[PATCH v2 02/25] perf sample: Make sure perf_sample__init/exit are used

[Ian Rogers <irogers@google.com>]

The deferred stack trace code wasn't using perf_sample__init/exit. Add
the deferred stack trace clean up to perf_sample__exit which requires
proper NULL initialization in perf_sample__init. Make the
perf_sample__exit robust to being called more than once by using
zfree. Make the error paths in evsel__parse_sample exit the sample.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/builtin-inject.c |  5 ++++-
 tools/perf/util/evlist.c    |  5 ++++-
 tools/perf/util/evsel.c     | 28 +++++++++++++++++-----------
 tools/perf/util/sample.c    | 10 ++++++++--
 tools/perf/util/session.c   | 13 +++++++++----
 5 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 5b29f4296861..039323908ebf 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -1087,6 +1087,7 @@ static int perf_inject__sched_stat(const struct perf_tool *tool,
 	struct perf_sample sample_sw;
 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
 	u32 pid = evsel__intval(evsel, sample, "pid");
+	int ret;
 
 	list_for_each_entry(ent, &inject->samples, node) {
 		if (pid == ent->tid)
@@ -1103,7 +1104,9 @@ static int perf_inject__sched_stat(const struct perf_tool *tool,
 	perf_event__synthesize_sample(event_sw, evsel->core.attr.sample_type,
 				      evsel->core.attr.read_format, &sample_sw);
 	build_id__mark_dso_hit(tool, event_sw, &sample_sw, evsel, machine);
-	return perf_event__repipe(tool, event_sw, &sample_sw, machine);
+	ret = perf_event__repipe(tool, event_sw, &sample_sw, machine);
+	perf_sample__exit(&sample_sw);
+	return ret;
 }
 #endif
 
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 591bdf0b3e2a..bdb196425071 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1622,8 +1622,11 @@ int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct
 	struct evsel *evsel = evlist__event2evsel(evlist, event);
 	int ret;
 
-	if (!evsel)
+	if (!evsel) {
+		/* Ensure the sample is okay for perf_sample__exit. */
+		perf_sample__init(sample, /*all=*/false);
 		return -EFAULT;
+	}
 	ret = evsel__parse_sample(evsel, event, sample);
 	if (ret)
 		return ret;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index f59228c1a39e..34ae388750db 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -3067,7 +3067,7 @@ static inline bool overflow(const void *endp, u16 max_size, const void *offset,
 #define OVERFLOW_CHECK(offset, size, max_size)				\
 	do {								\
 		if (overflow(endp, (max_size), (offset), (size)))	\
-			return -EFAULT;					\
+			goto out_efault;				\
 	} while (0)
 
 #define OVERFLOW_CHECK_u64(offset) \
@@ -3199,6 +3199,8 @@ static int __set_offcpu_sample(struct perf_sample *data)
 	data->cgroup = *array;
 
 	return 0;
+out_efault:
+	return -EFAULT;
 }
 
 int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
@@ -3217,7 +3219,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 	 */
 	union u64_swap u;
 
-	memset(data, 0, sizeof(*data));
+	perf_sample__init(data, /*all=*/true);
 	data->cpu = data->pid = data->tid = -1;
 	data->stream_id = data->id = data->time = -1ULL;
 	data->period = evsel->core.attr.sample_period;
@@ -3231,25 +3233,26 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 
 		data->callchain = (struct ip_callchain *)&event->callchain_deferred.nr;
 		if (data->callchain->nr > max_callchain_nr)
-			return -EFAULT;
+			goto out_efault;
 
 		data->deferred_cookie = event->callchain_deferred.cookie;
 
 		if (evsel->core.attr.sample_id_all)
 			perf_evsel__parse_id_sample(evsel, event, data);
+
 		return 0;
 	}
 
 	if (event->header.type != PERF_RECORD_SAMPLE) {
-		if (!evsel->core.attr.sample_id_all)
-			return 0;
-		return perf_evsel__parse_id_sample(evsel, event, data);
+		if (evsel->core.attr.sample_id_all)
+			perf_evsel__parse_id_sample(evsel, event, data);
+		return 0;
 	}
 
 	array = event->sample.array;
 
 	if (perf_event__check_size(event, evsel->sample_size))
-		return -EFAULT;
+		goto out_efault;
 
 	if (type & PERF_SAMPLE_IDENTIFIER) {
 		data->id = *array;
@@ -3342,7 +3345,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 					sizeof(struct sample_read_value);
 
 			if (data->read.group.nr > max_group_nr)
-				return -EFAULT;
+				goto out_efault;
 
