Re: [PATCH v2 17/19] kasan: remove atomic accesses to stack ring entries

From: Andrey Konovalov
Date: Mon Oct 23 2023 - 12:18:18 EST


On Mon, Oct 9, 2023 at 2:05 PM Alexander Potapenko <glider@xxxxxxxxxx> wrote:
>
> On Wed, Sep 13, 2023 at 7:17 PM <andrey.konovalov@xxxxxxxxx> wrote:
> >
> > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> >
> > Remove the atomic accesses to entry fields in save_stack_info and
> > kasan_complete_mode_report_info for tag-based KASAN modes.
> >
> > These atomics are not required, as the read/write lock prevents the
> > entries from being read (in kasan_complete_mode_report_info) while being
> > written (in save_stack_info) and the try_cmpxchg prevents the same entry
> > from being rewritten (in save_stack_info) in the unlikely case of wrapping
> > during writing.
>
> Given that you removed all atomic accesses, it should be fine to
> remove the inclusion of atomic.h as well.

Not all of them are removed: stack_ring.pos is still accessed via atomics.

> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>

Thanks!