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 ADFC6C433FE for ; Fri, 4 Dec 2020 16:36:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 16472229C4 for ; Fri, 4 Dec 2020 16:36:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 16472229C4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4875C6B0068; Fri, 4 Dec 2020 11:36:24 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 410906B006C; Fri, 4 Dec 2020 11:36:24 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2DA116B006E; Fri, 4 Dec 2020 11:36:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0082.hostedemail.com [216.40.44.82]) by kanga.kvack.org (Postfix) with ESMTP id 148C76B0068 for ; Fri, 4 Dec 2020 11:36:24 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id C4682181AEF2A for ; Fri, 4 Dec 2020 16:36:23 +0000 (UTC) X-FDA: 77556152646.14.look84_3217974273c5 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id 7EE38182299A8 for ; Fri, 4 Dec 2020 16:36:23 +0000 (UTC) X-HE-Tag: look84_3217974273c5 X-Filterd-Recvd-Size: 3638 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Fri, 4 Dec 2020 16:36:22 +0000 (UTC) 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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