[PATCH v5 16/25] perf inject: Don't pass evsel with sample
From: Ian Rogers
Date: Fri Apr 03 2026 - 16:43:50 EST
The sample contains the evsel and so it is unnecessary to pass the
evsel as well. Clean up handling of sample and mmap_evsel when
synthesizing build id events and mmap2 events with build ids. For
callchain walking and things that expect the evsel to match sample,
the sample->evsel shouldn't change. The mmap_evsel should be used when
making mmap2 events.
Add space for sample identifiers in
perf_event__synthesize_mmap2_build_id to avoid Sashiko caught
potential buffer overrun. Also add a NULL check to avoid an unlikely
SEGV.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/builtin-inject.c | 52 +++++++++--------
tools/perf/util/synthetic-events.c | 92 +++++++++++++++++++-----------
tools/perf/util/synthetic-events.h | 2 -
3 files changed, 86 insertions(+), 60 deletions(-)
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index ebcbe7a7202c..1989feedd6ff 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -146,14 +146,12 @@ struct event_entry {
static int tool__inject_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
- const struct evsel *evsel,
__u16 misc,
const char *filename,
struct dso *dso, u32 flags);
static int tool__inject_mmap2_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
- const struct evsel *evsel,
__u16 misc,
__u32 pid, __u32 tid,
__u64 start, __u64 len, __u64 pgoff,
@@ -357,7 +355,6 @@ perf_inject__cut_auxtrace_sample(struct perf_inject *inject,
typedef int (*inject_handler)(const struct perf_tool *tool,
union perf_event *event,
struct perf_sample *sample,
- struct evsel *evsel,
struct machine *machine);
static int perf_event__repipe_sample(const struct perf_tool *tool,
@@ -370,7 +367,7 @@ static int perf_event__repipe_sample(const struct perf_tool *tool,
if (evsel && evsel->handler) {
inject_handler f = evsel->handler;
- return f(tool, event, sample, evsel, machine);
+ return f(tool, event, sample, machine);
}
build_id__mark_dso_hit(tool, event, sample, machine);
@@ -584,11 +581,12 @@ static int perf_event__repipe_common_mmap(const struct perf_tool *tool,
}
if (dso && !dso__hit(dso)) {
- struct evsel *evsel = evlist__event2evsel(inject->session->evlist, event);
+ if (!sample->evsel)
+ sample->evsel = evlist__event2evsel(inject->session->evlist, event);
- if (evsel) {
+ if (sample->evsel) {
dso__set_hit(dso);
- tool__inject_build_id(tool, sample, machine, evsel,
+ tool__inject_build_id(tool, sample, machine,
/*misc=*/sample->cpumode,
filename, dso, flags);
}
@@ -615,23 +613,26 @@ static int perf_event__repipe_common_mmap(const struct perf_tool *tool,
}
if ((inject->build_id_style == BID_RWS__MMAP2_BUILDID_ALL) &&
!(event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID)) {
- struct evsel *evsel = evlist__event2evsel(inject->session->evlist, event);
+ struct evsel *saved_evsel = sample->evsel;
- if (evsel && !dso_sought) {
+ sample->evsel = evlist__event2evsel(inject->session->evlist, event);
+ if (sample->evsel && !dso_sought) {
dso = findnew_dso(pid, tid, filename, dso_id, machine);
dso_sought = true;
}
- if (evsel && dso &&
- !tool__inject_mmap2_build_id(tool, sample, machine, evsel,
+ if (sample->evsel && dso &&
+ !tool__inject_mmap2_build_id(tool, sample, machine,
sample->cpumode | PERF_RECORD_MISC_MMAP_BUILD_ID,
pid, tid, start, len, pgoff,
dso,
prot, flags,
filename)) {
/* Injected mmap2 so no need to repipe. */
+ sample->evsel = saved_evsel;
dso__put(dso);
return 0;
}
+ sample->evsel = saved_evsel;
}
dso__put(dso);
if (inject->build_id_style == BID_RWS__MMAP2_BUILDID_LAZY)
@@ -836,7 +837,6 @@ static bool perf_inject__lookup_known_build_id(struct perf_inject *inject,
