[PATCH v11 07/16] sched: Split the guts of sched_setaffinity() into a helper function

[Peter Zijlstra]

On Fri, Jul 30, 2021 at 12:24:34PM +0100, Will Deacon wrote:
> In preparation for replaying user affinity requests using a saved mask,
> split sched_setaffinity() up so that the initial task lookup and
> security checks are only performed when the request is coming directly
> from userspace.
> 
> Reviewed-by: Valentin Schneider <Valentin.Schneider at arm.com>
> Signed-off-by: Will Deacon <will at kernel.org>

Should not sched_setaffinity() update user_cpus_ptr when it isn't NULL,
such that the upcoming relax_compatible_cpus_allowed_ptr() preserve the
full user mask?