From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757991AbXKTD3U (ORCPT ); Mon, 19 Nov 2007 22:29:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755496AbXKTD3J (ORCPT ); Mon, 19 Nov 2007 22:29:09 -0500 Received: from tomts36.bellnexxia.net ([209.226.175.93]:36762 "EHLO tomts36-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755504AbXKTD3I (ORCPT ); Mon, 19 Nov 2007 22:29:08 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ah4FAErjQUdMROHU/2dsb2JhbACBW48G Date: Mon, 19 Nov 2007 22:29:04 -0500 From: Mathieu Desnoyers To: Christoph Lameter Cc: ak@suse.de, akpm@linux-foundation.org, travis@sgi.com, linux-kernel@vger.kernel.org Subject: Re: [rfc 45/45] Modules: Hack to handle symbols that have a zero value Message-ID: <20071120032904.GB21743@Krystal> References: <20071120011132.143632442@sgi.com> <20071120011342.426906810@sgi.com> <20071120022007.GA16899@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 22:19:14 up 16 days, 8:24, 3 users, load average: 0.57, 0.69, 0.99 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Christoph Lameter (clameter@sgi.com) wrote: > On Mon, 19 Nov 2007, Mathieu Desnoyers wrote: > > > * clameter@sgi.com (clameter@sgi.com) wrote: > > > The module subsystem cannot handle symbols that are zero. It prints out > > > a message that these symbols are unresolved. Define a constant > > > > > > UNRESOLVED > > > > > > that is used to hold the value used for unresolved symbols. Set it to 1 > > > (its hopefully unlikely that a symbol will have the value 1). This is necessary > > > so that the pda variable which is placed at offset 0 of the per cpu > > > segment is handled correctly. > > > > > > > Wouldn't it be better to simply return a standard ERR_PTR(-ENO....) ? > > Good idea. But can you guarantee that this wont clash with an address? > linux/err.h assumes that the last page of the address space is never ever used. Is that a correct assumption ? -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68