Message-ID: <CAGS_qxrkjx73udd3MnOBOo+N4rU+QfH=5vZiF5beCnesMYHOjQ@mail.gmail.com>
Date:   Tue, 10 Aug 2021 08:21:34 -0700
From:   Daniel Latypov <dlatypov@...gle.com>
To:     David Gow <davidgow@...gle.com>
Cc:     Brendan Higgins <brendanhiggins@...gle.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        KUnit Development <kunit-dev@...glegroups.com>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@...r.kernel.org>,
        Shuah Khan <skhan@...uxfoundation.org>
Subject: Re: [PATCH v2] kunit: tool: allow filtering test cases via glob

On Mon, Aug 9, 2021 at 7:58 PM David Gow <davidgow@...gle.com> wrote:
>
> On Tue, Aug 10, 2021 at 6:34 AM Daniel Latypov <dlatypov@...gle.com> wrote:
> >
> > Commit 1d71307a6f94 ("kunit: add unit test for filtering suites by
> > names") introduced the ability to filter which suites we run via glob.
> >
> > This change extends it so we can also filter individual test cases
> > inside of suites as well.
> >
> > This is quite useful when, e.g.
> > * trying to run just the tests cases you've just added or are working on
> > * trying to debug issues with test hermeticity
> >
> > Examples:
> > $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit '*exec*.parse*'
> > ...
> > ============================================================
> > ======== [PASSED] kunit_executor_test ========
> > [PASSED] parse_filter_test
> > ============================================================
> > Testing complete. 1 tests run. 0 failed. 0 crashed.
> >
> > $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit '*.no_matching_tests'
> > ...
> > [ERROR] no tests run!
> >
> > Signed-off-by: Daniel Latypov <dlatypov@...gle.com>
>
> Thanks! This works a treat. A minor documentation suggestion and a bad
> optimisation idea lurk below, but I'm happy with this as-is
> regardless.
>
> Reviewed-by: David Gow <davidgow@...gle.com>
>
> -- David
>
> > ---
> > v1 -> v2: update Documentation/.../running_tips.rst
> > ---
> >  .../dev-tools/kunit/running_tips.rst          |  11 +-
> >  lib/kunit/executor.c                          | 107 +++++++++++++++--
> >  lib/kunit/executor_test.c                     | 109 +++++++++++++++---
> >  3 files changed, 201 insertions(+), 26 deletions(-)
> >
> > diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
> > index d1626d548fa5..f471bcbdabd4 100644
> > --- a/Documentation/dev-tools/kunit/running_tips.rst
> > +++ b/Documentation/dev-tools/kunit/running_tips.rst
> > @@ -25,8 +25,8 @@ It can be handy to create a bash function like:
> >  Running a subset of tests
> >  -------------------------
> >
> > -``kunit.py run`` accepts an optional glob argument to filter tests. Currently
> > -this only matches against suite names, but this may change in the future.
> > +``kunit.py run`` accepts an optional glob argument to filter tests. The format
> > +is ``"<suite_glob>[.test_glob]"``.
>
> It might be worth having an even more explicit note that this is two
> separate globs separated by a '.', rather than one glob which matches
> a string formed by 'suite.test'. e.g., you do need 'sysctl*.*write'
> instead of 'sysctl*write' to match those tests. (And hope no-one gets

Good point.
Perhaps this would be clearer w/o `*.*`.
The sysctl test cases all begin with `sysctl_test_[api_]_dointvec_`,
so it's not the most amenable to a simple test glob.

I used '*exec*.parse*' in the commit desc, which might be easier to understand?

(Another alternative is to make it match on the 'suite.test' string,
but I'd rather not since glob doesn't really have something like
`[^.]+` and we'd have to actually create this string for each test,
given the current glob_match() api).

