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| author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2015-12-15 17:33:40 +0900 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-12-21 17:26:01 +0000 |
| commit | fe13f95b720075327a761fe6ddb45b0c90cab504 (patch) | |
| tree | 60a9b93da92658289371e6bb2307401bba4bdc5e /arch/arm64/kernel/stacktrace.c | |
| parent | 79fdee9b6355c9720f14717e1ad66af51bb331b5 (diff) | |
| download | linux-fe13f95b720075327a761fe6ddb45b0c90cab504.tar.gz linux-fe13f95b720075327a761fe6ddb45b0c90cab504.tar.bz2 linux-fe13f95b720075327a761fe6ddb45b0c90cab504.zip | |
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/stacktrace.c')
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index b9fd3a8abfc1..f7ee597ec883 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -36,7 +36,7 @@ * ldp x29, x30, [sp] * add sp, sp, #0x10 */ -int notrace unwind_frame(struct stackframe *frame) +int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) { unsigned long high, low; unsigned long fp = frame->fp; @@ -99,7 +99,7 @@ int notrace unwind_frame(struct stackframe *frame) return 0; } -void notrace walk_stackframe(struct stackframe *frame, +void notrace walk_stackframe(struct task_struct *tsk, struct stackframe *frame, int (*fn)(struct stackframe *, void *), void *data) { while (1) { @@ -107,7 +107,7 @@ void notrace walk_stackframe(struct stackframe *frame, if (fn(frame, data)) break; - ret = unwind_frame(frame); + ret = unwind_frame(tsk, frame); if (ret < 0) break; } @@ -159,7 +159,7 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) frame.pc = (unsigned long)save_stack_trace_tsk; } - walk_stackframe(&frame, save_trace, &data); + walk_stackframe(tsk, &frame, save_trace, &data); if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } |