From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754488Ab1GIGIb (ORCPT ); Sat, 9 Jul 2011 02:08:31 -0400 Received: from out5.smtp.messagingengine.com ([66.111.4.29]:37663 "EHLO out5.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752781Ab1GIGAy (ORCPT ); Sat, 9 Jul 2011 02:00:54 -0400 X-Sasl-enc: cP47rvEwzh2O1cpcW4HBnSvEWRm/fiUh0WMD9EnAiG+n 1310191253 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Jul 8 16:01:10 2011 Message-Id: <20110708230110.847411874@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 08 Jul 2011 16:00:29 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Marcin Slusarz , Catalin Marinas , Tejun Heo , Dipankar Sarma , "Paul E. McKenney" , Thomas Gleixner Subject: [13/35] debugobjects: Fix boot crash when kmemleak and debugobjects enabled In-Reply-To: <20110708230122.GA18807@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.33-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Marcin Slusarz commit 161b6ae0e067e421b20bb35caf66bdb405c929ac upstream. Order of initialization look like this: ... debugobjects kmemleak ...(lots of other subsystems)... workqueues (through early initcall) ... debugobjects use schedule_work for batch freeing of its data and kmemleak heavily use debugobjects, so when it comes to freeing and workqueues were not initialized yet, kernel crashes: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] __queue_work+0x29/0x41a [] queue_work_on+0x16/0x1d [] queue_work+0x29/0x55 [] schedule_work+0x13/0x15 [] free_object+0x90/0x95 [] debug_check_no_obj_freed+0x187/0x1d3 [] ? _raw_spin_unlock_irqrestore+0x30/0x4d [] ? free_object_rcu+0x68/0x6d [] kmem_cache_free+0x64/0x12c [] free_object_rcu+0x68/0x6d [] __rcu_process_callbacks+0x1b6/0x2d9 ... because system_wq is NULL. Fix it by checking if workqueues susbystem was initialized before using. Signed-off-by: Marcin Slusarz Cc: Catalin Marinas Cc: Tejun Heo Cc: Dipankar Sarma Cc: Paul E. McKenney Link: http://lkml.kernel.org/r/20110528112342.GA3068@joi.lan Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- lib/debugobjects.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -196,7 +196,7 @@ static void free_object(struct debug_obj * initialized: */ if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache) - sched = !work_pending(&debug_obj_work); + sched = keventd_up() && !work_pending(&debug_obj_work); hlist_add_head(&obj->node, &obj_pool); obj_pool_free++; obj_pool_used--;