perf/core: Check sample_type in perf_sample_save_callchain

Check sample_type in perf_sample_save_callchain() to prevent
saving callchain data when it isn't required.

Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240515193610.2350456-3-yabinc@google.com

diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index c3a2f6f57770ab9c037ac57eb45d1acdb40cb559..f02939655b2ac819773d86f0626a5264975493d6 100644 (file)
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -1129,8 +1129,7 @@ fail:
         * recorded as part of interrupt regs. Thus we need to use rip from
         * interrupt regs while unwinding call stack.
         */
-       if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
-               perf_sample_save_callchain(&data, event, iregs);
+       perf_sample_save_callchain(&data, event, iregs);
 
        throttle = perf_event_overflow(event, &data, &regs);
 out:

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 8afc4ad3cd16eb8039c75f89e5e44ead7db1fdb1..4990a24098072397d631cdd2de7c1f815a502153 100644 (file)
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1789,8 +1789,7 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event,
         * previous PMI context or an (I)RET happened between the record and
         * PMI.
         */
-       if (sample_type & PERF_SAMPLE_CALLCHAIN)
-               perf_sample_save_callchain(data, event, iregs);
+       perf_sample_save_callchain(data, event, iregs);
 
        /*
         * We use the interrupt regs as a base because the PEBS record does not
@@ -1957,8 +1956,7 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
         * previous PMI context or an (I)RET happened between the record and
         * PMI.
         */
-       if (sample_type & PERF_SAMPLE_CALLCHAIN)
-               perf_sample_save_callchain(data, event, iregs);
+       perf_sample_save_callchain(data, event, iregs);
 
        *regs = *iregs;
        /* The ip in basic is EventingIP */

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f7c0a3f2f502d0ef927030779a98d4491006c7de..3ac202d971fb7669de006d9d7e05c7325e8b64f5 100644 (file)
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1279,6 +1279,11 @@ static inline void perf_sample_save_callchain(struct perf_sample_data *data,
 {
        int size = 1;
 
+       if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN))
+               return;
+       if (WARN_ON_ONCE(data->sample_flags & PERF_SAMPLE_CALLCHAIN))
+               return;
+
        data->callchain = perf_callchain(event, regs);
        size += data->callchain->nr;