perf metric: Do not free metric when failed to resolve

It's dangerous to free the original metric when it's called from
resolve_metric() as it's already in the metric_list and might have other
resources too.  Instead, it'd better let them bail out and be released
properly at the later stage.

So add a check when it's called from metricgroup__add_metric() and
release it.  Also make sure that mp is set properly.

Fixes: aec16d025ee01 ("perf metric: Collect referenced metrics in struct metric_ref_node")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-10-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index c8904e471a71efed0d839640a1d2bd17563c207f..ab5030fcfed4e2082c0472ee398ebb429d536a59 100644 (file)
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -672,7 +672,6 @@ static int __add_metric(struct list_head *metric_list,
                m->has_constraint = metric_no_group || metricgroup__has_constraint(pe);
                INIT_LIST_HEAD(&m->metric_refs);
                m->metric_refs_cnt = 0;
-               *mp = m;
 
                parent = expr_ids__alloc(ids);
                if (!parent) {
@@ -685,6 +684,7 @@ static int __add_metric(struct list_head *metric_list,
                        free(m);
                        return -ENOMEM;
                }
+               *mp = m;
        } else {
                /*
                 * We got here for the referenced metric, via the
@@ -719,8 +719,11 @@ static int __add_metric(struct list_head *metric_list,
         * all the metric's IDs and add it to the parent context.
         */
        if (expr__find_other(pe->metric_expr, NULL, &m->pctx, runtime) < 0) {
-               expr__ctx_clear(&m->pctx);
-               free(m);
+               if (m->metric_refs_cnt == 0) {
+                       expr__ctx_clear(&m->pctx);
+                       free(m);
+                       *mp = NULL;
+               }
                return -EINVAL;
        }