On Mon, 2014-01-06 at 10:09 +0100, Julia Lawall wrote:

quoted

BUILD_BUG_ON(sizeof(struct foo) - offsetof(struct foo, addr) < 8);

with the user(s?) and that should catch the scenario I was worrying
about?

OK, thanks.  That is what I had in mind.  But I was hoping to be able to
put it with the structure.  

Right - you might be able to do that with BUILD_BUG_ON_ZERO() as you
pointed out, I haven't looked at these macros in a while.

Perhaps there is a way to make a macro that
expands to a dummy function that contains the BUILD_BUG_ON?  But I guess
that would waste space?

I think that 8 should be 16?

No, that should be ETH_ALEN+2 really, I guess - it's not taking into
account the size of the address member itself at all.

johannes