perf: Fix STATE_EXIT usage

We should never attempt to enable a STATE_EXIT event.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/events/core.c

@@ -2253,7 +2253,8 @@ static void __perf_event_enable(struct perf_event *event,
 	struct perf_event *leader = event->group_leader;
 	struct perf_event_context *task_ctx;
 
-	if (event->state >= PERF_EVENT_STATE_INACTIVE)
+	if (event->state >= PERF_EVENT_STATE_INACTIVE ||
+	    event->state <= PERF_EVENT_STATE_ERROR)
 		return;
 
 	update_context_time(ctx);
@@ -2298,7 +2299,8 @@ static void _perf_event_enable(struct perf_event *event)
 	struct perf_event_context *ctx = event->ctx;
 
 	raw_spin_lock_irq(&ctx->lock);
-	if (event->state >= PERF_EVENT_STATE_INACTIVE) {
+	if (event->state >= PERF_EVENT_STATE_INACTIVE ||
+	    event->state <  PERF_EVENT_STATE_ERROR) {
 		raw_spin_unlock_irq(&ctx->lock);
 		return;
 	}