Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754182AbaDRRPb (ORCPT ); Fri, 18 Apr 2014 13:15:31 -0400 Received: from merlin.infradead.org ([205.233.59.134]:59495 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751782AbaDRRP3 (ORCPT ); Fri, 18 Apr 2014 13:15:29 -0400 Date: Fri, 18 Apr 2014 19:15:16 +0200 From: Peter Zijlstra To: Vince Weaver Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Thomas Gleixner , Steven Rostedt Subject: Re: [perf] more perf_fuzzer memory corruption Message-ID: <20140418171516.GR13658@twins.programming.kicks-ass.net> References: <20140417094815.GA9348@gmail.com> <20140417114533.GJ11096@twins.programming.kicks-ass.net> <20140417142213.GA29338@gmail.com> <20140417145418.GM11096@twins.programming.kicks-ass.net> <20140418152314.GY11182@twins.programming.kicks-ass.net> <20140418165958.GQ13658@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140418165958.GQ13658@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 18, 2014 at 06:59:58PM +0200, Peter Zijlstra wrote: > On Fri, Apr 18, 2014 at 05:23:14PM +0200, Peter Zijlstra wrote: > > OK, that's a good clue. That looks like we're freeing events that still > > are on the owner list, which would indicate we're freeing events that > > have a refcount. > > > > I added a WARN in free_event() to check the refcount, along with a > > number of false positives (through the perf_event_open() fail path) I do > > appear to be getting actual fails here. > > > > At least I can 'reproduce' this. Earlier attempts, even based on your > > .config only got me very mysterious lockups -- I suspect the corruption > > happens on a slightly different spot or so and completely messes up the > > machine. > > The below should have only made the false positives go away, but my > machine has magically stopped going all funny on me. Could you give it a > go? > Hmm the fuzzer task seems stuck in kernel space, can't kill it anymore. So its likely it just didn't get around to doing enough to wreck the system or so. /me goes stab it in the eye. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/