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=-2.3 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 A5673C32751 for ; Wed, 31 Jul 2019 17:05:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81A1121851 for ; Wed, 31 Jul 2019 17:05:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730501AbfGaRFH (ORCPT ); Wed, 31 Jul 2019 13:05:07 -0400 Received: from relay.sw.ru ([185.231.240.75]:36950 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726582AbfGaRFH (ORCPT ); Wed, 31 Jul 2019 13:05:07 -0400 Received: from [172.16.25.12] by relay.sw.ru with esmtp (Exim 4.92) (envelope-from ) id 1hss1z-0001ux-M2; Wed, 31 Jul 2019 20:04:51 +0300 Subject: Re: [PATCH v3] kasan: add memory corruption identification for software tag-based mode To: Walter Wu Cc: Dmitry Vyukov , Alexander Potapenko , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Matthias Brugger , Martin Schwidefsky , Arnd Bergmann , Vasily Gorbik , Andrey Konovalov , "Jason A . Donenfeld" , Miles Chen , kasan-dev , LKML , Linux-MM , Linux ARM , linux-mediatek@lists.infradead.org, wsd_upstream References: <20190613081357.1360-1-walter-zh.wu@mediatek.com> <1560447999.15814.15.camel@mtksdccf07> <1560479520.15814.34.camel@mtksdccf07> <1560744017.15814.49.camel@mtksdccf07> <1560774735.15814.54.camel@mtksdccf07> <1561974995.18866.1.camel@mtksdccf07> <1562640832.9077.32.camel@mtksdccf07> <1562839579.5846.12.camel@mtksdccf07> <37897fb7-88c1-859a-dfcc-0a5e89a642e0@virtuozzo.com> <1563160001.4793.4.camel@mtksdccf07> <9ab1871a-2605-ab34-3fd3-4b44a0e17ab7@virtuozzo.com> <1563789162.31223.3.camel@mtksdccf07> <1564144097.515.3.camel@mtksdccf07> <71df2bd5-7bc8-2c82-ee31-3f68c3b6296d@virtuozzo.com> <1564147164.515.10.camel@mtksdccf07> From: Andrey Ryabinin Message-ID: Date: Wed, 31 Jul 2019 20:04:59 +0300 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: <1564147164.515.10.camel@mtksdccf07> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/26/19 4:19 PM, Walter Wu wrote: > On Fri, 2019-07-26 at 15:52 +0300, Andrey Ryabinin wrote: >> >> On 7/26/19 3:28 PM, Walter Wu wrote: >>> On Fri, 2019-07-26 at 15:00 +0300, Andrey Ryabinin wrote: >>>> >>> >>>>> >>>>> >>>>> I remember that there are already the lists which you concern. Maybe we >>>>> can try to solve those problems one by one. >>>>> >>>>> 1. deadlock issue? cause by kmalloc() after kfree()? >>>> >>>> smp_call_on_cpu() >>> >>>>> 2. decrease allocation fail, to modify GFP_NOWAIT flag to GFP_KERNEL? >>>> >>>> No, this is not gonna work. Ideally we shouldn't have any allocations there. >>>> It's not reliable and it hurts performance. >>>> >>> I dont know this meaning, we need create a qobject and put into >>> quarantine, so may need to call kmem_cache_alloc(), would you agree this >>> action? >>> >> >> How is this any different from what you have now? > > I originally thought you already agreed the free-list(tag-based > quarantine) after fix those issue. If no allocation there, If no allocation there, than it must be somewhere else. We known exactly the amount of memory we need, so it's possible to preallocate it in advance. > i think maybe > only move generic quarantine into tag-based kasan, but its memory > consumption is more bigger our patch. what do you think? >