Re: [PATCH v4 4/9] perf tools: splice events onto evlist even on error

Jiri Olsa
2019-10-28T21:07:39Z

On Fri, Oct 25, 2019 at 11:08:22AM -0700, Ian Rogers wrote:
> If event parsing fails the event list is leaked, instead splice the list
> onto the out result and let the caller cleanup.
>
> An example input for parse_events found by libFuzzer that reproduces
> this memory leak is 'm{'.
>
> Signed-off-by: Ian Rogers <irogers@google.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> ---
> tools/perf/util/parse-events.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index c516d0cce946..4c4c6f3e866a 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1952,15 +1952,20 @@ int parse_events(struct evlist *evlist, const char *str,
>
> ret = parse_events__scanner(str, &parse_state, PE_START_EVENTS);
> perf_pmu__parse_cleanup();
> +
> + if (!ret && list_empty(&parse_state.list)) {
> + WARN_ONCE(true, "WARNING: event parser found nothing\n");
> + return -1;
> + }
> +
> + /*
> + * Add list to the evlist even with errors to allow callers to clean up.
> + */
> + perf_evlist__splice_list_tail(evlist, &parse_state.list);
> +
> if (!ret) {
> struct evsel *last;
>
> - if (list_empty(&parse_state.list)) {
> - WARN_ONCE(true, "WARNING: event parser found nothing\n");
> - return -1;
> - }
> -
> - perf_evlist__splice_list_tail(evlist, &parse_state.list);
> evlist->nr_groups += parse_state.nr_groups;
> last = evlist__last(evlist);
> last->cmdline_group_boundary = true;
> --
> 2.24.0.rc0.303.g954a862665-goog
>