Subject: Re: [PATCH] Fix initramfs size calculation
From: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reply-To: holzheu@linux.vnet.ibm.com
To: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: sam@ravnborg.org, tabbott@ksplice.com, vda.linux@googlemail.com,
        mmarek@suse.cz, akpm@linux-foundation.org,
        linux-kernel@vger.kernel.org, heiko.carstens@de.ibm.com,
        brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com
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	 <4C7578A6.2080303@linux.intel.com>
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Organization: IBM
Date: Thu, 26 Aug 2010 10:46:36 +0200
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Hello Peter,

On Wed, 2010-08-25 at 13:10 -0700, H. Peter Anvin wrote:
> On 08/25/2010 08:57 AM, Michael Holzheu wrote:
> > Certain s390 instructions, especially instructions for loading addresses
> > (larl) or branch addresses must be on even addresses. 
> 
> I have to admit to finding this fairly disturbing, as this is likely to
> come up again and again.  Is there any way to tell gcc (e.g. with an
> alignment attribute) that a particular symbol is not safe to be loaded
> with larl?

I think, it is not possible the change that in the compiler. The fact
that the compiler on s390 assumes that symbols are 2 byte aligned was a
design decission and is part of the ABI.

Michael 

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