Re: Adding ifam_pid to ifa_msghdr

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Thu, Sep 01, 2016 at 08:00:12AM +0700, Robert Elz wrote:
>     Date:        Thu, 01 Sep 2016 00:40:14 +0100
>     From:        Roy Marples <roy%marples.name@localhost>
>     Message-ID:  <4026094.yb7LW5zMxf%uberpc.marples.name@localhost>
> 
>   | Hopefully this satisfies your alignment 
>   | requirement, otherwise please explain more fully.
> 
> In structs that are part of the ABI, to avoid potential messes from
> any of different compilers being used, or compiler version changes
> altering things, or even parts of the code being compiled with different
> compiler options, there should be no (rational) potential for anonymous
> padding fields (which the compiler might, or might not, decide to include).

There are many reasons for avoiding padding fields, the hassle of
avoiding information leaks through them being one of the biggest, but
arguing that compilers can't implement the platform ABI correctly is
somewhat of a stretch. If you are using such a broken compiler, you are
likely to run into far more problematic issues in userland much earlier.

Joerg