linux-kernel - Re: Absolute symbols in vmlinux

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Message-ID: <m1k56x2hq9.fsf@fess.ebiederm.org>
Date:	Tue, 10 Mar 2009 14:25:18 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	"H. Peter Anvin" <hpa@...nel.org>
Cc:	Sam Ravnborg <sam@...nborg.org>, Yinghai Lu <yinghai@...nel.org>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	Ingo Molnar <mingo@...e.hu>,
	the arch/x86 maintainers <x86@...nel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Absolute symbols in vmlinux_64.lds.S

"H. Peter Anvin" <hpa@...nel.org> writes:

> Eric W. Biederman wrote:
>> 
>> I have no complaint with that.  I believe the symbols are absolute
>> simply because they were originally coded that way and the relocatable
>> kernel work on x86_64 didn't need them to change.
>> 
>
> I have a vague memory of a bug in the x86-64 ld.

Oh.  I'm certain of it.  ld has all kinds of bugs off and on,
occasionally we are bound to run into a few of them.

ld bugs isn't the reason for using absolute linker symbols.  We use a
bunch of relative linker symbols as well.  All of the generic linker
scripts sections use them as well as a few of the x86_64 specific
sections.

For crazy things like 0 relative per cpu sections it might matter.
For the rest of the symbols absolute or relative simply
doesn't matter.

Is anyone interested in writing a patch testing it and changing things?

If not things should be good enough for now.

Eric
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