[PATCH v3 0/8] perf timechart: Fix memory leaks

[PATCH v3 0/8] perf timechart: Fix memory leaks

[Namhyung Kim]

Hello,

This patchset fixes memory leaks in the perf timechart code.
I've extended and verified the timechart test with ASAN.

I'm sending it with my previous work on backtrace optimization.

v3)
 * combine small optimization series

v2)
 * use zfree() and explicit clear for potential misuse  (Arnaldo)
 * fix a wrong condition in the draw_wakeups()  (Sashiko)
 * move misplaced hunk in the second commit to the first

Thanks,
Namhyung


Namhyung Kim (8):
  perf timechart: Don't pass @event to cat_backtrace()
  perf timechart: Generate backtrace only if needed
  perf timechart: Remove unused backtrace in trace_handler
  perf timechart: Remove unnecessary copy of backtrace
  perf timechart: Release event samples at the end
  perf timechart: Fix memory leaks during record
  perf timechart: Fix memory leaks in draw_wakeups()
  perf test: Update perf timechart test

 tools/perf/builtin-timechart.c      | 212 +++++++++++++++++++---------
 tools/perf/tests/shell/timechart.sh |  24 ++--
 2 files changed, 158 insertions(+), 78 deletions(-)

-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 1/8] perf timechart: Don't pass @event to cat_backtrace()

[Namhyung Kim]

The cat_backtrace() is only called from process_sample_event() which
means the event type is always PERF_RECORD_SAMPLE.  We don't need to
pass the event just because to print already known info.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 85a9ad0455aecccd..dafd361ecf9d8cd7 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -493,8 +493,7 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp,
  * Returns a malloc'd backtrace string built via open_memstream, or NULL
  * on error.  Caller must free() the returned pointer.
  */
-static char *cat_backtrace(union perf_event *event,
-			   struct perf_sample *sample,
+static char *cat_backtrace(struct perf_sample *sample,
 			   struct machine *machine)
 {
 	struct addr_location al;
@@ -516,9 +515,8 @@ static char *cat_backtrace(union perf_event *event,
 		goto exit;
 
 	if (machine__resolve(machine, &al, sample) < 0) {
-		pr_err("problem processing %s (%u) event at offset %#" PRIx64 ", skipping it.\n",
-		       perf_event__name(event->header.type), event->header.type,
-		       sample->file_offset);
+		pr_err("problem processing SAMPLE (%u) event at offset %#" PRIx64 ", skipping it.\n",
+		       PERF_RECORD_SAMPLE, sample->file_offset);
 		goto exit;
 	}
 
@@ -578,7 +576,7 @@ typedef int (*tracepoint_handler)(struct timechart *tchart,
 				  const char *backtrace);
 
 static int process_sample_event(const struct perf_tool *tool,
-				union perf_event *event,
+				union perf_event *event __maybe_unused,
 				struct perf_sample *sample,
 				struct machine *machine)
 {
@@ -595,7 +593,7 @@ 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);
+		char *backtrace = cat_backtrace(sample, machine);
 
 		ret = f(tchart, sample, backtrace);
 		free(backtrace);
-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 2/8] perf timechart: Generate backtrace only if needed

[Namhyung Kim]

The backtrace was used by sched-switch and sched-wakeup only.  No need
to call cat_backtrace() in the process_sample_event().  Let's pass NULL
backtrace and generate it from the sched events.

As it needs a pointer to the 'machine', let's save the session in the
timechart struct and use the host machine of the session instead of
passing the pointer to all handlers.  It should be fine to assume the
host machine as timechart command doesn't deal with guest machines and
there's no way to get tracepoints from the guest events.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index dafd361ecf9d8cd7..337ae547d008ea0b 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -56,6 +56,7 @@ struct timechart {
 	struct per_pid		*all_data;
 	struct power_event	*power_events;
 	struct wake_event	*wake_events;
+	struct perf_session	*session;
 	int			proc_num;
 	unsigned int		numcpus;
 	u64			min_freq,	/* Lowest CPU frequency seen */
@@ -578,7 +579,7 @@ typedef int (*tracepoint_handler)(struct timechart *tchart,
 static int process_sample_event(const struct perf_tool *tool,
 				union perf_event *event __maybe_unused,
 				struct perf_sample *sample,
-				struct machine *machine)
+				struct machine *machine __maybe_unused)
 {
 	struct timechart *tchart = container_of(tool, struct timechart, tool);
 	struct evsel *evsel = sample->evsel;
@@ -593,10 +594,8 @@ static int process_sample_event(const struct perf_tool *tool,
 
 	if (evsel->handler != NULL) {
 		tracepoint_handler f = evsel->handler;
-		char *backtrace = cat_backtrace(sample, machine);
 
