From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759472AbYDTLcc (ORCPT ); Sun, 20 Apr 2008 07:32:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752712AbYDTLcY (ORCPT ); Sun, 20 Apr 2008 07:32:24 -0400 Received: from main.gmane.org ([80.91.229.2]:48072 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbYDTLcX (ORCPT ); Sun, 20 Apr 2008 07:32:23 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Sitsofe Wheeler Subject: Possible circular lockdep when doing modprobe -r hostap_pci Date: Sun, 20 Apr 2008 11:32:12 +0000 (UTC) Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: cpc3-cwma2-0-0-cust739.swan.cable.ntl.com User-Agent: Pan/0.129 (Benson & Hedges Moscow Gold) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When doing modprobe -r hostap_pci on latest git the following output was printed: [ 2040.662987] ======================================================= [ 2040.663006] [ INFO: possible circular locking dependency detected ] [ 2040.663016] 2.6.25skw #10 [ 2040.663021] ------------------------------------------------------- [ 2040.663029] ifconfig/5608 is trying to acquire lock: [ 2040.663036] (events){--..}, at: [] flush_workqueue+0x0/0x60 [ 2040.663070] [ 2040.663072] but task is already holding lock: [ 2040.663078] (rtnl_mutex){--..}, at: [] rtnl_lock+0xf/0x20 [ 2040.663103] [ 2040.663105] which lock already depends on the new lock. [ 2040.663109] [ 2040.663114] [ 2040.663116] the existing dependency chain (in reverse order) is: [ 2040.663122] [ 2040.663124] -> #2 (rtnl_mutex){--..}: [ 2040.663134] [] __lock_acquire+0xe63/0xf60 [ 2040.663161] [] lock_acquire+0x5e/0x80 [ 2040.663179] [] mutex_lock_nested+0x78/0x230 [ 2040.663209] [] rtnl_lock+0xf/0x20 [ 2040.663209] [] linkwatch_event+0x8/0x30 [ 2040.663209] [] run_workqueue+0x11f/0x1d0 [ 2040.663209] [] worker_thread+0x97/0xf0 [ 2040.663209] [] kthread+0x42/0x70 [ 2040.663209] [] kernel_thread_helper+0x7/0x1c [ 2040.663209] [] 0xffffffff [ 2040.663209] [ 2040.663209] -> #1 ((linkwatch_work).work){--..}: [ 2040.663209] [] __lock_acquire+0xe63/0xf60 [ 2040.663209] [] lock_acquire+0x5e/0x80 [ 2040.663209] [] run_workqueue+0x11a/0x1d0 [ 2040.663209] [] worker_thread+0x97/0xf0 [ 2040.663209] [] kthread+0x42/0x70 [ 2040.663209] [] kernel_thread_helper+0x7/0x1c [ 2040.663209] [] 0xffffffff [ 2040.663209] [ 2040.663209] -> #0 (events){--..}: [ 2040.663209] [] __lock_acquire+0x9f5/0xf60 [ 2040.663209] [] lock_acquire+0x5e/0x80 [ 2040.663209] [] flush_workqueue+0x38/0x60 [ 2040.663209] [] flush_scheduled_work+0xd/0x10 [ 2040.663209] [] prism2_close+0x35/0x110 [hostap] [ 2040.663209] [] dev_close+0x46/0x60 [ 2040.663209] [] dev_change_flags+0x7d/0x180 [ 2040.663209] [] devinet_ioctl+0x4c7/0x660 [ 2040.663209] [] inet_ioctl+0x61/0x80 [ 2040.663209] [] sock_ioctl+0xb7/0x210 [ 2040.663209] [] vfs_ioctl+0x20/0x70 [ 2040.663209] [] do_vfs_ioctl+0x57/0x240 [ 2040.663209] [] sys_ioctl+0x60/0x70 [ 2040.663209] [] sysenter_past_esp+0x6a/0xb1 [ 2040.663209] [] 0xffffffff [ 2040.663209] [ 2040.663209] other info that might help us debug this: [ 2040.663209] [ 2040.663209] 1 lock held by ifconfig/5608: [ 2040.663209] #0: (rtnl_mutex){--..}, at: [] rtnl_lock +0xf/0x20 [ 2040.663209] [ 2040.663209] stack backtrace: [ 2040.663209] Pid: 5608, comm: ifconfig Not tainted 2.6.25skw #10 [ 2040.663209] [] print_circular_bug_tail+0x6e/0x80 [ 2040.663209] [] ? print_circular_bug_entry+0x43/0x50 [ 2040.663209] [] __lock_acquire+0x9f5/0xf60 [ 2040.663209] [] ? _spin_unlock_irqrestore+0x47/0x60 [ 2040.663209] [] ? trace_hardirqs_on+0xb5/0x140 [ 2040.663209] [] lock_acquire+0x5e/0x80 [ 2040.663209] [] ? flush_workqueue+0x0/0x60 [ 2040.663209] [] flush_workqueue+0x38/0x60 [ 2040.663209] [] ? flush_workqueue+0x0/0x60 [ 2040.663209] [] flush_scheduled_work+0xd/0x10 [ 2040.663209] [] prism2_close+0x35/0x110 [hostap] [ 2040.663209] [] dev_close+0x46/0x60 [ 2040.663209] [] dev_change_flags+0x7d/0x180 [ 2040.663209] [] ? __dev_get_by_name+0x7e/0xa0 [ 2040.663209] [] devinet_ioctl+0x4c7/0x660 [ 2040.663209] [] ? copy_to_user+0x3e/0x60 [ 2040.663209] [] inet_ioctl+0x61/0x80 [ 2040.663209] [] sock_ioctl+0xb7/0x210 [ 2040.663209] [] ? do_page_fault+0x176/0x640 [ 2040.663209] [] ? sock_ioctl+0x0/0x210 [ 2040.663209] [] vfs_ioctl+0x20/0x70 [ 2040.663209] [] do_vfs_ioctl+0x57/0x240 [ 2040.663209] [] sys_ioctl+0x60/0x70 [ 2040.663209] [] sysenter_past_esp+0x6a/0xb1 [ 2040.663209] ======================= -- Sitsofe | http://sucs.org/~sits/