From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266256AbUGBBlX (ORCPT ); Thu, 1 Jul 2004 21:41:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266372AbUGBBlX (ORCPT ); Thu, 1 Jul 2004 21:41:23 -0400 Received: from are.twiddle.net ([64.81.246.98]:15501 "EHLO are.twiddle.net") by vger.kernel.org with ESMTP id S266256AbUGBBkL (ORCPT ); Thu, 1 Jul 2004 21:40:11 -0400 Date: Thu, 1 Jul 2004 18:36:36 -0700 From: Richard Henderson To: Jamie Lokier Cc: linux-kernel@vger.kernel.org, David Mosberger-Tang , linux-ia64@linuxia64.org, Matthew Wilcox , Grant Grundler , parisc-linux@parisc-linux.org, Richard Curnow , Paul Mundt , linuxsh-shmedia-dev@lists.sourceforge.net, Ivan Kokshaysky Subject: Re: Comparing PROT_EXEC-only pages on different CPUs Message-ID: <20040702013636.GA29154@twiddle.net> Mail-Followup-To: Jamie Lokier , linux-kernel@vger.kernel.org, David Mosberger-Tang , linux-ia64@linuxia64.org, Matthew Wilcox , Grant Grundler , parisc-linux@parisc-linux.org, Richard Curnow , Paul Mundt , linuxsh-shmedia-dev@lists.sourceforge.net, Ivan Kokshaysky References: <20040701224016.GB7928@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040701224016.GB7928@mail.shareable.org> User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 01, 2004 at 11:40:16PM +0100, Jamie Lokier wrote: > Richard raises an interesting point: exec-only pages are useless if > the code needs to read jump tables and constant pools. It seems very > likely Alpha and IA64 have these. Only if the processor is crippled enough that mixing jump tables and constant pools in the same pages as code is considered reasonable. Anyway, that's a strawman -- it's the toolchain's job to get the bits on the pt_load segments correct. If the pt_load segment or the mmap prot argument says execute-only, then you should honor it. r~