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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 83DFDC433DB for ; Mon, 22 Feb 2021 12:10:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BDE664E29 for ; Mon, 22 Feb 2021 12:10:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230099AbhBVMKL (ORCPT ); Mon, 22 Feb 2021 07:10:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:43954 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230090AbhBVMKK (ORCPT ); Mon, 22 Feb 2021 07:10:10 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 23A8E60C3E; Mon, 22 Feb 2021 12:09:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613995769; bh=vkn91XSEQHym5zKtY83o4vZak+yc+4d2glFxeuvEa3A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kdoClrqPsqQJvuHVAsqzA23cnbbgUVBjy4WIU4/1dWdtDtufSVrLOI6QT2zvCSbnA nXP2F1NUsdyMy6h2EicBCRXHwYsxST/CfQesrbJLD4QipaWEYpYxCJsjU60QtZdBV8 zFemL0Kt4oaXbt7no6Cw0Z+l8xlIG7FQYHa/kRPA= Date: Mon, 22 Feb 2021 13:09:24 +0100 From: Greg KH To: Xiaoming Ni Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, sashal@kernel.org, tglx@linutronix.de, wangle6@huawei.com, zhengyejian1@huawei.com Subject: Re: [PATCH stable-rc queue/4.9 1/1] futex: Provide distinct return value when owner is exiting Message-ID: References: <20210222070328.102384-1-nixiaoming@huawei.com> <20210222070328.102384-2-nixiaoming@huawei.com> <3bc570f6-f8af-b0a2-4d62-13ed4adc1f33@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3bc570f6-f8af-b0a2-4d62-13ed4adc1f33@huawei.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Feb 22, 2021 at 06:54:06PM +0800, Xiaoming Ni wrote: > On 2021/2/22 18:16, Greg KH wrote: > > On Mon, Feb 22, 2021 at 03:03:28PM +0800, Xiaoming Ni wrote: > > > From: Thomas Gleixner > > > > > > commit ac31c7ff8624409ba3c4901df9237a616c187a5d upstream. > > This commit is already in the 4.9 tree. If the backport was incorrect, > > say that here, and describe what went wrong and why this commit fixes > > it. > > > > Also state what commit this fixes as well, otherwise this changelog just > > looks like it is being applied again to the tree, which doesn't make > > much sense. > > > > thanks, > > > > greg k-h > > . > > I wrote a cover for it. but forgot to adjust the title of the cover: > > https://lore.kernel.org/lkml/20210222070328.102384-1-nixiaoming@huawei.com/ > > > I found a dead code in the queue/4.9 branch of the stable-rc repository. > > 2021-02-03: > commit c27f392040e2f6 ("futex: Provide distinct return value when > owner is exiting") > The function handle_exit_race does not exist. Therefore, the > change in handle_exit_race() is ignored in the patch round. > > 2021-02-22: > commit e55cb811e612 ("futex: Cure exit race") > Define the handle_exit_race() function, > but no branch in the function returns EBUSY. > As a result, dead code occurs in the attach_to_pi_owner(): > > int ret = handle_exit_race(uaddr, uval, p); > ... > if (ret == -EBUSY) > *exiting = p; /* dead code */ > > To fix the dead code, modify the commit e55cb811e612 ("futex: Cure exit > race"), > or install a patch to incorporate the changes in handle_exit_race(). > > I am unfamiliar with the processing of the stable-rc queue branch, > and I cannot find the patch mail of the current branch in > https://lore.kernel.org/lkml/?q=%22futex%3A+Cure+exit+race%22 > Therefore, I re-integrated commit ac31c7ff8624 ("futex: Provide distinct > return value when owner is exiting"). > And wrote a cover (but forgot to adjust the title of the cover): > > https://lore.kernel.org/lkml/20210222070328.102384-1-nixiaoming@huawei.com/ So this is a "fixup" patch, right? Please clearly label it as such in your patch description and resend this as what is here I can not apply at all. thanks, greg k-h