From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DA50D3C76AF; Tue, 2 Jun 2026 23:57:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780444651; cv=none; b=KdORGgONZgpepcQh1Tjydqauyopf0n6O4BNfJMGZUSATS51Tt6th1lijX/Bq/BZ/xh3F9Y7j/1buWnVaZzWVfC5NdWETgrX+CTjzRstezZsFuK/4uMeTsf5S3mwXWxMsLbXRlFJIjlrpXzkW+pN20V2zss8LArtMAhb4GCKQJbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780444651; c=relaxed/simple; bh=FizgIGoqxIYieXEQd67/TFnY4gePAIZsmdbaF6lKoWk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XEkVBiFQps0tuGFhg2qqi3X30MZPnkPXI7W+jSeBOc/YvtctrWGrnSqQEHbhnYAPY5neS8ToxF3kp1BgGS99ym1lXMOAoPCsC8kFjFSYpJV/+5NPaq+VO8NbUPHUYUeuyGHW1fqXZ7iFcF6Q/2G/RBbU15cqe25LKIB5KWS7zN0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vgsr6AdF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vgsr6AdF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A919A1F00893; Tue, 2 Jun 2026 23:57:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780444649; bh=78qyVSIOLPMH4ADifqB4NJQ/0qW2+qa/hZS/twONP98=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Vgsr6AdFg5ObLEnl7w5fPW5wZrgbzhpyjX/gqSNBg5zpXq/1YWKcxaTNJqYTuFNX+ XAduxqHG6ToID7/tfE9nLDQLVLaWzZg4z60cablK4qtKr9Ay8j8txxh/brp+GI9CgC uCqoeGBrwSQJcXvhe5EgU5vD2+lj7pGRqxj8mc1dyN/R0jhZ96jqKlimabSVdbI+7u Hwa4Hb//Ag2Gushecnw5siGH57fQEKLc1rLQnKZ+Gah0rsR7NC5jTl+vyA4HTTdYxD dldu2ETp+6d0xrBBLA5ujY/WzqMp1mJSpE067fcnuFyhvI4FdeYy66anaIeAHnxAEQ KAukl43HN+tnQ== From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , "Claude Opus 4.6" Subject: [PATCH 2/8] perf session: Include file offset in event skip/stop messages Date: Tue, 2 Jun 2026 20:57:01 -0300 Message-ID: <20260602235709.1541603-3-acme@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260602235709.1541603-1-acme@kernel.org> References: <20260602235709.1541603-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo Add 'at offset %#' to all warning and error messages in session.c that fire when events are skipped or processing stops due to validation failures. This lets users cross-reference with 'perf report -D' output to inspect the surrounding records and understand the corruption context. Covers messages in perf_session__process_event() (alignment, min size, swap failure), perf_session__deliver_event() (no evsel, parse failure, CPU clamping), machines__deliver_event() (NAMESPACES, TEXT_POKE, null-terminated string checks for MMAP/MMAP2/COMM/CGROUP/KSYMBOL), and perf_session__process_user_event() (THREAD_MAP, CPU_MAP, STAT_CONFIG, BPF_METADATA, HEADER_BUILD_ID). Assisted-by: Claude Opus 4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/session.c | 112 ++++++++++++++++++++------------------ 1 file changed, 60 insertions(+), 52 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 7996787d742e32c6..e4efb75509278a4e 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1931,13 +1931,14 @@ static int session__flush_deferred_samples(struct perf_session *session, * read-only (MAP_SHARED + PROT_READ) so we cannot write a * null byte in place; skip the event instead. */ -static bool perf_event__check_nul(const char *str, const void *end, const char *event_name) +static bool perf_event__check_nul(const char *str, const void *end, + const char *event_name, u64 file_offset) { size_t max_len = (const char *)end - str; if (max_len == 0 || strnlen(str, max_len) == max_len) { - pr_warning("WARNING: PERF_RECORD_%s: string not null-terminated, skipping event\n", - event_name); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_%s: string not null-terminated, skipping event\n", + file_offset, event_name); return false; } @@ -1995,7 +1996,7 @@ static int machines__deliver_event(struct machines *machines, case PERF_RECORD_MMAP: if (!perf_event__check_nul(event->mmap.filename, (void *)event + event->header.size, - "MMAP")) + "MMAP", file_offset)) return 0; return