From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933658AbWKWNMN (ORCPT ); Thu, 23 Nov 2006 08:12:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757365AbWKWNMN (ORCPT ); Thu, 23 Nov 2006 08:12:13 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:9454 "EHLO ogre.sisk.pl") by vger.kernel.org with ESMTP id S1757003AbWKWNMM (ORCPT ); Thu, 23 Nov 2006 08:12:12 -0500 From: "Rafael J. Wysocki" To: Greg KH Subject: Re: 2.6.19-rc5-mm2 (end earlier): WARNING at lib/kobject.c:172 kobject_init() on resume from disk Date: Thu, 23 Nov 2006 14:07:59 +0100 User-Agent: KMail/1.9.1 Cc: Andrew Morton , LKML References: <200611222207.07143.rjw@sisk.pl> <20061122134406.f3a30fc4.akpm@osdl.org> <20061123003935.GA1679@kroah.com> In-Reply-To: <20061123003935.GA1679@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200611231407.59544.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, 23 November 2006 01:39, Greg KH wrote: > On Wed, Nov 22, 2006 at 01:44:06PM -0800, Andrew Morton wrote: > > On Wed, 22 Nov 2006 22:07:06 +0100 > > "Rafael J. Wysocki" wrote: > > > > > Hi, > > > > > > I get similar traces on every resume from disk on SMP systems: > > > > > > WARNING at lib/kobject.c:172 kobject_init() > > > > > > Call Trace: > > > [] dump_trace+0xaa/0x3fd > > > [] show_trace+0x3c/0x52 > > > [] dump_stack+0x15/0x17 > > > [] kobject_init+0x3f/0x8a > > > [] kobject_register+0x1a/0x3e > > > [] sysdev_register+0x5f/0xec > > > [] mce_create_device+0x79/0x103 > > > [] mce_cpu_callback+0x2a/0xbd > > > [] notifier_call_chain+0x29/0x3e > > > [] raw_notifier_call_chain+0x9/0xb > > > [] _cpu_up+0xc2/0xd5 > > > [] cpu_up+0x2b/0x42 > > > [] enable_nonboot_cpus+0x4e/0x9b > > > [] snapshot_ioctl+0x1a0/0x5d2 > > > [] do_ioctl+0x5e/0x77 > > > [] vfs_ioctl+0x256/0x273 > > > [] sys_ioctl+0x5f/0x82 > > > [] system_call+0x7e/0x83 > > > DWARF2 unwinder stuck at system_call+0x7e/0x83 > > > Leftover inexact backtrace: > > > > > > False positive? > > > > > > > Don't know. The changelog in > > http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/gregkh-01-driver/kobject-warn.patch > > is pretty pathetic. > > Heh, I would think that it's a big "obvious", oh well. > > There are 2 changes in this patch. > > First one is to ensure that the kobject is properly initialized _before_ > kobject_init() is called. Yeah, seems funny, right? Turns out this has > caught a lot of issues where kobject_init() is called twice on the same > object, not a good thing at all. > > And this looks like that is exactly what is happening here, as you > mention: > > > Perhaps mce_remove_device() isn't being called. > > That's probably the issue. > > The second change in that patch tries to enforce the "everything needs a > release() function" rule for kobjects, but it turns out, a lot of static > kobjects trigger this inproperly (struct bus and friends), so that can't > go to mainline, and it only shows up if you enable CONFIG_KOBJECT_DEBUG. CONFIG_DEBUG_KOBJECT is not set here, so it looks like kobject_init() is being called for the second time on the same object. Greetings, Rafael -- You never change things by fighting the existing reality. R. Buckminster Fuller