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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 C3511C49ED6 for ; Tue, 10 Sep 2019 11:53:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 770AA208E4 for ; Tue, 10 Sep 2019 11:53:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 770AA208E4 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 DFF5B6B0003; Tue, 10 Sep 2019 07:53:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DDF506B0006; Tue, 10 Sep 2019 07:53:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CEC496B0007; Tue, 10 Sep 2019 07:53:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0038.hostedemail.com [216.40.44.38]) by kanga.kvack.org (Postfix) with ESMTP id AD7256B0003 for ; Tue, 10 Sep 2019 07:53:29 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 0F78D8243768 for ; Tue, 10 Sep 2019 11:53:29 +0000 (UTC) X-FDA: 75918850938.18.leg50_3b7a20896c84f X-HE-Tag: leg50_3b7a20896c84f X-Filterd-Recvd-Size: 2451 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Sep 2019 11:53:28 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 82DF2B061; Tue, 10 Sep 2019 11:53:26 +0000 (UTC) Subject: Re: [PATCH v2 0/2] mm/kasan: dump alloc/free stack for page allocator To: Andrey Ryabinin , walter-zh.wu@mediatek.com, Alexander Potapenko , Dmitry Vyukov , Matthias Brugger , Andrew Morton , Martin Schwidefsky , Will Deacon , Andrey Konovalov , Arnd Bergmann , Thomas Gleixner , Michal Hocko , Qian Cai Cc: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com References: <20190909082412.24356-1-walter-zh.wu@mediatek.com> From: Vlastimil Babka Message-ID: <4faedb4d-f16c-1917-9eaa-b0f9c169fa50@suse.cz> Date: Tue, 10 Sep 2019 13:53:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed 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 9/10/19 12:50 PM, Andrey Ryabinin wrote: > > > For slab objects we memorize both alloc and free stacks. You'll never know in advance what information will be usefull > to fix an issue, so it usually better to provide more information. I don't think we should do anything different for pages. Exactly, thanks. > Given that we already have the page_owner responsible for providing alloc/free stacks for pages, all that we should in KASAN do is to > enable the feature by default. Free stack saving should be decoupled from debug_pagealloc into separate option so that it can be enabled > by KASAN and/or debug_pagealloc. Right. Walter, can you do it that way, or should I? Thanks, Vlastimil