[PATCH 2/5] kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites

From: David Gow
Date: Sat Jun 18 2022 - 05:03:51 EST

From: Daniel Latypov <dlatypov@xxxxxxxxxx>

We currently store kunit suites in the .kunit_test_suites ELF section as
a `struct kunit_suite***` (modulo some `const`s).
For every test file, we store a struct kunit_suite** NULL-terminated array.

This adds quite a bit of complexity to the test filtering code in the
executor.

Instead, let's just make the .kunit_test_suites section contain a single
giant array of struct kunit_suite pointers, which can then be directly
manipulated.

Signed-off-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
Co-developed-by: David Gow <davidgow@xxxxxxxxxx>
Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
---

Original RFC version of part of this patch:
https://lore.kernel.org/linux-kselftest/20211013191320.2490913-1-dlatypov@xxxxxxxxxx/

This version updates the way the .kunit_test_suites section is
generated, rather than constructing the flattened version at runtime.

---
include/kunit/test.h | 13 ++--
include/linux/module.h | 2 +-
lib/kunit/executor.c | 117 ++++++++------------------------
lib/kunit/executor_test.c | 139 +++++++++++---------------------------
lib/kunit/test.c | 18 ++---
5 files changed, 82 insertions(+), 207 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 54306271cfbf..bd8d772979a6 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -237,9 +237,9 @@ size_t kunit_suite_num_test_cases(struct kunit_suite *suite);
unsigned int kunit_test_case_num(struct kunit_suite *suite,
struct kunit_case *test_case);

-int __kunit_test_suites_init(struct kunit_suite * const * const suites);
+int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites);

-void __kunit_test_suites_exit(struct kunit_suite **suites);
+void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites);

#if IS_BUILTIN(CONFIG_KUNIT)
int kunit_run_all_tests(void);
@@ -250,10 +250,10 @@ static inline int kunit_run_all_tests(void)
}
#endif /* IS_BUILTIN(CONFIG_KUNIT) */

-#define __kunit_test_suites(unique_array, unique_suites, ...) \
- static struct kunit_suite *unique_array[] = { __VA_ARGS__, NULL }; \
- static struct kunit_suite **unique_suites \
- __used __section(".kunit_test_suites") = unique_array
+#define __kunit_test_suites(unique_array, ...) \
+ static struct kunit_suite *unique_array[] \
+ __aligned(sizeof(struct kunit_suite *)) \
+ __used __section(".kunit_test_suites") = { __VA_ARGS__ }

/**
* kunit_test_suites() - used to register one or more &struct kunit_suite
@@ -271,7 +271,6 @@ static inline int kunit_run_all_tests(void)
*/
#define kunit_test_suites(__suites...) \
__kunit_test_suites(__UNIQUE_ID(array), \
- __UNIQUE_ID(suites), \
##__suites)

#define kunit_test_suite(suite) kunit_test_suites(&suite)
diff --git a/include/linux/module.h b/include/linux/module.h
index e3cd6c325794..a9e9180ba3c3 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -507,7 +507,7 @@ struct module {
#endif
#ifdef CONFIG_KUNIT
int num_kunit_suites;
- struct kunit_suite ***kunit_suites;
+ struct kunit_suite **kunit_suites;
#endif


diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index 96f96e42ce06..53fab8d76a00 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -9,8 +9,8 @@
* These symbols point to the .kunit_test_suites section and are defined in
* include/asm-generic/vmlinux.lds.h, and consequently must be extern.
*/
-extern struct kunit_suite * const * const __kunit_suites_start[];
-extern struct kunit_suite * const * const __kunit_suites_end[];
+extern struct kunit_suite * const __kunit_suites_start[];
+extern struct kunit_suite * const __kunit_suites_end[];

#if IS_BUILTIN(CONFIG_KUNIT)

