From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752629AbaEAV3V (ORCPT ); Thu, 1 May 2014 17:29:21 -0400 Received: from mail-qg0-f41.google.com ([209.85.192.41]:46999 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752231AbaEAV3T (ORCPT ); Thu, 1 May 2014 17:29:19 -0400 X-Google-Original-From: Vince Weaver Date: Thu, 1 May 2014 17:32:55 -0400 (EDT) From: Vince Weaver To: Vince Weaver cc: Thomas Gleixner , Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, Steven Rostedt Subject: Re: [perf] more perf_fuzzer memory corruption In-Reply-To: Message-ID: References: <20140429094632.GP27561@twins.programming.kicks-ass.net> <20140429190108.GB30445@twins.programming.kicks-ass.net> <20140430184437.GH17778@laptop.programming.kicks-ass.net> <20140501150948.GR11096@twins.programming.kicks-ass.net> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org OK, with the following patch I've been running the problem test case for an hour without triggering the bug. I'm sure this is the wrong fix (maybe patching over the problem istead of fixing the root cause), but it works for me. It looks like this whole mess got introduced with 76e1d9047 in Linux 2.6.35 when the swevent code was converted to use a hashed list. Signed-off-by: Vince Weaver diff --git a/kernel/events/core.c b/kernel/events/core.c index f83a71a..970d711 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5775,6 +5800,11 @@ static void sw_perf_event_destroy(struct perf_event *event) WARN_ON(event->parent); + perf_pmu_disable(event->pmu); + if ((event->hlist_entry.pprev) && (event->hlist_entry.pprev!=LIST_POISON2)) + event->pmu->del(event, 0); + perf_pmu_enable(event->pmu); + static_key_slow_dec(&perf_swevent_enabled[event_id]); swevent_hlist_put(event); }