From bb30b1915be745fa2ef499580ac5a74e8e50e7b9 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 3 Aug 2011 13:49:31 +0200 Subject: [PATCH] perf: overflow/perf_count_sw_cpu_clock crashes recent kernels The below patch is for -stable only, upstream has a much larger patch that contains the below hunk in commit a8b0ca17b80e92faab46ee7179ba9e99ccb61233 Vince found that under certain circumstances software event overflows go wrong and deadlock. Avoid trying to delete a timer from the timer callback. Reported-by: Vince Weaver Signed-off-by: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman --- kernel/perf_event.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index fc5ab8e444f0..37ebc14c9ce4 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3694,12 +3694,8 @@ static int __perf_event_overflow(struct perf_event *event, int nmi, if (events && atomic_dec_and_test(&event->event_limit)) { ret = 1; event->pending_kill = POLL_HUP; - if (nmi) { - event->pending_disable = 1; - perf_pending_queue(&event->pending, - perf_pending_event); - } else - perf_event_disable(event); + event->pending_disable = 1; + perf_pending_queue(&event->pending, perf_pending_event); } perf_event_output(event, nmi, data, regs); -- 2.47.3