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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A99AFC433FE for ; Fri, 4 Dec 2020 16:37:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B197229C5 for ; Fri, 4 Dec 2020 16:37:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730755AbgLDQhE (ORCPT ); Fri, 4 Dec 2020 11:37:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:50878 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726330AbgLDQhD (ORCPT ); Fri, 4 Dec 2020 11:37:03 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 71851AC9A; Fri, 4 Dec 2020 16:36:21 +0000 (UTC) Subject: Re: [PATCH] mm: mmap_lock: fix use-after-free race and css ref leak in tracepoints To: Shakeel Butt , Steven Rostedt Cc: Axel Rasmussen , Tejun Heo , Greg Thelen , Andrew Morton , Chinwen Chang , Daniel Jordan , David Rientjes , Davidlohr Bueso , Ingo Molnar , Jann Horn , Laurent Dufour , Michel Lespinasse , Stephen Rothwell , Yafang Shao , "David S . Miller" , dsahern@kernel.org, Greg Kroah-Hartman , Jakub Kicinski , liuhangbin@gmail.com, LKML , Linux MM References: <20201130233504.3725241-1-axelrasmussen@google.com> <20201201200715.6171d39b@oasis.local.home> From: Vlastimil Babka Message-ID: <1eb44e95-1fae-5d64-d114-d305c9b8ef63@suse.cz> Date: Fri, 4 Dec 2020 17:36:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/2/20 2:11 AM, Shakeel Butt wrote: > On Tue, Dec 1, 2020 at 5:07 PM Steven Rostedt wrote: >> >> On Tue, 1 Dec 2020 16:36:32 -0800 >> Shakeel Butt wrote: >> >> > SGTM but note that usually Andrew squash all the patches into one >> > before sending to Linus. If you plan to replace the path buffer with >> > integer IDs then no need to spend time fixing buffer related bug. >> >> I don't think Andrew squashes all the patches. I believe he sends Linus >> a patch series. > > I am talking about the patch and the following fixes to that patch. > Those are usually squashed into one patch. Yeah, if there's a way forward that doesn't need to construct full path on each event and the associated complexity and just use an ID, let's convert to the ID and squash it, for less churn. Especially if there are other existing tracepoints that use the ID. If there's further (somewhat orthogonal) work to make the IDs easier for userspace, it can be added on top later, but really shouldn't need to add the current complex solution only to remove it later? Thanks, Vlastimil