lkml.org 
[lkml]   [2023]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST
Hi Kees,

On Sat, Jan 7, 2023 at 5:02 AM Kees Cook <keescook@chromium.org> wrote:
> Since the long memcpy tests may stall a system for tens of seconds
> in virtualized architecture environments, split those tests off under
> CONFIG_MEMCPY_SLOW_KUNIT_TEST so they can be separately disabled.
>
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Link: https://lore.kernel.org/lkml/20221226195206.GA2626419@roeck-us.net
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Thanks for your patch!

> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2621,6 +2621,15 @@ config MEMCPY_KUNIT_TEST
>
> If unsure, say N.
>
> +config MEMCPY_SLOW_KUNIT_TEST
> + tristate "Include exhaustive memcpy tests" if !KUNIT_ALL_TESTS

Why the tristate?

> + depends on MEMCPY_KUNIT_TEST
> + default KUNIT_ALL_TESTS
> + help
> + Some memcpy tests are quite exhaustive in checking for overlaps
> + and bit ranges. These can be very slow, so they are split out
> + as a separate config.
> +
> config IS_SIGNED_TYPE_KUNIT_TEST
> tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
> depends on KUNIT
> diff --git a/lib/memcpy_kunit.c b/lib/memcpy_kunit.c
> index 89128551448d..cc1f36335a9b 100644
> --- a/lib/memcpy_kunit.c
> +++ b/lib/memcpy_kunit.c
> @@ -307,8 +307,12 @@ static void set_random_nonzero(struct kunit *test, u8 *byte)
> }
> }
>
> -static void init_large(struct kunit *test)
> +static int init_large(struct kunit *test)
> {
> + if (!IS_ENABLED(CONFIG_MEMCPY_SLOW_KUNIT_TEST)) {
> + kunit_skip(test, "Slow test skipped. Enable with CONFIG_MEMCPY_SLOW_KUNIT_TEST=y");

So I can't make the slower tests available for when I need them,
but not run them by default?
I guess that's why you made MEMCPY_SLOW_KUNIT_TEST tristate originally,
to have a separate module with the slow tests?

> + return -EBUSY;
> + }
>
> /* Get many bit patterns. */
> get_random_bytes(large_src, ARRAY_SIZE(large_src));

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

\
 
 \ /
  Last update: 2023-03-26 23:31    [W:0.371 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site