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author | Frederic Weisbecker <fweisbec@gmail.com> | 2008-11-23 06:22:56 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-11-23 09:17:26 +0100 |
commit | f201ae2356c74bcae130b2177b3dca903ea98071 (patch) | |
tree | c4b1b43fbe0a4594cb86749b2e7098fe15eb86ba /kernel/exit.c | |
parent | a0a70c735ef714fe1b6777b571630c3d50c7b008 (diff) | |
download | blackbird-op-linux-f201ae2356c74bcae130b2177b3dca903ea98071.tar.gz blackbird-op-linux-f201ae2356c74bcae130b2177b3dca903ea98071.zip |
tracing/function-return-tracer: store return stack into task_struct and allocate it dynamically
Impact: use deeper function tracing depth safely
Some tests showed that function return tracing needed a more deeper depth
of function calls. But it could be unsafe to store these return addresses
to the stack.
So these arrays will now be allocated dynamically into task_struct of current
only when the tracer is activated.
Typical scheme when tracer is activated:
- allocate a return stack for each task in global list.
- fork: allocate the return stack for the newly created task
- exit: free return stack of current
- idle init: same as fork
I chose a default depth of 50. I don't have overruns anymore.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/exit.c')
-rw-r--r-- | kernel/exit.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 35c8ec2ba03a..b9d446329da1 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -47,6 +47,7 @@ #include <linux/task_io_accounting_ops.h> #include <linux/tracehook.h> #include <trace/sched.h> +#include <linux/ftrace.h> #include <asm/uaccess.h> #include <asm/unistd.h> @@ -1127,7 +1128,9 @@ NORET_TYPE void do_exit(long code) preempt_disable(); /* causes final put_task_struct in finish_task_switch(). */ tsk->state = TASK_DEAD; - +#ifdef CONFIG_FUNCTION_RET_TRACER + ftrace_retfunc_exit_task(tsk); +#endif schedule(); BUG(); /* Avoid "noreturn function does return". */ |