From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756417Ab1I3P4s (ORCPT ); Fri, 30 Sep 2011 11:56:48 -0400 Received: from arkanian.console-pimps.org ([212.110.184.194]:34874 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014Ab1I3P4r (ORCPT ); Fri, 30 Sep 2011 11:56:47 -0400 Subject: Re: [RFC][PATCH 2/5] signal: Add rwlock to protect sighand->action From: Matt Fleming To: Oleg Nesterov Cc: Tejun Heo , linux-kernel@vger.kernel.org, Tony Luck , Peter Zijlstra , Thomas Gleixner , Anirudh Badam In-Reply-To: <1317395577-14091-3-git-send-email-matt@console-pimps.org> References: <1317395577-14091-1-git-send-email-matt@console-pimps.org> <1317395577-14091-3-git-send-email-matt@console-pimps.org> Content-Type: text/plain; charset="UTF-8" Date: Fri, 30 Sep 2011 16:56:43 +0100 Message-ID: <1317398203.3375.25.camel@mfleming-mobl1.ger.corp.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 (2.32.2-1.fc14) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2011-09-30 at 16:12 +0100, Matt Fleming wrote: > @@ -2935,9 +3025,11 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) > if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) > return -EINVAL; > > + spin_lock_irq(¤t->sighand->siglock); > + read_lock(¤t->sighand->action_lock); > + > k = &t->sighand->action[sig-1]; > > - spin_lock_irq(¤t->sighand->siglock); > if (oact) > *oact = *k; > > @@ -2967,6 +3059,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) > } > } > > + read_unlock(¤t->sighand->action_lock); > spin_unlock_irq(¤t->sighand->siglock); > return 0; > } Guh! I just noticed this. That should obviously be write-locked. -- Matt Fleming, Intel Open Source Technology Center