Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759215AbZACB6A (ORCPT ); Fri, 2 Jan 2009 20:58:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757589AbZACB5w (ORCPT ); Fri, 2 Jan 2009 20:57:52 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:39581 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757423AbZACB5v (ORCPT ); Fri, 2 Jan 2009 20:57:51 -0500 Date: Fri, 2 Jan 2009 17:57:48 -0800 From: "Paul E. McKenney" To: Eric Sesterhenn Cc: Kamalesh Babulal , linux-kernel@vger.kernel.org, josh@freedesktop.org, dipankar@in.ibm.com Subject: Re: [BUG] NULL pointer deref with rcutorture Message-ID: <20090103015748.GL6842@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20090102111819.GC6088@alice> <20090102175853.GC6842@linux.vnet.ibm.com> <20090102185303.GC5743@linux.vnet.ibm.com> <20090102195326.GF6842@linux.vnet.ibm.com> <20090102231239.GA19778@alice> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090102231239.GA19778@alice> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1761 Lines: 43 On Sat, Jan 03, 2009 at 12:12:39AM +0100, Eric Sesterhenn wrote: > * Paul E. McKenney (paulmck@linux.vnet.ibm.com) wrote: > > On Sat, Jan 03, 2009 at 12:23:03AM +0530, Kamalesh Babulal wrote: > > > * Paul E. McKenney [2009-01-02 09:58:53]: > > > > > > > On Fri, Jan 02, 2009 at 12:18:19PM +0100, Eric Sesterhenn wrote: > > > > > Hi, > > > > > > > > > > modprobing rcutorture and removing it again gives me the following oops: > > > > > > > > This looks similar to something that Kamalesh ran into a few weeks ago. > > > > > > > > Kamalesh, did the fixes for that make it to 2.6.28? > > > > > > > > Thanx, Paul > > > > > > > > > > Hi Paul, > > > > > > The fix was available in linux-next from Dec 23 2008 (commit 392ddc32982a5c661dd90dd49a3cb37f1c68b782 > > > 'bio: add support for inlining a number of bio_vecs inside the bio') and it has be pushed for merger in 2.6.29. > > > > Thank you, Kamalesh! > > > > Eric, could you please try applying the above commit and see if the > > problem reproduces? > > I tried to apply the patch from > http://git.kernel.dk/?p=linux-2.6-block.git;a=commitdiff_plain;h=392ddc32982a5c661dd90dd49a3cb37f1c68b782;hp=bb799ca0202a360fa74d5f17039b9100caebdde7 > but get a message that it is already applied. Seems i already got that > one. Is your configuration able to support ftrace? Looks like someone is (wrongly) freeing some memory that was sent to call_rcu(), and ftrace might be one way to locate the problem. Thanx, Paul -- 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/