From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754627Ab3BFQ6w (ORCPT ); Wed, 6 Feb 2013 11:58:52 -0500 Received: from mail.candelatech.com ([208.74.158.172]:59215 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716Ab3BFQ6u (ORCPT ); Wed, 6 Feb 2013 11:58:50 -0500 Message-ID: <51128BC3.40304@candelatech.com> Date: Wed, 06 Feb 2013 08:58:43 -0800 From: Ben Greear Organization: Candela Technologies User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Steven Rostedt CC: Linux Kernel Mailing List , Peter Zijlstra , Ingo Molnar Subject: Re: Question on lockdep and MAX_LOCK_DEPTH References: <5111AD8D.1080005@candelatech.com> <20130206015430.GA9161@home.goodmis.org> <5111BF51.5010607@candelatech.com> <1360119124.2621.37.camel@gandalf.local.home> <5111CE60.4080403@candelatech.com> <1360125419.2621.39.camel@gandalf.local.home> <5111F6F6.7010402@candelatech.com> <1360156888.2621.42.camel@gandalf.local.home> <51127D15.7080503@candelatech.com> <1360166840.2621.45.camel@gandalf.local.home> In-Reply-To: <1360166840.2621.45.camel@gandalf.local.home> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/06/2013 08:07 AM, Steven Rostedt wrote: > On Wed, 2013-02-06 at 07:56 -0800, Ben Greear wrote: > >>> I'm 99% sure that the bug is in your modifications. >> >> I'm sorry, I tried to make that clear. > > You said it was an out of tree module, I didn't realize it had changes > to the core Linux as well. > > >> My tree is here, minus a few debugging patches related to this bug: >> >> http://dmz2.candelatech.com/git/gitweb.cgi?p=linux-3.7.dev.y/.git;a=summary > > Here's your bug: > > 3319 list_for_each_entry_rcu(ptype, &ptype_all, list) { > 3320 if (!ptype->dev || ptype->dev == skb->dev) { > 3321 if (pt_prev) { > 3322 ret = deliver_skb(skb, pt_prev, orig_dev); > 3323 if (ret == NET_RX_CONSUMED) { > 3324 kfree_skb(skb); /* we made a copy in deliver_skb */ > 3325 goto out; > 3326 } > 3327 } > > One of many. All those "goto out;"s skip the rcu_read_unlock(). Thank you so much! I'll fix this and continue testing... I can also post a patch to print the held locks when the max-lock-depth overflows unless someone else prefers to... Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com