From: Yabin Cui Date: Wed, 15 May 2024 19:36:09 +0000 (-0700) Subject: perf/core: Check sample_type in perf_sample_save_brstack X-Git-Tag: v6.14-rc1~186^2~32 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=faac6f105ef169e2e5678c14e1ffebf2a7d780b6;p=thirdparty%2Fkernel%2Flinux.git perf/core: Check sample_type in perf_sample_save_brstack Check sample_type in perf_sample_save_brstack() to prevent saving branch stack data when it isn't required. Suggested-by: Namhyung Kim Signed-off-by: Yabin Cui Signed-off-by: Ingo Molnar Reviewed-by: Ian Rogers Acked-by: Namhyung Kim Link: https://lore.kernel.org/r/20240515193610.2350456-4-yabinc@google.com --- diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index b4a1a2576510e..30d6ceb4c8ad4 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -1001,8 +1001,7 @@ 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 c75c482d4c52f..8f218ac0d445c 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -1707,8 +1707,7 @@ 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 4990a24098072..acfd872075473 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1888,8 +1888,7 @@ 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 3ac202d971fb7..bf831b1485ff5 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1320,6 +1320,11 @@ 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, @@ -1327,6 +1332,11 @@ 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); @@ -1716,11 +1726,6 @@ static inline unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs) # define perf_arch_guest_misc_flags(regs) perf_arch_guest_misc_flags(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;