MIPS: oprofile: Backtrace: don't fail on leaf functions (569309b4) · Commits · 戴 / test

Continue the backtrace if we cannot find SP adjustment and RA save. In that case, just assume the current RA. This allows us to get samples of frequent callers of e.g. GLIBC memset(). Signed-off-by:

Aaro Koskinen <aaro.koskinen@nsn.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8109/ Signed-off-by:

Ralf Baechle <ralf@linux-mips.org>

arch/mips/oprofile/backtrace.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -65,7 +65,7 @@ static inline int is_end_of_function_marker(union mips_instruction *ip)
		* - handle cases where the stack is adjusted inside a function
		* (generally doesn't happen)
		* - find optimal value for max_instr_check
		* - try to find a way to handle leaf functions
		* - try to find a better way to handle leaf functions
		*/

		static inline int unwind_user_frame(struct stackframe *old_frame,
		@@ -104,7 +104,7 @@ static inline int unwind_user_frame(struct stackframe *old_frame,
		}

		if (!ra_offset \|\| !stack_size)
		return -1;
		goto done;

		if (ra_offset) {
		new_frame.ra = old_frame->sp + ra_offset;
		@@ -121,6 +121,7 @@ static inline int unwind_user_frame(struct stackframe *old_frame,
		if (new_frame.sp > old_frame->sp)
		return -2;

		done:
		new_frame.pc = old_frame->ra;
		*old_frame = new_frame;

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