+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@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> >> Link: https://lore.kernel.org/lkml/20221226195206.GA2626419@xxxxxxxxxxxx >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >> Cc: Nathan Chancellor <nathan@xxxxxxxxxx> >> Cc: linux-hardening@xxxxxxxxxxxxxxx >> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > > 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? 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@xxxxxxxxxxxxxx > > 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