-		ret = f(tchart, sample, backtrace);
-		free(backtrace);
+		ret = f(tchart, sample, NULL);
 	}
 
 	return ret;
@@ -656,7 +655,10 @@ process_sample_sched_wakeup(struct timechart *tchart,
 			 sample->file_offset, sample->cpu);
 		return -1;
 	}
+
+	backtrace = cat_backtrace(sample, &tchart->session->machines.host);
 	sched_wakeup(tchart, sample->cpu, sample->time, waker, wakee, flags, backtrace);
+	free((char *)backtrace);
 	return 0;
 }
 
@@ -675,8 +677,11 @@ process_sample_sched_switch(struct timechart *tchart,
 			 sample->file_offset, sample->cpu);
 		return -1;
 	}
+
+	backtrace = cat_backtrace(sample, &tchart->session->machines.host);
 	sched_switch(tchart, sample->cpu, sample->time, prev_pid, next_pid,
 		     prev_state, backtrace);
+	free((char *)backtrace);
 	return 0;
 }
 
@@ -1661,6 +1666,7 @@ static int __cmd_timechart(struct timechart *tchart, const char *output_name)
 	if (IS_ERR(session))
 		return PTR_ERR(session);
 
+	tchart->session = session;
 	symbol__init(perf_session__env(session));
 
 	(void)perf_header__process_sections(&session->header,
-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 3/8] perf timechart: Remove unused backtrace in trace_handler

[Namhyung Kim]

Now the backtrace argument is not used in any handler.  Let's get rid of
it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 64 ++++++++++++----------------------
 1 file changed, 23 insertions(+), 41 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 337ae547d008ea0b..4efac73a714c5e5f 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -573,8 +573,7 @@ static char *cat_backtrace(struct perf_sample *sample,
 }
 
 typedef int (*tracepoint_handler)(struct timechart *tchart,
-				  struct perf_sample *sample,
-				  const char *backtrace);
+				  struct perf_sample *sample);
 
 static int process_sample_event(const struct perf_tool *tool,
 				union perf_event *event __maybe_unused,
@@ -595,7 +594,7 @@ static int process_sample_event(const struct perf_tool *tool,
 	if (evsel->handler != NULL) {
 		tracepoint_handler f = evsel->handler;
 
-		ret = f(tchart, sample, NULL);
+		ret = f(tchart, sample);
 	}
 
 	return ret;
@@ -603,8 +602,7 @@ static int process_sample_event(const struct perf_tool *tool,
 
 static int
 process_sample_cpu_idle(struct timechart *tchart __maybe_unused,
-			struct perf_sample *sample,
-			const char *backtrace __maybe_unused)
+			struct perf_sample *sample)
 {
 	u32 state  = perf_sample__intval(sample, "state");
 	u32 cpu_id = perf_sample__intval(sample, "cpu_id");
@@ -624,8 +622,7 @@ process_sample_cpu_idle(struct timechart *tchart __maybe_unused,
 
 static int
 process_sample_cpu_frequency(struct timechart *tchart,
-			     struct perf_sample *sample,
-			     const char *backtrace __maybe_unused)
+			     struct perf_sample *sample)
 {
 	u32 state  = perf_sample__intval(sample, "state");
 	u32 cpu_id = perf_sample__intval(sample, "cpu_id");
@@ -642,12 +639,12 @@ process_sample_cpu_frequency(struct timechart *tchart,
 
 static int
 process_sample_sched_wakeup(struct timechart *tchart,
-			    struct perf_sample *sample,
-			    const char *backtrace)
+			    struct perf_sample *sample)
 {
 	u8 flags  = perf_sample__intval(sample, "common_flags");
 	int waker = perf_sample__intval(sample, "common_pid");
 	int wakee = perf_sample__intval(sample, "pid");
+	char *backtrace;
 