> scared off by the MS-DOS style *.* :-) )
>
> >  Say that we wanted to run the sysctl tests, we could do so via:
> >
> > @@ -35,6 +35,13 @@ Say that we wanted to run the sysctl tests, we could do so via:
> >         $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
> >         $ ./tools/testing/kunit/kunit.py run 'sysctl*'
> >
> > +We can filter down to just the "write" tests via:
> > +
> > +.. code-block:: bash
> > +
> > +       $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
> > +       $ ./tools/testing/kunit/kunit.py run 'sysctl*.*write*'
> > +
> >  We're paying the cost of building more tests than we need this way, but it's
> >  easier than fiddling with ``.kunitconfig`` files or commenting out
> >  ``kunit_suite``'s.
> > diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
> > index acd1de436f59..bab3ab940acc 100644
> > --- a/lib/kunit/executor.c
> > +++ b/lib/kunit/executor.c
> > @@ -17,21 +17,80 @@ extern struct kunit_suite * const * const __kunit_suites_end[];
> >  static char *filter_glob_param;
> >  module_param_named(filter_glob, filter_glob_param, charp, 0);
> >  MODULE_PARM_DESC(filter_glob,
> > -               "Filter which KUnit test suites run at boot-time, e.g. list*");
> > +               "Filter which KUnit test suites/tests run at boot-time, e.g. list* or list*.*del_test");
> > +
> > +/* glob_match() needs NULL terminated strings, so we need a copy of filter_glob_param. */
> > +struct kunit_test_filter {
> > +       char *suite_glob;
> > +       char *test_glob;
> > +};
> > +
> > +/* Split "suite_glob.test_glob" into two. Assumes filter_glob is not empty. */
> > +static void kunit_parse_filter_glob(struct kunit_test_filter *parsed,
> > +                                   const char *filter_glob)
> > +{
> > +       const int len = strlen(filter_glob);
> > +       const char *period = strchr(filter_glob, '.');
> > +
> > +       if (!period) {
> > +               parsed->suite_glob = kmalloc(len, GFP_KERNEL);
> > +               parsed->test_glob = NULL;
> > +               strcpy(parsed->suite_glob, filter_glob);
> > +               return;
> > +       }
> > +
> > +       parsed->suite_glob = kzalloc(period - filter_glob + 1, GFP_KERNEL);
> > +       parsed->test_glob = kzalloc(len - (period - filter_glob) + 1, GFP_KERNEL);
>
> If you're in the mood for premature optimisation (and I don't actually
> think this function is a good candidate for it), you could just
> replace the '.' with a '\0' in this function. It'd be easy to coalesce

That might be more readable/more obviously correct than this code.
It's harder to verify as-is if this has no off-by-one errors (it has a
unit test, so not that big of a problem).
e.g. this whole func becomes just
 const int len = strlen(filter_glob);
 const char *period = strchr(filter_glob, '.');

parsed->suite_glob=kzalloc(len, GFP_KERNEL);
strncpy(parsed->suite_glob, filter_glob, len);

if (!period) {
  parsed->suite_glob[period - filter_glob] = '\0';
  parsed->test_glob = parsed->suite_glob + (period - filter_glob) + 1;
} else {
  parsed->test_glob = NULL;
}

I was just nervous about this since it makes deallocating a filter more subtle.
What happens if we decide this is too much magic and have them as
separate allocations?

Code in executor.c might be updated (the most important spot), but I
imagine the unit tests are more likely to drift.
I just added a double-free in executor_test.c, and it caused a test
case several test files later to crash.

But I could add a static helper to free the test filter as well, which
makes this more palatable, imo.

Let me know what you think.

