From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=vtn1=VX=vger.kernel.org=linux-kernel-owner@kernel.org>
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 1A168C7618B
	for <linux-kernel@archiver.kernel.org>; Fri, 26 Jul 2019 13:19:32 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id EB3AC218D4
	for <linux-kernel@archiver.kernel.org>; Fri, 26 Jul 2019 13:19:31 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727219AbfGZNTb (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Fri, 26 Jul 2019 09:19:31 -0400
Received: from mailgw02.mediatek.com ([210.61.82.184]:40279 "EHLO
        mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org
        with ESMTP id S1726001AbfGZNTa (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 26 Jul 2019 09:19:30 -0400
X-UUID: 0811d90d0f9943609049e07c27e9d03e-20190726
X-UUID: 0811d90d0f9943609049e07c27e9d03e-20190726
Received: from mtkmrs01.mediatek.inc [(172.21.131.159)] by mailgw02.mediatek.com
        (envelope-from <walter-zh.wu@mediatek.com>)
        (Cellopoint E-mail Firewall v4.1.10 Build 0707 with TLS)
        with ESMTP id 1211687384; Fri, 26 Jul 2019 21:19:23 +0800
Received: from mtkcas08.mediatek.inc (172.21.101.126) by
 mtkmbs06n1.mediatek.inc (172.21.101.129) with Microsoft SMTP Server (TLS) id
 15.0.1395.4; Fri, 26 Jul 2019 21:19:24 +0800
Received: from [172.21.84.99] (172.21.84.99) by mtkcas08.mediatek.inc
 (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend
 Transport; Fri, 26 Jul 2019 21:19:24 +0800
Message-ID: <1564147164.515.10.camel@mtksdccf07>
Subject: Re: [PATCH v3] kasan: add memory corruption identification for
 software tag-based mode
From:   Walter Wu <walter-zh.wu@mediatek.com>
To:     Andrey Ryabinin <aryabinin@virtuozzo.com>
CC:     Dmitry Vyukov <dvyukov@google.com>,
        Alexander Potapenko <glider@google.com>,
        Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        "Martin Schwidefsky" <schwidefsky@de.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        "Vasily Gorbik" <gor@linux.ibm.com>,
        Andrey Konovalov <andreyknvl@google.com>,
        "Jason A . Donenfeld" <Jason@zx2c4.com>,
        Miles Chen <miles.chen@mediatek.com>,
        kasan-dev <kasan-dev@googlegroups.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux-MM <linux-mm@kvack.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>,
        wsd_upstream <wsd_upstream@mediatek.com>
Date:   Fri, 26 Jul 2019 21:19:24 +0800
In-Reply-To: <71df2bd5-7bc8-2c82-ee31-3f68c3b6296d@virtuozzo.com>
References: <20190613081357.1360-1-walter-zh.wu@mediatek.com>
         <da7591c9-660d-d380-d59e-6d70b39eaa6b@virtuozzo.com>
         <1560447999.15814.15.camel@mtksdccf07>
         <1560479520.15814.34.camel@mtksdccf07>
         <1560744017.15814.49.camel@mtksdccf07>
         <CACT4Y+Y3uS59rXf92ByQuFK_G4v0H8NNnCY1tCbr4V+PaZF3ag@mail.gmail.com>
         <1560774735.15814.54.camel@mtksdccf07>
         <1561974995.18866.1.camel@mtksdccf07>
         <CACT4Y+aMXTBE0uVkeZz+MuPx3X1nESSBncgkScWvAkciAxP1RA@mail.gmail.com>
         <ebc99ee1-716b-0b18-66ab-4e93de02ce50@virtuozzo.com>
         <1562640832.9077.32.camel@mtksdccf07>
         <d9fd1d5b-9516-b9b9-0670-a1885e79f278@virtuozzo.com>
         <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>
         <e62da62a-2a63-3a1c-faeb-9c5561a5170c@virtuozzo.com>
         <1564144097.515.3.camel@mtksdccf07>
         <71df2bd5-7bc8-2c82-ee31-3f68c3b6296d@virtuozzo.com>
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: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

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, i think maybe
only move generic quarantine into tag-based kasan, but its memory
consumption is more bigger our patch. what do you think?