From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751576AbdIOWMx (ORCPT ); Fri, 15 Sep 2017 18:12:53 -0400 Received: from foss.arm.com ([217.140.101.70]:52924 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750873AbdIOWMv (ORCPT ); Fri, 15 Sep 2017 18:12:51 -0400 Date: Fri, 15 Sep 2017 22:51:48 +0100 From: Mark Rutland To: Pavel Tatashin Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, mhocko@kernel.org, ard.biesheuvel@linaro.org, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net, Steven.Sistare@oracle.com, daniel.m.jordan@oracle.com, bob.picco@oracle.com Subject: Re: [PATCH v8 10/11] arm64/kasan: explicitly zero kasan shadow memory Message-ID: <20170915215147.GA11849@remoulade> References: <20170914223517.8242-1-pasha.tatashin@oracle.com> <20170914223517.8242-11-pasha.tatashin@oracle.com> <20170915011035.GA6936@remoulade> <20170915203852.GA10749@remoulade> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 15, 2017 at 05:20:59PM -0400, Pavel Tatashin wrote: > Hi Mark, > > I had this option  back upto version 3, where zero flag was passed into > vmemmap_alloc_block(), but I was asked to remove it, because it required too > many changes in other places. Ok. Sorry for bringing back a point that had already been covered. > So, the current approach is cleaner, but the idea is that kasan should use > its own version of vmemmap_populate() for both x86 and ARM, but I think it is > outside of the scope of this work. I appreciate that this is unrelated to your ultimate goal, and that this is somewhat frustrating given the KASAN code is arguably abusing the vmemmap_populate() interface. However, I do think we need to migrate the KASAN code to a proper interface immediately, rather than making it worse in the interim. > If you think I should add these function in this project, than sure I can > send a new version with kasanmap_populate() functions. I would very much appreciate if you could send a version with a kasan_map_populate() interface. I'm more than happy to review/test that portion of the series, or to help if there's some problem which makes that difficult. Thanks, Mark.