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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6955BC433EF for ; Wed, 15 Sep 2021 13:45:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40AB861250 for ; Wed, 15 Sep 2021 13:45:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233698AbhIONrH (ORCPT ); Wed, 15 Sep 2021 09:47:07 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:59352 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233395AbhIONrG (ORCPT ); Wed, 15 Sep 2021 09:47:06 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]:37058) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mQVEQ-001Gjm-C7; Wed, 15 Sep 2021 07:45:46 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:48038 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mQVEO-00AL6P-AQ; Wed, 15 Sep 2021 07:45:45 -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> Date: Wed, 15 Sep 2021 08:45:37 -0500 In-Reply-To: <20210913223339.435347-19-sashal@kernel.org> (Sasha Levin's message of "Mon, 13 Sep 2021 18:33:33 -0400") Message-ID: <87v932ar5q.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=1mQVEO-00AL6P-AQ;;;mid=<87v932ar5q.fsf@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19qhAbvPIGFi9CV+a16T7+aUe76EzEZfR4= 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 in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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? Eric > > Link: https://lkml.kernel.org/r/20210701133458epcms1p68e9eb9bd0eee8903ba26679a37d9d960@epcms1p6 > Signed-off-by: Ohhoon Kwon > Cc: Ingo Molnar > Cc: David S. Miller > Cc: Christian Brauner > Cc: Eric W. Biederman > Cc: Alexey Dobriyan > Signed-off-by: Andrew Morton > Signed-off-by: Linus Torvalds > Signed-off-by: Sasha Levin > --- > fs/proc/base.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index e5b5f7709d48..533d5836eb9a 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -95,6 +95,7 @@ > #include > #include > #include > +#include > #include > #include "internal.h" > #include "fd.h" > @@ -1674,8 +1675,10 @@ static ssize_t comm_write(struct file *file, const char __user *buf, > if (!p) > return -ESRCH; > > - if (same_thread_group(current, p)) > + if (same_thread_group(current, p)) { > set_task_comm(p, buffer); > + proc_comm_connector(p); > + } > else > count = -EINVAL;