Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756337AbYJWN6u (ORCPT ); Thu, 23 Oct 2008 09:58:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753791AbYJWN6V (ORCPT ); Thu, 23 Oct 2008 09:58:21 -0400 Received: from saeurebad.de ([85.214.36.134]:56450 "EHLO saeurebad.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753530AbYJWN6U (ORCPT ); Thu, 23 Oct 2008 09:58:20 -0400 From: Johannes Weiner To: Linux Kernel Mailing List Cc: Andrea Righi , Dave Jones , Dave Airlie , Stefan Richter Subject: lockdep splat from ioctl and mmap fops sharing lock References: <87ljwgj8p1.fsf@saeurebad.de> Date: Thu, 23 Oct 2008 15:58:10 +0200 In-Reply-To: <87ljwgj8p1.fsf@saeurebad.de> (Johannes Weiner's message of "Thu, 23 Oct 2008 05:23:38 +0200") Message-ID: <87ej27jtvx.fsf@saeurebad.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 894 Lines: 27 Johannes Weiner writes: > Hi, > > fb_mmap() is called under mmap_sem and acquires fb_info->lock. > > Since 3e680aae4e53ab "fb: convert lock/unlock_kernel() into local fb > mutex", fb_ioctl() takes fb_info->lock and does copy_to/from_user() > under it, which in turn might acquire mmap_sem. More affected drivers: agp_ioctl() doing usercopy under agp_fe.agp_mutex agp_mmap() taking agp_fe.agp_mutex under mmap_sem dv1394_write() doing usercopy under video->mtx dv1394_mmap() taking video->mtx under mmap_sem raw1394_ioctl() doing usercopy under fi->state_mutex raw1394_mmap() taking fi->state_mutex under mmap_sem Hannes -- 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/