On Tue, Jan 07, 2020 at 05:48:55PM +0000, Ben Hutchings wrote:
> I noticed that backports of commit 69d927bba395 "x86/atomic: Fix
> smp_mb__{before,after}_atomic()" didn't touch atomic_or_long() (present
> in 3.16) or atomic_inc_short() (present in 4.9 and earlier).
>
> These functions were only implemented on x86 and not actually used in-
> tree. But it's possible they are used by some out-of-tree module, and
> that commit removed compiler barriers for them.
>
> Would it might make sense to either
> 1. Add the memory clobber to these functions, or
> 2. Delete them
> on the affected stable branches?
Looks like we can drop atomic_inc_short for 4.9 as there are no users,
same for 4.4. I'll go do that now. It's not like the "fix" is really
needed here because of that :)
Good catch!
thanks,
greg k-h
