From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Bergner <bergner@vnet.ibm.com>
Date: Wed, 01 Feb 2012 19:04:01 +0000
Subject: Re: Memory corruption due to word sharing
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To: David Miller <davem@davemloft.net>
Cc: matz@suse.de, jkosina@suse.cz, torvalds@linux-foundation.org, walters@verbum.org, jack@suse.cz, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, dsterba@suse.cz, ptesarik@suse.cz, rguenther@suse.de, gcc@gcc.gnu.org

On Wed, 2012-02-01 at 13:09 -0500, David Miller wrote:
> From: Michael Matz <matz@suse.de>
> Date: Wed, 1 Feb 2012 18:41:05 +0100 (CET)
> 
> > One problem is that it's not a new problem, GCC emitted similar code since 
> > about forever, and still they turned up only now (well, probably because 
> > ia64 is dead, but sparc64 should have similar problems). 
> 
> Indeed, on sparc64 it does do the silly 64-bit access too:
> 
> wrong:
>         ldx     [%o0+8], %g2
>         sethi   %hi(2147483648), %g1
>         or      %g2, %g1, %g1
>         jmp     %o7+8
>          stx    %g1, [%o0+8]

Ditto for powerpc64-linux:

        ld 9,8(3)
        li 10,1
        rldimi 9,10,31,32
        std 9,8(3)
        blr


Peter