 	/* perf.data is untrusted input — CPU may be absent or corrupted */
 	if (sample->cpu >= MAX_CPUS) {
@@ -664,12 +661,12 @@ process_sample_sched_wakeup(struct timechart *tchart,
 
 static int
 process_sample_sched_switch(struct timechart *tchart,
-			    struct perf_sample *sample,
-			    const char *backtrace)
+			    struct perf_sample *sample)
 {
 	int prev_pid   = perf_sample__intval(sample, "prev_pid");
 	int next_pid   = perf_sample__intval(sample, "next_pid");
 	u64 prev_state = perf_sample__intval(sample, "prev_state");
+	char *backtrace;
 
 	/* perf.data is untrusted input — CPU may be absent or corrupted */
 	if (sample->cpu >= MAX_CPUS) {
@@ -688,8 +685,7 @@ process_sample_sched_switch(struct timechart *tchart,
 #ifdef SUPPORT_OLD_POWER_EVENTS
 static int
 process_sample_power_start(struct timechart *tchart __maybe_unused,
-			   struct perf_sample *sample,
-			   const char *backtrace __maybe_unused)
+			   struct perf_sample *sample)
 {
 	u64 cpu_id = perf_sample__intval(sample, "cpu_id");
 	u64 value  = perf_sample__intval(sample, "value");
@@ -706,8 +702,7 @@ process_sample_power_start(struct timechart *tchart __maybe_unused,
 
 static int
 process_sample_power_end(struct timechart *tchart,
-			 struct perf_sample *sample,
-			 const char *backtrace __maybe_unused)
+			 struct perf_sample *sample)
 {
 	/* perf.data is untrusted input — CPU may be absent or corrupted */
 	if (sample->cpu >= MAX_CPUS) {
@@ -721,8 +716,7 @@ process_sample_power_end(struct timechart *tchart,
 
 static int
 process_sample_power_frequency(struct timechart *tchart,
-			       struct perf_sample *sample,
-			       const char *backtrace __maybe_unused)
+			       struct perf_sample *sample)
 {
 	u64 cpu_id = perf_sample__intval(sample, "cpu_id");
 	u64 value  = perf_sample__intval(sample, "value");
@@ -895,8 +889,7 @@ static int pid_end_io_sample(struct timechart *tchart, int pid, int type,
 
 static int
 process_enter_read(struct timechart *tchart,
-		   struct perf_sample *sample,
-		   const char *backtrace __maybe_unused)
+		   struct perf_sample *sample)
 {
 	long fd = perf_sample__intval(sample, "fd");
 	return pid_begin_io_sample(tchart, sample->tid, IOTYPE_READ,
@@ -905,8 +898,7 @@ process_enter_read(struct timechart *tchart,
 
 static int
 process_exit_read(struct timechart *tchart,
-		  struct perf_sample *sample,
-		  const char *backtrace __maybe_unused)
+		  struct perf_sample *sample)
 {
 	long ret = perf_sample__intval(sample, "ret");
 	return pid_end_io_sample(tchart, sample->tid, IOTYPE_READ,
@@ -915,8 +907,7 @@ process_exit_read(struct timechart *tchart,
 
 static int
 process_enter_write(struct timechart *tchart,
-		    struct perf_sample *sample,
-		    const char *backtrace __maybe_unused)
+		    struct perf_sample *sample)
 {
 	long fd = perf_sample__intval(sample, "fd");
 	return pid_begin_io_sample(tchart, sample->tid, IOTYPE_WRITE,
@@ -925,8 +916,7 @@ process_enter_write(struct timechart *tchart,
 
 static int
 process_exit_write(struct timechart *tchart,
-		   struct perf_sample *sample,
-		   const char *backtrace __maybe_unused)
+		   struct perf_sample *sample)
 {
 	long ret = perf_sample__intval(sample, "ret");
 	return pid_end_io_sample(tchart, sample->tid, IOTYPE_WRITE,
@@ -935,8 +925,7 @@ process_exit_write(struct timechart *tchart,
 
