From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753910AbaCCIdF (ORCPT ); Mon, 3 Mar 2014 03:33:05 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:15200 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753631AbaCCIdC (ORCPT ); Mon, 3 Mar 2014 03:33:02 -0500 Message-ID: <53143E2E.6010302@huawei.com> Date: Mon, 3 Mar 2014 16:32:46 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Sasha Levin CC: Subject: Re: [PATCH] cpuset: Add missing rcu read locks References: <1393510855-8771-1-git-send-email-sasha.levin@oracle.com> In-Reply-To: <1393510855-8771-1-git-send-email-sasha.levin@oracle.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.18.230] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/2/27 22:20, Sasha Levin wrote: > We call task_cs() which ends up going into cgroup code without having rcu > read lock. Fix it by grabbing the lock before retrival of task_cs() and usage > of the result. > Thanks for the patch. Fengguang already reported it, and I've made a patch for it, but I was fixing two bugs for 3.14 and then waiting for them to be applied. There're other places that rcu_read_lock() should be used, and we need to remove task_lock().