[PATCH] perf metric: Fix some memory leaks

[PATCH] perf metric: Fix some memory leaks

[Namhyung Kim]

I found some memory leaks while reading the metric code.  Some are
real and others only occur in the error path.

Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Fixes: 9afe5658a6fa8 ("perf tools: Release metric_events rblist")
Fixes: 4ea2896715e67 ("perf metric: Collect referenced metrics in struct metric_expr")
Fixes: 71b0acce78d12 ("perf list: Add metric groups to perf list")
Fixes: b18f3e365019d ("perf stat: Support JSON metrics in perf stat")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
I'm not sure it'd better have them together or split each fix as
they came from different commits.  Please let me know if you prefer
split.

 tools/perf/util/metricgroup.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 8831b964288f..7e31c4578ce8 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -85,6 +85,7 @@ static void metric_event_delete(struct rblist *rblist __maybe_unused,
 
 	list_for_each_entry_safe(expr, tmp, &me->head, nd) {
 		free(expr->metric_refs);
+		free(expr->metric_events);
 		free(expr);
 	}
 
@@ -316,6 +317,7 @@ static int metricgroup__setup_events(struct list_head *groups,
 			if (!metric_refs) {
 				ret = -ENOMEM;
 				free(metric_events);
+				free(expr);
 				break;
 			}
 
@@ -530,6 +532,9 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
 						continue;
 					strlist__add(me->metrics, s);
 				}
+
+				if (!raw)
+					free(s);
 			}
 			free(omg);
 		}
@@ -1048,11 +1053,11 @@ static int parse_groups(struct evlist *perf_evlist, const char *str,
 		parse_events_print_error(&parse_error, extra_events.buf);
 		goto out;
 	}
-	strbuf_release(&extra_events);
 	ret = metricgroup__setup_events(&metric_list, metric_no_merge,
 					perf_evlist, metric_events);
 out:
 	metricgroup__free_metrics(&metric_list);
+	strbuf_release(&extra_events);
 	return ret;
 }
 
-- 
2.28.0.526.ge36021eeef-goog

Re: [PATCH] perf metric: Fix some memory leaks

[Ian Rogers]

On Thu, Sep 3, 2020 at 8:21 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> I found some memory leaks while reading the metric code.  Some are
> real and others only occur in the error path.

Thanks Namhyung! Is it possible to get test coverage?
Ian

> Cc: Kajol Jain <kjain@linux.ibm.com>
> Cc: John Garry <john.garry@huawei.com>
> Cc: Ian Rogers <irogers@google.com>
> Fixes: 9afe5658a6fa8 ("perf tools: Release metric_events rblist")
> Fixes: 4ea2896715e67 ("perf metric: Collect referenced metrics in struct metric_expr")
> Fixes: 71b0acce78d12 ("perf list: Add metric groups to perf list")
> Fixes: b18f3e365019d ("perf stat: Support JSON metrics in perf stat")
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> I'm not sure it'd better have them together or split each fix as
> they came from different commits.  Please let me know if you prefer
> split.
>
>  tools/perf/util/metricgroup.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index 8831b964288f..7e31c4578ce8 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -85,6 +85,7 @@ static void metric_event_delete(struct rblist *rblist __maybe_unused,
>
>         list_for_each_entry_safe(expr, tmp, &me->head, nd) {
>                 free(expr->metric_refs);
> +               free(expr->metric_events);
>                 free(expr);
>         }
>
> @@ -316,6 +317,7 @@ static int metricgroup__setup_events(struct list_head *groups,
>                         if (!metric_refs) {
>                                 ret = -ENOMEM;
>                                 free(metric_events);
> +                               free(expr);
>                                 break;
>                         }
>
> @@ -530,6 +532,9 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
>                                                 continue;
>                                         strlist__add(me->metrics, s);
>                                 }
> +
> +                               if (!raw)
> +                                       free(s);
>                         }
>                         free(omg);
>                 }
> @@ -1048,11 +1053,11 @@ static int parse_groups(struct evlist *perf_evlist, const char *str,
>                 parse_events_print_error(&parse_error, extra_events.buf);
>                 goto out;
>         }
> -       strbuf_release(&extra_events);
>         ret = metricgroup__setup_events(&metric_list, metric_no_merge,
>                                         perf_evlist, metric_events);
>  out:
>         metricgroup__free_metrics(&metric_list);
> +       strbuf_release(&extra_events);
>         return ret;
>  }
>
> --
> 2.28.0.526.ge36021eeef-goog
>

Re: [PATCH] perf metric: Fix some memory leaks

[Namhyung Kim]

On Fri, Sep 4, 2020 at 1:02 PM Ian Rogers <irogers@google.com> wrote:
>
> On Thu, Sep 3, 2020 at 8:21 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > I found some memory leaks while reading the metric code.  Some are
> > real and others only occur in the error path.
>
> Thanks Namhyung! Is it possible to get test coverage?
> Ian

Not sure what you want..

As I found it from code inspection I don't know if there's a test covering this.

But as far as I can see, 2 of them are on the error path so maybe not easy
to add a test, other one is called from perf list code, and the last one is on
the normal code path so any test should cover it.

Thanks
Namhyung

Re: [PATCH] perf metric: Fix some memory leaks

[Arnaldo Carvalho de Melo]

Em Fri, Sep 04, 2020 at 10:39:50PM +0900, Namhyung Kim escreveu:
> On Fri, Sep 4, 2020 at 1:02 PM Ian Rogers <irogers@google.com> wrote:
> >
> > On Thu, Sep 3, 2020 at 8:21 PM Namhyung Kim <namhyung@kernel.org> wrote:
> > >
> > > I found some memory leaks while reading the metric code.  Some are
> > > real and others only occur in the error path.
> >
> > Thanks Namhyung! Is it possible to get test coverage?
> > Ian
> 
> Not sure what you want..
> 
> As I found it from code inspection I don't know if there's a test covering this.
> 
> But as far as I can see, 2 of them are on the error path so maybe not easy
> to add a test, other one is called from perf list code, and the last one is on
> the normal code path so any test should cover it.

Humm, I assume all those fixes were for csets in a single Linux version,
right? Otherwise I think it'd be better to have a fix per Fixes tag, so
that they would go to the kernel sources where those bugs were fixed.

Thanks!

- Arnaldo

Re: [PATCH] perf metric: Fix some memory leaks

[Namhyung Kim]

Hi Arnaldo,

On Sat, Sep 5, 2020 at 1:28 AM Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> Humm, I assume all those fixes were for csets in a single Linux version,
> right? Otherwise I think it'd be better to have a fix per Fixes tag, so
> that they would go to the kernel sources where those bugs were fixed.

$ git name-rev --tags 9afe5658a6fa8 4ea2896715e67 71b0acce78d12 b18f3e365019d
9afe5658a6fa8 tags/v5.9-rc1~66^2~135
4ea2896715e67 tags/v5.9-rc1~66^2~55
71b0acce78d12 tags/v4.15-rc1~160^2~38^2~36
b18f3e365019d tags/v4.15-rc1~160^2~38^2~37

I'll split it to two - one for v4.15 and another for v5.9.

Thanks
Namhyung