From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id 7B0156B0039 for ; Thu, 5 Jun 2014 10:18:42 -0400 (EDT) Received: by mail-pd0-f177.google.com with SMTP id g10so1144761pdj.36 for ; Thu, 05 Jun 2014 07:18:42 -0700 (PDT) Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com. [66.111.4.26]) by mx.google.com with ESMTPS id oy9si13015648pbc.166.2014.06.05.07.18.40 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Jun 2014 07:18:41 -0700 (PDT) Date: Thu, 5 Jun 2014 07:18:33 -0700 From: Greg KH Subject: Re: [PATCH] mm/mempolicy: fix sleeping function called from invalid context Message-ID: <20140605141833.GA26830@kroah.com> References: <53902A44.50005@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53902A44.50005@cn.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: Gu Zheng Cc: linux-kernel , Andrew Morton , Tejun Heo , linux-mm@kvack.org, Cgroups , stable@vger.kernel.org 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. -- 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