@@ -92,62 +92,18 @@ kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
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,
- struct kunit_test_filter *filter)
-{
- int i, n = 0;
- struct kunit_suite **filtered, *filtered_suite;
-
- n = 0;
- for (i = 0; subsuite[i]; ++i) {
- if (glob_match(filter->suite_glob, subsuite[i]->name))
- ++n;
- }
-
- if (n == 0)
- return NULL;
-
- filtered = kmalloc_array(n + 1, sizeof(*filtered), GFP_KERNEL);
- if (!filtered)
- return ERR_PTR(-ENOMEM);
-
- n = 0;
- for (i = 0; subsuite[i] != NULL; ++i) {
- if (!glob_match(filter->suite_glob, subsuite[i]->name))
- continue;
- filtered_suite = kunit_filter_tests(subsuite[i], filter->test_glob);
- if (IS_ERR(filtered_suite))
- return ERR_CAST(filtered_suite);
- else if (filtered_suite)
- filtered[n++] = filtered_suite;
- }
- filtered[n] = NULL;
-
- return filtered;
-}
-
+/* Stores a NULL-terminated array of suites. */
struct suite_set {
- struct kunit_suite * const * const *start;
- struct kunit_suite * const * const *end;
+ struct kunit_suite * const *start;
+ struct kunit_suite * 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;
+ struct kunit_suite * const *suites;

for (suites = suite_set.start; suites < suite_set.end; suites++)
- kunit_free_subsuite(*suites);
+ kfree(*suites);
kfree(suite_set.start);
}

@@ -156,10 +112,11 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
int *err)
{
int i;
- struct kunit_suite * const **copy, * const *filtered_subsuite;
+ struct kunit_suite **copy, *filtered_suite;
struct suite_set filtered;
struct kunit_test_filter filter;

+ /* Note: this includes space for the terminating NULL. */
const size_t max = suite_set->end - suite_set->start;

copy = kmalloc_array(max, sizeof(*filtered.start), GFP_KERNEL);
@@ -171,15 +128,21 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,

kunit_parse_filter_glob(&filter, filter_glob);

- for (i = 0; i < max; ++i) {
- filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], &filter);
- if (IS_ERR(filtered_subsuite)) {
- *err = PTR_ERR(filtered_subsuite);
+ for (i = 0; suite_set->start[i] != NULL; i++) {
+ if (!glob_match(filter.suite_glob, suite_set->start[i]->name))
+ continue;
+
+ filtered_suite = kunit_filter_tests(suite_set->start[i], filter.test_glob);
+ if (IS_ERR(filtered_suite)) {
+ *err = PTR_ERR(filtered_suite);
return filtered;
}
- if (filtered_subsuite)
- *copy++ = filtered_subsuite;
+ if (!filtered_suite)
+ continue;
+
+ *copy++ = filtered_suite;
}
+ *copy = NULL;
filtered.end = copy;

kfree(filter.suite_glob);
@@ -201,52 +164,33 @@ static void kunit_handle_shutdown(void)

}

-static void kunit_print_tap_header(struct suite_set *suite_set)
-{
- struct kunit_suite * const * const *suites, * const *subsuite;
- int num_of_suites = 0;
-
- for (suites = suite_set->start; suites < suite_set->end; suites++)
- for (subsuite = *suites; *subsuite != NULL; subsuite++)
- num_of_suites++;
-
- pr_info("TAP version 14\n");
- pr_info("1..%d\n", num_of_suites);
-}
-
static void kunit_exec_run_tests(struct suite_set *suite_set)
{
- struct kunit_suite * const * const *suites;
+ size_t num_suites = suite_set->end - suite_set->start;

- kunit_print_tap_header(suite_set);
+ pr_info("TAP version 14\n");
+ pr_info("1..%zu\n", num_suites);

- for (suites = suite_set->start; suites < suite_set->end; suites++)
- __kunit_test_suites_init(*suites);
+ __kunit_test_suites_init(suite_set->start, num_suites);
}

static void kunit_exec_list_tests(struct suite_set *suite_set)
{
- unsigned int i;
- struct kunit_suite * const * const *suites;
+ struct kunit_suite * const *suites;
struct kunit_case *test_case;

