2023-01-07 05:46:08

by Kees Cook

[permalink] [raw]
Subject: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

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 <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Cc: Andrew Morton <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
Guenter, does this give you the needed flexibility to turn on the memcpy
kunit tests again in your slower environments?
---
lib/Kconfig.debug | 9 +++++++++
lib/memcpy_kunit.c | 17 +++++++++++++----
2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c2c78d0e761c..b5e94807f41c 100644
--- 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
+ 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");
+ return -EBUSY;
+ }

/* Get many bit patterns. */
get_random_bytes(large_src, ARRAY_SIZE(large_src));
@@ -319,6 +323,8 @@ static void init_large(struct kunit *test)

/* Explicitly zero the entire destination. */
memset(large_dst, 0, ARRAY_SIZE(large_dst));
+
+ return 0;
}

/*
@@ -327,7 +333,9 @@ static void init_large(struct kunit *test)
*/
static void copy_large_test(struct kunit *test, bool use_memmove)
{
- init_large(test);
+
+ if (init_large(test))
+ return;

/* Copy a growing number of non-overlapping bytes ... */
for (int bytes = 1; bytes <= ARRAY_SIZE(large_src); bytes++) {
@@ -472,7 +480,8 @@ static void memmove_overlap_test(struct kunit *test)
static const int bytes_start = 1;
static const int bytes_end = ARRAY_SIZE(large_src) + 1;

- init_large(test);
+ if (init_large(test))
+ return;

/* Copy a growing number of overlapping bytes ... */
for (int bytes = bytes_start; bytes < bytes_end;
@@ -549,8 +558,8 @@ static void strtomem_test(struct kunit *test)
static struct kunit_case memcpy_test_cases[] = {
KUNIT_CASE(memset_test),
KUNIT_CASE(memcpy_test),
- KUNIT_CASE(memcpy_large_test),
KUNIT_CASE(memmove_test),
+ KUNIT_CASE(memcpy_large_test),
KUNIT_CASE(memmove_large_test),
KUNIT_CASE(memmove_overlap_test),
KUNIT_CASE(strtomem_test),
--
2.34.1


2023-01-07 11:06:38

by Geert Uytterhoeven

[permalink] [raw]
Subject: Re: [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 <[email protected]> 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 <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]
> Cc: Andrew Morton <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

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 -- [email protected]

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

2023-01-10 00:50:52

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

On Fri, Jan 06, 2023 at 08:02:07PM -0800, Kees Cook 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 <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]
> Cc: Andrew Morton <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> Guenter, does this give you the needed flexibility to turn on the memcpy
> kunit tests again in your slower environments?

Yes, it does, and it works.

Reviewed-and-tested-by: Guenter Roeck <[email protected]>

> ---
> lib/Kconfig.debug | 9 +++++++++
> lib/memcpy_kunit.c | 17 +++++++++++++----
> 2 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c2c78d0e761c..b5e94807f41c 100644
> --- 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

As Geert noticed, bool should be sufficient here since this is not a
separate test.

Thanks,
Guenter

> + 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");
> + return -EBUSY;
> + }
>
> /* Get many bit patterns. */
> get_random_bytes(large_src, ARRAY_SIZE(large_src));
> @@ -319,6 +323,8 @@ static void init_large(struct kunit *test)
>
> /* Explicitly zero the entire destination. */
> memset(large_dst, 0, ARRAY_SIZE(large_dst));
> +
> + return 0;
> }
>
> /*
> @@ -327,7 +333,9 @@ static void init_large(struct kunit *test)
> */
> static void copy_large_test(struct kunit *test, bool use_memmove)
> {
> - init_large(test);
> +
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of non-overlapping bytes ... */
> for (int bytes = 1; bytes <= ARRAY_SIZE(large_src); bytes++) {
> @@ -472,7 +480,8 @@ static void memmove_overlap_test(struct kunit *test)
> static const int bytes_start = 1;
> static const int bytes_end = ARRAY_SIZE(large_src) + 1;
>
> - init_large(test);
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of overlapping bytes ... */
> for (int bytes = bytes_start; bytes < bytes_end;
> @@ -549,8 +558,8 @@ static void strtomem_test(struct kunit *test)
> static struct kunit_case memcpy_test_cases[] = {
> KUNIT_CASE(memset_test),
> KUNIT_CASE(memcpy_test),
> - KUNIT_CASE(memcpy_large_test),
> KUNIT_CASE(memmove_test),
> + KUNIT_CASE(memcpy_large_test),
> KUNIT_CASE(memmove_large_test),
> KUNIT_CASE(memmove_overlap_test),
> KUNIT_CASE(strtomem_test),
> --
> 2.34.1
>

2023-01-10 01:10:14

by Nick Desaulniers

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

On Fri, Jan 6, 2023 at 8:02 PM Kees Cook <[email protected]> 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 <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]
> Cc: Andrew Morton <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <[email protected]>

