Check sample_type in perf_sample_save_brstack() to prevent
saving branch stack data when it isn't required.
Suggested-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Yabin Cui <yabinc@xxxxxxxxxx>
---
arch/x86/events/amd/core.c | 3 +--
arch/x86/events/core.c | 3 +--
arch/x86/events/intel/ds.c | 3 +--
include/linux/perf_event.h | 15 ++++++++++-----
4 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 1fc4ce44e743..f71a9ef932c5 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -998,8 +998,7 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
if (!x86_perf_event_set_period(event))
continue;
- if (has_branch_stack(event))
- perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
+ perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 5b0dd07b1ef1..ff5577315938 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1702,8 +1702,7 @@ int x86_pmu_handle_irq(struct pt_regs *regs)
perf_sample_data_init(&data, 0, event->hw.last_period);
- if (has_branch_stack(event))
- perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
+ perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index c2b5585aa6d1..f25236ffa28f 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1754,8 +1754,7 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event,
if (x86_pmu.intel_cap.pebs_format >= 3)
setup_pebs_time(event, data, pebs->tsc);
- if (has_branch_stack(event))
- perf_sample_save_brstack(data, event, &cpuc->lbr_stack, NULL);
+ perf_sample_save_brstack(data, event, &cpuc->lbr_stack, NULL);
}
static void adaptive_pebs_save_regs(struct pt_regs *regs,
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index bda066c33120..f6637f3cbe84 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1276,6 +1276,11 @@ static inline void perf_sample_save_raw_data(struct perf_sample_data *data,
data->sample_flags |= PERF_SAMPLE_RAW;
}
+static inline bool has_branch_stack(struct perf_event *event)
+{
+ return event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK;
+}
+
static inline void perf_sample_save_brstack(struct perf_sample_data *data,
struct perf_event *event,
struct perf_branch_stack *brs,
@@ -1283,6 +1288,11 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data,
{
int size = sizeof(u64); /* nr */
+ if (!has_branch_stack(event))
+ return;
+ if (WARN_ON_ONCE(data->sample_flags & PERF_SAMPLE_BRANCH_STACK))
+ return;
+
if (branch_sample_hw_index(event))
size += sizeof(u64);
size += brs->nr * sizeof(struct perf_branch_entry);
@@ -1658,11 +1668,6 @@ extern void perf_bp_event(struct perf_event *event, void *data);
# define perf_arch_bpf_user_pt_regs(regs) regs
#endif
-static inline bool has_branch_stack(struct perf_event *event)
-{
- return event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK;
-}
-
static inline bool needs_branch_stack(struct perf_event *event)
{
return event->attr.branch_sample_type != 0;
--
2.45.0.rc1.225.g2a3ae87e7f-goog
