[PATCH v2 3/5] ARM: stacktrace: Allow stack trace saving for non-current tasks
From: Li Huafei <hidden>
Date: 2022-07-13 11:03:08
Also in:
linux-perf-users, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
The current ARM implementation of save_stack_trace_tsk() does not allow saving stack trace for non-current tasks, which may limit the scenarios in which stack_trace_save_tsk() can be used. Like other architectures, or like ARM's unwind_backtrace(), we can leave it up to the caller to ensure that the task that needs to be unwound is not running. Signed-off-by: Li Huafei <redacted> --- arch/arm/kernel/stacktrace.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index 3acf51ee46bb..836420c00938 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c@@ -171,19 +171,11 @@ static noinline void __save_stack_trace(struct task_struct *tsk, data.no_sched_functions = nosched; if (tsk != current) { -#ifdef CONFIG_SMP - /* - * What guarantees do we have here that 'tsk' is not - * running on another CPU? For now, ignore it as we - * can't guarantee we won't explode. - */ - return; -#else + /* task blocked in __switch_to */ frame.fp = thread_saved_fp(tsk); frame.sp = thread_saved_sp(tsk); frame.lr = 0; /* recovered from the stack */ frame.pc = thread_saved_pc(tsk); -#endif } else { /* We don't want this function nor the caller */ data.skip += 2;
--
2.17.1
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