svn commit: r315949 - in stable: 10/sys/kern 10/sys/sys 10/tests/sys/kern 11/sys/kern 11/sys/sys 11/tests/sys/kern

[Konstantin Belousov]

On Fri, Apr 21, 2017 at 03:11:00PM -0700, John Baldwin wrote:
> So this MFC happens to break the KBI of 'struct thread' because
> 'struct sigqueue' is embedded in 'struct thread' (rather than
> a pointer). This apparently results in panics if you use an
> nvidia-driver package built on 11.0-release on 11.0-stable, and
> that's the type of KBI we try to preserve. (We tend to only add new
> fields to the end of 'struct thread' and 'struct proc' in stable for
> example.) This one is a bit ugly to deal with though. I wonder if
> for the stable branches only if we could move the sq_ptrace out of
> the sigqueue struct and add it as a new field to the end of 'struct
> thread' explicitly? It would probably be pretty hacky, but it would be
> good to fix this before 11.1 so that the KBI wouldn't be broken for a
> user going from 11.0 to 11.1.

It might be easier to repurpose existing td_sigqueue as padding with
corrected size, and place real sigqueue at the end of the structure.
add