From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by lists.ozlabs.org (Postfix) with ESMTP id 3xv6h90h9ZzDrZl for ; Sat, 16 Sep 2017 06:39:19 +1000 (AEST) Date: Fri, 15 Sep 2017 21:38:53 +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: <20170915203852.GA10749@remoulade> References: <20170914223517.8242-1-pasha.tatashin@oracle.com> <20170914223517.8242-11-pasha.tatashin@oracle.com> <20170915011035.GA6936@remoulade> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Sep 14, 2017 at 09:30:28PM -0400, Pavel Tatashin wrote: > Hi Mark, > > Thank you for looking at this. We can't do this because page table is not > set until cpu_replace_ttbr1() is called. So, we can't do memset() on this > memory until then. I see. Sorry, I had missed that we were on the temporary tables at this point in time. I'm still not keen on duplicating the iteration. Can we split the vmemmap code so that we have a variant that takes a GFP? That way we could explicitly pass __GFP_ZERO for those cases where we want a zeroed page, and are happy to pay the cost of initialization. Thanks Mark.