+Cc rest of kunit from MAINTAINERS
On 1/7/23 11:55, Geert Uytterhoeven wrote:
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_TESTSWhy the tristate?
depends on MEMCPY_KUNIT_TESTdefault KUNIT_ALL_TESTShelpSome memcpy tests are quite exhaustive in checking for overlapsand bit ranges. These can be very slow, so they are split outas 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?
Indeed it seems weird to tie this to a config option without runtime override.
I guess that's why you made MEMCPY_SLOW_KUNIT_TEST tristate originally, to have a separate module with the slow tests?
On the other hand I can imagine requiring a separate module for slow tests would lead to more churn - IIUC there would need to be two files instead of memcpy_kunit.c, possibly a duplicated boilerplate code (or another shared .c file).
So the idea is to have a generic way to mark some tests as slow and a way to opt-in/opt-out for those when running the tests. Maybe KUnit folks already have such mechanism or have an idea how to implement that.
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