[PATCH v12 25/33] perf timechart: Fix memory leaks

Ian Rogers
2026-04-13T04:12:55Z

Fix missing free from cat_backtrace, which requires copies of the
backtrace being made in functions that save it.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/builtin-timechart.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 1d24d8738519..64f69bd67c6b 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -299,7 +299,7 @@ static void pid_put_sample(struct timechart *tchart, int pid, int type,
sample->type = type;
sample->next = c->samples;
sample->cpu = cpu;
- sample->backtrace = backtrace;
+ sample->backtrace = backtrace ? strdup(backtrace) : NULL;
c->samples = sample;

if (sample->type == TYPE_RUNNING && end > start && start > 0) {
@@ -433,7 +433,7 @@ static void sched_wakeup(struct timechart *tchart, int cpu, u64 timestamp,

we->time = timestamp;
we->waker = waker;
- we->backtrace = backtrace;
+ we->backtrace = backtrace ? strdup(backtrace) : NULL;

if ((flags & TRACE_FLAG_HARDIRQ) || (flags & TRACE_FLAG_SOFTIRQ))
we->waker = -1;
@@ -489,9 +489,9 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp,
}
}

-static const char *cat_backtrace(union perf_event *event,
- struct perf_sample *sample,
- struct machine *machine)
+static char *cat_backtrace(union perf_event *event,
+ struct perf_sample *sample,
+ struct machine *machine)
{
struct addr_location al;
unsigned int i;
@@ -544,8 +544,10 @@ static const char *cat_backtrace(union perf_event *event,
* It seems the callchain is corrupted.
* Discard all.
*/
- zfree(&p);
- goto exit;
+ addr_location__exit(&al);
+ fclose(f);
+ free(p);
+ return NULL;
}
continue;
}
@@ -577,6 +579,7 @@ static int process_sample_event(const struct perf_tool *tool,
{
struct timechart *tchart = container_of(tool, struct timechart, tool);
struct evsel *evsel = sample->evsel;
+ int ret = 0;

if (evsel->core.attr.sample_type & PERF_SAMPLE_TIME) {
if (!tchart->first_time || tchart->first_time > sample->time)
@@ -587,11 +590,13 @@ static int process_sample_event(const struct perf_tool *tool,

if (evsel->handler != NULL) {
tracepoint_handler f = evsel->handler;
+ char *backtrace = cat_backtrace(event, sample, machine);

- return f(tchart, sample, cat_backtrace(event, sample, machine));
+ ret = f(tchart, sample, backtrace);
+ free(backtrace);
}

- return 0;
+ return ret;
}

static int
--
2.53.0.1213.gd9a14994de-goog