static int tool__inject_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
- const struct evsel *evsel,
__u16 misc,
const char *filename,
struct dso *dso, u32 flags)
@@ -860,7 +860,7 @@ static int tool__inject_build_id(const struct perf_tool *tool,
err = perf_event__synthesize_build_id(tool, sample, machine,
perf_event__repipe,
- evsel, misc, dso__bid(dso),
+ misc, dso__bid(dso),
filename);
if (err) {
pr_err("Can't synthesize build_id event for %s\n", filename);
@@ -873,7 +873,6 @@ static int tool__inject_build_id(const struct perf_tool *tool,
static int tool__inject_mmap2_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
- const struct evsel *evsel,
__u16 misc,
__u32 pid, __u32 tid,
__u64 start, __u64 len, __u64 pgoff,
@@ -896,7 +895,6 @@ static int tool__inject_mmap2_build_id(const struct perf_tool *tool,
err = perf_event__synthesize_mmap2_build_id(tool, sample, machine,
perf_event__repipe,
- evsel,
misc, pid, tid,
start, len, pgoff,
dso__bid(dso),
@@ -913,7 +911,7 @@ static int mark_dso_hit(const struct perf_inject *inject,
const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
- const struct evsel *mmap_evsel,
+ struct evsel *mmap_evsel,
struct map *map, bool sample_in_dso)
{
struct dso *dso;
@@ -941,9 +939,13 @@ static int mark_dso_hit(const struct perf_inject *inject,
dso = map__dso(map);
if (inject->build_id_style == BID_RWS__INJECT_HEADER_LAZY) {
if (dso && !dso__hit(dso)) {
+ /*
+ * The sample is just read for identifiers which we want
+ * to match the for the event of the sample.
+ */
dso__set_hit(dso);
tool__inject_build_id(tool, sample, machine,
- mmap_evsel, misc, dso__long_name(dso), dso,
+ misc, dso__long_name(dso), dso,
map__flags(map));
}
} else if (inject->build_id_style == BID_RWS__MMAP2_BUILDID_LAZY) {
@@ -951,11 +953,13 @@ static int mark_dso_hit(const struct perf_inject *inject,
const struct build_id null_bid = { .size = 0 };
const struct build_id *bid = dso ? dso__bid(dso) : &null_bid;
const char *filename = dso ? dso__long_name(dso) : "";
+ struct evsel *saved_evsel = sample->evsel;
map__set_hit(map);
+ /* Creating a new mmap2 event which has an evsel for the mmap event. */
+ sample->evsel = mmap_evsel;
perf_event__synthesize_mmap2_build_id(tool, sample, machine,
perf_event__repipe,
- mmap_evsel,
misc,
sample->pid, sample->tid,
map__start(map),
@@ -965,6 +969,7 @@ static int mark_dso_hit(const struct perf_inject *inject,
map__prot(map),
map__flags(map),
filename);
+ sample->evsel = saved_evsel;
}
}
return 0;
@@ -975,7 +980,7 @@ struct mark_dso_hit_args {
const struct perf_tool *tool;
struct perf_sample *sample;
struct machine *machine;
- const struct evsel *mmap_evsel;
+ struct evsel *mmap_evsel;
};
static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data)
@@ -1030,7 +1035,6 @@ static int perf_event__inject_buildid(const struct perf_tool *tool, union perf_e
static int perf_inject__sched_process_exit(const struct perf_tool *tool,
union perf_event *event __maybe_unused,
struct perf_sample *sample,
- struct evsel *evsel __maybe_unused,
struct machine *machine __maybe_unused)
{
struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
@@ -1050,13 +1054,12 @@ static int perf_inject__sched_process_exit(const struct perf_tool *tool,
static int perf_inject__sched_switch(const struct perf_tool *tool,
union perf_event *event,
struct perf_sample *sample,
- struct evsel *evsel,
struct machine *machine)
{
struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
struct event_entry *ent;
- perf_inject__sched_process_exit(tool, event, sample, evsel, machine);
+ perf_inject__sched_process_exit(tool, event, sample, machine);
