From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753709AbaJASOk (ORCPT ); Wed, 1 Oct 2014 14:14:40 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42632 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753540AbaJASOQ (ORCPT ); Wed, 1 Oct 2014 14:14:16 -0400 Message-ID: <542C4463.1020208@zytor.com> Date: Wed, 01 Oct 2014 11:13:55 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Kees Cook CC: LKML , Baoquan He , Vivek Goyal , Thomas Gleixner , Ingo Molnar , "x86@kernel.org" , "Rafael J. Wysocki" , Wei Yongjun , Pavel Machek Subject: Re: [PATCH] x86, kaslr: avoid setup_data when picking location References: <20140911161931.GA12001@www.outflux.net> <542C4177.6060409@zytor.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/01/2014 11:08 AM, Kees Cook wrote: >> >> The use of (u64) in the assignment to avoid.start gives a nuisance >> warning on 32 bits. > > Ah, good catch! This should be (unsigned long), I think. Shall I send > a follow-up patch, or do you want to fix this directly? > Please do. In theory it is possible for a bootloader to put an object above 4G even for a 32-bit kernel, but that is likely to break any kind of other things, so I'm not worried about it. You don't need to worry about avoiding such a zone, the problem is mostly that you can't follow the list any further without adding PAE-handling code. -hpa