 static int
 process_enter_sync(struct timechart *tchart,
-		   struct perf_sample *sample,
-		   const char *backtrace __maybe_unused)
+		   struct perf_sample *sample)
 {
 	long fd = perf_sample__intval(sample, "fd");
 	return pid_begin_io_sample(tchart, sample->tid, IOTYPE_SYNC,
@@ -945,8 +934,7 @@ process_enter_sync(struct timechart *tchart,
 
 static int
 process_exit_sync(struct timechart *tchart,
-		  struct perf_sample *sample,
-		  const char *backtrace __maybe_unused)
+		  struct perf_sample *sample)
 {
 	long ret = perf_sample__intval(sample, "ret");
 	return pid_end_io_sample(tchart, sample->tid, IOTYPE_SYNC,
@@ -955,8 +943,7 @@ process_exit_sync(struct timechart *tchart,
 
 static int
 process_enter_tx(struct timechart *tchart,
-		 struct perf_sample *sample,
-		 const char *backtrace __maybe_unused)
+		 struct perf_sample *sample)
 {
 	long fd = perf_sample__intval(sample, "fd");
 	return pid_begin_io_sample(tchart, sample->tid, IOTYPE_TX,
@@ -965,8 +952,7 @@ process_enter_tx(struct timechart *tchart,
 
 static int
 process_exit_tx(struct timechart *tchart,
-		struct perf_sample *sample,
-		const char *backtrace __maybe_unused)
+		struct perf_sample *sample)
 {
 	long ret = perf_sample__intval(sample, "ret");
 	return pid_end_io_sample(tchart, sample->tid, IOTYPE_TX,
@@ -975,8 +961,7 @@ process_exit_tx(struct timechart *tchart,
 
 static int
 process_enter_rx(struct timechart *tchart,
-		 struct perf_sample *sample,
-		 const char *backtrace __maybe_unused)
+		 struct perf_sample *sample)
 {
 	long fd = perf_sample__intval(sample, "fd");
 	return pid_begin_io_sample(tchart, sample->tid, IOTYPE_RX,
@@ -985,8 +970,7 @@ process_enter_rx(struct timechart *tchart,
 
 static int
 process_exit_rx(struct timechart *tchart,
-		struct perf_sample *sample,
-		const char *backtrace __maybe_unused)
+		struct perf_sample *sample)
 {
 	long ret = perf_sample__intval(sample, "ret");
 	return pid_end_io_sample(tchart, sample->tid, IOTYPE_RX,
@@ -995,8 +979,7 @@ process_exit_rx(struct timechart *tchart,
 
 static int
 process_enter_poll(struct timechart *tchart,
-		   struct perf_sample *sample,
-		   const char *backtrace __maybe_unused)
+		   struct perf_sample *sample)
 {
 	long fd = perf_sample__intval(sample, "fd");
 	return pid_begin_io_sample(tchart, sample->tid, IOTYPE_POLL,
@@ -1005,8 +988,7 @@ process_enter_poll(struct timechart *tchart,
 
 static int
 process_exit_poll(struct timechart *tchart,
-		  struct perf_sample *sample,
-		  const char *backtrace __maybe_unused)
+		  struct perf_sample *sample)
 {
 	long ret = perf_sample__intval(sample, "ret");
 	return pid_end_io_sample(tchart, sample->tid, IOTYPE_POLL,
-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 4/8] perf timechart: Remove unnecessary copy of backtrace

[Namhyung Kim]

The pattern of strdup() and free() is found, and I think it just can
use the original backtrace directly.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 4efac73a714c5e5f..04dbb944a42720b4 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -300,7 +300,7 @@ 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 ? strdup(backtrace) : NULL;
+	sample->backtrace = backtrace;
 	c->samples = sample;
 
 	if (sample->type == TYPE_RUNNING && end > start && start > 0) {
@@ -429,12 +429,14 @@ static void sched_wakeup(struct timechart *tchart, int cpu, u64 timestamp,
 	struct per_pid *p;
 	struct wake_event *we = zalloc(sizeof(*we));
 
