Re: [PATCH v3 03/23] arm64: Make cpu_logical_map() take unsigned int

David Brazdil
2020-12-02T15:45:58Z

On Thu, Nov 26, 2020 at 05:28:38PM +0000, Mark Rutland wrote:
> On Thu, Nov 26, 2020 at 03:54:01PM +0000, David Brazdil wrote:
> > CPU index should never be negative. Change the signature of
> > (set_)cpu_logical_map to take an unsigned int.
> >
> > Signed-off-by: David Brazdil <dbrazdil@google.com>
>
> Is there a function problem here, or is this just cleanup from
> inspection?
>
> Core code including the cpuhp_*() callbacks uses an int, so if there's a
> strong justification to change this, it suggests there's some treewide
> cleanup that should be done.
>
> I don't have strong feelings on the matter, but I'd like to understand
> the rationale.

Yeah, it's a mess. Marc and I felt that using a uint was less error-prone wrt
bounds checks. If this gets an int, it still works and only checking the upper
bound is required. Does that make sense?

David