On Thu, May 23, 2019 at 1:34 PM Song Liu <[email protected]> wrote: > > Commit d15d356887e7 removes regs->ip for !perf_hw_regs(regs) case. 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 >
Hi, this will make !perf_hw_regs(regs) case print a double first level stack trace, which is wrong. And the actual problem that unwinder give empty calltrace in bpf is still not fixed. -- Best Regards, Kairui Song