ent = malloc(event->header.size + sizeof(struct event_entry));
if (ent == NULL) {
@@ -1075,13 +1078,13 @@ static int perf_inject__sched_switch(const struct perf_tool *tool,
static int perf_inject__sched_stat(const struct perf_tool *tool,
union perf_event *event __maybe_unused,
struct perf_sample *sample,
- struct evsel *evsel,
struct machine *machine)
{
struct event_entry *ent;
union perf_event *event_sw;
struct perf_sample sample_sw;
struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
+ struct evsel *evsel = sample->evsel;
u32 pid = perf_sample__intval(sample, "pid");
int ret;
@@ -1446,7 +1449,7 @@ static int synthesize_build_id(struct perf_inject *inject, struct dso *dso, pid_
dso__set_hit(dso);
return perf_event__synthesize_build_id(&inject->tool, &synth_sample, machine,
- process_build_id, inject__mmap_evsel(inject),
+ process_build_id,
/*misc=*/synth_sample.cpumode,
dso__bid(dso), dso__long_name(dso));
}
@@ -2008,7 +2011,6 @@ static int evsel__check_stype(struct evsel *evsel, u64 sample_type, const char *
static int drop_sample(const struct perf_tool *tool __maybe_unused,
union perf_event *event __maybe_unused,
struct perf_sample *sample __maybe_unused,
- struct evsel *evsel __maybe_unused,
struct machine *machine __maybe_unused)
{
return 0;
diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index ddf1cbda1902..e848129db996 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -1802,7 +1802,12 @@ int perf_event__synthesize_sample(union perf_event *event, u64 type, u64 read_fo
return 0;
}
-int perf_event__synthesize_id_sample(__u64 *array, u64 type, const struct perf_sample *sample)
+static int __perf_event__synthesize_id_sample(__u64 *array, u64 type,
+ __u32 pid, __u32 tid,
+ __u64 sample_time,
+ __u64 sample_id,
+ __u64 stream_id,
+ __u32 cpu)
{
__u64 *start = array;
@@ -1813,42 +1818,52 @@ int perf_event__synthesize_id_sample(__u64 *array, u64 type, const struct perf_s
union u64_swap u;
if (type & PERF_SAMPLE_TID) {
- u.val32[0] = sample->pid;
- u.val32[1] = sample->tid;
+ u.val32[0] = pid;
+ u.val32[1] = tid;
*array = u.val64;
array++;
}
if (type & PERF_SAMPLE_TIME) {
- *array = sample->time;
+ *array = sample_time;
array++;
}
if (type & PERF_SAMPLE_ID) {
- *array = sample->id;
+ *array = sample_id;
array++;
}
if (type & PERF_SAMPLE_STREAM_ID) {
- *array = sample->stream_id;
+ *array = stream_id;
array++;
}
if (type & PERF_SAMPLE_CPU) {
- u.val32[0] = sample->cpu;
+ u.val32[0] = cpu;
u.val32[1] = 0;
*array = u.val64;
array++;
}
if (type & PERF_SAMPLE_IDENTIFIER) {
- *array = sample->id;
+ *array = sample_id;
array++;
}
return (void *)array - (void *)start;
}
+int perf_event__synthesize_id_sample(__u64 *array, u64 type, const struct perf_sample *sample)
+{
+ return __perf_event__synthesize_id_sample(array, type,
+ sample->pid, sample->tid,
+ sample->time,
+ sample->id,
+ sample->stream_id,
+ sample->cpu);
+}
+
int __perf_event__synthesize_id_index(const struct perf_tool *tool, perf_event__handler_t process,
struct evlist *evlist, struct machine *machine, size_t from)
{
@@ -2252,7 +2267,6 @@ int perf_event__synthesize_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
perf_event__handler_t process,
- const struct evsel *evsel,
__u16 misc,
const struct build_id *bid,
const char *filename)
@@ -2275,12 +2289,13 @@ int perf_event__synthesize_build_id(const struct perf_tool *tool,
ev.build_id.header.size = len;
strcpy(ev.build_id.filename, filename);
- if (evsel) {
+ if (sample->evsel) {
void *array = &ev;
int ret;
array += ev.header.size;
- ret = perf_event__synthesize_id_sample(array, evsel->core.attr.sample_type, sample);
+ ret = perf_event__synthesize_id_sample(array, sample->evsel->core.attr.sample_type,
