Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757940Ab2BXRIq (ORCPT ); Fri, 24 Feb 2012 12:08:46 -0500 Received: from smtp108.prem.mail.ac4.yahoo.com ([76.13.13.47]:39478 "HELO smtp108.prem.mail.ac4.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1757393Ab2BXRIo (ORCPT ); Fri, 24 Feb 2012 12:08:44 -0500 X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: Mqt_UMAVM1krxXoTwwI5DXe4flWleuuvaGAsU3JF.oz1YgB HL1TpySiOoEK66lHHKBj42ghBcGvz2iXXGqpTVoBrLH7BEJDkAVlAnpkvmLa Z3ct9wVV887zeleiK1a7I62AXQkD4clvknL9ptb78_lG3vIydoOKGw20IxmO JLUPwYaNTyKgUc6plxPHmcil_2jVL6O76LhmpW6xx.0ULeJmCSL_ovWqyJ0E ELNMuS4xP3_6H37WkJl.h4MSKQadBeffzv7Ps0clgA7eSGndjhdLEZ1i4JrZ HxriwLkC0oTc0OF4iySXJsN7SYwaqJvFgKr.4ZcHEaZOdUm1tPRV.PRiD9pC IU45Qt6j7fUnwR8NUGPTJ00Cxm_Mi9bCP9v9uggZTGJOwDz6FBycvY.zaU8r 0 X-Yahoo-SMTP: _Dag8S.swBC1p4FJKLCXbs8NQzyse1SYSgnAbY0- Date: Fri, 24 Feb 2012 11:08:41 -0600 (CST) From: Christoph Lameter X-X-Sender: cl@router.home To: Dave Hansen cc: "Eric W. Biederman" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC][PATCH] fix move/migrate_pages() race on task struct In-Reply-To: Message-ID: References: <20120223180740.C4EC4156@kernel> <4F468F09.5050200@linux.vnet.ibm.com> <4F469BC7.50705@linux.vnet.ibm.com> <4F47BF56.6010602@linux.vnet.ibm.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 596 Lines: 23 Oh and another thing. There are certain functions that are now called under rcu read lock() security_task_movememory and cpuset_mems_allowed cpuset_mems_allowed takes a mutex. Hmmm... Under rcu? security_task_movememory does some kind of security hook. Is that all safe? If not then we need to take a refcount on the task struct after all. -- 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/