Re: [RFC PATCH v3 for 4.15 08/24] Provide cpu_opv system call

Having cpu_opv do a 4k memcpy allow it to handle scenarios where
rseq fails to progress.

If anybody ever gets that right. It will be really hard to just
test such a path.

It also seems fairly theoretical to me. Do you even have a 
test case where the normal path stops making forward progress?

-Andi