linux-kernel - Re: [PATCH 3/12] i386: Force section size to be non-zero to prevent a symbol becoming absolute

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Message-ID: <m1fye4cgyf.fsf@ebiederm.dsl.xmission.com>
Date:	Wed, 04 Oct 2006 08:07:36 -0600
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Andi Kleen <ak@...e.de>
Cc:	vgoyal@...ibm.com,
	linux kernel mailing list <linux-kernel@...r.kernel.org>,
	Reloc Kernel List <fastboot@...ts.osdl.org>,
	ebiederm@...ssion.com, akpm@...l.org, horms@...ge.net.au,
	lace@...kratochvil.net, hpa@...or.com, magnus.damm@...il.com,
	lwang@...hat.com, dzickus@...hat.com, maneesh@...ibm.com
Subject: Re: [PATCH 3/12] i386: Force section size to be non-zero to prevent a symbol becoming absolute

Andi Kleen <ak@...e.de> writes:

>>    /* writeable */
>> @@ -64,6 +66,7 @@ SECTIONS
>>  	*(.data.nosave)
>>    	. = ALIGN(4096);
>>    	__nosave_end = .;
>> +	LONG(0)
>>    }
>>  
>>    . = ALIGN(4096);
>
> You're wasting one full page once for each of these LONG(0)s because
> of the following 4096 alignment.
>
> Isn't there some way to do this less wastefull?

So the problem is that we have sections that don't get relocated which
confuses things.  If the first that happened was that the size was
check to see if it was non-zero before we did anything I think we
wouldn't care if the linker messed up in this way.

But I may be wrong on that point.

Eric

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