From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
James Clark <james.clark@linaro.org>,
Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Clark Williams <williams@redhat.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@redhat.com>,
"Claude Opus 4.6" <noreply@anthropic.com>
Subject: [PATCH 2/8] perf session: Include file offset in event skip/stop messages
Date: Tue, 2 Jun 2026 20:57:01 -0300 [thread overview]
Message-ID: <20260602235709.1541603-3-acme@kernel.org> (raw)
In-Reply-To: <20260602235709.1541603-1-acme@kernel.org>
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Add 'at offset %#<hex>' 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 <noreply@anthropic.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
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
next prev parent reply other threads:[~2026-06-02 23:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-02 23:56 [PATCHES 0/8] perf tools: Diagnostic offsets in skip messages + two hardening fixes Arnaldo Carvalho de Melo
2026-06-02 23:57 ` [PATCH 1/8] perf sample: Add file_offset field to struct perf_sample Arnaldo Carvalho de Melo
2026-06-03 15:11 ` Ian Rogers
2026-06-02 23:57 ` Arnaldo Carvalho de Melo [this message]
2026-06-03 15:12 ` [PATCH 2/8] perf session: Include file offset in event skip/stop messages Ian Rogers
2026-06-02 23:57 ` [PATCH 3/8] perf sched: Include file offset in event skip messages Arnaldo Carvalho de Melo
2026-06-03 15:13 ` Ian Rogers
2026-06-02 23:57 ` [PATCH 4/8] perf timechart: Include file offset in CPU bounds check messages Arnaldo Carvalho de Melo
2026-06-03 0:36 ` sashiko-bot
2026-06-03 15:14 ` Ian Rogers
2026-06-02 23:57 ` [PATCH 5/8] perf tools: Include file offset and event type name in skip messages Arnaldo Carvalho de Melo
2026-06-03 15:14 ` Ian Rogers
2026-06-02 23:57 ` [PATCH 6/8] perf timechart: Fix cat_backtrace() use-after-free on corrupted callchain Arnaldo Carvalho de Melo
2026-06-03 15:16 ` Ian Rogers
2026-06-02 23:57 ` [PATCH 7/8] perf sched: Replace BUG_ON on invalid CPU with graceful skip Arnaldo Carvalho de Melo
2026-06-03 1:16 ` sashiko-bot
2026-06-03 15:17 ` Ian Rogers
2026-06-02 23:57 ` [PATCH 8/8] perf test: Add file offset diagnostic test for corrupted perf.data Arnaldo Carvalho de Melo
2026-06-03 1:32 ` sashiko-bot
2026-06-03 15:19 ` Ian Rogers
2026-06-03 15:06 ` [PATCHES 0/8] perf tools: Diagnostic offsets in skip messages + two hardening fixes Ian Rogers
2026-06-03 19:27 ` Arnaldo Carvalho de Melo
2026-06-03 19:44 ` Ian Rogers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260602235709.1541603-3-acme@kernel.org \
--to=acme@kernel.org \
--cc=acme@redhat.com \
--cc=adrian.hunter@intel.com \
--cc=irogers@google.com \
--cc=james.clark@linaro.org \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=namhyung@kernel.org \
--cc=noreply@anthropic.com \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.