Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753979AbYJDUw6 (ORCPT ); Sat, 4 Oct 2008 16:52:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753118AbYJDUwt (ORCPT ); Sat, 4 Oct 2008 16:52:49 -0400 Received: from nf-out-0910.google.com ([64.233.182.189]:13300 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791AbYJDUwt (ORCPT ); Sat, 4 Oct 2008 16:52:49 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=knSAdpq4CEG2ZblNl6wdw+ur47ihjNZqeDRScxWZVJsaVNBBD9fMFMVBphmIc+PMSa 5L9OtqOl22B3WiqyPHqlH8U+szY8X0HuBZ8ivCAWCy+20abBWiYFi21/UWR8UK3ePSYt fmouuUDcnh1mjRMgnHy4RgGDmiTNomNcLtiS0= Date: Sun, 5 Oct 2008 00:55:22 +0400 From: Alexey Dobriyan To: Oleg Nesterov , Lai Jiangshan Cc: Ingo Molnar , Andrew Morton , Linux Kernel Mailing List , "Paul E. McKenney" Subject: Re: [PATCH] signal, procfs: lock_task_sighand() do not need rcu_read_lock() Message-ID: <20081004205522.GA4259@x200.localdomain> References: <48E5ED4D.4030102@cn.fujitsu.com> <20081003162915.GA624@tv-sign.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081003162915.GA624@tv-sign.ru> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 783 Lines: 19 On Fri, Oct 03, 2008 at 08:29:15PM +0400, Oleg Nesterov wrote: > On 10/03, Lai Jiangshan wrote: > > > > lock_task_sighand() make sure task->sighand is being protected, > > so we do not need rcu_read_lock(). > > [ exec() will get task->sighand->siglock before change task->sighand! ] > > > > But code using rcu_read_lock() _just_ to protect lock_task_sighand() > > only appear in procfs. (and some code in procfs use lock_task_sighand() > > without such redundant protection.) > > Yes, the patch looks correct. Yeah, applied to proc.git -- 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/