Message-ID: <1388999147.5891.2.camel@jlt4.sipsolutions.net> (sfid-20140106_100636_667862_5AF477A8)
Subject: Re: [PATCH 4/11]  use ether_addr_equal_64bits
From: Johannes Berg <johannes@sipsolutions.net>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ben Greear <greearb@candelatech.com>,
	Joe Perches <joe@perches.com>,
	Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
	kernel-janitors@vger.kernel.org,
	Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
	Intel Linux Wireless <ilw@linux.intel.com>,
	"John W. Linville" <linville@tuxdriver.com>,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Date: Mon, 06 Jan 2014 10:05:47 +0100
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On Tue, 2013-12-31 at 17:40 +0100, Julia Lawall wrote:

> > If nothing else, then some run-time code that calculates the offset off
> > and asserts if it is broken in module initialization or similar might
> > be good enough.
> 
> Could be OK.  Something right in or after the structure declaration would
> be nicest.

I don't think you can put a BUILD_BUG_ON() into the structure
declaration (it's code, not declarations), but I think you could just
put

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?

johannes