From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755498Ab1AKJGl (ORCPT ); Tue, 11 Jan 2011 04:06:41 -0500 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:42675 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753015Ab1AKJG3 (ORCPT ); Tue, 11 Jan 2011 04:06:29 -0500 Date: Tue, 11 Jan 2011 09:06:15 +0000 From: Russell King - ARM Linux To: Stephen Boyd Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm: mm: Poison freed init memory Message-ID: <20110111090615.GH12552@n2100.arm.linux.org.uk> References: <1294256845-29517-1-git-send-email-sboyd@codeaurora.org> <20110105202645.GL8638@n2100.arm.linux.org.uk> <4D255263.7040106@codeaurora.org> <20110106090741.GQ8638@n2100.arm.linux.org.uk> <4D2BE3E1.5060706@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D2BE3E1.5060706@codeaurora.org> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 10, 2011 at 09:00:17PM -0800, Stephen Boyd wrote: > Ok it seems that 0xcc was chosen by Pavel since it's a breakpoint > instruction (sorry for not noticing that earlier [1]). It may be on x86, but on ARM: 0: cccccccc stclgt 12, cr12, [ip], {204} That's a co-processor #12 instruction which will only be executed of the processor condition codes satisfy 'gt'. > There was some discussion about handling initdata with Pavel's patch > but it seems that nothing came of it? I'm not sure who this Pavel is who you keep referring to - the message you link to is a discussion between William Irvin and hpa. > How about we use 0xe7fddef0? This seems to satisfy at least your first > point for both ARM and Thumb mode (Thumb will branch to the 0xdef0 > instruction). Yup.