Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030694AbWAKAC7 (ORCPT ); Tue, 10 Jan 2006 19:02:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030698AbWAKAC7 (ORCPT ); Tue, 10 Jan 2006 19:02:59 -0500 Received: from mail.ocs.com.au ([202.147.117.210]:24006 "EHLO mail.ocs.com.au") by vger.kernel.org with ESMTP id S1030694AbWAKAC5 (ORCPT ); Tue, 10 Jan 2006 19:02:57 -0500 X-Mailer: exmh version 2.7.0 06/18/2004 with nmh-1.1 From: Keith Owens To: Keshavamurthy Anil S cc: Paulo Marques , Linux Kernel , akpm@osdl.org, tony.luck@intel.com, Systemtap , Jim Keniston Subject: Re: [patch 1/2] [BUG]kallsyms_lookup_name should return the text addres In-reply-to: Your message of "Tue, 10 Jan 2006 15:29:05 -0800." <20060110152904.A16312@unix-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 11 Jan 2006 11:02:55 +1100 Message-ID: <19866.1136937775@ocs3.ocs.com.au> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1569 Lines: 31 Keshavamurthy Anil S (on Tue, 10 Jan 2006 15:29:05 -0800) wrote: >On Wed, Jan 11, 2006 at 10:11:26AM +1100, Keith Owens wrote: >> Keshavamurthy Anil S (on Tue, 10 Jan 2006 13:07:37 -0800) wrote: >> >On Tue, Jan 10, 2006 at 08:45:02PM +0000, Paulo Marques wrote: >> >But my [patch 2/2] speeds up the lookup and that can go in, I think. >> >Please ack that patch if you think so. >> >> Your second patch changes the behaviour of kallsyms lookup w.r.t >> duplicate symbols. >With this send patch, kallsyms lookup first finds >the real text address which is what we want. If you consider >this as the change in behaviour, what is the negetive effect of this >I am unable to get it. Local symbols can be (and are) duplicated in the kernel code, and these duplicate symbols can appear in modules. Changing the list order of loaded modules also changes which version of a duplicated symbol is returned by the kallsyms code. Not a big deal, but annoying enough to say "don't change the module list order". Changing the thread slightly, kallsyms_lookup_name() has never coped with duplicate local symbols and it cannot do so without changing its API, and all its callers. For debugging purposes, it would be nicer if the kernel did not have any duplicate symbols. Perhaps some kernel janitor would like to take that task on. - 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/