From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753981AbdK2J1Y (ORCPT ); Wed, 29 Nov 2017 04:27:24 -0500 Received: from mail-pf0-f180.google.com ([209.85.192.180]:38484 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178AbdK2J1V (ORCPT ); Wed, 29 Nov 2017 04:27:21 -0500 X-Google-Smtp-Source: AGs4zMbL/WuFZgxLqQT1HEJkeB+LkfiAJIqm/oZSxGvticgMiCkAkwJygi7alr2fbUdRZCfJ1BhZyvWnBaeiWbBBOLY= MIME-Version: 1.0 In-Reply-To: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> From: Dmitry Vyukov Date: Wed, 29 Nov 2017 10:27:00 +0100 Message-ID: Subject: Re: [PATCH 00/18] introduce a new tool, valid access checker To: Joonsoo Kim Cc: Andrew Morton , Andrey Ryabinin , Alexander Potapenko , kasan-dev , Linux-MM , LKML , Namhyung Kim , Wengang Wang , Joonsoo Kim , Andi Kleen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 28, 2017 at 8:48 AM, wrote: > From: Joonsoo Kim > > Hello, > > This patchset introduces a new tool, valid access checker. > > Vchecker is a dynamic memory error detector. It provides a new debug feature > that can find out an un-intended access to valid area. Valid area here means > the memory which is allocated and allowed to be accessed by memory owner and > un-intended access means the read/write that is initiated by non-owner. > Usual problem of this class is memory overwritten. > > Most of debug feature focused on finding out un-intended access to > in-valid area, for example, out-of-bound access and use-after-free, and, > there are many good tools for it. But, as far as I know, there is no good tool > to find out un-intended access to valid area. This kind of problem is really > hard to solve so this tool would be very useful. > > This tool doesn't automatically catch a problem. Manual runtime configuration > to specify the target object is required. > > Note that there was a similar attempt for the debugging overwritten problem > however it requires manual code modifying and recompile. > > http://lkml.kernel.org/r/<20171117223043.7277-1-wen.gang.wang@oracle.com> > > To get more information about vchecker, please see a documention at > the last patch. > > Patchset can also be available at > > https://github.com/JoonsooKim/linux/tree/vchecker-master-v1.0-next-20171122 > > Enjoy it. Hi Joonsoo, I skimmed through the code and this looks fine from KASAN point of view (minimal code changes and no perf impact). I don't feel like I can judge if this should go in or not. I will not use this, we use KASAN for large-scale testing, but vchecker is in a different bucket, it is meant for developers debugging hard bugs. Wengang come up with a very similar change, and Andi said that this looks useful. If the decision is that this goes in, please let me take a closer look before this is merged. Thanks From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id A96D96B0033 for ; Wed, 29 Nov 2017 04:27:22 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id q3so1804096pgv.16 for ; Wed, 29 Nov 2017 01:27:22 -0800 (PST) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id r18sor387789pgd.80.2017.11.29.01.27.21 for (Google Transport Security); Wed, 29 Nov 2017 01:27:21 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1511855333-3570-1-git-send-email-iamjoonsoo.kim@lge.com> From: Dmitry Vyukov Date: Wed, 29 Nov 2017 10:27:00 +0100 Message-ID: Subject: Re: [PATCH 00/18] introduce a new tool, valid access checker Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Andrew Morton , Andrey Ryabinin , Alexander Potapenko , kasan-dev , Linux-MM , LKML , Namhyung Kim , Wengang Wang , Joonsoo Kim , Andi Kleen On Tue, Nov 28, 2017 at 8:48 AM, wrote: > From: Joonsoo Kim > > Hello, > > This patchset introduces a new tool, valid access checker. > > Vchecker is a dynamic memory error detector. It provides a new debug feature > that can find out an un-intended access to valid area. Valid area here means > the memory which is allocated and allowed to be accessed by memory owner and > un-intended access means the read/write that is initiated by non-owner. > Usual problem of this class is memory overwritten. > > Most of debug feature focused on finding out un-intended access to > in-valid area, for example, out-of-bound access and use-after-free, and, > there are many good tools for it. But, as far as I know, there is no good tool > to find out un-intended access to valid area. This kind of problem is really > hard to solve so this tool would be very useful. > > This tool doesn't automatically catch a problem. Manual runtime configuration > to specify the target object is required. > > Note that there was a similar attempt for the debugging overwritten problem > however it requires manual code modifying and recompile. > > http://lkml.kernel.org/r/<20171117223043.7277-1-wen.gang.wang@oracle.com> > > To get more information about vchecker, please see a documention at > the last patch. > > Patchset can also be available at > > https://github.com/JoonsooKim/linux/tree/vchecker-master-v1.0-next-20171122 > > Enjoy it. Hi Joonsoo, I skimmed through the code and this looks fine from KASAN point of view (minimal code changes and no perf impact). I don't feel like I can judge if this should go in or not. I will not use this, we use KASAN for large-scale testing, but vchecker is in a different bucket, it is meant for developers debugging hard bugs. Wengang come up with a very similar change, and Andi said that this looks useful. If the decision is that this goes in, please let me take a closer look before this is merged. Thanks -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org