From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Subject: Re: "N" symbols and System.map Date: Mon, 4 May 2009 21:33:36 +0200 Message-ID: <20090504193336.GA10453@uranus.ravnborg.org> References: <49FB7692.2000508@linux.intel.com> <20090501232149.GA28888@uranus.ravnborg.org> <49FB8D27.3000305@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from pfepa.post.tele.dk ([195.41.46.235]:47119 "EHLO pfepa.post.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbZEDTb0 (ORCPT ); Mon, 4 May 2009 15:31:26 -0400 Content-Disposition: inline In-Reply-To: <49FB8D27.3000305@linux.intel.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: "H. Peter Anvin" Cc: Andreas Schwab , LKML , linux-arch@vger.kernel.org On Fri, May 01, 2009 at 05:00:39PM -0700, H. Peter Anvin wrote: > Sam Ravnborg wrote: > >On Sat, May 02, 2009 at 01:10:18AM +0200, Andreas Schwab wrote: > >>"H. Peter Anvin" writes: > >> > >>>right now, we filter out symbols that nm tag N, meaning "debugging > >>>symbols", from System.map. However, at least on x86, the > >>>linker-generated > >>>symbol _end is tagged N, and in fact is the only N in the entire image. > >>> > >>>Are there other architectures which would suffer if N were included in > >>>System.map, or would that be a reasonable thing to do? > >>There should not be any N symbols unless you are using stabs debugging. > > > >We have in vmlinux: > > .end : AT(ADDR(.end) - LOAD_OFFSET) { > > _end = .; > > } > > > > > >And I see: > >c1834000 N _end > > > >This is the _only_ 'N' symbol in my vmlinux. > > > > Yup, this is what happens. I don't know why the linker does this, and > if there is a way around it. Andreas - can you explain what is happning here? I can include 'N' symbols in System.map - but I have not yet reached a level of understanding that make me go and do it. Sam From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pfepa.post.tele.dk ([195.41.46.235]:47119 "EHLO pfepa.post.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbZEDTb0 (ORCPT ); Mon, 4 May 2009 15:31:26 -0400 Date: Mon, 4 May 2009 21:33:36 +0200 From: Sam Ravnborg Subject: Re: "N" symbols and System.map Message-ID: <20090504193336.GA10453@uranus.ravnborg.org> References: <49FB7692.2000508@linux.intel.com> <20090501232149.GA28888@uranus.ravnborg.org> <49FB8D27.3000305@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49FB8D27.3000305@linux.intel.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: "H. Peter Anvin" , Andreas Schwab Cc: LKML , linux-arch@vger.kernel.org Message-ID: <20090504193336.TRtJdTrsQw7xS_xxDMlwk-zFqLREHAOicNITXqj_fFQ@z> On Fri, May 01, 2009 at 05:00:39PM -0700, H. Peter Anvin wrote: > Sam Ravnborg wrote: > >On Sat, May 02, 2009 at 01:10:18AM +0200, Andreas Schwab wrote: > >>"H. Peter Anvin" writes: > >> > >>>right now, we filter out symbols that nm tag N, meaning "debugging > >>>symbols", from System.map. However, at least on x86, the > >>>linker-generated > >>>symbol _end is tagged N, and in fact is the only N in the entire image. > >>> > >>>Are there other architectures which would suffer if N were included in > >>>System.map, or would that be a reasonable thing to do? > >>There should not be any N symbols unless you are using stabs debugging. > > > >We have in vmlinux: > > .end : AT(ADDR(.end) - LOAD_OFFSET) { > > _end = .; > > } > > > > > >And I see: > >c1834000 N _end > > > >This is the _only_ 'N' symbol in my vmlinux. > > > > Yup, this is what happens. I don't know why the linker does this, and > if there is a way around it. Andreas - can you explain what is happning here? I can include 'N' symbols in System.map - but I have not yet reached a level of understanding that make me go and do it. Sam