From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757322Ab1HFAKE (ORCPT ); Fri, 5 Aug 2011 20:10:04 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39291 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932133Ab1HFAJv (ORCPT ); Fri, 5 Aug 2011 20:09:51 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Aug 5 17:02:54 2011 Message-Id: <20110806000254.303730660@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 05 Aug 2011 17:02:24 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, Greg KH Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Vince Weaver , Ingo Molnar , Paul Mackerras , Arnaldo Carvalho de Melo , Peter Zijlstra Subject: [54/55] perf: overflow/perf_count_sw_cpu_clock crashes recent kernels In-Reply-To: <20110806000257.GA25498@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Peter Zijlstra 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(-) --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3694,12 +3694,8 @@ static int __perf_event_overflow(struct 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);