From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: net: alignment problem in icmp code
Date: Sun, 21 Oct 2007 22:15:24 -0700 (PDT)
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From: Pierre Ossman <drzeus@drzeus.cx>
Date: Mon, 22 Oct 2007 06:54:43 +0200

> On Sun, 21 Oct 2007 16:02:15 -0700 (PDT)
> David Miller <davem@davemloft.net> wrote:
> 
> > You will get a 64-bit load and a 64-bit store emitted by
> > the compiler.  Here is what we get on sparc64:
> 
> I assume those ops cause a bus error on unaligned addresses?

Sure.  But the language defines that the types in question
must be 64-bit aligned, so it is legal for the compiler to
emit this code.

It's not a GCC bug.

If you want to let the compiler know that a pointer to a type might
not be aligned, you have to tell it so.