From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751666AbaJZOpl (ORCPT ); Sun, 26 Oct 2014 10:45:41 -0400 Received: from www.linutronix.de ([62.245.132.108]:52291 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751363AbaJZOpk (ORCPT ); Sun, 26 Oct 2014 10:45:40 -0400 Date: Sun, 26 Oct 2014 15:45:37 +0100 (CET) From: Thomas Gleixner To: Brian Silverman cc: austin.linux@gmail.com, linux-kernel@vger.kernel.org, darren@dvhart.com, peterz@infradead.org Subject: Re: [PATCH v2] futex: fix a race condition between REQUEUE_PI and task death In-Reply-To: <1414282837-23092-1-git-send-email-bsilver16384@gmail.com> Message-ID: References: <1414092159-17697-1-git-send-email-bsilver16384@gmail.com> <1414282837-23092-1-git-send-email-bsilver16384@gmail.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 25 Oct 2014, Brian Silverman wrote: > @@ -1558,6 +1558,12 @@ retry_private: > ret = get_futex_value_locked(&curval, uaddr1); > > if (unlikely(ret)) { > + /* > + * We will have to lookup the pi_state again, so > + * free this one to keep the accounting correct. > + */ > + free_pi_state(pi_state, hb2); > + pi_state = NULL; pi_state is always NULL here. No point for this call. Thanks, tglx