From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754011AbYIJMdT (ORCPT ); Wed, 10 Sep 2008 08:33:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752101AbYIJMdK (ORCPT ); Wed, 10 Sep 2008 08:33:10 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:60283 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751744AbYIJMdI (ORCPT ); Wed, 10 Sep 2008 08:33:08 -0400 Date: Wed, 10 Sep 2008 14:32:46 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Nick Piggin , Linux Kernel Mailing List Subject: Re: [patch] x86: some lock annotations for user copy paths Message-ID: <20080910123246.GA2564@elte.hu> References: <20080910113717.GB16811@wotan.suse.de> <1221046892.30429.85.camel@twins.programming.kicks-ass.net> <20080910114755.GA9696@elte.hu> <20080910121217.GA16013@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080910121217.GA16013@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org here's another one found on another box: [ 574.380319] ======================================================= [ 574.380381] [ INFO: possible circular locking dependency detected ] [ 574.380413] 2.6.27-rc6-tip #30918 [ 574.380440] ------------------------------------------------------- [ 574.380472] sshd/8255 is trying to acquire lock: [ 574.380500] (&sb->s_type->i_mutex_key#9){--..}, at: [] do_truncate+0x59/0x83 [ 574.380628] [ 574.380629] but task is already holding lock: [ 574.380679] (&mm->mmap_sem){----}, at: [] sys32_mmap2+0x64/0xa7 [ 574.380781] [ 574.380781] which lock already depends on the new lock. [ 574.380782] [ 574.380857] [ 574.380857] the existing dependency chain (in reverse order) is: [ 574.380910] [ 574.380911] -> #1 (&mm->mmap_sem){----}: [ 574.381025] [] __lock_acquire+0x9b4/0xb3b [ 574.381081] [] lock_acquire+0x8d/0xba [ 574.381219] [] iov_iter_fault_in_readable+0x84/0x169 [ 574.381359] [] generic_file_buffered_write+0x119/0x5ad [ 574.381584] [] __generic_file_aio_write_nolock+0x260/0x294 [ 574.381809] [] generic_file_aio_write+0x69/0xc5 [ 574.381948] [] do_sync_write+0xeb/0x132 [ 574.382086] [] vfs_write+0xa7/0xe1 [ 574.382222] [] sys_write+0x47/0x6d [ 574.382359] [] cstar_dispatch+0x7/0x4b [ 574.382496] [] 0xffffffffffffffff [ 574.382635] [ 574.382636] -> #0 (&sb->s_type->i_mutex_key#9){--..}: [ 574.382942] [] __lock_acquire+0x856/0xb3b [ 574.383080] [] lock_acquire+0x8d/0xba [ 574.383218] [] __mutex_lock_common+0xe4/0x333 [ 574.383358] [] mutex_lock_nested+0x30/0x35 [ 574.383495] [] do_truncate+0x59/0x83 [ 574.383633] [] shmem_file_setup+0xcf/0x106 [ 574.383772] [] shmem_zero_setup+0x22/0x5e [ 574.383910] [] mmap_region+0x250/0x438 [ 574.384031] [] do_mmap_pgoff+0x2fe/0x363 [ 574.384031] [] sys32_mmap2+0x7d/0xa7 [ 574.384031] [] cstar_dispatch+0x7/0x4b [ 574.384031] [] 0xffffffffffffffff [ 574.384031] [ 574.384031] other info that might help us debug this: [ 574.384031] [ 574.384031] 1 lock held by sshd/8255: [ 574.384031] #0: (&mm->mmap_sem){----}, at: [] sys32_mmap2+0x64/0xa7 [ 574.384031] [ 574.384031] stack backtrace: [ 574.384031] Pid: 8255, comm: sshd Not tainted 2.6.27-rc6-tip #30918 [ 574.384031] Call Trace: [ 574.384031] [] print_circular_bug_tail+0x71/0x7c [ 574.384031] [] __lock_acquire+0x856/0xb3b [ 574.384031] [] lock_acquire+0x8d/0xba [ 574.384031] [] ? do_truncate+0x59/0x83 [ 574.384031] [] __mutex_lock_common+0xe4/0x333 [ 574.384031] [] ? do_truncate+0x59/0x83 [ 574.384031] [] ? do_truncate+0x59/0x83 [ 574.384031] [] ? _raw_spin_unlock+0x8e/0x93 [ 574.384031] [] mutex_lock_nested+0x30/0x35 [ 574.384031] [] do_truncate+0x59/0x83 [ 574.384031] [] ? init_file+0x99/0xbb [ 574.384031] [] ? alloc_file+0x3e/0x4e [ 574.384031] [] shmem_file_setup+0xcf/0x106 [ 574.384031] [] shmem_zero_setup+0x22/0x5e [ 574.384031] [] mmap_region+0x250/0x438 [ 574.384031] [] ? arch_get_unmapped_area_topdown+0x192/0x294 [ 574.384031] [] do_mmap_pgoff+0x2fe/0x363 [ 574.384031] [] sys32_mmap2+0x7d/0xa7 [ 574.384031] [] cstar_dispatch+0x7/0x4b Ingo