-	if (!we)
+	if (!we) {
+		free((char *)backtrace);
 		return;
+	}
 
 	we->time = timestamp;
 	we->waker = waker;
-	we->backtrace = backtrace ? strdup(backtrace) : NULL;
+	we->backtrace = backtrace;
 
 	if ((flags & TRACE_FLAG_HARDIRQ) || (flags & TRACE_FLAG_SOFTIRQ))
 		we->waker = -1;
@@ -461,20 +463,28 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp,
 			 const char *backtrace)
 {
 	struct per_pid *p = NULL, *prev_p;
+	bool backtrace_used = false;
 
 	prev_p = find_create_pid(tchart, prev_pid);
 
 	p = find_create_pid(tchart, next_pid);
 
-	if (prev_p->current && prev_p->current->state != TYPE_NONE)
+	if (prev_p->current && prev_p->current->state != TYPE_NONE) {
 		pid_put_sample(tchart, prev_pid, TYPE_RUNNING, cpu,
 			       prev_p->current->state_since, timestamp,
 			       backtrace);
+		backtrace_used = true;
+	}
 	if (p && p->current) {
-		if (p->current->state != TYPE_NONE)
+		if (p->current->state != TYPE_NONE) {
+			if (backtrace && backtrace_used)
+				backtrace = strdup(backtrace);
+
 			pid_put_sample(tchart, next_pid, p->current->state, cpu,
 				       p->current->state_since, timestamp,
 				       backtrace);
+			backtrace_used = true;
+		}
 
 		p->current->state_since = timestamp;
 		p->current->state = TYPE_RUNNING;
@@ -488,6 +498,9 @@ static void sched_switch(struct timechart *tchart, int cpu, u64 timestamp,
 		if (prev_state == 0)
 			prev_p->current->state = TYPE_WAITING;
 	}
+
+	if (!backtrace_used)
+		free((char *)backtrace);
 }
 
 /*
@@ -655,7 +668,6 @@ process_sample_sched_wakeup(struct timechart *tchart,
 
 	backtrace = cat_backtrace(sample, &tchart->session->machines.host);
 	sched_wakeup(tchart, sample->cpu, sample->time, waker, wakee, flags, backtrace);
-	free((char *)backtrace);
 	return 0;
 }
 
@@ -678,7 +690,6 @@ process_sample_sched_switch(struct timechart *tchart,
 	backtrace = cat_backtrace(sample, &tchart->session->machines.host);
 	sched_switch(tchart, sample->cpu, sample->time, prev_pid, next_pid,
 		     prev_state, backtrace);
-	free((char *)backtrace);
 	return 0;
 }
 
-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 5/8] perf timechart: Release event samples at the end

[Namhyung Kim]

Add timechart__release() to free all data structures added during the
sample processing.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 68 ++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 04dbb944a42720b4..27d17268395ed760 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -1548,6 +1548,73 @@ static void write_svg_file(struct timechart *tchart, const char *filename)
 	svg_close();
 }
 
+static void timechart__release(struct timechart *tchart)
+{
+	struct per_pid *p = tchart->all_data;
+	struct power_event *pwr = tchart->power_events;
+	struct wake_event *we = tchart->wake_events;
+
+	while (p) {
+		struct per_pid *next_pid = p->next;
+		struct per_pidcomm *c = p->all;
+
+		while (c) {
+			struct per_pidcomm *next_comm = c->next;
+			struct cpu_sample *cs = c->samples;
+			struct io_sample *ios = c->io_samples;
+
+			while (cs) {
+				struct cpu_sample *next = cs->next;
+
+				zfree(&cs->backtrace);
+				cs->next = NULL;
+				free(cs);
+
+				cs = next;
+			}
+
+			while (ios) {
+				struct io_sample *next = ios->next;
+
+				ios->next = NULL;
+				free(ios);
+
+				ios = next;
+			}
+
+			zfree(&c->comm);
+			c->next = NULL;
+			free(c);
+
+			c = next_comm;
+		}
+
+		p->next = NULL;
+		free(p);
+
+		p = next_pid;
+	}
+
+	while (pwr) {
+		struct power_event *next = pwr->next;
+
+		pwr->next = NULL;
+		free(pwr);
+
+		pwr = next;
+	}
+
+	while (we) {
+		struct wake_event *next = we->next;
+
+		zfree(&we->backtrace);
+		we->next = NULL;
+		free(we);
+
+		we = next;
+	}
+}
+
 static int process_header(struct perf_file_section *section __maybe_unused,
 			  struct perf_header *ph,
 			  int feat,
@@ -2079,6 +2146,7 @@ int cmd_timechart(int argc, const char **argv)
 
 	ret = __cmd_timechart(&tchart, output_name);
 out:
+	timechart__release(&tchart);
 	zfree(&cpus_cstate_start_times);
 	zfree(&cpus_cstate_state);
 	zfree(&cpus_pstate_start_times);
-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 6/8] perf timechart: Fix memory leaks during record

