Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755830Ab3JCWrW (ORCPT ); Thu, 3 Oct 2013 18:47:22 -0400 Received: from terminus.zytor.com ([198.137.202.10]:50985 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755451Ab3JCWrW (ORCPT ); Thu, 3 Oct 2013 18:47:22 -0400 Message-ID: <524DF3DA.7060204@zytor.com> Date: Thu, 03 Oct 2013 15:46:50 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Kees Cook CC: LKML , "x86@kernel.org" , "kernel-hardening@lists.openwall.com" , Aaron Durbin , Eric Northup , Julien Tinnes , Will Drewry , Mathias Krause , Zhang Yanfei Subject: Re: [PATCH 3/7] x86, kaslr: find minimum safe relocation position References: <1380833605-26313-1-git-send-email-keescook@chromium.org> <1380833605-26313-4-git-send-email-keescook@chromium.org> <524DEE6B.2060105@zytor.com> In-Reply-To: X-Enigmail-Version: 1.5.2 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 Content-Length: 982 Lines: 26 On 10/03/2013 03:43 PM, Kees Cook wrote: >> This is highly problematic. The standard protocol is to hoist the >> initramfs as high as possible in memory, so this may really unacceptably >> restrict the available range. > > Doesn't this depend on the boot loader's behavior? It does, but the recommended (and *required* for compatibility with older kernels) behavior is to hoist as high as possible. >> It would be better to treat these the same as reserved regions in the >> e820 map as far as the address space picking algorithm is concerned. > > Could this be considered a future optimization, or do you feel this is > required even for this first patch series landing? Yes, I consider it required because of the above. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/