On Tue, May 21, 2019 at 01:48:13PM -0700, Song Liu wrote:
> Commit d15d356887e7 removes regs->ip for !perf_hw_regs(regs) case. This
> breaks tests like test_stacktrace_map from selftests/bpf/tests_prog.
That test is broken by something else; just the one entry is wrong too.
That said, yes the patch below is actually correct, but the above
description is misleading at best.
> This patch adds regs->ip back.
>
> Fixes: d15d356887e7 ("perf/x86: Make perf callchains work without
> CONFIG_FRAME_POINTER")
> Cc: Kairui Song <[email protected]>
> Cc: Peter Zijlstra (Intel) <[email protected]>
> Signed-off-by: Song Liu <[email protected]>
> ---
> arch/x86/events/core.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
> index f315425d8468..7b8a9eb4d5fd 100644
> --- a/arch/x86/events/core.c
> +++ b/arch/x86/events/core.c
> @@ -2402,9 +2402,9 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx
> *entry, struct pt_regs *re
> return;
> }
>
> + if (perf_callchain_store(entry, regs->ip))
> + return;
> if (perf_hw_regs(regs)) {
> - if (perf_callchain_store(entry, regs->ip))
> - return;
> unwind_start(&state, current, regs, NULL);
> } else {
> unwind_start(&state, current, NULL, (void *)regs->sp);
> --
> 2.17.1
>
