[v4] powerpc: Export thread_struct.used_vr/used_vsr to user space

[Simon Guo]

Michael, Ben,
On Fri, Jul 08, 2016 at 08:02:42PM +1000, Michael Ellerman wrote:
> Benjamin Herrenschmidt <benh at kernel.crashing.org> writes:
> 
> > On Thu, 2016-07-07 at 23:21 +1000, Benjamin Herrenschmidt wrote:
> >> 
> >> I think the right fix is that if a restore_sigcontext() has the MSR
> >> bits set,
> >> it should set the corresponding used_* flag.
> >
> > Something like this:
> >
> > (totally untested)
> 
> Simon/Laurent, can you guys test this and let me know if it works for
> your usecase.
> 

Sorry for the late reply. I tested Ben's patch and the fix works for the CRIU
case mentioned before.

Thanks,
Simon