Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932888AbbDJMp1 (ORCPT ); Fri, 10 Apr 2015 08:45:27 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34956 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932212AbbDJMpX (ORCPT ); Fri, 10 Apr 2015 08:45:23 -0400 Date: Fri, 10 Apr 2015 14:45:19 +0200 From: Greg KH To: "Liu, XinwuX" Cc: linux-kernel@vger.kernel.org, lin.z.chen@intel.com, bo.he@intel.com Subject: Re: [PATCH] Fix the deadlock in uevent_buffer_pm_notify Message-ID: <20150410124519.GA12218@kroah.com> References: <1428720557-13690-1-git-send-email-xinwux.liu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1428720557-13690-1-git-send-email-xinwux.liu@intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2226 Lines: 53 On Sat, Apr 11, 2015 at 10:49:17AM +0800, Liu, XinwuX wrote: > From: "Liu, XinwuX" > > When suspend finish uevent_buffer_pm_notify will traverse buffer_list > and clean up some kobj that refcount equals zero, it will trigger > kobject_event and get uevent_buffer_mutex again. That will cause deadlock. > > Workqueue: auto_suspend try_to_suspend > Call Trace: > [<8086a9ad>] ? preempt_count_sub+0xad/0x100 > [<8087c237>] ? __wake_up_common+0x47/0x70 > [<8086a9ad>] ? preempt_count_sub+0xad/0x100 > [<80ee5ea3>] schedule+0x23/0x60 > [<80ee6147>] schedule_preempt_disabled+0x17/0x30 > [<80ee876b>] __mutex_lock_slowpath+0x10b/0x370 > [<80ee89e0>] mutex_lock+0x10/0x1c > [<80ab5813>] kobject_uevent_env+0x2d3/0x4a0 > [<80ab59ea>] kobject_uevent+0xa/0x10 > [<80ab4339>] kobject_cleanup+0xb9/0x1b0 > [<80ee865d>] ? mutex_unlock+0xd/0x10 > [<80ab53c4>] ? kobject_deliver_uevent+0x174/0x220 > [<80ab5110>] ? uevent_net_exit+0x70/0x70 > [<80ab41a5>] kobject_put+0x25/0x60 > [<80ab550e>] ? uevent_buffer_pm_notify+0x9e/0xd0 > [<80ac78bb>] ? list_del+0xb/0x20 > [<80ab54ef>] uevent_buffer_pm_notify+0x7f/0xd0 > [<80861597>] notifier_call_chain+0x47/0x90 > [<80861713>] __blocking_notifier_call_chain+0x43/0x70 > [<8086175f>] blocking_notifier_call_chain+0x1f/0x30 > [<808865d6>] pm_notifier_call_chain+0x16/0x30 > [<8088730d>] pm_suspend+0x1ad/0x220 > [<808879c5>] try_to_suspend+0xa5/0xc0 > [<80ee9b5d>] ? _raw_spin_unlock_irq+0x1d/0x40 > [<80856893>] process_one_work+0x113/0x3e0 > [<8084b49d>] ? mod_timer+0xed/0x200 > [<8086aa55>] ? preempt_count_add+0x55/0xa0 > [<80857a37>] worker_thread+0xf7/0x320 > [<80857940>] ? manage_workers.isra.24+0x290/0x290 > [<8085d21b>] kthread+0x9b/0xb0 > [<80eea9f7>] ret_from_kernel_thread+0x1b/0x28 > [<8085d180>] ? flush_kthread_worker+0xb0/0xb0 > > Change-Id: Iaf62ccd7a729f3eff1b5565f4b7b0d7eb01bc6a6 I can't do anything with a patch that has a line like this in it, except delete it from my inbox. Please fix and resend. -- 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/