tool->mmap(tool, event, sample, machine); case PERF_RECORD_MMAP2: @@ -2003,13 +2004,13 @@ static int machines__deliver_event(struct machines *machines, ++evlist->stats.nr_proc_map_timeout; if (!perf_event__check_nul(event->mmap2.filename, (void *)event + event->header.size, - "MMAP2")) + "MMAP2", file_offset)) return 0; return tool->mmap2(tool, event, sample, machine); case PERF_RECORD_COMM: if (!perf_event__check_nul(event->comm.comm, (void *)event + event->header.size, - "COMM")) + "COMM", file_offset)) return 0; return tool->comm(tool, event, sample, machine); case PERF_RECORD_NAMESPACES: { @@ -2027,8 +2028,8 @@ static int machines__deliver_event(struct machines *machines, * cross-endian path. */ if (event->namespaces.nr_namespaces > max_nr) { - pr_warning("WARNING: PERF_RECORD_NAMESPACES: nr_namespaces %" PRIu64 " exceeds payload (max %" PRIu64 "), skipping\n", - (u64)event->namespaces.nr_namespaces, max_nr); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_NAMESPACES: nr_namespaces %" PRIu64 " exceeds payload (max %" PRIu64 "), skipping\n", + file_offset, (u64)event->namespaces.nr_namespaces, max_nr); return 0; } return tool->namespaces(tool, event, sample, machine); @@ -2036,7 +2037,7 @@ static int machines__deliver_event(struct machines *machines, case PERF_RECORD_CGROUP: if (!perf_event__check_nul(event->cgroup.path, (void *)event + event->header.size, - "CGROUP")) + "CGROUP", file_offset)) return 0; return tool->cgroup(tool, event, sample, machine); case PERF_RECORD_FORK: @@ -2078,7 +2079,7 @@ static int machines__deliver_event(struct machines *machines, case PERF_RECORD_KSYMBOL: if (!perf_event__check_nul(event->ksymbol.name, (void *)event + event->header.size, - "KSYMBOL")) + "KSYMBOL", file_offset)) return 0; return tool->ksymbol(tool, event, sample, machine); case PERF_RECORD_BPF_EVENT: @@ -2090,7 +2091,8 @@ static int machines__deliver_event(struct machines *machines, event->text_poke.new_len; if (event->header.size < text_poke_len) { - pr_warning("WARNING: PERF_RECORD_TEXT_POKE: old_len+new_len exceeds event, skipping\n"); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_TEXT_POKE: old_len+new_len exceeds event, skipping\n", + file_offset); return 0; } return tool->text_poke(tool, event, sample, machine); @@ -2120,14 +2122,17 @@ static int perf_session__deliver_event(struct perf_session *session, perf_sample__init(&sample, /*all=*/false); evsel = evlist__event2evsel(session->evlist, event); if (!evsel) { - pr_err("No evsel found for event type %u\n", + pr_err("ERROR: at offset %#" PRIx64 ": no evsel found for %s (%u) event\n", + file_offset, perf_event__name(event->header.type), event->header.type); ret = -EFAULT; goto out; } ret = evsel__parse_sample(evsel, event, &sample); if (ret) { - pr_err("Can't parse sample, err = %d\n", ret); + pr_err("ERROR: at offset %#" PRIx64 ": can't parse %s (%u) sample, err = %d\n", + file_offset, perf_event__name(event->header.type), + event->header.type, ret); goto out; } sample.file_offset = file_offset; @@ -2204,8 +2209,8 @@ static int perf_session__deliver_event(struct perf_session *session, * Downstream array users (timechart, kwork) have * their own per-callback bounds checks. */ - pr_warning_once("WARNING: sample CPU %u >= nr_cpus_avail %u, clamping to 0\n", - sample.cpu, nr_cpus_avail); + pr_warning_once("WARNING: at offset %#" PRIx64 ": sample CPU %u >= nr_cpus_avail %u, clamping to 0\n", + file_offset, sample.cpu, nr_cpus_avail); sample.cpu = 0; } } @@ -2278,7 +2283,7 @@ static s64 perf_session__process_user_event(struct perf_session *session, case PERF_RECORD_HEADER_BUILD_ID: if (!perf_event__check_nul(event->build_id.filename, (void *)event + event_size, - "HEADER_BUILD_ID")) { + "HEADER_BUILD_ID", file_offset)) { err = 0; break; } @@ -2311,8 +2316,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, u64 max_nr; if (event_size < sizeof(event->thread_map)) { - pr_err("PERF_RECORD_THREAD_MAP: header.size (%u) too small\n", - event_size); + pr_err("ERROR: at offset %#" PRIx64 ": PERF_RECORD_THREAD_MAP: header.size (%u) too small\n", + file_offset, event_size); err = -EINVAL; break; } @@ -2320,8 +2325,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, max_nr = (event_size - sizeof(event->thread_map)) / sizeof(event->thread_map.entries[0]); if (event->thread_map.nr > max_nr) { - pr_err("PERF_RECORD_THREAD_MAP: nr %" PRIu64 " exceeds max %" PRIu64 "\n", - (u64)event->thread_map.nr, max_nr); + pr_err("ERROR: at offset %#" PRIx64 ": PERF_RECORD_THREAD_MAP: nr %" PRIu64 " exceeds max %" PRIu64 "\n", + file_offset, (u64)event->thread_map.nr, max_nr); err = -EINVAL; break; } @@ -2345,8 +2350,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, sizeof(data->cpus_data.cpu[0]); if (data->cpus_data.nr > max_nr) { - pr_warning("WARNING: PERF_RECORD_CPU_MAP: nr %u exceeds payload (max %u), skipping\n", - data->cpus_data.nr, max_nr); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_CPU_MAP: nr %u exceeds payload (max %u), skipping\n", + file_offset, data->cpus_data.nr, max_nr); err = 0; goto out; } @@ -2359,8 +2364,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, sizeof(data->mask32_data.mask[0]); if (data->mask32_data.nr > max_nr) { - pr_warning("WARNING: PERF_RECORD_CPU_MAP mask32: nr %u exceeds payload (max %u), skipping\n", - data->mask32_data.nr, max_nr); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_CPU_MAP mask32: nr %u exceeds payload (max %u), skipping\n", + file_offset, data->mask32_data.nr, max_nr); err = 0; goto out; } @@ -2375,14 +2380,14 @@ static s64 perf_session__process_user_event(struct perf_session *session, mask64_data.mask)) / sizeof(data->mask64_data.mask[0]); if (data->mask64_data.nr > max_nr) { - pr_warning("WARNING: PERF_RECORD_CPU_MAP mask64: nr %u exceeds payload (max %u), skipping\n", - data->mask64_data.nr, max_nr); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_CPU_MAP mask64: nr %u exceeds payload (max %u), skipping\n", + file_offset, data->mask64_data.nr, max_nr); err = 0; goto out; } } else { - pr_warning("WARNING: PERF_RECORD_CPU_MAP: unsupported long_size %u, skipping\n", - data->mask32_data.long_size); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_CPU_MAP: unsupported long_size %u, skipping\n", + file_offset, data->mask32_data.long_size); err = 0; goto out; } @@ -2404,8 +2409,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, * cannot clamp nr in place. Skip the event instead. */ if (event->stat_config.nr > max_nr) { - pr_warning("WARNING: PERF_RECORD_STAT_CONFIG: nr %" PRIu64 " exceeds payload (max %" PRIu64 "), skipping\n", - (u64)event->stat_config.nr, max_nr); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_STAT_CONFIG: nr %" PRIu64 " exceeds payload (max %" PRIu64 "), skipping\n", + file_offset, (u64)event->stat_config.nr, max_nr); err = 0; goto out; } @@ -2446,8 +2451,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, u64 nr_entries, max_entries; if (event_size < sizeof(event->bpf_metadata)) { - pr_warning("WARNING: PERF_RECORD_BPF_METADATA: header.size (%u) too small, skipping\n", - event_size); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_BPF_METADATA: header.size (%u) too small, skipping\n", + file_offset, event_size); err = 0; break; } @@ -2458,7 +2463,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, */ if (strnlen(event->bpf_metadata.prog_name, BPF_PROG_NAME_LEN) == BPF_PROG_NAME_LEN) { - pr_warning("WARNING: PERF_RECORD_BPF_METADATA: prog_name not null-terminated, skipping\n"); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_BPF_METADATA: prog_name not null-terminated, skipping\n", + file_offset); err = 0; break; } @@ -2467,8 +2473,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, max_entries = (event_size - sizeof(event->bpf_metadata)) / sizeof(event->bpf_metadata.entries[0]); if (nr_entries > max_entries) { - pr_warning("WARNING: PERF_RECORD_BPF_METADATA: nr_entries %" PRIu64 " exceeds max %" PRIu64 ", skipping\n", - nr_entries, max_entries); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_BPF_METADATA: nr_entries %" PRIu64 " exceeds max %" PRIu64 ", skipping\n", + file_offset, nr_entries, max_entries); err = 0; break; } @@ -2478,7 +2484,8 @@ static s64 perf_session__process_user_event(struct perf_session *session, BPF_METADATA_KEY_LEN) == BPF_METADATA_KEY_LEN || strnlen(event->bpf_metadata.entries[i].value, BPF_METADATA_VALUE_LEN) == BPF_METADATA_VALUE_LEN) { - pr_warning("WARNING: PERF_RECORD_BPF_METADATA: entry %" PRIu64 " key/value not null-terminated, skipping\n", i); + pr_warning("WARNING: at offset %#" PRIx64 ": PERF_RECORD_BPF_METADATA: entry %" PRIu64 " key/value not null-terminated, skipping\n", + file_offset, i); err = 0; goto out; } @@ -2752,22 +2759,22 @@ int perf_session__peek_event(struct perf_session *session, off_t file_offset, event->header.type != PERF_RECORD_HEADER_TRACING_DATA && event->header.type != PERF_RECORD_COMPRESSED && event->header.type != PERF_RECORD_HEADER_FEATURE) { - pr_warning("WARNING: peek_event: event type %u size %u not aligned to %zu\n", - event->header.type, - event->header.size, sizeof(u64)); + pr_warning("WARNING: at offset %#" PRIx64 ": %s (%u) event size %u not aligned to %zu\n", + (u64)file_offset, perf_event__name(event->header.type), + event->header.type, event->header.size, sizeof(u64)); return -1; } if (event->header.type >= PERF_RECORD_HEADER_MAX) { - pr_warning("WARNING: peek_event: unsupported event type %u, skipping\n", - event->header.type); + pr_warning("WARNING: at offset %#" PRIx64 ": unsupported event type %u, skipping\n", + (u64)file_offset, event->header.type); return 0; } if (perf_event__too_small(event, &min_sz)) { - pr_warning("WARNING: peek_event: %s event size %u too small (min %u)\n", - perf_event__name(event->header.type), - event->header.size, min_sz); + pr_warning("WARNING: at offset %#" PRIx64 ": %s (%u) event size %u too small (min %u)\n", + (u64)file_offset, perf_event__name(event->header.type), + event->header.type, event->header.size, min_sz); return -1; } @@ -2883,9 +2890,9 @@ static s64 perf_session__process_event(struct perf_session *session, event->header.type != PERF_RECORD_HEADER_TRACING_DATA && event->header.type != PERF_RECORD_COMPRESSED && event->header.type != PERF_RECORD_HEADER_FEATURE) { - pr_err("ERROR: %s event size %u is not 8-byte aligned, aborting\n", - perf_event__name(event->header.type), - event->header.size); + pr_err("ERROR: at offset %#" PRIx64 ": %s (%u) event size %u is not 8-byte aligned, aborting\n", + file_offset, perf_event__name(event->header.type), + event->header.type, event->header.size); return -EINVAL; } @@ -2905,16 +2912,17 @@ static s64 perf_session__process_event(struct perf_session *session, * can be safely stepped over without misaligning the stream. */ if (perf_event__too_small(event, &min_sz)) { - pr_warning("WARNING: %s event size %u too small (min %u), skipping\n", - perf_event__name(event->header.type), - event->header.size, min_sz); + pr_warning("WARNING: at offset %#" PRIx64 ": %s (%u) event size %u too small (min %u), skipping\n", + file_offset, perf_event__name(event->header.type), + event->header.type, event->header.size, min_sz); return 0; } if (session->header.needs_swap && event_swap(event, evlist__sample_id_all(evlist))) { - pr_warning("WARNING: swap failed for %s event, skipping\n", - perf_event__name(event->header.type)); + pr_warning("WARNING: at offset %#" PRIx64 ": swap failed for %s (%u) event, skipping\n", + file_offset, perf_event__name(event->header.type), + event->header.type); return 0; } -- 2.54.0