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-rw-r--r--tools/perf/util/comm.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c
index 7798a2cc8a86..31279a7bd919 100644
--- a/tools/perf/util/comm.c
+++ b/tools/perf/util/comm.c
@@ -20,9 +20,10 @@ static struct rw_semaphore comm_str_lock = {.lock = PTHREAD_RWLOCK_INITIALIZER,}
static struct comm_str *comm_str__get(struct comm_str *cs)
{
- if (cs)
- refcount_inc(&cs->refcnt);
- return cs;
+ if (cs && refcount_inc_not_zero(&cs->refcnt))
+ return cs;
+
+ return NULL;
}
static void comm_str__put(struct comm_str *cs)
@@ -67,9 +68,14 @@ struct comm_str *__comm_str__findnew(const char *str, struct rb_root *root)
parent = *p;
iter = rb_entry(parent, struct comm_str, rb_node);
+ /*
+ * If we race with comm_str__put, iter->refcnt is 0
+ * and it will be removed within comm_str__put call
+ * shortly, ignore it in this search.
+ */
cmp = strcmp(str, iter->str);
- if (!cmp)
- return comm_str__get(iter);
+ if (!cmp && comm_str__get(iter))
+ return iter;
if (cmp < 0)
p = &(*p)->rb_left;