Date:   Mon, 10 Jul 2023 11:07:18 -0700
From:   Daniel Latypov <dlatypov@...gle.com>
To:     Rae Moar <rmoar@...gle.com>
Cc:     shuah@...nel.org, davidgow@...gle.com, brendan.higgins@...ux.dev,
        linux-kselftest@...r.kernel.org, kunit-dev@...glegroups.com,
        linux-kernel@...r.kernel.org, keescook@...omium.org,
        linux-hardening@...r.kernel.org, jstultz@...gle.com,
        tglx@...utronix.de, sboyd@...nel.org
Subject: Re: [RFC v2 8/9] kunit: add tests for filtering attributes

On Fri, Jul 7, 2023 at 2:10 PM Rae Moar <rmoar@...gle.com> wrote:
>
> Add four tests to executor_test.c to test behavior of filtering attributes.
>
> - parse_filter_attr_test - to test the parsing of inputted filters
>
> - filter_attr_test - to test the filtering procedure on attributes
>
> - filter_attr_empty_test - to test the behavior when all tests are filtered
>   out
>
> - filter_attr_skip_test - to test the configurable filter_skip option
>
> Signed-off-by: Rae Moar <rmoar@...gle.com>

I love that I'm able to read this patch first and get a feel for what
exactly the patch series is doing overall.

Some nits and suggestions below.

> ---
>
> Changes since v1:
> - This is a new patch
>
>  lib/kunit/executor_test.c | 107 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 107 insertions(+)
>
> diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
> index d7ab069324b5..145a78ade33d 100644
> --- a/lib/kunit/executor_test.c
> +++ b/lib/kunit/executor_test.c
> @@ -7,6 +7,7 @@
>   */
>
>  #include <kunit/test.h>
> +#include <kunit/attributes.h>
>
>  static void kfree_at_end(struct kunit *test, const void *to_free);
>  static struct kunit_suite *alloc_fake_suite(struct kunit *test,
> @@ -22,6 +23,14 @@ static struct kunit_case dummy_test_cases[] = {
>         {},
>  };
>
> +static struct kunit_case dummy_attr_test_cases[] = {
> +       /* .run_case is not important, just needs to be non-NULL */
> +       { .name = "test1", .run_case = dummy_test, .module_name = "dummy",
> +         .attr.speed = KUNIT_SPEED_SLOW },
> +       { .name = "test2", .run_case = dummy_test, .module_name = "dummy" },
> +       {},
> +};

1) can we move this array to be just above parse_filter_attr_test so
it's next to where it's used?

2) How about renaming "test1" to "slow" to make the assertions in the
test case a bit easier to follow?
Right now readers need to remember which test case was supposed to be
filtered out.


> +
>  static void parse_filter_test(struct kunit *test)
>  {
>         struct kunit_glob_filter filter = {NULL, NULL};
> @@ -108,11 +117,109 @@ static void filter_suites_to_empty_test(struct kunit *test)
>                                 "should be empty to indicate no match");
>  }
>
> +static void parse_filter_attr_test(struct kunit *test)
> +{
> +       int j, filter_count;
> +       struct kunit_attr_filter *parsed_filters;
> +       char *filters = "speed>slow, module!=example";
> +       int err = 0;
> +
> +       filter_count = kunit_get_filter_count(filters);
> +       KUNIT_EXPECT_EQ(test, filter_count, 2);
> +
> +       parsed_filters = kcalloc(filter_count + 1, sizeof(*parsed_filters), GFP_KERNEL);

nit: kunit_kcalloc() instead?

> +       for (j = 0; j < filter_count; j++)
> +               parsed_filters[j] = kunit_next_attr_filter(&filters, &err);

then here we probably want to check err, i.e.
  KUNIT_ASSERT_EQ_MSG(test, err, 0, "failed to parse filter '%s'", filters[i]);


> +
> +       KUNIT_EXPECT_STREQ(test, kunit_attr_filter_name(parsed_filters[0]), "speed");
> +       KUNIT_EXPECT_STREQ(test, parsed_filters[0].input, ">slow");
> +
> +       KUNIT_EXPECT_STREQ(test, kunit_attr_filter_name(parsed_filters[1]), "module");
> +       KUNIT_EXPECT_STREQ(test, parsed_filters[1].input, "!=example");
> +
> +       kfree(parsed_filters);
> +}
> +
> +static void filter_attr_test(struct kunit *test)
> +{
> +       struct kunit_suite *subsuite[3] = {NULL, NULL};
> +       struct suite_set suite_set = {.start = subsuite, .end = &subsuite[2]};
> +       struct suite_set got;
> +       int err = 0;
> +
> +       subsuite[0] = alloc_fake_suite(test, "suite1", dummy_attr_test_cases);
> +       subsuite[1] = alloc_fake_suite(test, "suite2", dummy_attr_test_cases);
> +       subsuite[1]->attr.speed = KUNIT_SPEED_SLOW; // Set suite attribute

Similarly, perhaps we can rename suite2 to "slow_suite"?
That would cause this line to go over 80 characters wide, but since
that's no longer a hard limit, I think this would be a decent place to
go past it.