> ---
> Guenter, does this give you the needed flexibility to turn on the memcpy
> kunit tests again in your slower environments?
> ---
> lib/Kconfig.debug | 9 +++++++++
> lib/memcpy_kunit.c | 17 +++++++++++++----
> 2 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c2c78d0e761c..b5e94807f41c 100644
> --- 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
> + 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");
> + return -EBUSY;
> + }
>
> /* Get many bit patterns. */
> get_random_bytes(large_src, ARRAY_SIZE(large_src));
> @@ -319,6 +323,8 @@ static void init_large(struct kunit *test)
>
> /* Explicitly zero the entire destination. */
> memset(large_dst, 0, ARRAY_SIZE(large_dst));
> +
> + return 0;
> }
>
> /*
> @@ -327,7 +333,9 @@ static void init_large(struct kunit *test)
> */
> static void copy_large_test(struct kunit *test, bool use_memmove)
> {
> - init_large(test);
> +
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of non-overlapping bytes ... */
> for (int bytes = 1; bytes <= ARRAY_SIZE(large_src); bytes++) {
> @@ -472,7 +480,8 @@ static void memmove_overlap_test(struct kunit *test)
> static const int bytes_start = 1;
> static const int bytes_end = ARRAY_SIZE(large_src) + 1;
>
> - init_large(test);
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of overlapping bytes ... */
> for (int bytes = bytes_start; bytes < bytes_end;
> @@ -549,8 +558,8 @@ static void strtomem_test(struct kunit *test)
> static struct kunit_case memcpy_test_cases[] = {
> KUNIT_CASE(memset_test),
> KUNIT_CASE(memcpy_test),
> - KUNIT_CASE(memcpy_large_test),
> KUNIT_CASE(memmove_test),
> + KUNIT_CASE(memcpy_large_test),
> KUNIT_CASE(memmove_large_test),
> KUNIT_CASE(memmove_overlap_test),
> KUNIT_CASE(strtomem_test),
> --
> 2.34.1
>


--
Thanks,
~Nick Desaulniers

2023-01-10 08:33:53

by Vlastimil Babka

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

+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 <[email protected]> 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 <[email protected]>
>> Link: https://lore.kernel.org/lkml/[email protected]
>> Cc: Andrew Morton <[email protected]>
>> Cc: Nathan Chancellor <[email protected]>
>> Cc: [email protected]
>> Signed-off-by: Kees Cook <[email protected]>
>
> 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 -- [email protected]
>
> 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

2023-01-10 21:30:26

by Daniel Latypov

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

On Mon, Jan 9, 2023 at 11:51 PM Vlastimil Babka <[email protected]> wrote:
>
> +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 <[email protected]> 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.

<snip>

> >>
> >> -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.

There is no mechanism atm, and we'd still need to figure it out so
it'll be a while.
So I think a patch like this makes sense in the short-term.

This is definitely something we've always thought would be useful eventually.
See this TODO which has been there since day 1 ;)
https://elixir.bootlin.com/linux/latest/source/lib/kunit/try-catch.c#L36

It just felt like it would be premature to come up with something when
basically all the tests up until now ran ~instantly.

Throwing out some rough implementation ideas:
I was thinking the granularity for these timeout annotations would be
at the suite-level.
If we go with that, then I guess the intended flow is to group slow
tests into their own suite and mark them as such.

Then maybe we'd have some runtime way of disabling/enabling "long"
tests, like a cmdline opt.
E.g. you'd pass `kunit.max_test_size=30` to exclude tests longer than
30 seconds.

Daniel

2023-01-11 07:45:56

by David Gow

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

On Sat, 7 Jan 2023 at 12:02, Kees Cook <[email protected]> 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 <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]
> Cc: Andrew Morton <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> Guenter, does this give you the needed flexibility to turn on the memcpy
> kunit tests again in your slower environments?
> ---

Sorry for the delay: I've just got back from holidays.

This looks good to me (modulo the tristate/bool issue mentioned).

Having a specific way to tag tests as "slow" is something we've
considered having in KUnit for a while, but (at least initially),
there weren't any tests slow enough for it to be worthwhile. It looks
like that's changing (alongside this, there are a few DRM tests which
are quite slow, as well as some of the KCSAN tests. Even the
time64_to_tm_test_date_range test, while very quick under UML on a
modern system, is noticeably slow under qemu and times out on
something like an old 486...). Daniel's comments elsewhere in this
thread have some good ideas.

That being said, it'll probably take long enough to work out and
implement a good way of giving tests "properties" and requesting only
fast tests run that just putting tests which are slow enough to cause
problems behind a kconfig entry seems a pretty solid intermediate
solution.

So this is:
Reviewed-by: David Gow <[email protected]>

(assuming the tristate goes to bool), and I'll look into getting a way
of marking tests as "slow" and enabling/disabling them at runtime.

