From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261496AbVFMX4G (ORCPT ); Mon, 13 Jun 2005 19:56:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261572AbVFMXzC (ORCPT ); Mon, 13 Jun 2005 19:55:02 -0400 Received: from one.firstfloor.org ([213.235.205.2]:4838 "EHLO one.firstfloor.org") by vger.kernel.org with ESMTP id S261496AbVFMXyC (ORCPT ); Mon, 13 Jun 2005 19:54:02 -0400 To: "David S. Miller" Cc: jesper.juhl@gmail.com, mru@inprovide.com, rommer@active.by, bernd@firmix.at, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: udp.c References: <20050613.145716.88477054.davem@davemloft.net> <20050613230422.GA7269@gondor.apana.org.au> <20050613.162052.41635836.davem@davemloft.net> From: Andi Kleen Date: Tue, 14 Jun 2005 01:53:56 +0200 In-Reply-To: <20050613.162052.41635836.davem@davemloft.net> (David S. Miller's message of "Mon, 13 Jun 2005 16:20:52 -0700 (PDT)") Message-ID: User-Agent: Gnus/5.110002 (No Gnus v0.2) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "David S. Miller" writes: > From: Herbert Xu > Date: Tue, 14 Jun 2005 09:04:22 +1000 > >> On Mon, Jun 13, 2005 at 02:57:16PM -0700, David S. Miller wrote: >> > From: Herbert Xu >> > Date: Tue, 14 Jun 2005 07:42:52 +1000 >> > >> > > It'll dump the stack anyway if we just make it a NULL pointer. >> > >> > Some platforms don't handle that very cleanly, for example >> > it may be necessary to have something mapped at page zero >> > for one reason or another. >> >> Are there any existing platforms that do that in kernel mode? > > X86 did, especially during bootup, for a long time. Still does, as does x86-64, but actually it could be changed now using change_page_attr (and then later undoing it). Is it worth it? -Andi