> +
> +       /* Want: suite1(test1, test2), suite2(test1, test2), NULL -> suite1(test2), NULL */
> +       got = kunit_filter_suites(&suite_set, NULL, "speed>slow", NULL, &err);
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
> +       KUNIT_ASSERT_EQ(test, err, 0);
> +       kfree_at_end(test, got.start);
> +
> +       /* Validate we just have suite1 */
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
> +       KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->name, "suite1");
> +       KUNIT_ASSERT_EQ(test, got.end - got.start, 1);
> +
> +       /* Now validate we just have test2 */
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]->test_cases);
> +       KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->test_cases[0].name, "test2");
> +       KUNIT_EXPECT_FALSE(test, got.start[0]->test_cases[1].name);
> +}
> +
> +static void filter_attr_empty_test(struct kunit *test)
> +{
> +       struct kunit_suite *subsuite[3] = {NULL, NULL};
> +       struct suite_set suite_set = {.start = subsuite, .end = &subsuite[2]};
> +       struct suite_set got;
> +       int err = 0;
> +
> +       subsuite[0] = alloc_fake_suite(test, "suite1", dummy_attr_test_cases);
> +       subsuite[1] = alloc_fake_suite(test, "suite2", dummy_attr_test_cases);
> +
> +       got = kunit_filter_suites(&suite_set, NULL, "module!=dummy", NULL, &err);
> +       KUNIT_ASSERT_EQ(test, err, 0);
> +       kfree_at_end(test, got.start); /* just in case */
> +
> +       KUNIT_EXPECT_PTR_EQ_MSG(test, got.start, got.end,
> +                               "should be empty to indicate no match");
> +}
> +
> +static void filter_attr_skip_test(struct kunit *test)
> +{
> +       struct kunit_suite *subsuite[2] = {NULL};
> +       struct suite_set suite_set = {.start = subsuite, .end = &subsuite[1]};
> +       struct suite_set got;
> +       int err = 0;
> +
> +       subsuite[0] = alloc_fake_suite(test, "suite1", dummy_attr_test_cases);
> +
> +       /* Want: suite1(test1, test2), NULL -> suite1(test1 with SKIP, test2), NULL */
> +       got = kunit_filter_suites(&suite_set, NULL, "speed>slow", "skip", &err);
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
> +       KUNIT_ASSERT_EQ(test, err, 0);
> +       kfree_at_end(test, got.start);
> +
> +       /* Validate we have both test1 and test2 */
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]->test_cases);

Should we assert that we have 2 test cases before we dereference the second one?
The other code in this file (that I wrote) is being a bit sloppy and
deref'ing test_cases[0] without checking. It's doing that since I was
relying on the fact that the filtering code drops suites with no test
cases, so we don't necessarily need to check len(test_cases) >= 1.
(In terms of best practices, we should be defensive and checking that, though).

But in this case, we have no such guarantee about the second element.

> +       KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->test_cases[0].name, "test1");
> +       KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->test_cases[1].name, "test2");

Trying to remember, I think the cast to `const char *` is no longer
necessary after one of David's changes...
I think we might just never have gotten around to cleaning that up due
to the ordering in which the patches went in...

> +
> +       /* Now ensure test1 is skipped and test2 is not */
> +       KUNIT_EXPECT_EQ(test, got.start[0]->test_cases[0].status, KUNIT_SKIPPED);
> +       KUNIT_EXPECT_FALSE(test, got.start[0]->test_cases[1].status);

Should we check that it's equal to KUNIT_SUCCESS instead?


> +}
> +
>  static struct kunit_case executor_test_cases[] = {
>         KUNIT_CASE(parse_filter_test),
>         KUNIT_CASE(filter_suites_test),
>         KUNIT_CASE(filter_suites_test_glob_test),
>         KUNIT_CASE(filter_suites_to_empty_test),
> +       KUNIT_CASE(parse_filter_attr_test),
> +       KUNIT_CASE(filter_attr_test),
> +       KUNIT_CASE(filter_attr_empty_test),
> +       KUNIT_CASE(filter_attr_skip_test),
>         {}
>  };
>
> --
> 2.41.0.255.g8b1d071c50-goog
>

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