From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id 1B83B6B0253 for ; Tue, 25 Aug 2015 05:15:56 -0400 (EDT) Received: by pacdd16 with SMTP id dd16so119020182pac.2 for ; Tue, 25 Aug 2015 02:15:55 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id il3si31992512pbc.160.2015.08.25.02.15.55 for ; Tue, 25 Aug 2015 02:15:55 -0700 (PDT) Date: Tue, 25 Aug 2015 10:15:47 +0100 From: Will Deacon Subject: Re: [PATCH v2 5/5] arm64: add KASan support Message-ID: <20150825091547.GA21300@arm.com> References: <55AE56DB.4040607@samsung.com> <20150824131557.GB7557@n2100.arm.linux.org.uk> <20150824174736.GD7557@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150824174736.GD7557@n2100.arm.linux.org.uk> Sender: owner-linux-mm@kvack.org List-ID: To: Russell King - ARM Linux Cc: Andrey Ryabinin , Linus Walleij , Arnd Bergmann , "linux-mm@kvack.org" , Catalin Marinas , "linux-kernel@vger.kernel.org" , David Keitel , Alexander Potapenko , "linux-arm-kernel@lists.infradead.org" , Andrew Morton , Dmitry Vyukov On Mon, Aug 24, 2015 at 06:47:36PM +0100, Russell King - ARM Linux wrote: > On Mon, Aug 24, 2015 at 05:15:22PM +0300, Andrey Ryabinin wrote: > > Yes, ~130Mb (3G/1G split) should work. 512Mb shadow is optional. > > The only advantage of 512Mb shadow is better handling of user memory > > accesses bugs > > (access to user memory without copy_from_user/copy_to_user/strlen_user etc API). > > No need for that to be handed by KASan. I have patches in linux-next, > now acked by Will, which prevent the kernel accessing userspace with > zero memory footprint. No need for remapping, we have a way to quickly > turn off access to userspace mapped pages on non-LPAE 32-bit CPUs. > (LPAE is not supported yet - Catalin will be working on that using the > hooks I'm providing once he returns.) Hey, I only acked the "Efficiency cleanups" series so far! The PAN emulation is still on my list. Will -- 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