Re: [RFC][PATCH] locking/refcount: Provide __refcount API to obtain the old value

[Kees Cook]

On Wed, Jul 29, 2020 at 01:11:20PM +0200, peterz@xxxxxxxxxxxxx wrote:
> Subject: locking/refcount: Provide __refcount API to obtain the old value
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Date: Wed Jul 29 13:00:57 CEST 2020
> 
> David requested means to obtain the old/previous value from the
> refcount API for tracing purposes.
> 
> Duplicate (most of) the API as __refcount*() with an additional
> 'int *' argument into which, if !NULL, the old value will be stored.
> 
> Requested-by: David Howells <dhowells@xxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

This looks good to me. Thanks for poking at it!

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook