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authorFrederic Weisbecker <fweisbec@gmail.com>2008-12-05 21:40:00 -0500
committerIngo Molnar <mingo@elte.hu>2008-12-08 09:11:44 -0500
commit8b96f0119818964e4944fd1c423bf6770027d3ac (patch)
tree02b5ec86d2fe45d6935d63913b997989f9339bf4 /arch/x86/kernel/process_64.c
parentdecbec3838d10ecd7aabdb4c0e05aac0e5f5dc0c (diff)
tracing/function-graph-tracer: introduce __notrace_funcgraph to filter special functions
Impact: trace more functions When the function graph tracer is configured, three more files are not traced to prevent only four functions to be traced. And this impacts the normal function tracer too. arch/x86/kernel/process_64/32.c: I had crashes when I let this file traced. After some debugging, I saw that the "current" task point was changed inside__swtich_to(), ie: "write_pda(pcurrent, next_p);" inside process_64.c Since the tracer store the original return address of the function inside current, we had crashes. Only __switch_to() has to be excluded from tracing. kernel/module.c and kernel/extable.c: Because of a function used internally by the function graph tracer: __kernel_text_address() To let the other functions inside these files to be traced, this patch introduces the __notrace_funcgraph function prefix which is __notrace if function graph tracer is configured and nothing if not. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r--arch/x86/kernel/process_64.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index c958120fb1b6..fbb321d53d34 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -39,6 +39,7 @@
39#include <linux/prctl.h> 39#include <linux/prctl.h>
40#include <linux/uaccess.h> 40#include <linux/uaccess.h>
41#include <linux/io.h> 41#include <linux/io.h>
42#include <linux/ftrace.h>
42 43
43#include <asm/pgtable.h> 44#include <asm/pgtable.h>
44#include <asm/system.h> 45#include <asm/system.h>
@@ -551,8 +552,9 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
551 * - could test fs/gs bitsliced 552 * - could test fs/gs bitsliced
552 * 553 *
553 * Kprobes not supported here. Set the probe on schedule instead. 554 * Kprobes not supported here. Set the probe on schedule instead.
555 * Function graph tracer not supported too.
554 */ 556 */
555struct task_struct * 557__notrace_funcgraph struct task_struct *
556__switch_to(struct task_struct *prev_p, struct task_struct *next_p) 558__switch_to(struct task_struct *prev_p, struct task_struct *next_p)
557{ 559{
558 struct thread_struct *prev = &prev_p->thread; 560 struct thread_struct *prev = &prev_p->thread;