Re: [PATCH] Fix ARM BUILD_BUG_ON() errors with batman-adv

[David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>]

From: Simon Wunderlich <sw-2YrNx6rUIHYiY0qSoAWiAoQuADTiUCJX@public.gmane.org>
Date: Mon, 2 Dec 2013 18:58:47 +0100

> Therefore I'd suggest to pick Russels patch, I can send a fix for 
> batadv_interface_rx() later, too.

You are ignoring the downside of Russel's patch which is that it
negatively impacts many architectures, in that now the compiler
can make no assumptions as to the alignment of a structure marked
with "packed" and therefore, for example, a 32-bit load will
be done with 4 byte loads, shifts, and masking.

Please just 4 byte align your structures.  I can't believe that
you cannot make this work cleanly.

Why can't you just include that fourth final byte in the batadv_header
structure and have the sub-header types just interpret it differently
or ignore it?

This is getting frustrating, I seemed clear to me that the non-packed
suggestions given to you so far were both reasonable and easy to
implement.