| Message ID | 20190523053429.3567376-1-songliubraving@fb.com |
|---|---|
| State | Not Applicable |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [v2] perf/x86: always include regs->ip in callchain | expand |
On Thu, May 23, 2019 at 1:34 PM Song Liu <songliubraving@fb.com> 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 <kasong@redhat.com> > Cc: Peter Zijlstra (Intel) <peterz@infradead.org> > Signed-off-by: Song Liu <songliubraving@fb.com> > --- > 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.
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);
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 <kasong@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Song Liu <songliubraving@fb.com> --- arch/x86/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)