On Wed, May 04, 2016 at 02:49:00PM +0200, Nicolas Dichtel wrote:

Le 04/05/2016 11:05, Lars Ellenberg a écrit :
[snip]

quoted

We don't have an "alignment problem" there, btw.
Last time I checked, we did work fine without this alignment magic,
we already take care of that, yes, even on affected architectures.

The code adds several consecutive u64 attributes. The nl attribute header is 4
bytes, thus the full attribute length is 12 bytes. If the first u64 is aligned
on 8 (nla_data()), the next one is not aligned on 8: it starts 12 bytes (8 (u64)
+ 4 (nl attr hdr)) after the previous u64.

Yes.  Which in our case is not a problem.
But I don't object to the padding per se,
if that is how things "should be".

I try to understand why you so much object to using 0 as pad.

    Lars