 			sz = data->read.group.nr * sample_read_value_size(read_format);
 			OVERFLOW_CHECK(array, sz, max_size);
@@ -3370,7 +3373,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 		data->callchain = (struct ip_callchain *)array++;
 		callchain_nr = data->callchain->nr;
 		if (callchain_nr > max_callchain_nr)
-			return -EFAULT;
+			goto out_efault;
 		sz = callchain_nr * sizeof(u64);
 		/*
 		 * Save the cookie for the deferred user callchain.  The last 2
@@ -3428,7 +3431,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 		data->branch_stack = (struct branch_stack *)array++;
 
 		if (data->branch_stack->nr > max_branch_nr)
-			return -EFAULT;
+			goto out_efault;
 
 		sz = data->branch_stack->nr * sizeof(struct branch_entry);
 		if (evsel__has_branch_hw_idx(evsel)) {
@@ -3505,7 +3508,7 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 			data->user_stack.size = *array++;
 			if (WARN_ONCE(data->user_stack.size > sz,
 				      "user stack dump failure\n"))
-				return -EFAULT;
+				goto out_efault;
 		}
 	}
 
@@ -3586,6 +3589,9 @@ int evsel__parse_sample(struct evsel *evsel, union perf_event *event,
 		return __set_offcpu_sample(data);
 
 	return 0;
+out_efault:
+	perf_sample__exit(data);
+	return -EFAULT;
 }
 
 int evsel__parse_sample_timestamp(struct evsel *evsel, union perf_event *event,
diff --git a/tools/perf/util/sample.c b/tools/perf/util/sample.c
index 8f82aaf1aab6..b04cbad7edd3 100644
--- a/tools/perf/util/sample.c
+++ b/tools/perf/util/sample.c
@@ -21,13 +21,19 @@ void perf_sample__init(struct perf_sample *sample, bool all)
 	} else {
 		sample->user_regs = NULL;
 		sample->intr_regs = NULL;
+		sample->deferred_callchain = false;
+		sample->callchain = NULL;
 	}
 }
 
 void perf_sample__exit(struct perf_sample *sample)
 {
-	free(sample->user_regs);
-	free(sample->intr_regs);
+	zfree(&sample->user_regs);
+	zfree(&sample->intr_regs);
+	if (sample->deferred_callchain) {
+		zfree(&sample->callchain);
+		sample->deferred_callchain = false;
+	}
 }
 
 struct regs_dump *perf_sample__user_regs(struct perf_sample *sample)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 4b465abfa36c..c48e840da7d4 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1367,14 +1367,18 @@ static int evlist__deliver_deferred_callchain(struct evlist *evlist,
 	list_for_each_entry_safe(de, tmp, &evlist->deferred_samples, list) {
 		struct perf_sample orig_sample;
 
+		perf_sample__init(&orig_sample, /*all=*/false);
 		ret = evlist__parse_sample(evlist, de->event, &orig_sample);
 		if (ret < 0) {
 			pr_err("failed to parse original sample\n");
+			perf_sample__exit(&orig_sample);
 			break;
 		}
 
-		if (sample->tid != orig_sample.tid)
+		if (sample->tid != orig_sample.tid) {
+			perf_sample__exit(&orig_sample);
 			continue;
+		}
 
 		if (event->callchain_deferred.cookie == orig_sample.deferred_cookie)
 			sample__merge_deferred_callchain(&orig_sample, sample);
@@ -1385,9 +1389,7 @@ static int evlist__deliver_deferred_callchain(struct evlist *evlist,
 		ret = evlist__deliver_sample(evlist, tool, de->event,
 					     &orig_sample, evsel, machine);
 
-		if (orig_sample.deferred_callchain)
-			free(orig_sample.callchain);
-
+		perf_sample__exit(&orig_sample);
 		list_del(&de->list);
 		free(de->event);
 		free(de);
@@ -1414,9 +1416,11 @@ static int session__flush_deferred_samples(struct perf_session *session,
 	list_for_each_entry_safe(de, tmp, &evlist->deferred_samples, list) {
 		struct perf_sample sample;
 
+		perf_sample__init(&sample, /*all=*/false);
 		ret = evlist__parse_sample(evlist, de->event, &sample);
 		if (ret < 0) {
 			pr_err("failed to parse original sample\n");
+			perf_sample__exit(&sample);
 			break;
 		}
 
@@ -1424,6 +1428,7 @@ static int session__flush_deferred_samples(struct perf_session *session,
 		ret = evlist__deliver_sample(evlist, tool, de->event,
 					     &sample, evsel, machine);
 
+		perf_sample__exit(&sample);
 		list_del(&de->list);
 		free(de->event);
 		free(de);
-- 
2.53.0.959.g497ff81fa9-goog