+ sample);
if (ret < 0)
return ret;
@@ -2299,7 +2314,6 @@ int perf_event__synthesize_mmap2_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
perf_event__handler_t process,
- const struct evsel *evsel,
__u16 misc,
__u32 pid, __u32 tid,
__u64 start, __u64 len, __u64 pgoff,
@@ -2307,39 +2321,51 @@ int perf_event__synthesize_mmap2_build_id(const struct perf_tool *tool,
__u32 prot, __u32 flags,
const char *filename)
{
- union perf_event ev;
+ struct {
+ union perf_event ev;
+ /* Esnure there is sufficient storage space for sample ids. */
+ __u64 sample_ids[MAX_ID_HDR_ENTRIES];
+ } ev;
size_t ev_len;
void *array;
int ret;
- ev_len = sizeof(ev.mmap2) - sizeof(ev.mmap2.filename) + strlen(filename) + 1;
+ if (!sample->evsel)
+ return -EINVAL; /* Evsel is needed for sample_type data. */
+
+ ev_len = sizeof(ev.ev.mmap2) - sizeof(ev.ev.mmap2.filename) + strlen(filename) + 1;
ev_len = PERF_ALIGN(ev_len, sizeof(u64));
memset(&ev, 0, ev_len);
- ev.mmap2.header.type = PERF_RECORD_MMAP2;
- ev.mmap2.header.misc = misc | PERF_RECORD_MISC_MMAP_BUILD_ID;
- ev.mmap2.header.size = ev_len;
+ ev.ev.mmap2.header.type = PERF_RECORD_MMAP2;
+ ev.ev.mmap2.header.misc = misc | PERF_RECORD_MISC_MMAP_BUILD_ID;
+ ev.ev.mmap2.header.size = ev_len;
- ev.mmap2.pid = pid;
- ev.mmap2.tid = tid;
- ev.mmap2.start = start;
- ev.mmap2.len = len;
- ev.mmap2.pgoff = pgoff;
+ ev.ev.mmap2.pid = pid;
+ ev.ev.mmap2.tid = tid;
+ ev.ev.mmap2.start = start;
+ ev.ev.mmap2.len = len;
+ ev.ev.mmap2.pgoff = pgoff;
- ev.mmap2.build_id_size = bid->size;
- if (ev.mmap2.build_id_size > sizeof(ev.mmap2.build_id))
- ev.build_id.size = sizeof(ev.mmap2.build_id);
- memcpy(ev.mmap2.build_id, bid->data, ev.mmap2.build_id_size);
+ ev.ev.mmap2.build_id_size = bid->size;
+ if (ev.ev.mmap2.build_id_size > sizeof(ev.ev.mmap2.build_id))
+ ev.ev.build_id.size = sizeof(ev.ev.mmap2.build_id);
+ memcpy(ev.ev.mmap2.build_id, bid->data, ev.ev.mmap2.build_id_size);
- ev.mmap2.prot = prot;
- ev.mmap2.flags = flags;
+ ev.ev.mmap2.prot = prot;
+ ev.ev.mmap2.flags = flags;
- memcpy(ev.mmap2.filename, filename, min(strlen(filename), sizeof(ev.mmap.filename)));
+ memcpy(ev.ev.mmap2.filename, filename, min(strlen(filename), sizeof(ev.ev.mmap.filename)));
array = &ev;
- array += ev.header.size;
- ret = perf_event__synthesize_id_sample(array, evsel->core.attr.sample_type, sample);
+ array += ev.ev.header.size;
+ ret = __perf_event__synthesize_id_sample(array, sample->evsel->core.attr.sample_type,
+ pid, tid,
+ sample->time,
+ sample->id,
+ sample->stream_id,
+ sample->cpu);
if (ret < 0)
return ret;
@@ -2348,9 +2374,9 @@ int perf_event__synthesize_mmap2_build_id(const struct perf_tool *tool,
return -EINVAL;
}
- ev.header.size += ret;
+ ev.ev.header.size += ret;
- return process(tool, &ev, sample, machine);
+ return process(tool, &ev.ev, sample, machine);
}
int perf_event__synthesize_stat_events(struct perf_stat_config *config, const struct perf_tool *tool,
diff --git a/tools/perf/util/synthetic-events.h b/tools/perf/util/synthetic-events.h
index b0edad0c3100..473a43a78993 100644
--- a/tools/perf/util/synthetic-events.h
+++ b/tools/perf/util/synthetic-events.h
@@ -50,7 +50,6 @@ int perf_event__synthesize_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
perf_event__handler_t process,
- const struct evsel *evsel,
__u16 misc,
const struct build_id *bid,
const char *filename);
@@ -58,7 +57,6 @@ int perf_event__synthesize_mmap2_build_id(const struct perf_tool *tool,
struct perf_sample *sample,
struct machine *machine,
perf_event__handler_t process,
- const struct evsel *evsel,
__u16 misc,
__u32 pid, __u32 tid,
__u64 start, __u64 len, __u64 pgoff,
--
2.53.0.1213.gd9a14994de-goog