Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754926AbZARTWA (ORCPT ); Sun, 18 Jan 2009 14:22:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752995AbZARTVv (ORCPT ); Sun, 18 Jan 2009 14:21:51 -0500 Received: from nf-out-0910.google.com ([64.233.182.184]:14537 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752549AbZARTVu (ORCPT ); Sun, 18 Jan 2009 14:21:50 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:reply-to:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=X2MEE+8ddASA1+KUPr8wvclu96SSFAh6ZvM3+KfyWlu85OzKtNTd8yAQO3+AFNiFrC +rR7TiDlS1iUyL4qMgyiPzJYo2yzh34kBJ9bEDmSPoMq4uMYw0cuvTar76yf81a0Ha3C dVaPEcfJitCMFqW7usQo42y+fPJ65+6wyT1CU= Message-ID: <49738149.5080200@gmail.com> Date: Sun, 18 Jan 2009 20:21:45 +0100 From: Andrea Righi Reply-To: righi.andrea@gmail.com User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Johannes Weiner CC: Dave Jones , Linux Kernel Subject: Re: .29rc2 lockdep report. fb_mmap vs sys_mmap2 References: <20090117231925.GA28055@redhat.com> <20090118020038.GA17489@cmpxchg.org> In-Reply-To: <20090118020038.GA17489@cmpxchg.org> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3060 Lines: 84 On 2009-01-18 03:00, Johannes Weiner wrote: > On Sat, Jan 17, 2009 at 06:19:25PM -0500, Dave Jones wrote: >> Two mmaps enter! Fight! >> >> >> ======================================================= >> [ INFO: possible circular locking dependency detected ] >> 2.6.29-0.41.rc2.fc11.i686 #1 >> ------------------------------------------------------- >> plymouthd/669 is trying to acquire lock: >> (&fb_info->lock){--..}, at: [] fb_mmap+0x87/0x156 >> >> but task is already holding lock: >> (&mm->mmap_sem){----}, at: [] sys_mmap2+0x44/0x7b >> >> which lock already depends on the new lock. >> >> >> the existing dependency chain (in reverse order) is: >> >> -> #1 (&mm->mmap_sem){----}: >> [] __lock_acquire+0x9af/0xb22 >> [] lock_acquire+0x5b/0x81 >> [] might_fault+0x60/0x80 >> [] copy_to_user+0x2c/0xfc >> [] fb_ioctl+0x247/0x338 >> [] vfs_ioctl+0x22/0x69 >> [] do_vfs_ioctl+0x46a/0x4a3 >> [] sys_ioctl+0x40/0x5a >> [] syscall_call+0x7/0xb >> [] 0xffffffff >> >> -> #0 (&fb_info->lock){--..}: >> [] __lock_acquire+0x884/0xb22 >> [] lock_acquire+0x5b/0x81 >> [] __mutex_lock_common+0xd5/0x329 >> [] mutex_lock_nested+0x2e/0x36 >> [] fb_mmap+0x87/0x156 >> [] mmap_region+0x22b/0x43c >> [] do_mmap_pgoff+0x271/0x2d1 >> [] sys_mmap2+0x5a/0x7b >> [] syscall_call+0x7/0xb >> [] 0xffffffff >> >> other info that might help us debug this: >> >> 1 lock held by plymouthd/669: >> #0: (&mm->mmap_sem){----}, at: [] sys_mmap2+0x44/0x7b >> >> stack backtrace: >> Pid: 669, comm: plymouthd Not tainted 2.6.29-0.41.rc2.fc11.i686 #1 >> Call Trace: >> [] ? printk+0xf/0x11 >> [] print_circular_bug_tail+0x5d/0x68 >> [] __lock_acquire+0x884/0xb22 >> [] lock_acquire+0x5b/0x81 >> [] ? fb_mmap+0x87/0x156 >> [] __mutex_lock_common+0xd5/0x329 >> [] ? fb_mmap+0x87/0x156 >> [] mutex_lock_nested+0x2e/0x36 >> [] ? fb_mmap+0x87/0x156 >> [] fb_mmap+0x87/0x156 >> [] mmap_region+0x22b/0x43c >> [] do_mmap_pgoff+0x271/0x2d1 >> [] sys_mmap2+0x5a/0x7b >> [] syscall_call+0x7/0xb > > I reported this one already some time ago [1], Andrea Righi [cc'd] > also had a fix [2] but it seemed to not have made it in. Andrea, > perhaps you can resend it? > > Hannes > > [1] http://lkml.org/lkml/2008/10/22/759 > [2] http://lkml.org/lkml/2008/10/28/377 Sure, I can resend it soon, after a test. -Andrea -- 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/