From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752885AbXLDTPl (ORCPT ); Tue, 4 Dec 2007 14:15:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751444AbXLDTPd (ORCPT ); Tue, 4 Dec 2007 14:15:33 -0500 Received: from tomts36-srv.bellnexxia.net ([209.226.175.93]:48474 "EHLO tomts36-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbXLDTPc (ORCPT ); Tue, 4 Dec 2007 14:15:32 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ah4FAFA2VUdMROHU/2dsb2JhbACBWg Date: Tue, 4 Dec 2007 14:15:28 -0500 From: Mathieu Desnoyers To: Andrew Morton Cc: linux-kernel@vger.kernel.org, roland@redhat.com, dsmith@redhat.com, Sam Ravnborg Subject: Re: [patch 2/2] Linux Kernel Markers - Create modpost file Message-ID: <20071204191528.GA31752@Krystal> References: <20071204181845.895090222@polymtl.ca> <20071204182403.319351701@polymtl.ca> <20071204111026.9f7d8ed5.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20071204111026.9f7d8ed5.akpm@linux-foundation.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 14:12:52 up 31 days, 18 min, 6 users, load average: 0.14, 0.73, 0.90 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Morton (akpm@linux-foundation.org) wrote: > On Tue, 04 Dec 2007 13:18:47 -0500 > Mathieu Desnoyers wrote: > > > This adds some new magic in the MODPOST phase for CONFIG_MARKERS. > > Analogous to the Module.symvers file, the build will now write a > > Module.markers file when CONFIG_MARKERS=y is set. This file lists > > the name, defining module, and format string of each marker, > > separated by \t characters. This simple text file can be used by > > offline build procedures for instrumentation code, analogous to > > how System.map and Module.symvers can be useful to have for > > kernels other than the one you are running right now. > > > > The strings are made easy to extract by having the __trace_mark macro > > define the name and format together in a single array called __mstrtab_* > > in the __markers_strings section. This is straightforward and reliable > > as long as the marker structs are always defined by this macro. It is > > an unreasonable amount of hairy work to extract the string pointers from > > the __markers section structs, which entails handling a relocation type > > for every machine under the sun. > > > > Mathieu : > > - Ran through checkpatch.pl > > > > ... > > > > --- linux-2.6-lttng.orig/scripts/mod/modpost.c 2007-11-21 20:54:17.000000000 -0500 > > +++ linux-2.6-lttng/scripts/mod/modpost.c 2007-11-21 21:19:19.000000000 -0500 > > @@ -11,6 +11,8 @@ > > * Usage: modpost vmlinux module1.o module2.o ... > > */ > > > > +#define _GNU_SOURCE > > Why was the mystery addition of _GNU_SOURCE made? > I think Roland needed it for asprintf(). > > +#include > > #include > > #include "modpost.h" > > #include "../../include/linux/license.h" > > @@ -424,6 +426,8 @@ static int parse_elf(struct elf_info *in > > These two patches are unfortunately large, intrusive and tricky to be > turning up in -rc4. > Yup. What I would really like is to, at least, get the API stabilised for 2.6.24. It that means extracting the API changes from the first patch, I could do it. Then we would have plenty of time to discuss the multiple probes support. API changes : - Remove marker arm/disarm - Probe callback now takes a va_list * instead of a ... argument. Does it sound like a good idea ? -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68