Re: [PATCH] locking/atomic: cmpxchg: Make __generic_cmpxchg_local compare against zero-extended 'old' value

[Arnd Bergmann]

On Wed, Mar 1, 2023, at 16:19, Matt Evans wrote:
>> On 26 Feb 2023, at 10:13, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> Proposed patch LGTM, but one query:  are the casts in 
> arch_[cmp]xchg()’s args necessary?  The new masks should deal with the 
> issue (and consistency would imply same for all other users of 
> arch_cmpxchg(), not ideal).

I don't think they are necessary, but I'd like to stay on the
safe side here since there are so many different implementations of
arch_cmpxchg() across architectures that it's likely that I missed
one that has a similar but, or that another one will get added
in the future.

> FWIW (including the casts in atomic.h, if you prefer):
>
> Reviewed-by: Matt Evans <mev@xxxxxxxxxxxx>

Thanks!

     Arnd