[Namhyung Kim]

The command line options can be passed without copy as their lifetime is
limited within the same function.

Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 27d17268395ed760..a73f0ab22fd64241 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -1834,6 +1834,7 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
 		"syscalls:sys_exit_select",
 	};
 	unsigned int poll_events_nr = ARRAY_SIZE(poll_events);
+	int ret;
 
 	rec_argc = common_args_nr +
 		disk_events_nr * 4 +
@@ -1852,7 +1853,7 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
 
 	p = rec_argv;
 	for (i = 0; i < common_args_nr; i++)
-		*p++ = strdup(common_args[i]);
+		*p++ = common_args[i];
 
 	for (i = 0; i < disk_events_nr; i++) {
 		if (!is_valid_tracepoint(disk_events[i])) {
@@ -1861,7 +1862,7 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
 		}
 
 		*p++ = "-e";
-		*p++ = strdup(disk_events[i]);
+		*p++ = disk_events[i];
 		*p++ = "--filter";
 		*p++ = filter;
 	}
@@ -1872,7 +1873,7 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
 		}
 
 		*p++ = "-e";
-		*p++ = strdup(net_events[i]);
+		*p++ = net_events[i];
 		*p++ = "--filter";
 		*p++ = filter;
 	}
@@ -1883,7 +1884,7 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
 		}
 
 		*p++ = "-e";
-		*p++ = strdup(poll_events[i]);
+		*p++ = poll_events[i];
 		*p++ = "--filter";
 		*p++ = filter;
 	}
@@ -1891,7 +1892,11 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
 	for (i = 0; i < (unsigned int)argc; i++)
 		*p++ = argv[i];
 
-	return cmd_record(rec_argc, rec_argv);
+	ret = cmd_record(rec_argc, rec_argv);
+
+	free(rec_argv);
+	free(filter);
+	return ret;
 }
 
 
@@ -1902,6 +1907,7 @@ static int timechart__record(struct timechart *tchart, int argc, const char **ar
 	const char **rec_argv;
 	const char **p;
 	unsigned int record_elems;
+	int ret;
 
 	const char * const common_args[] = {
 		"record", "-a", "-R", "-c", "1", "-o", output_data,
@@ -1966,24 +1972,27 @@ static int timechart__record(struct timechart *tchart, int argc, const char **ar
 
 	p = rec_argv;
 	for (i = 0; i < common_args_nr; i++)
-		*p++ = strdup(common_args[i]);
+		*p++ = common_args[i];
 
 	for (i = 0; i < backtrace_args_no; i++)
-		*p++ = strdup(backtrace_args[i]);
+		*p++ = backtrace_args[i];
 
 	for (i = 0; i < tasks_args_nr; i++)
-		*p++ = strdup(tasks_args[i]);
+		*p++ = tasks_args[i];
 
 	for (i = 0; i < power_args_nr; i++)
-		*p++ = strdup(power_args[i]);
+		*p++ = power_args[i];
 
 	for (i = 0; i < old_power_args_nr; i++)
-		*p++ = strdup(old_power_args[i]);
+		*p++ = old_power_args[i];
 
 	for (j = 0; j < (unsigned int)argc; j++)
 		*p++ = argv[j];
 
-	return cmd_record(rec_argc, rec_argv);
+	ret = cmd_record(rec_argc, rec_argv);
+
+	free(rec_argv);
+	return ret;
 }
 
 static int
-- 
2.55.0.rc0.799.gd6f94ed593-goog

Re: [PATCH v3 6/8] perf timechart: Fix memory leaks during record

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Missing explicit POSIX header inclusion for `free()` (musl compatibility guide violation)
--

commit e9f4fbcd6ed720db9d6b0daaf8a565c9bbbd415e
Author: Namhyung Kim <namhyung@kernel.org>

perf timechart: Fix memory leaks during record

The command line options can be passed without copy as their lifetime is
limited within the same function.

> diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
> index 27d17268395ed..a73f0ab22fd64 100644
> --- a/tools/perf/builtin-timechart.c
> +++ b/tools/perf/builtin-timechart.c
[ ... ]
> @@ -1891,7 +1892,11 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
>  	for (i = 0; i < (unsigned int)argc; i++)
>  		*p++ = argv[i];
>  
> -	return cmd_record(rec_argc, rec_argv);
> +	ret = cmd_record(rec_argc, rec_argv);
> +
> +	free(rec_argv);
> +	free(filter);

[Severity: Medium]
Does this code need an explicit inclusion of <stdlib.h> at the top of the
file?

The perf subsystem musl compatibility guidelines mention that files using
POSIX libc functions must explicitly include the relevant headers, as musl
strictly separates declarations unlike glibc. Could these new free() calls
cause a build failure on systems using musl libc if the header is omitted?

> +	return ret;
>  }
>  
>  
[ ... ]
> @@ -1966,24 +1972,27 @@ static int timechart__record(struct timechart *tchart, int argc, const char **ar
[ ... ]
>  	for (j = 0; j < (unsigned int)argc; j++)
>  		*p++ = argv[j];
>  
> -	return cmd_record(rec_argc, rec_argv);
> +	ret = cmd_record(rec_argc, rec_argv);
> +
> +	free(rec_argv);

[Severity: Medium]
Is it possible this free() call also requires an explicit <stdlib.h>
inclusion to ensure it builds correctly against musl libc?

> +	return ret;
>  }
>  
>  static int

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260624205852.3864874-1-namhyung@kernel.org?part=6

Re: [PATCH v3 6/8] perf timechart: Fix memory leaks during record

[Namhyung Kim]

On Wed, Jun 24, 2026 at 09:06:44PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] Missing explicit POSIX header inclusion for `free()` (musl compatibility guide violation)
> --
> 
> commit e9f4fbcd6ed720db9d6b0daaf8a565c9bbbd415e
> Author: Namhyung Kim <namhyung@kernel.org>
> 
> perf timechart: Fix memory leaks during record
> 
> The command line options can be passed without copy as their lifetime is
> limited within the same function.
> 
> > diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
> > index 27d17268395ed..a73f0ab22fd64 100644
> > --- a/tools/perf/builtin-timechart.c
> > +++ b/tools/perf/builtin-timechart.c
> [ ... ]
> > @@ -1891,7 +1892,11 @@ static int timechart__io_record(int argc, const char **argv, const char *output_
> >  	for (i = 0; i < (unsigned int)argc; i++)
> >  		*p++ = argv[i];
> >  
> > -	return cmd_record(rec_argc, rec_argv);
> > +	ret = cmd_record(rec_argc, rec_argv);
> > +
> > +	free(rec_argv);
> > +	free(filter);
> 
> [Severity: Medium]
> Does this code need an explicit inclusion of <stdlib.h> at the top of the
> file?
> 
> The perf subsystem musl compatibility guidelines mention that files using
> POSIX libc functions must explicitly include the relevant headers, as musl
> strictly separates declarations unlike glibc. Could these new free() calls
> cause a build failure on systems using musl libc if the header is omitted?

While it may be a valid concern, the free() function is already used in
many places of the file.  And I didn't get any reports about musl on
this yet.  So I think it's good to go.

Thanks,
Namhyung

[PATCH v3 7/8] perf timechart: Fix memory leaks in draw_wakeups()

[Namhyung Kim]

The second loop for per_pidcommd is meaningful only when it doesn't have
from and to tasks.  Also make sure c->Y is set before copying the comm
string otherwise it will be overwritten by next one.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-timechart.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index a73f0ab22fd64241..3f9153d5ecfb79b0 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -1110,12 +1110,12 @@ static void draw_wakeups(struct timechart *tchart)
 					c = c->next;
 				}
 				c = p->all;
-				while (c) {
-					if (p->pid == we->waker && !from) {
+				while (c && (!from || !to)) {
+					if (c->Y && p->pid == we->waker && !from) {
 						from = c->Y;
 						task_from = strdup(c->comm);
 					}
-					if (p->pid == we->wakee && !to) {
+					if (c->Y && p->pid == we->wakee && !to) {
 						to = c->Y;
 						task_to = strdup(c->comm);
 					}
-- 
2.55.0.rc0.799.gd6f94ed593-goog

[PATCH v3 8/8] perf test: Update perf timechart test

[Namhyung Kim]

To include IO-only and backtrace modes to test different code paths.

