From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753941AbYFEHI5 (ORCPT ); Thu, 5 Jun 2008 03:08:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752127AbYFEHIs (ORCPT ); Thu, 5 Jun 2008 03:08:48 -0400 Received: from main.gmane.org ([80.91.229.2]:42314 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751654AbYFEHIr (ORCPT ); Thu, 5 Jun 2008 03:08:47 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Sitsofe Wheeler Subject: Re: BUG: unable to handle kernel NULL pointer dereference (drm_getunique) Date: Thu, 05 Jun 2008 08:08:34 +0100 Message-ID: References: <873ansbwcq.fsf@saeurebad.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: cpc1-cwma5-0-0-cust137.swan.cable.ntl.com User-Agent: KNode/0.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Johannes Weiner wrote: > Sitsofe Wheeler writes: > >> [ 4305.767503] Pid: 8373, comm: unix2_chkpwd Tainted: G W >> [ (2.6.26-rc4-next-20080604skw #177) > > There was a warning before that oops already, could you post that too? The warning is: [ 42.949862] ------------[ cut here ]------------ [ 42.949873] WARNING: at kernel/lockdep.c:2680 check_flags+0x8a/0x12d() [ 42.949880] Modules linked in: [ 42.949887] Pid: 5, comm: watchdog/0 Not tainted 2.6.26-rc4-next-20080604skw #178 [ 42.949898] [] warn_on_slowpath+0x41/0x6a [ 42.949917] [] ? trace_hardirqs_off+0xb/0xd [ 42.949935] [] ? trace_hardirqs_on+0xb/0xd [ 42.951740] [] ? trace_hardirqs_on_caller+0xe8/0x124 [ 42.951759] [] ? trace_hardirqs_on+0xb/0xd [ 42.951778] [] ? hrtick_set+0xce/0xd6 [ 42.951799] [] check_flags+0x8a/0x12d [ 42.951816] [] lock_acquire+0x3b/0x89 [ 42.951830] [] _read_lock+0x1c/0x49 [ 42.951848] [] ? watchdog+0x97/0x1a9 [ 42.951867] [] ? watchdog+0x0/0x1a9 [ 42.951883] [] watchdog+0x97/0x1a9 [ 42.951900] [] ? watchdog+0x0/0x1a9 [ 42.951916] [] kthread+0x3b/0x63 [ 42.951933] [] ? kthread+0x0/0x63 [ 42.951952] [] kernel_thread_helper+0x7/0x10 [ 42.951969] ======================= [ 42.951976] ---[ end trace 199a1fe68fc13dfd ]--- [ 42.951983] possible reason: unannotated irqs-on. [ 42.951991] irq event stamp: 18 [ 42.951998] hardirqs last enabled at (17): [] trace_hardirqs_on+0xb/0xd [ 42.952018] hardirqs last disabled at (18): [] trace_hardirqs_off+0xb/0xd [ 42.952043] softirqs last enabled at (0): [] copy_process+0x2dd/0xf9a [ 42.952062] softirqs last disabled at (0): [<00000000>] 0x0 I've mentioned it before ( http://lkml.org/lkml/2008/5/29/502 ) and even bisected it ( http://lkml.org/lkml/2008/6/4/313 ). I guess the problem is that everyone is busy and it's hard to tell if people didn't see it, if it's just not important. Perhaps there needs to be a rule that lockdep warnings always go into bugzilla (or that if you are willing to chase an issue for a minimum of six months it should be bugzillad...). Thanks for your work looking at the real bug though! -- Sitsofe | http://sucs.org/~sits/