Re: [PATCH 0/3] Convert nsproxy, groups, and creds to refcount_t

[Kees Cook]

On Tue, Jul 21, 2020 at 11:51:04AM +0100, David Howells wrote:
> Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> 
> > > Should mm->mm_users also be replaced by refcount_t?
> > 
> > I'll say "yes". :)
> > https://lore.kernel.org/lkml/1487671124-11188-1-git-send-email-elena.reshetova@xxxxxxxxx/
> > 
> > > In addition, is it better to change all variables that use
> > > atomic_dec_and_test to control the release process to refconut_t?
> > 
> > For the most part, yes. The following may find a lot of them:
> > scripts/coccinelle/api/atomic_as_refcounter.cocci
> 
> I've been gradually undoing some of the conversions as there's no equivalent
> of atomic_add_return() and atomic_dec_return() that allow me to log the
> altered refcount through a tracepoint.

Please do not _undo_ the changes; just add the API you need.

-- 
Kees Cook