Re: [PATCH v12 7/7] kasan: don't run tests in async mode

From: Andrey Konovalov
Date: Tue Feb 09 2021 - 10:03:41 EST


On Tue, Feb 9, 2021 at 1:16 PM Vincenzo Frascino
<vincenzo.frascino@xxxxxxx> wrote:
>
>
>
> On 2/9/21 12:02 PM, Catalin Marinas wrote:
> > On Mon, Feb 08, 2021 at 04:56:17PM +0000, Vincenzo Frascino wrote:
> >> From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> >>
> >> Asynchronous KASAN mode doesn't guarantee that a tag fault will be
> >> detected immediately and causes tests to fail. Forbid running them
> >> in asynchronous mode.
> >>
> >> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> >
> > That's missing your SoB.
> >
>
> Yes, I will add it in the next iteration.
>
> >> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> >> index 7285dcf9fcc1..f82d9630cae1 100644
> >> --- a/lib/test_kasan.c
> >> +++ b/lib/test_kasan.c
> >> @@ -51,6 +51,10 @@ static int kasan_test_init(struct kunit *test)
> >> kunit_err(test, "can't run KASAN tests with KASAN disabled");
> >> return -1;
> >> }
> >> + if (kasan_flag_async) {
> >> + kunit_err(test, "can't run KASAN tests in async mode");
> >> + return -1;
> >> + }
> >>
> >> multishot = kasan_save_enable_multi_shot();
> >> hw_set_tagging_report_once(false);
> >
> > I think we can still run the kasan tests in async mode if we check the
> > TFSR_EL1 at the end of each test by calling mte_check_tfsr_exit().
> >
>
> IIUC this was the plan for the future. But I let Andrey comment for more details.

If it's possible to implement, then it would be good to have. Doesn't
have to be a part of this series though.