linux-kernel - Re: /proc/kallsyms broken in 2.6.26-rc1-git6

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Message-ID: <20080519182115.GA24285@uranus.ravnborg.org>
Date:	Mon, 19 May 2008 20:21:15 +0200
From:	Sam Ravnborg <sam@...nborg.org>
To:	Cyrill Gorcunov <gorcunov@...il.com>
Cc:	Andi Kleen <andi@...stfloor.org>,
	Paulo Marques <pmarques@...popie.com>,
	Alexey Dobriyan <adobriyan@...il.com>,
	linux-kernel@...r.kernel.org
Subject: Re: /proc/kallsyms broken in 2.6.26-rc1-git6

On Mon, May 19, 2008 at 10:15:43PM +0400, Cyrill Gorcunov wrote:
> [Sam Ravnborg - Mon, May 19, 2008 at 08:11:18PM +0200]
> | On Tue, May 13, 2008 at 11:54:37AM +0200, Andi Kleen wrote:
> | > > I expect it to be a toolchain issue. Andi is often running with gcc versions
> | > > that are very new (fresh from svn maybe). I dunno about binutils.
> | > 
> | > No actually that's a pretty old version from SUSE 10.2
> | > 
> | > gcc-4.1.3-29
> | > binutils-2.17.50.0.5-21
> | > 
> | > This means i've been recently trying to get the x86-64 kernel to work
> | > with the new gold linker from binutils mainline, but it's far from
> | > booting yet and was not used here.
> | > 
> | > > To reproduce I would expect that a very recent gcc/binutils is needed.
> | > > Andi?
> | > 
> | > Just a SUSE 10.2 toolchain. You can probably rpm2cpio it from any 
> | > SUSE mirror.
> | 
> | I have just commit the following that should fix it.
> | 
> | 	Sam
> | 
> | commit aab34ac8582303ef57b792710fc5dd5991477475
> | Author: Sam Ravnborg <sam@...nborg.org>
> | Date:   Mon May 19 20:07:58 2008 +0200
> | 
> |     kbuild: filter away debug symbols from kernel symbols
> |     
> |     Andi Kleen <andi@...stfloor.org>
> |     reported that he saw a lot of symbols like this:
> |     
> |     0000000000000b24 N DW.aio.h.903a6d92.2
> |     0000000000000bce N DW.task_io_accounting.h.8d8de327.0
> |     0000000000000bec N DW.hrtimer.h.c23659c6.0
> |     
> |     in his System.map / kallsyms output.
> |     
> |     Simple solution is to skip all debugging
> |     symbols (they are marked 'N').
> |     
> |     Signed-off-by: Sam Ravnborg <sam@...nborg.org>
> |     Cc: Paulo Marques <pmarques@...popie.com>
> | 
> | diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
> | index 5d20a2e..ad2434b 100644
> | --- a/scripts/kallsyms.c
> | +++ b/scripts/kallsyms.c
> | @@ -108,6 +108,9 @@ static int read_symbol(FILE *in, struct sym_entry *s)
> |  	/* exclude also MIPS ELF local symbols ($L123 instead of .L123) */
> |  	else if (str[0] == '$')
> |  		return -1;
> | +	/* exclude debugging symbols */
> | +	else if (stype == 'N')
> | +		return -1;
> |  
> |  	/* include the type field in the symbol name, so that it gets
> |  	 * compressed together */
> | diff --git a/scripts/mksysmap b/scripts/mksysmap
> | index 4390fab..6e133a0 100644
> | --- a/scripts/mksysmap
> | +++ b/scripts/mksysmap
> | @@ -32,6 +32,7 @@
> |  # For System.map filter away:
> |  #   a - local absolute symbols
> |  #   U - undefined global symbols
> | +#   N - debugging symbols
> |  #   w - local weak symbols
> |  
> |  # readprofile starts reading symbols when _stext is found, and
> | @@ -40,5 +41,5 @@
> |  # so we just ignore them to let readprofile continue to work.
> |  # (At least sparc64 has __crc_ in the middle).
> |  
> | -$NM -n $1 | grep -v '\( [aUw] \)\|\(__crc_\)\|\( \$[adt]\)' > $2
> | +$NM -n $1 | grep -v '\( [aNUw] \)\|\(__crc_\)\|\( \$[adt]\)' > $2
> |  
> | 
> 
> Hi Sam,
> 
> should not there be
> 
> 	toupper(stype) == 'N'
> 
> (just a guess)

I conisered this. But decided that we could do so if we needed it later.
In the nm output I got they were all 'N'.

	Sam
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