> the allocations (or possibly remove them entirely if we could modify
> filter_glob_param). That being said, this is probably not the place to
> try to be too clever, since it's only called once, so ignore this. :-)
>
> > +
> > +       strncpy(parsed->suite_glob, filter_glob, period - filter_glob);
> > +       strncpy(parsed->test_glob, period + 1, len - (period - filter_glob));
> > +}
> > +
> > +/* Create a copy of suite with only tests that match test_glob. */
> > +static struct kunit_suite *
> > +kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
> > +{
> > +       int n = 0;
> > +       struct kunit_case *filtered, *test_case;
> > +       struct kunit_suite *copy;
> > +
> > +       kunit_suite_for_each_test_case(suite, test_case) {
> > +               if (!test_glob || glob_match(test_glob, test_case->name))
> > +                       ++n;
> > +       }
> > +
> > +       if (n == 0)
> > +               return NULL;
> > +
> > +       /* Use memcpy to workaround copy->name being const. */
> > +       copy = kmalloc(sizeof(*copy), GFP_KERNEL);
> > +       memcpy(copy, suite, sizeof(*copy));
> > +
> > +       filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
> > +
> > +       n = 0;
> > +       kunit_suite_for_each_test_case(suite, test_case) {
> > +               if (!test_glob || glob_match(test_glob, test_case->name))
> > +                       filtered[n++] = *test_case;
> > +       }
> > +
> > +       copy->test_cases = filtered;
> > +       return copy;
> > +}
> >
> >  static char *kunit_shutdown;
> >  core_param(kunit_shutdown, kunit_shutdown, charp, 0644);
> >
> >  static struct kunit_suite * const *
> >  kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
> > -                       const char *filter_glob)
> > +                     struct kunit_test_filter *filter)
> >  {
> >         int i, n = 0;
> > -       struct kunit_suite **filtered;
> > +       struct kunit_suite **filtered, *filtered_suite;
> >
> >         n = 0;
> > -       for (i = 0; subsuite[i] != NULL; ++i) {
> > -               if (glob_match(filter_glob, subsuite[i]->name))
> > +       for (i = 0; subsuite[i]; ++i) {
> > +               if (glob_match(filter->suite_glob, subsuite[i]->name))
> >                         ++n;
> >         }
> >
> > @@ -44,8 +103,11 @@ kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
> >
> >         n = 0;
> >         for (i = 0; subsuite[i] != NULL; ++i) {
> > -               if (glob_match(filter_glob, subsuite[i]->name))
> > -                       filtered[n++] = subsuite[i];
> > +               if (!glob_match(filter->suite_glob, subsuite[i]->name))
> > +                       continue;
> > +               filtered_suite = kunit_filter_tests(subsuite[i], filter->test_glob);
> > +               if (filtered_suite)
> > +                       filtered[n++] = filtered_suite;
> >         }
> >         filtered[n] = NULL;
> >
> > @@ -57,12 +119,32 @@ struct suite_set {
> >         struct kunit_suite * const * const *end;
> >  };
> >
> > +static void kunit_free_subsuite(struct kunit_suite * const *subsuite)
> > +{
> > +       unsigned int i;
> > +
> > +       for (i = 0; subsuite[i]; i++)
> > +               kfree(subsuite[i]);
> > +
> > +       kfree(subsuite);
> > +}
> > +
> > +static void kunit_free_suite_set(struct suite_set suite_set)
> > +{
> > +       struct kunit_suite * const * const *suites;
> > +
> > +       for (suites = suite_set.start; suites < suite_set.end; suites++)
> > +               kunit_free_subsuite(*suites);
> > +       kfree(suite_set.start);
> > +}
> > +
> >  static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
> >                                             const char *filter_glob)
> >  {
> >         int i;
> >         struct kunit_suite * const **copy, * const *filtered_subsuite;
> >         struct suite_set filtered;
> > +       struct kunit_test_filter filter;
> >
> >         const size_t max = suite_set->end - suite_set->start;
> >
> > @@ -73,12 +155,17 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
> >                 return filtered;
> >         }
> >
> > +       kunit_parse_filter_glob(&filter, filter_glob);
> > +
> >         for (i = 0; i < max; ++i) {
> > -               filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], filter_glob);
> > +               filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], &filter);
> >                 if (filtered_subsuite)
