us | .__enqueue_entity(); 0) + 15.536 us | } 0) | .pick_next_task_fair() { 0) 2.032 us | .__pick_next_entity(); 0) 2.064 us | .__clear_buddies(); 0) | .set_next_entity() { 0) 2.672 us | .__dequeue_entity(); 0) 6.864 us | } Geoff Lavand tested on PS3. Tested-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/kernel/Makefile9
-rw-r--r--arch/powerpc/kernel/entry_64.S58
-rw-r--r--arch/powerpc/kernel/ftrace.c79
-rw-r--r--arch/powerpc/kernel/process.c16
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S1
6 files changed, 154 insertions, 10 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ccdd8de3c55..e122d241f17 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -111,6 +111,7 @@ config PPC
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
select HAVE_FUNCTION_TRACER
+ select HAVE_FUNCTION_GRAPH_TRACER if !DYNAMIC_FTRACE && PPC64
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_IDE
select HAVE_IOREMAP_PROT
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d1599211908..583ba6493a6 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -18,12 +18,10 @@ CFLAGS_REMOVE_cputable.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_prom_init.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_btext.o = -pg -mno-sched-epilog
CFLAGS_REMOVE_prom.o = -pg -mno-sched-epilog
-
-ifdef CONFIG_DYNAMIC_FTRACE
-# dynamic ftrace setup.
+# do not trace tracer code
CFLAGS_REMOVE_ftrace.o = -pg -mno-sched-epilog
-endif
-
+# timers used by tracing
+CFLAGS_REMOVE_time.o = -pg -mno-sched-epilog
endif
obj-y := cputable.o ptrace.o syscalls.o \
@@ -95,6 +93,7 @@ obj-$(CONFIG_AUDIT) += audit.o
obj64-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_8XX_MINIMAL_FPEMU) += softemu8xx.o
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 383ed6eb008..a32699e74c3 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -931,13 +931,65 @@ _GLOBAL(_mcount)
ld r5,0(r5)
mtctr r5
bctrl
-
nop
+
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ b ftrace_graph_caller
+#endif
ld r0, 128(r1)
mtlr r0
addi r1, r1, 112
_GLOBAL(ftrace_stub)
blr
-#endif
-#endif
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ftrace_graph_caller:
+ /* load r4 with local address */
+ ld r4, 128(r1)
+ subi r4, r4, MCOUNT_INSN_SIZE
+
+ /* get the parent address */
+ ld r11, 112(r1)
+ addi r3, r11, 16
+
+ bl .prepare_ftrace_return
+ nop
+
+ ld r0, 128(r1)
+ mtlr r0
+ addi r1, r1, 112
+ blr
+
+_GLOBAL(return_to_handler)
+ /* need to save return values */
+ std r4, -32(r1)
+ std r3, -24(r1)
+ /* save TOC */
+ std r2, -16(r1)
+ std r31, -8(r1)
+ mr r31, r1
+ stdu r1, -112(r1)
+
+ /* update the TOC */
+ LOAD_REG_IMMEDIATE(r4,ftrace_return_to_handler)
+ ld r2, 8(r4)
+
+ bl .ftrace_return_to_handler
+ nop
+
+ /* return value has real return address */
+ mtlr r3
+
+ ld r1, 0(r1)
+ ld r4, -32(r1)
+ ld r3, -24(r1)
+ ld r2, -16(r1)
+ ld r31, -8(r1)
+
+ /* Jump back to real return address */
+ blr
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 4112175183d..c9b1547f65a 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -5,6 +5,9 @@
*
* Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
*
+ * Added function graph tracer code, taken from x86 that was written
+ * by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
+ *
*/
#include <linux/spinlock.h>
@@ -20,8 +23,6 @@
#include <asm/code-patching.h>
#include <asm/ftrace.h>
-static unsigned int ftrace_nop = PPC_NOP_INSTR;
-
#ifdef CONFIG_PPC32
# define GET_ADDR(addr) addr
#else
@@ -29,6 +30,8 @@ static unsigned int ftrace_nop = PPC_NOP_INSTR;
# define GET_ADDR(addr) (*(unsigned long *)addr)
#endif
+#ifdef CONFIG_DYNAMIC_FTRACE
+static unsigned int ftrace_nop = PPC_NOP_INSTR;
static unsigned int ftrace_calc_offset(long ip, long addr)
{
@@ -525,3 +528,75 @@ int __init ftrace_dyn_arch_init(void *data)
return 0;
}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+/*
+ * 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)
+{
+ unsigned long old;
+ unsigned long long calltime;
+ int faulted;
+ struct ftrace_graph_ent trace;
+ unsigned long return_hooker = (unsigned long)
+ &return_to_handler;
+
+ if (unlikely(atomic_read(&current->tracing_graph_pause)))
+ return;
+
+ return_hooker = GET_ADDR(return_hooker);
+
+ /*
+ * Protect against fault, even if it shouldn't
+ * happen. This tool is too much intrusive to
+ * ignore such a protection.
+ */
+ asm volatile(
+ "1: " PPC_LL "%[old], 0(%[parent])\n"
+ "2: " PPC_STL "%[return_hooker], 0(%[parent])\n"
+ " li %[faulted], 0\n"
+ "3:"
+
+ ".section .fixup, \"ax\"\n"
+ "4: li %[faulted], 1\n"
+ " b 3b\n"
+ ".previous\n"
+
+ ".section __ex_table,\"a\"\n"
+ PPC_LONG_ALIGN "\n"
+ PPC_LONG "1b,4b\n"
+ PPC_LONG "2b,4b\n"
+ ".previous"
+
+ : [old] "=r" (old), [faulted] "=r" (faulted)
+ : [parent] "r" (parent), [return_hooker] "r" (return_hooker)
+ : "memory"
+ );
+
+ if (unlikely(faulted)) {
+ ftrace_graph_stop();
+ WARN_ON(1);
+ return;
+ }
+
+ calltime = cpu_clock(raw_smp_processor_id());
+
+ if (ftrace_push_return_trace(old, calltime,
+ self_addr, &trace.depth) == -EBUSY) {
+ *parent = old;
+ return;
+ }
+
+ trace.func = self_addr;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace)) {
+ current->curr_ret_stack--;
+ *parent = old;
+ }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index fb7049c054c..8ede428e76c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -33,6 +33,7 @@
#include <linux/mqueue.h>
#include <linux/hardirq.h>
#include <linux/utsname.h>
+#include <linux/ftrace.h>
#include <linux/kernel_stat.h>
#include <asm/pgtable.h>
@@ -1008,6 +1009,14 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
unsigned long sp, ip, lr, newsp;
int count = 0;
int firstframe = 1;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ int curr_frame = current->curr_ret_stack;
+ extern void return_to_handler(void);
+ unsigned long addr = (unsigned long)return_to_handler;
+#ifdef CONFIG_PPC64
+ addr = *(unsigned long*)addr;
+#endif
+#endif
sp = (unsigned long) stack;
if (tsk == NULL)
@@ -1030,6 +1039,13 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
ip = stack[STACK_FRAME_LR_SAVE];
if (!firstframe || ip != lr) {
printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (ip == addr && curr_frame >= 0) {
+ printk(" (%pS)",
+ (void *)current->ret_stack[curr_frame].ret);
+ curr_frame--;
+ }
+#endif
if (firstframe)
printk(" (unreliable)");
printk("\n");
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 161b9b9691f..895af44bf1f 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -58,6 +58,7 @@ SECTIONS
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
+ IRQENTRY_TEXT
#ifdef CONFIG_PPC32
*(.got1)