perf: Fix perf_init_event()
We ought to return -ENOENT when non of the registered PMUs
recognise the requested event.
This fixes a boot crash that occurs if no PMU is available
but the NMI watchdog tries to register an event.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index f395fb4..f29b525 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -5236,12 +5236,15 @@
list_for_each_entry_rcu(pmu, &pmus, entry) {
int ret = pmu->event_init(event);
if (!ret)
- break;
+ goto unlock;
+
if (ret != -ENOENT) {
pmu = ERR_PTR(ret);
- break;
+ goto unlock;
}
}
+ pmu = ERR_PTR(-ENOENT);
+unlock:
srcu_read_unlock(&pmus_srcu, idx);
return pmu;
