Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752603AbaFFJpR (ORCPT ); Fri, 6 Jun 2014 05:45:17 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:27264 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752291AbaFFJpP (ORCPT ); Fri, 6 Jun 2014 05:45:15 -0400 X-IronPort-AV: E=Sophos;i="4.98,988,1392134400"; d="scan'208";a="31560960" Message-ID: <53918B25.5010703@cn.fujitsu.com> Date: Fri, 6 Jun 2014 17:34:29 +0800 From: Gu Zheng User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: Greg KH CC: linux-kernel , Andrew Morton , Tejun Heo , , Cgroups , Subject: Re: [PATCH] mm/mempolicy: fix sleeping function called from invalid context References: <53902A44.50005@cn.fujitsu.com> <20140605141833.GA26830@kroah.com> In-Reply-To: <20140605141833.GA26830@kroah.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.100] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, On 06/05/2014 10:18 PM, Greg KH wrote: > On Thu, Jun 05, 2014 at 04:28:52PM +0800, Gu Zheng wrote: >> When running with the kernel(3.15-rc7+), the follow bug occurs: >> [ 9969.258987] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 >> [ 9969.359906] in_atomic(): 1, irqs_disabled(): 0, pid: 160655, name: python >> [ 9969.441175] INFO: lockdep is turned off. >> [ 9969.488184] CPU: 26 PID: 160655 Comm: python Tainted: G A 3.15.0-rc7+ #85 >> [ 9969.581032] Hardware name: FUJITSU-SV PRIMEQUEST 1800E/SB, BIOS PRIMEQUEST 1000 Series BIOS Version 1.39 11/16/2012 >> [ 9969.706052] ffffffff81a20e60 ffff8803e941fbd0 ffffffff8162f523 ffff8803e941fd18 >> [ 9969.795323] ffff8803e941fbe0 ffffffff8109995a ffff8803e941fc58 ffffffff81633e6c >> [ 9969.884710] ffffffff811ba5dc ffff880405c6b480 ffff88041fdd90a0 0000000000002000 >> [ 9969.974071] Call Trace: >> [ 9970.003403] [] dump_stack+0x4d/0x66 >> [ 9970.065074] [] __might_sleep+0xfa/0x130 >> [ 9970.130743] [] mutex_lock_nested+0x3c/0x4f0 >> [ 9970.200638] [] ? kmem_cache_alloc+0x1bc/0x210 >> [ 9970.272610] [] cpuset_mems_allowed+0x27/0x140 >> [ 9970.344584] [] ? __mpol_dup+0x63/0x150 >> [ 9970.409282] [] __mpol_dup+0xe5/0x150 >> [ 9970.471897] [] ? __mpol_dup+0x63/0x150 >> [ 9970.536585] [] ? copy_process.part.23+0x606/0x1d40 >> [ 9970.613763] [] ? trace_hardirqs_on+0xd/0x10 >> [ 9970.683660] [] ? monotonic_to_bootbased+0x2f/0x50 >> [ 9970.759795] [] copy_process.part.23+0x670/0x1d40 >> [ 9970.834885] [] do_fork+0xd8/0x380 >> [ 9970.894375] [] ? __audit_syscall_entry+0x9c/0xf0 >> [ 9970.969470] [] SyS_clone+0x16/0x20 >> [ 9971.030011] [] stub_clone+0x69/0x90 >> [ 9971.091573] [] ? system_call_fastpath+0x16/0x1b >> >> The cause is that cpuset_mems_allowed() try to take mutex_lock(&callback_mutex) >> under the rcu_read_lock(which was hold in __mpol_dup()). And in cpuset_mems_allowed(), >> the access to cpuset is under rcu_read_lock, so in __mpol_dup, we can reduce the >> rcu_read_lock protection region to protect the access to cpuset only in >> current_cpuset_is_being_rebound(). So that we can avoid this bug. >> >> Signed-off-by: Gu Zheng >> --- >> kernel/cpuset.c | 8 +++++++- >> mm/mempolicy.c | 2 -- >> 2 files changed, 7 insertions(+), 3 deletions(-) > > > > This is not the correct way to submit patches for inclusion in the > stable kernel tree. Please read Documentation/stable_kernel_rules.txt > for how to do this properly. > > Thanks for your reminder. I'll follow the right rules. Regards, Gu > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org > . > -- 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/