From mboxrd@z Thu Jan  1 00:00:00 1970
From: Florian Westphal <fw@strlen.de>
Subject: Re: [PATCHv3 ipsec-next] xfrm: Do not parse 32bits compiled xfrm
 netlink msg on 64bits host
Date: Tue, 27 Jan 2015 12:04:13 +0100
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To: David Laight <David.Laight@ACULAB.COM>
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David Laight <David.Laight@ACULAB.COM> wrote:
> From: Fan Du
> > structure like xfrm_usersa_info or xfrm_userpolicy_info
> > has different sizeof when compiled as 32bits and 64bits
> > due to not appending pack attribute in their definition.
> 
> Don't 'pack' the structure, just ensure that all the fields
> are fixed sized and on their natural boundary.

How do you propose to do this without breaking ABI?

> Possibly add a compile-time check that the structure is
> of the expected size.

Uh, what?