> >                         *copy++ = filtered_subsuite;
> >         }
> >         filtered.end = copy;
> > +
> > +       kfree(filter.suite_glob);
> > +       kfree(filter.test_glob);
> >         return filtered;
> >  }
> >
> > @@ -126,9 +213,7 @@ int kunit_run_all_tests(void)
> >                 __kunit_test_suites_init(*suites);
> >
> >         if (filter_glob_param) { /* a copy was made of each array */
> > -               for (suites = suite_set.start; suites < suite_set.end; suites++)
> > -                       kfree(*suites);
> > -               kfree(suite_set.start);
> > +               kunit_free_suite_set(suite_set);
> >         }
> >
> >         kunit_handle_shutdown();
> > diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
> > index cdbe54b16501..dbb49c099e02 100644
> > --- a/lib/kunit/executor_test.c
> > +++ b/lib/kunit/executor_test.c
> > @@ -9,38 +9,103 @@
> >  #include <kunit/test.h>
> >
> >  static void kfree_at_end(struct kunit *test, const void *to_free);
> > +static void free_subsuite_at_end(struct kunit *test,
> > +                                struct kunit_suite *const *to_free);
> >  static struct kunit_suite *alloc_fake_suite(struct kunit *test,
> > -                                           const char *suite_name);
> > +                                           const char *suite_name,
> > +                                           struct kunit_case *test_cases);
> > +
> > +void dummy_test(struct kunit *test) {}
> > +
> > +struct kunit_case dummy_test_cases[] = {
> > +       /* .run_case is not important, just needs to be non-NULL */
> > +       { .name = "test1", .run_case = dummy_test },
> > +       { .name = "test2", .run_case = dummy_test },
> > +       {},
> > +};
> > +
> > +static void parse_filter_test(struct kunit *test)
> > +{
> > +       struct kunit_test_filter filter = {NULL, NULL};
> > +
> > +       kunit_parse_filter_glob(&filter, "suite");
> > +       KUNIT_EXPECT_STREQ(test, filter.suite_glob, "suite");
> > +       KUNIT_EXPECT_FALSE(test, filter.test_glob);
> > +       kfree(filter.suite_glob);
> > +       kfree(filter.test_glob);
> > +
> > +       kunit_parse_filter_glob(&filter, "suite.test");
> > +       KUNIT_EXPECT_STREQ(test, filter.suite_glob, "suite");
> > +       KUNIT_EXPECT_STREQ(test, filter.test_glob, "test");
> > +       kfree(filter.suite_glob);
> > +       kfree(filter.test_glob);
> > +}
> >
> >  static void filter_subsuite_test(struct kunit *test)
> >  {
> >         struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
> >         struct kunit_suite * const *filtered;
> > +       struct kunit_test_filter filter = {
> > +               .suite_glob = "suite2",
> > +               .test_glob = NULL,
> > +       };
> >
> > -       subsuite[0] = alloc_fake_suite(test, "suite1");
> > -       subsuite[1] = alloc_fake_suite(test, "suite2");
> > +       subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
> > +       subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
> >
> >         /* Want: suite1, suite2, NULL -> suite2, NULL */
> > -       filtered = kunit_filter_subsuite(subsuite, "suite2*");
> > +       filtered = kunit_filter_subsuite(subsuite, &filter);
> >         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
> > -       kfree_at_end(test, filtered);
> > +       free_subsuite_at_end(test, filtered);
> >
> > +       /* Validate we just have suite2 */
> >         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]);
> >         KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->name, "suite2");
> > +       KUNIT_EXPECT_FALSE(test, filtered[1]);
> > +}
> > +
> > +static void filter_subsuite_test_glob_test(struct kunit *test)
> > +{
> > +       struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
> > +       struct kunit_suite * const *filtered;
> > +       struct kunit_test_filter filter = {
> > +               .suite_glob = "suite2",
> > +               .test_glob = "test2",
> > +       };
> > +
> > +       subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
> > +       subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
> >
> > +       /* Want: suite1, suite2, NULL -> suite2 (just test1), NULL */
> > +       filtered = kunit_filter_subsuite(subsuite, &filter);
> > +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
> > +       free_subsuite_at_end(test, filtered);
> > +
> > +       /* Validate we just have suite2 */
