Re: [PATCH] perf tools: fix potential memory leak

From: Arnaldo Carvalho de Melo
Date: Thu Nov 21 2019 - 09:47:52 EST


Em Wed, Nov 20, 2019 at 10:09:25AM -0800, Ian Rogers escreveu:
> An error may be in place when tracepoint_error is called, use
> parse_events__handle_error to avoid a memory leak and to capture the
> first and last error. Error detected by LLVM's libFuzzer using the
> following event:
>
> $ perf stat -e 'msr/event/,f:e'
> event syntax error: 'msr/event/,f:e'
> \___ can't access trace events
>
> Error: No permissions to read /sys/kernel/debug/tracing/events/f/e
> Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing/'
>
> Initial error:
> event syntax error: 'msr/event/,f:e'
> \___ no value assigned for term
> Run 'perf list' for a list of valid events
>
> Usage: perf stat [<options>] [<command>]
>
> -e, --event <event> event selector. use 'perf list' to list available events

Thanks, applied.

- Arnaldo

> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> tools/perf/util/parse-events.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 6bae9d6edc12..ecef5b8037b4 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -511,6 +511,7 @@ int parse_events_add_cache(struct list_head *list, int *idx,
> static void tracepoint_error(struct parse_events_error *e, int err,
> const char *sys, const char *name)
> {
> + const char *str;
> char help[BUFSIZ];
>
> if (!e)
> @@ -524,18 +525,18 @@ static void tracepoint_error(struct parse_events_error *e, int err,
>
> switch (err) {
> case EACCES:
> - e->str = strdup("can't access trace events");
> + str = "can't access trace events";
> break;
> case ENOENT:
> - e->str = strdup("unknown tracepoint");
> + str = "unknown tracepoint";
> break;
> default:
> - e->str = strdup("failed to add tracepoint");
> + str = "failed to add tracepoint";
> break;
> }
>
> tracing_path__strerror_open_tp(err, help, sizeof(help), sys, name);
> - e->help = strdup(help);
> + parse_events__handle_error(e, 0, strdup(str), strdup(help));
> }
>
> static int add_tracepoint(struct list_head *list, int *idx,
> --
> 2.24.0.432.g9d3f5f5b63-goog

--

- Arnaldo