Re: [PATCH 00/18] xfrm: Add compat layer
Dmitry Safonov <dima(a)arista.com> wrote:
On Sat, 2018-07-28 at 14:18 -0700, David Miller wrote:
> From: Dmitry Safonov <dima(a)arista.com>
> Date: Sat, 28 Jul 2018 17:26:55 +0100
>
> > Well, I think, I'll rework my patches set according to critics and
> > separate compat xfrm layer. I've already a selftest to check that
> 32/64
> > bit xfrm works - so the most time-taking part is done.
>
> The way you've done the compat structures using __packed is only
> going
> to work on x86, just FYI.
Thanks for pointing, so I'll probably cover it under something like
HAS_COMPAT_XFRM.
(if there isn't any better idea).
You can do that, I suspect you can use
CONFIG_COMPAT_FOR_U64_ALIGNMENT
as AFAICR the only reason for the compat problem is different alignment
requirements of 64bit integer types in the structs, not e.g. due to
"long" size differences.
Instead of __packed, you can use the "compat" data types, e.g.
compat_u64 instead of u64:
struct compat_xfrm_lifetime_cur {
compat_u64 bytes, packets, add_time, use_time;
}; /* same size on i386, but only 4 byte alignment required even on x86_64*/
You might be able to reuse
https://git.breakpoint.cc/cgit/fw/net-next.git/commit/?h=xfrm_config_comp...
in your patch set.
I can try to submit the first few patches (which are not related to
compat, they just add const qualifiers) for inclusion later this week.