Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758748AbZCMPET (ORCPT ); Fri, 13 Mar 2009 11:04:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756981AbZCMPEG (ORCPT ); Fri, 13 Mar 2009 11:04:06 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:50279 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752314AbZCMPEE (ORCPT ); Fri, 13 Mar 2009 11:04:04 -0400 Message-ID: <49BA75CF.3040501@us.ibm.com> Date: Fri, 13 Mar 2009 08:03:43 -0700 From: Darren Hart User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu CC: linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/futexes] futex: remove the pointer math from double_unlock_hb, fix References: <20090312221118.11146.68610.stgit@Aeon> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1641 Lines: 57 Ingo Molnar wrote: > Commit-ID: 88f502fedba82eff252b6420e8b8328e4ae25c67 > Gitweb: http://git.kernel.org/tip/88f502fedba82eff252b6420e8b8328e4ae25c67 > Author: Ingo Molnar > AuthorDate: Fri, 13 Mar 2009 10:32:07 +0100 > Commit: Ingo Molnar > CommitDate: Fri, 13 Mar 2009 10:32:07 +0100 > > futex: remove the pointer math from double_unlock_hb, fix > > Impact: fix double unlock crash > > Thomas Gleixner noticed that the simplified double_unlock_hb() > became ... too unsophisticated: in the hb1 == hb2 case it will > do a double unlock. Gah. Thanks for catching it. > > Reported-by: Thomas Gleixner > Cc: Darren Hart > LKML-Reference: <20090312221118.11146.68610.stgit@Aeon> > Signed-off-by: Ingo Molnar Acked-by: Darren Hart > > > --- > kernel/futex.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/kernel/futex.c b/kernel/futex.c > index 2331b73..6b50a02 100644 > --- a/kernel/futex.c > +++ b/kernel/futex.c > @@ -659,7 +659,8 @@ static inline void > double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) > { > spin_unlock(&hb1->lock); > - spin_unlock(&hb2->lock); > + if (hb1 != hb2) > + spin_unlock(&hb2->lock); > } > > /* -- Darren Hart IBM Linux Technology Center Real-Time Linux Team -- 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/