From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga02-in.huawei.com ([119.145.14.65]:54162 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751489AbbIGInt (ORCPT ); Mon, 7 Sep 2015 04:43:49 -0400 Subject: Re: 3.4.106: futex: Wrong back port of 9e9aab5dbf? To: Dirk Behme References: <55C59DDE.5020908@gmail.com> CC: stable From: Zefan Li Message-ID: <55ED4E3C.7000101@huawei.com> Date: Mon, 7 Sep 2015 16:43:40 +0800 MIME-Version: 1.0 In-Reply-To: <55C59DDE.5020908@gmail.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: Hi Dirk, On 2015/8/8 14:12, Dirk Behme wrote: > Hello, > > from a private -stable review we think that the commit 9e9aab5dbf ("futex: Ensure get_futex_key_refs() always implies a barrier" [1]) is not correctly back ported to 3.4.x: > > The issue is that the memory barrier is introduced into drop_futex_key_refs() function instead of get_futex_key_refs() function. > > Additionally, we are unsure if the futex commits this commit is fixing are really in < 3.4.106. I.e. we are unsure if this fix is needed at all. Or at least if some additional futex commits are needed. > > Do you like to check? > I've confired this commit isn't needed for 3.4.y. It was backported quite long ago, and at that time I hadn't improved my scripts to check the Fixes tag. Fortunately seems this mistake won't cause serious issue. I'll revert it in the coming 3.4.109. Thanks for the review!