From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0981E41C2F4 for ; Wed, 29 Apr 2026 18:12:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777486332; cv=none; b=C9z8JuEVkOEiub9rrvNzR8QGcJ1wzFbeVaBAWJpiT+XOLeQIh2jr0aeel2P8IxmAwtTzVOeMSTee2psbRIueSV3PM68dgxhRxYDoxqzLwrs3yuUiu6Pl1MC3Azz7zxOPYl6Zg2SkjMGXozYIt2l92HGX0yWaaizEnoVtuih3b6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777486332; c=relaxed/simple; bh=lAl3czDkD/f+DrcoXOo6L7I6tPLct5f+0+ILlwcgu0c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=fzLKhVfxzhtyecGJIwGc5GcvRsHGXdwDt6duYK0hedveBxbKRK3TCN+m4VMKpqJkex4NPmjJWGybvDzoJCmyEowR0L6KXHs95lMJ8aXEYQ31FltJhnmcLYl6HOibjzYVoLBthsfa1gnEO049eaCPleyXmnugoJW7314uaWNzB/g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=gLPm+enX; arc=none smtp.client-ip=209.85.214.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="gLPm+enX" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2b99eb06178so788845ad.2 for ; Wed, 29 Apr 2026 11:12:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777486330; x=1778091130; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=d/8huAkyQztqOOP4DJuZU1ZW2j6w3MCnFzNy+nKN1Kk=; b=gLPm+enXcv3IW4C1QsFzTPHapcXz2u+dsfRlpBiTpOss/UFYSsw33vzY/UczUQCIpk +P6MKNjWx9Ep3Fnmve7fl7fDeVUsRHBucY9rOSd54+evITDCUoJwZnXk7A+aDScIyQad mUeY6tJWkEWZe0urATlZya+ewA1/V43NBw24UJcHn+d+H/538OBWA1nObzqQSGjicn8H CxEeyB0agi4yrWsThdvDh+DY80Cky7nU2Wbb8UO/c0ptKX4USymkmWMOLnkc1xvu/ucC zen9clr8Ob+YRoYshzpMfruo4NoIh4q6HCCzKjGdssW7lLYZw49FpUUa7bAg+ifr+bZC Bs0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777486330; x=1778091130; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=d/8huAkyQztqOOP4DJuZU1ZW2j6w3MCnFzNy+nKN1Kk=; b=NkPxqWaQUIRvfhqbkH2Mc8aF8icRGZ+yZ4MPh9jM9tleahl4Y0YfUbSEflDrv+FYc4 oWpI4w7Uf8kgOaobY5if2qmwvhFCbUysDZ7Dy+aqHQivI0VH+LEZRxhsX0d2qj6v6pgZ p2A1lJ0+V/4LpWHqqADPadjwxVYaS5jvNM3PEJWYLJUt5igwG5T32VQk66KWoV7J2WOB TvvPlRzgmkbxbfEWKmHs1SBSaVRDchALF2tAkzu1l04iWgiyhWDVtbaj59gBzp0Woeqr 1PKa3OuLT/UBnEApIKGEl2WI9uzv9oLxbnsZEooKJ8vuFdrj9dmBRUkzDyaKI+uhivEo f97w== X-Forwarded-Encrypted: i=1; AFNElJ9yqbstVQm1V3kNY9dLPKaQOArP4xJ62XG43yzQydKuzJCOSgdwQMpdV7SmoI931R06gK8pAhaNAghwc4w=@vger.kernel.org X-Gm-Message-State: AOJu0YydWtEucil0wYngLFrb9YKHmh2DNDYtdBkG+TFcN5KTBS2w4aoB Yt69ZC88Pvd2IBNwqiiYKxbqQDS2Gd9bP74XxcuJqjkLXJXZxHaabq9T3P5WviivZGGwu2DQnMl bQAaU9lSVSA== X-Received: from pgam24.prod.google.com ([2002:a05:6a02:2b58:b0:c79:26bb:5541]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:3d19:b0:3a2:e089:ae56 with SMTP id adf61e73a8af0-3a39c2c28f2mr9579080637.52.1777486330077; Wed, 29 Apr 2026 11:12:10 -0700 (PDT) Date: Wed, 29 Apr 2026 11:11:35 -0700 In-Reply-To: <20260429181136.2712655-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260428070328.1880314-1-irogers@google.com> <20260429181136.2712655-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog Message-ID: <20260429181136.2712655-2-irogers@google.com> Subject: [PATCH v2 1/2] perf event: Fix size of synthesized sample with branch stacks From: Ian Rogers To: acme@kernel.org, adrian.hunter@intel.com, dapeng1.mi@linux.intel.com, namhyung@kernel.org, thomas.falcon@intel.com Cc: james.clark@linaro.org, leo.yan@linux.dev, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, ravi.bangoria@amd.com, Ian Rogers Content-Type: text/plain; charset="UTF-8" Synthesizing branch stacks for Intel-PT highlighed an issue where PERF_SAMPLE_BRANCH_HW_INDEX was assumed to always be set in the perf_event_attr branch_sample_type. This caused an incorrect size calculation. Fix the writing of the nr and hw_idx values during sample event synthesis. Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Acked-by: Namhyung Kim --- tools/perf/bench/inject-buildid.c | 9 ++++++--- tools/perf/builtin-inject.c | 12 +++++++++--- tools/perf/tests/dlfilter-test.c | 8 ++++++-- tools/perf/tests/sample-parsing.c | 5 +++-- tools/perf/util/arm-spe.c | 7 +++++-- tools/perf/util/cs-etm.c | 6 ++++-- tools/perf/util/intel-bts.c | 3 ++- tools/perf/util/intel-pt.c | 7 +++++-- tools/perf/util/synthetic-events.c | 25 ++++++++++++++++++------- tools/perf/util/synthetic-events.h | 6 ++++-- 10 files changed, 62 insertions(+), 26 deletions(-) diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c index aad572a78d7f..bfd2c5ec9488 100644 --- a/tools/perf/bench/inject-buildid.c +++ b/tools/perf/bench/inject-buildid.c @@ -228,9 +228,12 @@ static ssize_t synthesize_sample(struct bench_data *data, struct bench_dso *dso, event.header.type = PERF_RECORD_SAMPLE; event.header.misc = PERF_RECORD_MISC_USER; - event.header.size = perf_event__sample_event_size(&sample, bench_sample_type, 0); - - perf_event__synthesize_sample(&event, bench_sample_type, 0, &sample); + event.header.size = perf_event__sample_event_size(&sample, bench_sample_type, + /*read_format=*/0, + /*branch_sample_type=*/0); + perf_event__synthesize_sample(&event, bench_sample_type, + /*read_format=*/0, + /*branch_sample_type=*/0, &sample); return writen(data->input_pipe[1], &event, event.header.size); } diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index f174bc69cec4..0c51cb4250d1 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -463,8 +463,13 @@ static int perf_event__convert_sample_callchain(const struct perf_tool *tool, /* remove sample_type {STACK,REGS}_USER for synthesize */ sample_type &= ~(PERF_SAMPLE_STACK_USER | PERF_SAMPLE_REGS_USER); - perf_event__synthesize_sample(event_copy, sample_type, - evsel->core.attr.read_format, sample); + ret = perf_event__synthesize_sample(event_copy, evsel->core.attr.sample_type, + evsel->core.attr.read_format, + evsel->core.attr.branch_sample_type, sample); + if (ret) { + pr_err("Failed to synthesize sample\n"); + return ret; + } return perf_event__repipe_synth(tool, event_copy); } @@ -1100,7 +1105,8 @@ static int perf_inject__sched_stat(const struct perf_tool *tool, sample_sw.period = sample->period; sample_sw.time = sample->time; perf_event__synthesize_sample(event_sw, evsel->core.attr.sample_type, - evsel->core.attr.read_format, &sample_sw); + evsel->core.attr.read_format, + evsel->core.attr.branch_sample_type, &sample_sw); build_id__mark_dso_hit(tool, event_sw, &sample_sw, evsel, machine); ret = perf_event__repipe(tool, event_sw, &sample_sw, machine); perf_sample__exit(&sample_sw); diff --git a/tools/perf/tests/dlfilter-test.c b/tools/perf/tests/dlfilter-test.c index e63790c61d53..204663571943 100644 --- a/tools/perf/tests/dlfilter-test.c +++ b/tools/perf/tests/dlfilter-test.c @@ -188,8 +188,12 @@ static int write_sample(struct test_data *td, u64 sample_type, u64 id, pid_t pid event->header.type = PERF_RECORD_SAMPLE; event->header.misc = PERF_RECORD_MISC_USER; - event->header.size = perf_event__sample_event_size(&sample, sample_type, 0); - err = perf_event__synthesize_sample(event, sample_type, 0, &sample); + event->header.size = perf_event__sample_event_size(&sample, sample_type, + /*read_format=*/0, + /*branch_sample_type=*/0); + err = perf_event__synthesize_sample(event, sample_type, + /*read_format=*/0, + /*branch_sample_type=*/0, &sample); if (err) return test_result("perf_event__synthesize_sample() failed", TEST_FAIL); diff --git a/tools/perf/tests/sample-parsing.c b/tools/perf/tests/sample-parsing.c index a7327c942ca2..55f0b73ca20e 100644 --- a/tools/perf/tests/sample-parsing.c +++ b/tools/perf/tests/sample-parsing.c @@ -310,7 +310,8 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format) sample.read.one.lost = 1; } - sz = perf_event__sample_event_size(&sample, sample_type, read_format); + sz = perf_event__sample_event_size(&sample, sample_type, read_format, + evsel.core.attr.branch_sample_type); bufsz = sz + 4096; /* Add a bit for overrun checking */ event = malloc(bufsz); if (!event) { @@ -324,7 +325,7 @@ static int do_test(u64 sample_type, u64 sample_regs, u64 read_format) event->header.size = sz; err = perf_event__synthesize_sample(event, sample_type, read_format, - &sample); + evsel.core.attr.branch_sample_type, &sample); if (err) { pr_debug("%s failed for sample_type %#"PRIx64", error %d\n", "perf_event__synthesize_sample", sample_type, err); diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c index e5835042acdf..c4ed9f10e731 100644 --- a/tools/perf/util/arm-spe.c +++ b/tools/perf/util/arm-spe.c @@ -484,8 +484,11 @@ static void arm_spe__prep_branch_stack(struct arm_spe_queue *speq) static int arm_spe__inject_event(union perf_event *event, struct perf_sample *sample, u64 type) { - event->header.size = perf_event__sample_event_size(sample, type, 0); - return perf_event__synthesize_sample(event, type, 0, sample); + event->header.type = PERF_RECORD_SAMPLE; + event->header.size = perf_event__sample_event_size(sample, type, /*read_format=*/0, + /*branch_sample_type=*/0); + return perf_event__synthesize_sample(event, type, /*read_format=*/0, + /*branch_sample_type=*/0, sample); } static inline int diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 8a639d2e51a4..1ebc1a6a5e75 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1425,8 +1425,10 @@ static void cs_etm__update_last_branch_rb(struct cs_etm_queue *etmq, static int cs_etm__inject_event(union perf_event *event, struct perf_sample *sample, u64 type) { - event->header.size = perf_event__sample_event_size(sample, type, 0); - return perf_event__synthesize_sample(event, type, 0, sample); + event->header.size = perf_event__sample_event_size(sample, type, /*read_format=*/0, + /*branch_sample_type=*/0); + return perf_event__synthesize_sample(event, type, /*read_format=*/0, + /*branch_sample_type=*/0, sample); } diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c index 382255393fb3..0b18ebd13f7c 100644 --- a/tools/perf/util/intel-bts.c +++ b/tools/perf/util/intel-bts.c @@ -303,7 +303,8 @@ static int intel_bts_synth_branch_sample(struct intel_bts_queue *btsq, event.sample.header.size = bts->branches_event_size; ret = perf_event__synthesize_sample(&event, bts->branches_sample_type, - 0, &sample); + /*read_format=*/0, /*branch_sample_type=*/0, + &sample); if (ret) return ret; } diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c index fc9eec8b54b8..5142983e3243 100644 --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -1731,8 +1731,11 @@ static void intel_pt_prep_b_sample(struct intel_pt *pt, static int intel_pt_inject_event(union perf_event *event, struct perf_sample *sample, u64 type) { - event->header.size = perf_event__sample_event_size(sample, type, 0); - return perf_event__synthesize_sample(event, type, 0, sample); + event->header.size = perf_event__sample_event_size(sample, type, /*read_format=*/0, + /*branch_sample_type=*/0); + + return perf_event__synthesize_sample(event, type, /*read_format=*/0, + /*branch_sample_type=*/0, sample); } static inline int intel_pt_opt_inject(struct intel_pt *pt, diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 85bee747f4cd..2461f25a4d7d 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -1455,7 +1455,8 @@ int perf_event__synthesize_stat_round(const struct perf_tool *tool, return process(tool, (union perf_event *) &event, NULL, machine); } -size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, u64 read_format) +size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, u64 read_format, + u64 branch_sample_type) { size_t sz, result = sizeof(struct perf_record_sample); @@ -1515,8 +1516,10 @@ size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, if (type & PERF_SAMPLE_BRANCH_STACK) { sz = sample->branch_stack->nr * sizeof(struct branch_entry); - /* nr, hw_idx */ - sz += 2 * sizeof(u64); + /* nr */ + sz += sizeof(u64); + if (branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX) + sz += sizeof(u64); result += sz; } @@ -1605,7 +1608,7 @@ static __u64 *copy_read_group_values(__u64 *array, __u64 read_format, } int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_format, - const struct perf_sample *sample) + u64 branch_sample_type, const struct perf_sample *sample) { __u64 *array; size_t sz; @@ -1719,9 +1722,17 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo if (type & PERF_SAMPLE_BRANCH_STACK) { sz = sample->branch_stack->nr * sizeof(struct branch_entry); - /* nr, hw_idx */ - sz += 2 * sizeof(u64); - memcpy(array, sample->branch_stack, sz); + + *array++ = sample->branch_stack->nr; + + if (branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX) { + if (sample->no_hw_idx) + *array++ = 0; + else + *array++ = sample->branch_stack->hw_idx; + } + + memcpy(array, perf_sample__branch_entries((struct perf_sample *)sample), sz); array = (void *)array + sz; } diff --git a/tools/perf/util/synthetic-events.h b/tools/perf/util/synthetic-events.h index b0edad0c3100..8c7f49f9ccf5 100644 --- a/tools/perf/util/synthetic-events.h +++ b/tools/perf/util/synthetic-events.h @@ -81,7 +81,8 @@ int perf_event__synthesize_mmap_events(const struct perf_tool *tool, union perf_ int perf_event__synthesize_modules(const struct perf_tool *tool, perf_event__handler_t process, struct machine *machine); int perf_event__synthesize_namespaces(const struct perf_tool *tool, union perf_event *event, pid_t pid, pid_t tgid, perf_event__handler_t process, struct machine *machine); int perf_event__synthesize_cgroups(const struct perf_tool *tool, perf_event__handler_t process, struct machine *machine); -int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_format, const struct perf_sample *sample); +int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_format, + u64 branch_sample_type, const struct perf_sample *sample); int perf_event__synthesize_stat_config(const struct perf_tool *tool, struct perf_stat_config *config, perf_event__handler_t process, struct machine *machine); int perf_event__synthesize_stat_events(struct perf_stat_config *config, const struct perf_tool *tool, struct evlist *evlist, perf_event__handler_t process, bool attrs); int perf_event__synthesize_stat_round(const struct perf_tool *tool, u64 time, u64 type, perf_event__handler_t process, struct machine *machine); @@ -97,7 +98,8 @@ void perf_event__synthesize_final_bpf_metadata(struct perf_session *session, int perf_tool__process_synth_event(const struct perf_tool *tool, union perf_event *event, struct machine *machine, perf_event__handler_t process); -size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, u64 read_format); +size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type, + u64 read_format, u64 branch_sample_type); int __machine__synthesize_threads(struct machine *machine, const struct perf_tool *tool, struct target *target, struct perf_thread_map *threads, -- 2.54.0.545.g6539524ca2-goog