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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 E3583C433FE for ; Thu, 16 Sep 2021 15:49:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7EED60F51 for ; Thu, 16 Sep 2021 15:49:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240193AbhIPPvM (ORCPT ); Thu, 16 Sep 2021 11:51:12 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:42372 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240195AbhIPPvG (ORCPT ); Thu, 16 Sep 2021 11:51:06 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]:56758) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mQtdv-004f0g-NP; Thu, 16 Sep 2021 09:49:43 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:38800 helo=email.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mQtdt-007UgB-Uh; Thu, 16 Sep 2021 09:49:42 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Ohhoon Kwon , Ingo Molnar , "David S . Miller" , Christian Brauner , Alexey Dobriyan , Andrew Morton , Linus Torvalds , linux-fsdevel@vger.kernel.org References: <20210913223339.435347-1-sashal@kernel.org> <20210913223339.435347-19-sashal@kernel.org> <87v932ar5q.fsf@disp2133> Date: Thu, 16 Sep 2021 10:49:03 -0500 In-Reply-To: (Sasha Levin's message of "Wed, 15 Sep 2021 20:36:30 -0400") Message-ID: <87sfy47c7k.fsf@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1mQtdt-007UgB-Uh;;;mid=<87sfy47c7k.fsf@disp2133>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+0Au3z3k7ifU/nnlh47JL4EIj11kK2IV4= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH AUTOSEL 5.14 19/25] connector: send event on write to /proc/[pid]/comm X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Sasha Levin writes: > On Wed, Sep 15, 2021 at 08:45:37AM -0500, Eric W. Biederman wrote: >>Sasha Levin writes: >> >>> From: Ohhoon Kwon >>> >>> [ Upstream commit c2f273ebd89a79ed87ef1025753343e327b99ac9 ] >>> >>> While comm change event via prctl has been reported to proc connector by >>> 'commit f786ecba4158 ("connector: add comm change event report to proc >>> connector")', connector listeners were missing comm changes by explicit >>> writes on /proc/[pid]/comm. >>> >>> Let explicit writes on /proc/[pid]/comm report to proc connector. >> >>This is a potential userspace ABI breakage? Why backport it? >> >>Especially if there is no one asking for the behavior change in >>userspace? > > This sounds like a concern with the patch going upstream rather than > going to stable? stable has the same policy around ABI changes such as > upstream. Let me say it another way. This looks more like an evolution of the functionality rather than a bug fix. With something like this unless someone cares I don't think it should be backported. It is all risk and no benefit. This is all doubly so because I think there are about 2 connector users and connector is not especially good at the job it tries to fulfill. It is for that exact reason that connector does not work in containers. We couldn't find any users who cared. After the fiasco with the rlimit/ucount changes getting backported before they are even stable is that I am tired of saying about backports meh whatever. If there is no one who actually cares (which is what I learned about autosel from the rlimit/ucount fiasco) it makes no sense to backport things unless they really are bug fixes. Backporting this just looks like senseless churn. Eric