Re: [RFC PATCH for 4.18] rseq: use __u64 for rseq_cs fields, validate user inputs

[Peter Zijlstra]

On Tue, Jul 03, 2018 at 01:58:37PM -0400, Mathieu Desnoyers wrote:
> I can modify the ABI to put the cpu_id_start and cpu_id fields inside
> a union, and update it with a single store.
> 
> Thoughts ?

Let's keep them for now, we can always frob this later, they are aligned
and proper, no need to expose that union to userspace.