Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261230AbVCQQ4A (ORCPT ); Thu, 17 Mar 2005 11:56:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261456AbVCQQ4A (ORCPT ); Thu, 17 Mar 2005 11:56:00 -0500 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:43025 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S261230AbVCQQzx (ORCPT ); Thu, 17 Mar 2005 11:55:53 -0500 Date: Thu, 17 Mar 2005 16:55:34 +0000 From: Russell King To: Albert Cahalan Cc: Christoph Lameter , Albert Cahalan , Matt Mackall , john stultz , lkml , Tim Schmielau , George Anzinger , Ulrich Windl , Dominik Brodowski , David Mosberger , Andi Kleen , paulus@samba.org, schwidefsky@de.ibm.com, keith maanthey , Patricia Gaughen , Chris McDermott , Max Asbock , mahuja@us.ibm.com, Nishanth Aravamudan , Darren Hart , "Darrick J. Wong" , Anton Blanchard , donf@us.ibm.com Subject: Re: [RFC][PATCH] new timeofday core subsystem (v. A3) Message-ID: <20050317165534.B12344@flint.arm.linux.org.uk> Mail-Followup-To: Albert Cahalan , Christoph Lameter , Albert Cahalan , Matt Mackall , john stultz , lkml , Tim Schmielau , George Anzinger , Ulrich Windl , Dominik Brodowski , David Mosberger , Andi Kleen , paulus@samba.org, schwidefsky@de.ibm.com, keith maanthey , Patricia Gaughen , Chris McDermott , Max Asbock , mahuja@us.ibm.com, Nishanth Aravamudan , Darren Hart , "Darrick J. Wong" , Anton Blanchard , donf@us.ibm.com References: <20050313004902.GD3163@waste.org> <1110825765.30498.370.camel@cog.beaverton.ibm.com> <20050314192918.GC32638@waste.org> <1110829401.30498.383.camel@cog.beaverton.ibm.com> <20050314195110.GD32638@waste.org> <1110830647.30498.388.camel@cog.beaverton.ibm.com> <20050314202702.GF32638@waste.org> <1110852973.1967.180.camel@cube> <1110900235.7893.207.camel@cube> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <1110900235.7893.207.camel@cube>; from albert@users.sf.net on Tue, Mar 15, 2005 at 10:23:54AM -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1319 Lines: 33 On Tue, Mar 15, 2005 at 10:23:54AM -0500, Albert Cahalan wrote: > On Mon, 2005-03-14 at 19:22 -0800, Christoph Lameter wrote: > > On Mon, 14 Mar 2005, Albert Cahalan wrote: > > > > > When the vsyscall page is created, copy the one needed function > > > into it. The kernel is already self-modifying in many places; this > > > is nothing new. > > > > AFAIK this will only works on ia32 and x86_64 and not definitely not > > on ia64. Who knows about the other platforms .... > > I'll bet it does work fine on IA-64. If it didn't, you would > be unable to load the kernel or load an executable. > > I know it works for PowerPC. You'll need an isync instruction > of course. You may also want a sync instruction and some code > to invalidate the cache. > > Setting up the page content should be a 1-time operation done > at boot. Check your processor manuals as needed. Won't work on ARM. We have XIP kernels, which prevents the use of self-modifying code. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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/