[PATCH 4/6] perf: cs-etm: Respect --no-itrace option
From: James Clark
Date: Fri Aug 21 2026 - 06:11:15 EST
If there is a bug in decoding then Perf will exit early and you can't
investigate by using the raw dump mode. Make the --no-itrace option stop
Coresight decoding after printing the aux header so decode errors don't
stop the rest of the samples being printed.
pmu_type and evsel_is_auxtrace need to be set so that the
unleader_auxtrace() behavior is the same as without --no-itrace.
Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
---
tools/perf/util/auxtrace.c | 2 +-
tools/perf/util/auxtrace.h | 1 +
tools/perf/util/cs-etm.c | 66 +++++++++++++++++++++++++---------------------
3 files changed, 38 insertions(+), 31 deletions(-)
diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index e3c770b46e94..caa53056d349 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -123,7 +123,7 @@ static int evlist__regroup(struct evlist *evlist, struct evsel *leader, struct e
return 0;
}
-static bool auxtrace__dont_decode(struct perf_session *session)
+bool auxtrace__dont_decode(struct perf_session *session)
{
return !session->itrace_synth_opts ||
session->itrace_synth_opts->dont_decode;
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index 971b817d3396..47fb97136836 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -651,6 +651,7 @@ void auxtrace__free(struct perf_session *session);
bool auxtrace__evsel_is_auxtrace(struct perf_session *session,
struct evsel *evsel);
u64 auxtrace_synth_id_range_start(struct evsel *evsel);
+bool auxtrace__dont_decode(struct perf_session *session);
#define ITRACE_HELP \
" i[period]: synthesize instructions events\n" \
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index dd15e91b7b38..22884c9fdff8 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -969,7 +969,7 @@ static int cs_etm__flush_events(struct perf_session *session,
struct cs_etm_auxtrace *etm = container_of(session->auxtrace,
struct cs_etm_auxtrace,
auxtrace);
- if (dump_trace)
+ if (dump_trace || auxtrace__dont_decode(session))
return 0;
if (!tool->ordered_events)
@@ -3040,7 +3040,7 @@ static int cs_etm__process_event(struct perf_session *session,
struct cs_etm_auxtrace,
auxtrace);
- if (dump_trace)
+ if (dump_trace || auxtrace__dont_decode(session))
return 0;
if (!tool->ordered_events) {
@@ -3603,27 +3603,49 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
int err = 0;
int aux_hw_id_found;
int i;
- u64 *ptr = NULL;
+ u64 *ptr = (u64 *) auxtrace_info->priv;
u64 **metadata = NULL;
- /* First the global part */
- ptr = (u64 *) auxtrace_info->priv;
- num_cpu = ptr[CS_PMU_TYPE_CPUS] & 0xffffffff;
+ etm = zalloc(sizeof(*etm));
+ if (!etm)
+ return -ENOMEM;
+
+ session->auxtrace = &etm->auxtrace;
+ etm->auxtrace.free = cs_etm__free;
+ etm->auxtrace.evsel_is_auxtrace = cs_etm__evsel_is_auxtrace;
+ etm->auxtrace.process_event = cs_etm__process_event;
+ etm->auxtrace.process_auxtrace_event = cs_etm__process_auxtrace_event;
+ etm->auxtrace.flush_events = cs_etm__flush_events;
+ etm->auxtrace.free_events = cs_etm__free_events;
+ etm->pmu_type = (unsigned int) ((ptr[CS_PMU_TYPE_CPUS] >> 32) & 0xffffffff);
+
+ /*
+ * Don't go further than the minimum required to identify this event as
+ * auxtrace with cs_etm__evsel_is_auxtrace() so unleader_auxtrace()
+ * works.
+ */
+ if (auxtrace__dont_decode(session))
+ return 0;
/*
* Bound num_cpu by the event size: the global header consumes
* CS_ETM_HEADER_SIZE bytes, and each CPU needs at least one u64
* metadata entry after that.
*/
+ num_cpu = ptr[CS_PMU_TYPE_CPUS] & 0xffffffff;
priv_size = total_size - event_header_size - INFO_HEADER_SIZE -
CS_ETM_HEADER_SIZE;
if (num_cpu <= 0 || priv_size <= 0 ||
- num_cpu > priv_size / (int)sizeof(u64))
- return -EINVAL;
+ num_cpu > priv_size / (int)sizeof(u64)) {
+ err = -EINVAL;
+ goto err_free_etm;
+ }
metadata = zalloc(sizeof(*metadata) * num_cpu);
- if (!metadata)
- return -ENOMEM;
+ if (!metadata) {
+ err = -ENOMEM;
+ goto err_free_etm;
+ }
/* Start parsing after the common part of the header */
i = CS_HEADER_VERSION_MAX;
@@ -3682,13 +3704,6 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
goto err_free_metadata;
}
- etm = zalloc(sizeof(*etm));
-
- if (!etm) {
- err = -ENOMEM;
- goto err_free_metadata;
- }
-
/*
* As all the ETMs run at the same exception level, the system should
* have the same PID format crossing CPUs. So cache the PID format
@@ -3698,7 +3713,7 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
err = auxtrace_queues__init_nr(&etm->queues, max_cpu + 1);
if (err)
- goto err_free_etm;
+ goto err_free_metadata;
for (unsigned int j = 0; j < etm->queues.nr_queues; ++j) {
err = cs_etm__setup_queue(etm, &etm->queues.queue_array[j], j);
@@ -3736,7 +3751,6 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
etm->session = session;
etm->num_cpu = num_cpu;
- etm->pmu_type = (unsigned int) ((ptr[CS_PMU_TYPE_CPUS] >> 32) & 0xffffffff);
etm->snapshot_mode = (ptr[CS_ETM_SNAPSHOT] != 0);
etm->metadata = metadata;
etm->auxtrace_type = auxtrace_info->type;
@@ -3763,14 +3777,6 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
"you can specify the itrace option 'T' for timestamp decoding\n"
"if the Coresight timestamp on the platform is same with the kernel time.\n\n");
- etm->auxtrace.process_event = cs_etm__process_event;
- etm->auxtrace.process_auxtrace_event = cs_etm__process_auxtrace_event;
- etm->auxtrace.flush_events = cs_etm__flush_events;
- etm->auxtrace.free_events = cs_etm__free_events;
- etm->auxtrace.free = cs_etm__free;
- etm->auxtrace.evsel_is_auxtrace = cs_etm__evsel_is_auxtrace;
- session->auxtrace = &etm->auxtrace;
-
cs_etm__setup_timeless_decoding(etm);
etm->tc.time_shift = tc->time_shift;
@@ -3853,13 +3859,13 @@ int cs_etm__process_auxtrace_info_full(union perf_event *event,
err_free_queues:
cs_etm__free_queues(etm);
- session->auxtrace = NULL;
-err_free_etm:
- zfree(&etm);
err_free_metadata:
/* No need to check @metadata[j], free(NULL) is supported */
for (int j = 0; j < num_cpu; j++)
zfree(&metadata[j]);
zfree(&metadata);
+err_free_etm:
+ session->auxtrace = NULL;
+ zfree(&etm);
return err;
}
--
2.43.0