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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_2 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 0D95BC3A5A7 for ; Wed, 4 Sep 2019 14:06:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E52E82339D for ; Wed, 4 Sep 2019 14:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730616AbfIDOGN (ORCPT ); Wed, 4 Sep 2019 10:06:13 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:44382 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1730462AbfIDOGM (ORCPT ); Wed, 4 Sep 2019 10:06:12 -0400 X-UUID: f362c8a6c104411aa10ef7ebe1987d5b-20190904 X-UUID: f362c8a6c104411aa10ef7ebe1987d5b-20190904 Received: from mtkexhb02.mediatek.inc [(172.21.101.103)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 2107079500; Wed, 04 Sep 2019 22:06:06 +0800 Received: from mtkcas09.mediatek.inc (172.21.101.178) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 4 Sep 2019 22:06:05 +0800 Received: from [172.21.84.99] (172.21.84.99) by mtkcas09.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Wed, 4 Sep 2019 22:06:04 +0800 Message-ID: <1567605965.32522.14.camel@mtksdccf07> Subject: Re: [PATCH 1/2] mm/kasan: dump alloc/free stack for page allocator From: Walter Wu To: Vlastimil Babka CC: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Matthias Brugger , Andrew Morton , "Martin Schwidefsky" , Arnd Bergmann , , , , , , Date: Wed, 4 Sep 2019 22:06:05 +0800 In-Reply-To: <401064ae-279d-bef3-a8d5-0fe155d0886d@suse.cz> References: <20190904065133.20268-1-walter-zh.wu@mediatek.com> <401064ae-279d-bef3-a8d5-0fe155d0886d@suse.cz> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-09-04 at 14:49 +0200, Vlastimil Babka wrote: > On 9/4/19 8:51 AM, Walter Wu wrote: > > This patch is KASAN report adds the alloc/free stacks for page allocator > > in order to help programmer to see memory corruption caused by page. > > > > By default, KASAN doesn't record alloc/free stack for page allocator. > > It is difficult to fix up page use-after-free issue. > > > > This feature depends on page owner to record the last stack of pages. > > It is very helpful for solving the page use-after-free or out-of-bound. > > > > KASAN report will show the last stack of page, it may be: > > a) If page is in-use state, then it prints alloc stack. > > It is useful to fix up page out-of-bound issue. > > I expect this will conflict both in syntax and semantics with my series [1] that > adds the freeing stack to page_owner when used together with debug_pagealloc, > and it's now in mmotm. Glad others see the need as well :) Perhaps you could > review the series, see if it fulfils your usecase (AFAICS the series should be a > superset, by storing both stacks at once), and perhaps either make KASAN enable > debug_pagealloc, or turn KASAN into an alternative enabler of the functionality > there? > > Thanks, Vlastimil > > [1] https://lore.kernel.org/linux-mm/20190820131828.22684-1-vbabka@suse.cz/t/#u > Thanks your information. We focus on the smartphone, so it doesn't enable CONFIG_TRANSPARENT_HUGEPAGE, Is it invalid for our usecase? And It looks like something is different, because we only need last stack of page, so it can decrease memory overhead. I will try to enable debug_pagealloc(with your patch) and KASAN, then we see the result. Thanks. Walter