[PATCH 7/9] perf metric: Do not free metric when failed to resolve

From: Namhyung Kim
Date: Sun Sep 06 2020 - 23:45:46 EST


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: 83de0b7d535de ("perf metric: Collect referenced metrics in struct metric_ref_node")
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/metricgroup.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index c8904e471a71..ab5030fcfed4 100644
--- 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;
}

--
2.28.0.526.ge36021eeef-goog