Re: [PATCH] selinux: convert struct sidtab count to refcount_t

From: Kees Cook
Date: Wed Jul 24 2019 - 11:54:08 EST

On Wed, Jul 24, 2019 at 04:28:31PM +0200, Jann Horn wrote:
> On Wed, Jul 24, 2019 at 12:17 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > Perhaps we need a "statistics" counter type for these kinds of counters?
> > "counter_t"? I bet there are a lot of atomic_t uses that are just trying
> > to be counters. (likely most of atomic_t that isn't now refcount_t ...)
> This isn't a statistics counter though; this thing needs ordered
> memory accesses, which you wouldn't need for statistics.

Okay, it'd be a "very accurate" counter type? It _could_ be used for
statistics. I guess what I mean is that there are a lot of places using
atomic_t just for upward counting that don't care about wrapping, etc.

Kees Cook