perf parse-event: Add init and exit to parse_event_error

parse_events() may succeed but leave string memory allocations reachable
in the error.

Add an init/exit that must be called to initialize and clean up the
error. This fixes a leak in metricgroup parse_ids.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20211107090002.3784612-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 19 insertions, 6 deletions

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index edd7180b24e4..1b43cbc1961d 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1339,7 +1339,7 @@ static int parse_ids(struct perf_pmu *fake_pmu, struct expr_parse_ctx *ids,
 		goto err_out;
 	}
 	pr_debug("Parsing metric events '%s'\n", events.buf);
-	bzero(&parse_error, sizeof(parse_error));
+	parse_events_error__init(&parse_error);
 	ret = __parse_events(parsed_evlist, events.buf, &parse_error, fake_pmu);
 	if (ret) {
 		parse_events_error__print(&parse_error, events.buf);
@@ -1352,6 +1352,7 @@ static int parse_ids(struct perf_pmu *fake_pmu, struct expr_parse_ctx *ids,
 	*out_evlist = parsed_evlist;
 	parsed_evlist = NULL;
 err_out:
+	parse_events_error__exit(&parse_error);
 	evlist__delete(parsed_evlist);
 	strbuf_release(&events);
 	return ret;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 75cafb9a0720..5bfb6f892489 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2301,6 +2301,19 @@ int __parse_events(struct evlist *evlist, const char *str,
 	return ret;
 }
 
+void parse_events_error__init(struct parse_events_error *err)
+{
+	bzero(err, sizeof(*err));
+}
+
+void parse_events_error__exit(struct parse_events_error *err)
+{
+	zfree(&err->str);
+	zfree(&err->help);
+	zfree(&err->first_str);
+	zfree(&err->first_help);
+}
+
 void parse_events_error__handle(struct parse_events_error *err, int idx,
 				char *str, char *help)
 {
@@ -2405,15 +2418,11 @@ void parse_events_error__print(struct parse_events_error *err,
 		return;
 
 	__parse_events_error__print(err->idx, err->str, err->help, event);
-	zfree(&err->str);
-	zfree(&err->help);
 
 	if (err->num_errors > 1) {
 		fputs("\nInitial error:\n", stderr);
 		__parse_events_error__print(err->first_idx, err->first_str,
 					err->first_help, event);
-		zfree(&err->first_str);
-		zfree(&err->first_help);
 	}
 }
 
@@ -2426,13 +2435,14 @@ int parse_events_option(const struct option *opt, const char *str,
 	struct parse_events_error err;
 	int ret;
 
-	bzero(&err, sizeof(err));
+	parse_events_error__init(&err);
 	ret = parse_events(evlist, str, &err);
 
 	if (ret) {
 		parse_events_error__print(&err, str);
 		fprintf(stderr, "Run 'perf list' for a list of valid events\n");
 	}
+	parse_events_error__exit(&err);
 
 	return ret;
 }
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 52ac26b3720a..c7fc93f54577 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -242,6 +242,8 @@ int is_valid_tracepoint(const char *event_string);
 int valid_event_mount(const char *eventfs);
 char *parse_events_formats_error_string(char *additional_terms);
 
+void parse_events_error__init(struct parse_events_error *err);
+void parse_events_error__exit(struct parse_events_error *err);
 void parse_events_error__handle(struct parse_events_error *err, int idx,
 				char *str, char *help);
 void parse_events_error__print(struct parse_events_error *err,