Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751367Ab3JRGaW (ORCPT ); Fri, 18 Oct 2013 02:30:22 -0400 Received: from mail-ee0-f43.google.com ([74.125.83.43]:57401 "EHLO mail-ee0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750859Ab3JRGaU (ORCPT ); Fri, 18 Oct 2013 02:30:20 -0400 Date: Fri, 18 Oct 2013 08:30:17 +0200 From: Ingo Molnar To: Frederic Weisbecker Cc: "Paul E. McKenney" , Linus Torvalds , Knut Petersen , Thomas Gleixner , Greg KH , linux-kernel Subject: Re: [BUG 3.12.rc4] Oops: unable to handle kernel paging request during shutdown Message-ID: <20131018063017.GE14264@gmail.com> References: <525BD08C.2080101@t-online.de> <20131014212830.GD5790@linux.vnet.ibm.com> <20131014215117.GE13538@localhost.localdomain> <20131015064025.GA22672@gmail.com> <20131017142458.GG28963@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131017142458.GG28963@localhost.localdomain> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1178 Lines: 32 * Frederic Weisbecker wrote: > On Tue, Oct 15, 2013 at 08:40:25AM +0200, Ingo Molnar wrote: > > > > * Frederic Weisbecker wrote: > > > > > I've been thinking that CONFIG_DEBUG_LIST could help. Unfortunately it's > > > good to spot list APIs misuse but, if Linus is right, the problem may be > > > that the list belongs to an object that has been freed, and I believe > > > that won't detect such a thing. > > > > Use-after free should be reliably detectable via CONFIG_DEBUG_PAGEALLOC=y. > > > > A couple of years ago I wrote a list debugging beast that would catch > > use-after-free mishaps (sent it to lkml too IIRC), but it was a bit > > complex and I never found the time to nurse it upstream. > > Ok, well CONFIG_DEBUG_PAGEALLOC=y should work for list as for anything, > right? Correct - but it adds non-trivial overhead so in some cases it hides races. Thanks, Ingo -- 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/