struct perf_event *leader = event->group_leader;
struct perf_event *sibling = NULL;
+ /*
+ * When this memload event is also the first event (no group
+ * exists yet), then there is no aux event before it.
+ */
+ if (leader == event)
+ return -ENODATA;
+
if (!is_mem_loads_aux_event(leader)) {
for_each_sibling_event(sibling, leader) {
if (is_mem_loads_aux_event(sibling))