Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752596AbdDKQ0D (ORCPT <rfc822;w@1wt.eu>);
        Tue, 11 Apr 2017 12:26:03 -0400
Received: from resqmta-ch2-03v.sys.comcast.net ([69.252.207.35]:59384 "EHLO
        resqmta-ch2-03v.sys.comcast.net" rhost-flags-OK-OK-OK-OK)
        by vger.kernel.org with ESMTP id S1750732AbdDKQ0B (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 11 Apr 2017 12:26:01 -0400
Date: Tue, 11 Apr 2017 11:26:00 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
X-X-Sender: cl@east.gentwo.org
To: Kees Cook <keescook@chromium.org>
cc: Michal Hocko <mhocko@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Linux-MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: Add additional consistency check
In-Reply-To: <CAGXu5jK1j3UWUakakFw=EfVwg+Rnovzst52+uZJYesLqLY+n5A@mail.gmail.com>
Message-ID: <alpine.DEB.2.20.1704111125320.25069@east.gentwo.org>
References: <20170404113022.GC15490@dhcp22.suse.cz> <alpine.DEB.2.20.1704041005570.23420@east.gentwo.org> <20170404151600.GN15132@dhcp22.suse.cz> <alpine.DEB.2.20.1704041412050.27424@east.gentwo.org> <20170404194220.GT15132@dhcp22.suse.cz>
 <alpine.DEB.2.20.1704041457030.28085@east.gentwo.org> <20170404201334.GV15132@dhcp22.suse.cz> <CAGXu5jL1t2ZZkwnGH9SkFyrKDeCugSu9UUzvHf3o_MgraDFL1Q@mail.gmail.com> <20170411134618.GN6729@dhcp22.suse.cz> <CAGXu5j+EVCU1WrjpMmr0PYW2N_RzF0tLUgFumDR+k4035uqthA@mail.gmail.com>
 <20170411141956.GP6729@dhcp22.suse.cz> <alpine.DEB.2.20.1704111110130.24725@east.gentwo.org> <CAGXu5jK1j3UWUakakFw=EfVwg+Rnovzst52+uZJYesLqLY+n5A@mail.gmail.com>
Content-Type: text/plain; charset=US-ASCII
X-CMAE-Envelope: MS4wfBwNLh2snsd1KofPzFDnwkokDL0tf4fzYyp/nwEim79NvSUQRPGmb0cAHXC7lSHnlddMZAHOYGa69ISM0HLGJ9y6Z7XDhfMT7L50UjoU/D0pYtu7OXhG
 Cd8sI9zSVXK1HfrfTy+0V4MPAevu/EyNj34+4gGfJ7g2hGsLEM1dRjQwf8h58kB8yZtx2ZPeM7bOHY8nuwVbr4XRDSMjgLTLqUUFqWUofJCNItpwcrasnEFb
 mYsGD3zgSbGdY+bo8eKxJbVldE24Da13uuC1g08LYjA0BIS7ssoRlOwaCimoYlT8ZR/BixjF0IsCVFg+ftHCQ7nxGxqIdOtz5VlAy7m2WlYpLshSFg6NAfIS
 EoiA15CF9NK7dp7VSI/WNxEXsO6wbMM0Og46FXedkjiH8TdwRew=
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 358
Lines: 9

On Tue, 11 Apr 2017, Kees Cook wrote:

> It seems that enabling the debug checks comes with a non-trivial
> performance impact. I'd like to see consistency checks by default so
> we can handle intentional heap corruption attacks better. This check
> isn't expensive...

Note also that these checks can be enabled and disabled at runtime for
each slab cache.