From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4D25C31E46 for ; Wed, 12 Jun 2019 07:15:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A00B22082C for ; Wed, 12 Jun 2019 07:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560323738; bh=Pgn4z8eXDtvYuB4h8Srt1Pl6cmZJ+jrdGbEb4/HW8F4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=z1ZNUhxKHDTDpzh2aOlJUJX+0mYSEgh14RaCQ/yKEv9ujQFx2+XWHxqmx1Q/1k0kq pPtoDJv2V+Iv5P+pHt5b+6q5ZL3QR/5C91zAT8D1YacDZpKKKeod4gx7VyTa76igso PIP7xnxKD1z0sQ3FGLGOi9kQLxjtElC3m7Sz9c/8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407270AbfFLHPi (ORCPT ); Wed, 12 Jun 2019 03:15:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:53680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405874AbfFLHPi (ORCPT ); Wed, 12 Jun 2019 03:15:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8B146205ED; Wed, 12 Jun 2019 07:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560323737; bh=Pgn4z8eXDtvYuB4h8Srt1Pl6cmZJ+jrdGbEb4/HW8F4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gyOXmd/Bk2MY+ObjQoit0TWOjS+A3rYkI8Ikbk1QNX/JbNILMih4G3ibdsrKy44JR 7ruaWDGVo8ybEPMU8WZhzsjFQSjflJ4nYRMnwH0bRWMfWVfNJbJKasKwZaLca/ZkSc gwOUUi5a8BqneqAbLIWnNU9FATVBUi5J1fmPsHFU= Date: Wed, 12 Jun 2019 09:15:34 +0200 From: Greg KH To: "zhangxiaoxu (A)" Cc: tglx@linutronix.de, mingo@redhat.com, peterz@infradead.org, dvhart@infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] futex: Fix futex lock the wrong page Message-ID: <20190612071534.GA14367@kroah.com> References: <1560304465-68966-1-git-send-email-zhangxiaoxu5@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Jun 12, 2019 at 09:50:25AM +0800, zhangxiaoxu (A) wrote: > This patch is for stable branch linux-4.4-y. > > On 2019/6/12 9:54, ZhangXiaoxu wrote: > > The upstram commit 65d8fc777f6d ("futex: Remove requirement > > for lock_page() in get_futex_key()") use variable 'page' as > > the page head, when merge it to stable branch, the variable > > `page_head` is page head. > > > > In the stable branch, the variable `page` not means the page > > head, when lock the page head, we should lock 'page_head', > > rather than 'page'. > > > > It maybe lead a hung task problem. > > > > Signed-off-by: ZhangXiaoxu > > Cc: stable@vger.kernel.org > > --- > > kernel/futex.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) I do not understand. Please read https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to submit a patch to the stable trees properly. If the commit is not in Linus's tree, then we can not take it, unless something is _very_ broken and it is the only way it can be resolved. thanks, greg k-h