Re: [PATCH 15/20] perf trace: free malloc'd trace fields on exit

From: Arnaldo Carvalho de Melo
Date: Thu Jul 15 2021 - 16:32:29 EST


Em Thu, Jul 15, 2021 at 06:07:20PM +0200, Riccardo Mancini escreveu:
> ASan reports several memory leaks running the perf test
> "88: Check open filename arg using perf trace + vfs_getname".
> The first of these leaks is related to struct trace fields never being
> deallocated.
>
> This patch adds the function trace__exit, which is called at the end of
> cmd_trace, replacing the existing deallocation, which is now moved
> inside the new function.
> This function deallocates:
> - ev_qualifier
> - ev_qualifier_ids.entries
> - syscalls.table
> - sctbl
> - perfconfig_events
>
> In order to prevent errors in case any of this field is never
> initialized, this patch also adds initialization to NULL to these
> fields.
>
> Signed-off-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
> ---
> tools/perf/builtin-trace.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index 7ec18ff57fc4ae35..fe26d87ca8ccc14d 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -4701,6 +4701,15 @@ static int trace__config(const char *var, const char *value, void *arg)
> return err;
> }
>
> +static void trace__exit(struct trace *trace)
> +{
> + strlist__delete(trace->ev_qualifier);
> + free(trace->ev_qualifier_ids.entries);
> + free(trace->syscalls.table);
> + syscalltbl__delete(trace->sctbl);
> + zfree(&trace->perfconfig_events);
> +}
> +
> int cmd_trace(int argc, const char **argv)
> {
> const char *trace_usage[] = {
> @@ -4731,6 +4740,12 @@ int cmd_trace(int argc, const char **argv)
> .kernel_syscallchains = false,
> .max_stack = UINT_MAX,
> .max_events = ULONG_MAX,
> + .ev_qualifier = NULL,
> + .sctbl = NULL,
> + .ev_qualifier_ids = {
> + .entries = NULL,
> + .nr = 0,
> + },
> };
> const char *map_dump_str = NULL;
> const char *output_name = NULL;

The above hunk is not needed, as all non explicitely initialized members
will be zeroed, so to reduce patch size I'm dropping it.

Thanks, applied.

- Arnaldo


> @@ -5135,6 +5150,6 @@ int cmd_trace(int argc, const char **argv)
> if (output_name != NULL)
> fclose(trace.output);
> out:
> - zfree(&trace.perfconfig_events);
> + trace__exit(&trace);
> return err;
> }
> --
> 2.31.1
>

--

- Arnaldo