From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759676AbYBEVFk (ORCPT ); Tue, 5 Feb 2008 16:05:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754773AbYBEVFb (ORCPT ); Tue, 5 Feb 2008 16:05:31 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:53447 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756247AbYBEVFa (ORCPT ); Tue, 5 Feb 2008 16:05:30 -0500 Date: Tue, 5 Feb 2008 22:05:08 +0100 From: Ingo Molnar To: Sam Ravnborg Cc: Linus Torvalds , Thomas Gleixner , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [git pull] x86 updates Message-ID: <20080205210508.GA14708@elte.hu> References: <20080204161219.GA8092@elte.hu> <20080205192236.GA26426@uranus.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080205192236.GA26426@uranus.ravnborg.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Sam Ravnborg wrote: > On Tue, Feb 05, 2008 at 10:47:07AM -0800, Linus Torvalds wrote: > > > > > > Ingo, Thomas, > > should we not do this? > > > > Otherwise, it seems we generate a section that isn't allocated? > > > > I think toolchain should add the right flags automatically for > > sections that start with ".[ro]data" and ".text", but not for the > > kernel-specific ".init.*" sections. > > With a bit of help from the bin-utils people (Alan Modra) I recently > discovered that the linker generate sections with different names when > the flags differs, so fogetting "aw" casues the linekr to generate a > section named .init.data.1 (or some other number). But I nevet got to > investigate if ld does something magically with these autogenerated > section names. But I added a check in modpost and it should warn about > the code below. > > I would prefer the use of > __CPUINITDATA > __FINITDATA > > as defined in linux/init.h but otherwise - yes it should be fixed. > With the use of __CPUINITDATA we can kill the ifdef too. ok, i've queued up your patch. btw., __CPUINITDATA/__FINITDATA is nice, except that the small patch below is needed to make the fun complete ;-) or, we could use __FINIT all the time. btw., what's the practical consequence of getting these section flags wrong - for example writable data can end up in executable section accidentally and be marked readonly by RODATA? Or can anything more serious happen? (they cannot get into any of the discarded sections, we filter for them explicitly in the linker scripts) Ingo --- include/linux/init.h | 1 + 1 file changed, 1 insertion(+) Index: linux-x86.q/include/linux/init.h =================================================================== --- linux-x86.q.orig/include/linux/init.h +++ linux-x86.q/include/linux/init.h @@ -110,6 +110,7 @@ #define __FINIT .previous #define __INITDATA .section ".init.data","aw" +#define __FINITDATA .previous #define __DEVINIT .section ".devinit.text", "ax" #define __DEVINITDATA .section ".devinit.data", "aw"