Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965854Ab2EOCyd (ORCPT ); Mon, 14 May 2012 22:54:33 -0400 Received: from mail.windriver.com ([147.11.1.11]:49599 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965048Ab2EOCRL (ORCPT ); Mon, 14 May 2012 22:17:11 -0400 From: Paul Gortmaker To: , Subject: [34-longterm 087/179] debugobjects: Fix boot crash when kmemleak and debugobjects enabled Date: Mon, 14 May 2012 22:13:03 -0400 Message-ID: <1337048075-6132-88-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.6 In-Reply-To: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> References: <1337048075-6132-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2663 Lines: 73 From: Marcin Slusarz ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- 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: Paul Gortmaker --- lib/debugobjects.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index b862b30..e60bd59 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -197,7 +197,7 @@ static void free_object(struct debug_obj *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--; -- 1.7.9.6 -- 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/