> > +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]);
> > +       KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->name, "suite2");
> >         KUNIT_EXPECT_FALSE(test, filtered[1]);
> > +
> > +       /* Now validate we just have test2 */
> > +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]->test_cases);
> > +       KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->test_cases[0].name, "test2");
> > +       KUNIT_EXPECT_FALSE(test, filtered[0]->test_cases[1].name);
> >  }
> >
> >  static void filter_subsuite_to_empty_test(struct kunit *test)
> >  {
> >         struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
> >         struct kunit_suite * const *filtered;
> > +       struct kunit_test_filter filter = {
> > +               .suite_glob = "not_found",
> > +               .test_glob = NULL,
> > +       };
> >
> > -       subsuite[0] = alloc_fake_suite(test, "suite1");
> > -       subsuite[1] = alloc_fake_suite(test, "suite2");
> > +       subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
> > +       subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
> >
> > -       filtered = kunit_filter_subsuite(subsuite, "not_found");
> > -       kfree_at_end(test, filtered); /* just in case */
> > +       filtered = kunit_filter_subsuite(subsuite, &filter);
> > +       free_subsuite_at_end(test, filtered); /* just in case */
> >
> >         KUNIT_EXPECT_FALSE_MSG(test, filtered,
> >                                "should be NULL to indicate no match");
> > @@ -52,7 +117,7 @@ static void kfree_subsuites_at_end(struct kunit *test, struct suite_set *suite_s
> >
> >         kfree_at_end(test, suite_set->start);
> >         for (suites = suite_set->start; suites < suite_set->end; suites++)
> > -               kfree_at_end(test, *suites);
> > +               free_subsuite_at_end(test, *suites);
> >  }
> >
> >  static void filter_suites_test(struct kunit *test)
> > @@ -74,8 +139,8 @@ static void filter_suites_test(struct kunit *test)
> >         struct suite_set filtered = {.start = NULL, .end = NULL};
> >
> >         /* Emulate two files, each having one suite */
> > -       subsuites[0][0] = alloc_fake_suite(test, "suite0");
> > -       subsuites[1][0] = alloc_fake_suite(test, "suite1");
> > +       subsuites[0][0] = alloc_fake_suite(test, "suite0", dummy_test_cases);
> > +       subsuites[1][0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
> >
> >         /* Filter out suite1 */
> >         filtered = kunit_filter_suites(&suite_set, "suite0");
> > @@ -88,7 +153,9 @@ static void filter_suites_test(struct kunit *test)
> >  }
> >
> >  static struct kunit_case executor_test_cases[] = {
> > +       KUNIT_CASE(parse_filter_test),
> >         KUNIT_CASE(filter_subsuite_test),
> > +       KUNIT_CASE(filter_subsuite_test_glob_test),
> >         KUNIT_CASE(filter_subsuite_to_empty_test),
> >         KUNIT_CASE(filter_suites_test),
> >         {}
> > @@ -120,14 +187,30 @@ static void kfree_at_end(struct kunit *test, const void *to_free)
> >                                      (void *)to_free);
> >  }
> >
> > +static void free_subsuite_res_free(struct kunit_resource *res)
> > +{
> > +       kunit_free_subsuite(res->data);
> > +}
> > +
> > +static void free_subsuite_at_end(struct kunit *test,
> > +                                struct kunit_suite *const *to_free)
> > +{
> > +       if (IS_ERR_OR_NULL(to_free))
> > +               return;
> > +       kunit_alloc_and_get_resource(test, NULL, free_subsuite_res_free,
> > +                                    GFP_KERNEL, (void *)to_free);
> > +}
> > +
> >  static struct kunit_suite *alloc_fake_suite(struct kunit *test,
> > -                                           const char *suite_name)
> > +                                           const char *suite_name,
> > +                                           struct kunit_case *test_cases)
> >  {
> >         struct kunit_suite *suite;
> >
> >         /* We normally never expect to allocate suites, hence the non-const cast. */
> >         suite = kunit_kzalloc(test, sizeof(*suite), GFP_KERNEL);
> >         strncpy((char *)suite->name, suite_name, sizeof(suite->name) - 1);
> > +       suite->test_cases = test_cases;
> >
> >         return suite;
> >  }
> >
> > base-commit: 36a21d51725af2ce0700c6ebcb6b9594aac658a6
> > --
> > 2.32.0.605.g8dce9f2422-goog
> >

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