Re: [PATCH] arm64: stacktrace: Move start_backtrace() out of the header
From: Mark Rutland <mark.rutland@arm.com>
Date: 2021-03-22 16:34:13
On Fri, Mar 19, 2021 at 05:40:22PM +0000, Mark Brown wrote:
Currently start_backtrace() is a static inline function in the header. Since it really shouldn't be sufficiently performance critical that we actually need to have it inlined move it into a C file, this will save anyone else scratching their head about why it is defined in the header. As far as I can see it's only there because it was factored out of the various callers. Signed-off-by: Mark Brown <broonie@kernel.org>
Given keeping this close to unwind_frame() makes it easier to see the whole story at once: Acked-by: Mark Rutland <mark.rutland@arm.com> It'd be nice to see users of this all moved over to arch_stack_walk(), so that we can make this static along with walk_stackframe(), and have all stack walks using the same interface. Thanks, Mark.
quoted hunk ↗ jump to hunk
--- arch/arm64/include/asm/stacktrace.h | 24 ++---------------------- arch/arm64/kernel/stacktrace.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+), 22 deletions(-)diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index eb29b1fe8255..4b33ca620679 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h@@ -148,27 +148,7 @@ static inline bool on_accessible_stack(const struct task_struct *tsk, return false; } -static inline void start_backtrace(struct stackframe *frame, - unsigned long fp, unsigned long pc) -{ - frame->fp = fp; - frame->pc = pc; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - frame->graph = 0; -#endif - - /* - * Prime the first unwind. - * - * In unwind_frame() we'll check that the FP points to a valid stack, - * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be - * treated as a transition to whichever stack that happens to be. The - * prev_fp value won't be used, but we set it to 0 such that it is - * definitely not an accessible stack address. - */ - bitmap_zero(frame->stacks_done, __NR_STACK_TYPES); - frame->prev_fp = 0; - frame->prev_type = STACK_TYPE_UNKNOWN; -} +void start_backtrace(struct stackframe *frame, unsigned long fp, + unsigned long pc); #endif /* __ASM_STACKTRACE_H */diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 7337506d6a7f..4c889bd098af 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c@@ -35,6 +35,30 @@ * add sp, sp, #0x10 */ + +void start_backtrace(struct stackframe *frame, unsigned long fp, + unsigned long pc) +{ + frame->fp = fp; + frame->pc = pc; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + frame->graph = 0; +#endif + + /* + * Prime the first unwind. + * + * In unwind_frame() we'll check that the FP points to a valid stack, + * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be + * treated as a transition to whichever stack that happens to be. The + * prev_fp value won't be used, but we set it to 0 such that it is + * definitely not an accessible stack address. + */ + bitmap_zero(frame->stacks_done, __NR_STACK_TYPES); + frame->prev_fp = 0; + frame->prev_type = STACK_TYPE_UNKNOWN; +} + /* * Unwind from one frame record (A) to the next frame record (B). *-- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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