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| author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2015-12-15 11:33:40 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-12-21 20:26:01 +0300 |
| commit | fe13f95b720075327a761fe6ddb45b0c90cab504 (patch) | |
| tree | 60a9b93da92658289371e6bb2307401bba4bdc5e /arch/arm64/kernel/process.c | |
| parent | 79fdee9b6355c9720f14717e1ad66af51bb331b5 (diff) | |
| download | linux-fe13f95b720075327a761fe6ddb45b0c90cab504.tar.xz | |
arm64: pass a task parameter to unwind_frame()
Function graph tracer modifies a return address (LR) in a stack frame
to hook a function's return. This will result in many useless entries
(return_to_handler) showing up in a call stack list.
We will fix this problem in a later patch ("arm64: ftrace: fix a stack
tracer's output under function graph tracer"). But since real return
addresses are saved in ret_stack[] array in struct task_struct,
unwind functions need to be notified of, in addition to a stack pointer
address, which task is being traced in order to find out real return
addresses.
This patch extends unwind functions' interfaces by adding an extra
argument of a pointer to task_struct.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index f75b540bc3b4..98bf5461d4b6 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -348,7 +348,7 @@ unsigned long get_wchan(struct task_struct *p) do { if (frame.sp < stack_page || frame.sp >= stack_page + THREAD_SIZE || - unwind_frame(&frame)) + unwind_frame(p, &frame)) return 0; if (!in_sched_functions(frame.pc)) return frame.pc; |