Re: [PATCH 1/5] refcount_t: A special purpose refcount type

[Kees Cook]

On Fri, Feb 3, 2017 at 5:25 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> Provide refcount_t, an atomic_t like primitive built just for
> refcounting.
>
> It provides saturation semantics such that overflow becomes impossible
> and thereby 'spurious' use-after-free is avoided.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---
>  include/linux/refcount.h |  294 +++++++++++++++++++++++++++++++++++++++++++++++
>  lib/Kconfig.debug        |   13 ++
>  2 files changed, 307 insertions(+)
>
> --- /dev/null
> +++ b/include/linux/refcount.h
> @@ -0,0 +1,294 @@
> [...]
> +#if CONFIG_DEBUG_REFCOUNT

Oh, and I just hit this too, it should be "#ifdef" ... I didn't notice
until after I sent my improvement series. Whoops. :P Yay Friday.

-Kees

-- 
Kees Cook
Pixel Security