  $ sudo perf test -vv timechart
  135: perf timechart tests                        : Running
  135: perf timechart tests:
  ---- start ----
  test child forked, pid 2413665
  perf timechart Basic test
  perf timechart Basic test [Success]
  perf timechart IO-only test
  perf timechart IO-only test [Success]
  perf timechart Backtrace test
  perf timechart Backtrace test [Success]
  ---- end(0) ----
  135: perf timechart tests                        : Ok

  === Test Summary ===
  Passed main tests : 1
  Passed subtests   : 0
  Skipped tests     : 0
  Failed tests      : 0

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/shell/timechart.sh | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/tools/perf/tests/shell/timechart.sh b/tools/perf/tests/shell/timechart.sh
index b14b3472c2846b32..40072b32171a9a1c 100755
--- a/tools/perf/tests/shell/timechart.sh
+++ b/tools/perf/tests/shell/timechart.sh
@@ -9,7 +9,7 @@ perfdata=$(mktemp /tmp/__perf_timechart_test.perf.data.XXXXX)
 output=$(mktemp /tmp/__perf_timechart_test.output.XXXXX.svg)
 
 cleanup() {
-	rm -f "${perfdata}"
+	rm -f "${perfdata}"*
 	rm -f "${output}"
 	trap - EXIT TERM INT
 }
@@ -22,38 +22,41 @@ trap_cleanup() {
 trap trap_cleanup EXIT TERM INT
 
 test_timechart() {
-	echo "Basic perf timechart test"
+	NAME=$1
+	OPTION=$2
+
+	echo "perf timechart ${NAME} test"
 
 	# Try to record timechart data.
 	# perf timechart record uses system-wide recording and specific tracepoints.
 	# If it fails (e.g. permissions, missing tracepoints), skip the test.
-	if ! perf timechart record -o "${perfdata}" true > /dev/null 2>&1; then
-		echo "Basic perf timechart test [Skipped: perf timechart record failed (permissions/events?)]"
+	if ! perf timechart record -o "${perfdata}" ${OPTION} true > /dev/null 2>&1; then
+		echo "perf timechart ${NAME} test [Skipped: perf timechart record failed (permissions/events?)]"
 		return
 	fi
 
 	# Generate the timechart
 	if ! perf timechart -i "${perfdata}" -o "${output}" > /dev/null 2>&1; then
-		echo "Basic perf timechart test [Failed: perf timechart command failed]"
+		echo "perf timechart ${NAME} test [Failed: perf timechart command failed]"
 		err=1
 		return
 	fi
 
 	# Check if output file exists and is not empty
 	if [ ! -s "${output}" ]; then
-		echo "Basic perf timechart test [Failed: output file is empty or missing]"
+		echo "perf timechart ${NAME} test [Failed: output file is empty or missing]"
 		err=1
 		return
 	fi
 
 	# Check if it looks like an SVG
 	if ! grep -q "svg" "${output}"; then
-		echo "Basic perf timechart test [Failed: output doesn't look like SVG]"
+		echo "perf timechart ${NAME} test [Failed: output doesn't look like SVG]"
 		err=1
 		return
 	fi
 
-	echo "Basic perf timechart test [Success]"
+	echo "perf timechart ${NAME} test [Success]"
 }
 
 if ! perf check feature -q libtraceevent ; then
@@ -62,6 +65,9 @@ if ! perf check feature -q libtraceevent ; then
 	exit 2
 fi
 
-test_timechart
+test_timechart "Basic" ""
+test_timechart "IO-only" "-I"
+test_timechart "Backtrace" "-g"
+
 cleanup
 exit $err
-- 
2.55.0.rc0.799.gd6f94ed593-goog