linux-kernel - Re: "N" symbols and System.map

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 01 May 2009 17:00:39 -0700
From:	"H. Peter Anvin" <hpa@...ux.intel.com>
To:	Sam Ravnborg <sam@...nborg.org>
CC:	Andreas Schwab <schwab@...ux-m68k.org>,
	LKML <linux-kernel@...r.kernel.org>, linux-arch@...r.kernel.org
Subject: Re: "N" symbols and System.map

Sam Ravnborg wrote:
> On Sat, May 02, 2009 at 01:10:18AM +0200, Andreas Schwab wrote:
>> "H. Peter Anvin" <hpa@...ux.intel.com> 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.

	-hpa

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/