Cheers,
-- David

> lib/Kconfig.debug | 9 +++++++++
> lib/memcpy_kunit.c | 17 +++++++++++++----
> 2 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c2c78d0e761c..b5e94807f41c 100644
> --- 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

As mentioned, if this is just going to be a toggle, it can be a "bool".


> + 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");
> + return -EBUSY;
> + }
>
> /* Get many bit patterns. */
> get_random_bytes(large_src, ARRAY_SIZE(large_src));
> @@ -319,6 +323,8 @@ static void init_large(struct kunit *test)
>
> /* Explicitly zero the entire destination. */
> memset(large_dst, 0, ARRAY_SIZE(large_dst));
> +
> + return 0;
> }
>
> /*
> @@ -327,7 +333,9 @@ static void init_large(struct kunit *test)
> */
> static void copy_large_test(struct kunit *test, bool use_memmove)
> {
> - init_large(test);
> +
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of non-overlapping bytes ... */
> for (int bytes = 1; bytes <= ARRAY_SIZE(large_src); bytes++) {
> @@ -472,7 +480,8 @@ static void memmove_overlap_test(struct kunit *test)
> static const int bytes_start = 1;
> static const int bytes_end = ARRAY_SIZE(large_src) + 1;
>
> - init_large(test);
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of overlapping bytes ... */
> for (int bytes = bytes_start; bytes < bytes_end;
> @@ -549,8 +558,8 @@ static void strtomem_test(struct kunit *test)
> static struct kunit_case memcpy_test_cases[] = {
> KUNIT_CASE(memset_test),
> KUNIT_CASE(memcpy_test),
> - KUNIT_CASE(memcpy_large_test),
> KUNIT_CASE(memmove_test),
> + KUNIT_CASE(memcpy_large_test),
> KUNIT_CASE(memmove_large_test),
> KUNIT_CASE(memmove_overlap_test),
> KUNIT_CASE(strtomem_test),
> --
> 2.34.1
>


Attachments:
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2023-01-14 01:25:59

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

gah. this is actually v2. :(

On Fri, Jan 13, 2023 at 04:54:12PM -0800, Kees Cook 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 <[email protected]>
> Link: https://lore.kernel.org/lkml/[email protected]
> Reviewed-by: Nick Desaulniers <[email protected]>
> Reviewed-and-tested-by: Guenter Roeck <[email protected]>
> Reviewed-by: David Gow <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Nathan Chancellor <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> v2: fix tristate to bool
> v1: https://lore.kernel.org/lkml/[email protected]
> ---
> lib/Kconfig.debug | 9 +++++++++
> lib/memcpy_kunit.c | 15 ++++++++++++---
> 2 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c2c78d0e761c..f90637171453 100644
> --- 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
> + bool "Include exhaustive memcpy tests" if !KUNIT_ALL_TESTS
> + 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..5a545e1b5dbb 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");
> + return -EBUSY;
> + }
>
> /* Get many bit patterns. */
> get_random_bytes(large_src, ARRAY_SIZE(large_src));
> @@ -319,6 +323,8 @@ static void init_large(struct kunit *test)
>
> /* Explicitly zero the entire destination. */
> memset(large_dst, 0, ARRAY_SIZE(large_dst));
> +
> + return 0;
> }
>
> /*
> @@ -327,7 +333,9 @@ static void init_large(struct kunit *test)
> */
> static void copy_large_test(struct kunit *test, bool use_memmove)
> {
> - init_large(test);
> +
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of non-overlapping bytes ... */
> for (int bytes = 1; bytes <= ARRAY_SIZE(large_src); bytes++) {
> @@ -472,7 +480,8 @@ static void memmove_overlap_test(struct kunit *test)
> static const int bytes_start = 1;
> static const int bytes_end = ARRAY_SIZE(large_src) + 1;
>
> - init_large(test);
> + if (init_large(test))
> + return;
>
> /* Copy a growing number of overlapping bytes ... */
> for (int bytes = bytes_start; bytes < bytes_end;
> --
> 2.34.1
>

--
Kees Cook

2023-01-14 01:51:24

by Daniel Latypov

[permalink] [raw]
Subject: Re: [PATCH] kunit: memcpy: Split slow memcpy tests into MEMCPY_SLOW_KUNIT_TEST

On Fri, Jan 13, 2023 at 4:54 PM Kees Cook <[email protected]> wrote:
> diff --git a/lib/memcpy_kunit.c b/lib/memcpy_kunit.c
> index 89128551448d..5a545e1b5dbb 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");
> + return -EBUSY;

Note: kunit_skip() here means you don't need explicit returns in the test cases.
kunit_skip() is basically
kunit_mark_skipped(test, "reason");
kthread_complete_and_exit(...);

So the diff in this file could be reduced down to just these 2 lines
if (!IS_ENABLED(...))
kunit_skip(test, "...")

But I can see the appeal of being more explicit about the control flow.
In that case, you could switch kunit_mark_skipped(), which just sets
the status and doesn't affect control flow at all.

Daniel