From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.genesippc.com (mithrandir.softwarenexus.net [66.98.186.96]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 93F2567BC4 for ; Mon, 14 Aug 2006 21:51:01 +1000 (EST) From: "Matt Sealey" To: "'Paul Mackerras'" , "'Albert Cahalan'" Subject: RE: PowerPC paxtest results w/ gcc-4.1 Date: Mon, 14 Aug 2006 13:50:53 +0200 Message-ID: <000301c6bf97$e9151e00$99dfdfdf@bakuhatsu.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <17630.27174.711916.643790@cargo.ozlabs.ibm.com> Cc: linuxppc-dev@ozlabs.org, debian-powerpc@lists.debian.org Reply-To: matt@genesi-usa.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > Of course, that won't make all that much difference on your > Cube, because the G4 CPU doesn't have hardware support for > non-executable pages (any readable page is executable) I don't think this is true? Book I compatible PowerPC's have had a "no-executable" bit in the page protection flags since the dark ages.. see page 7-38 and 7-39 of the 'Programming Environments Manual for 32-Bit Microprocessors'.. this document predates even the G3. As far as the documentation goes, you can make the page readable and writable to the LSU, but the N bit causes the instruction fetch to cause a machine check. That's pretty "not-executable" to me at least :) -- Matt Sealey Manager, Genesi, Developer Relations