/* Hack: print a tap header so kunit.py can find the start of KUnit output. */
pr_info("TAP version 14\n");

for (suites = suite_set->start; suites < suite_set->end; suites++)
- for (i = 0; (*suites)[i] != NULL; i++) {
- kunit_suite_for_each_test_case((*suites)[i], test_case) {
- pr_info("%s.%s\n", (*suites)[i]->name, test_case->name);
- }
+ kunit_suite_for_each_test_case((*suites), test_case) {
+ pr_info("%s.%s\n", (*suites)->name, test_case->name);
}
}

int kunit_run_all_tests(void)
{
- struct suite_set suite_set = {
- .start = __kunit_suites_start,
- .end = __kunit_suites_end,
- };
+ struct suite_set suite_set = {__kunit_suites_start, __kunit_suites_end};
int err = 0;

if (filter_glob_param) {
@@ -264,11 +208,10 @@ int kunit_run_all_tests(void)
else
pr_err("kunit executor: unknown action '%s'\n", action_param);

- if (filter_glob_param) { /* a copy was made of each array */
+ if (filter_glob_param) { /* a copy was made of each suite */
kunit_free_suite_set(suite_set);
}

-
out:
kunit_handle_shutdown();
return err;
diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
index eac6ff480273..acbc44af49ed 100644
--- a/lib/kunit/executor_test.c
+++ b/lib/kunit/executor_test.c
@@ -9,8 +9,6 @@
#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,
struct kunit_case *test_cases);
@@ -41,126 +39,81 @@ static void parse_filter_test(struct kunit *test)
kfree(filter.test_glob);
}

-static void filter_subsuite_test(struct kunit *test)
+static void filter_suites_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,
- };
+ 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_test_cases);
subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);

/* Want: suite1, suite2, NULL -> suite2, NULL */
- filtered = kunit_filter_subsuite(subsuite, &filter);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
- free_subsuite_at_end(test, filtered);
+ got = kunit_filter_suites(&suite_set, "suite2", &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 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]);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
+ KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->name, "suite2");
+ // DO NOT SUBMIT: null-terminated for now.
+ KUNIT_ASSERT_EQ(test, got.end - got.start, 1);
+ KUNIT_EXPECT_FALSE(test, *got.end);
}

-static void filter_subsuite_test_glob_test(struct kunit *test)
+static void filter_suites_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",
- };
+ 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_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);
+ got = kunit_filter_suites(&suite_set, "suite2.test2", &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 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]);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
+ KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->name, "suite2");
+ KUNIT_ASSERT_EQ(test, got.end - got.start, 1);
+ KUNIT_EXPECT_FALSE(test, *got.end);

/* 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);
+ 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_subsuite_to_empty_test(struct kunit *test)
+static void filter_suites_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,
- };
+ 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_test_cases);
subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);

- 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");
-}
-
-static void kfree_subsuites_at_end(struct kunit *test, struct suite_set *suite_set)
-{
- struct kunit_suite * const * const *suites;
-
- kfree_at_end(test, suite_set->start);
- for (suites = suite_set->start; suites < suite_set->end; suites++)
- free_subsuite_at_end(test, *suites);
-}
-
-static void filter_suites_test(struct kunit *test)
-{
- /* Suites per-file are stored as a NULL terminated array */
- struct kunit_suite *subsuites[2][2] = {
- {NULL, NULL},
- {NULL, NULL},
- };
- /* Match the memory layout of suite_set */
- struct kunit_suite * const * const suites[2] = {
- subsuites[0], subsuites[1],
- };
-
- const struct suite_set suite_set = {
- .start = suites,
- .end = suites + 2,
- };
- struct suite_set filtered = {.start = NULL, .end = NULL};
- int err = 0;
-
- /* Emulate two files, each having one suite */
- subsuites[0][0] = alloc_fake_suite(test, "suite0", dummy_test_cases);
- subsuites[1][0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+ got = kunit_filter_suites(&suite_set, "not_found", &err);
+ KUNIT_ASSERT_EQ(test, err, 0);
+ kfree_at_end(test, got.start); /* just in case */

- /* Filter out suite1 */
- filtered = kunit_filter_suites(&suite_set, "suite0", &err);
- kfree_subsuites_at_end(test, &filtered); /* let us use ASSERTs without leaking */
- KUNIT_EXPECT_EQ(test, err, 0);
- KUNIT_ASSERT_EQ(test, filtered.end - filtered.start, (ptrdiff_t)1);
-
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0]);
- KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0][0]);
- KUNIT_EXPECT_STREQ(test, (const char *)filtered.start[0][0]->name, "suite0");
+ KUNIT_EXPECT_PTR_EQ_MSG(test, got.start, got.end,
+ "should be empty to indicate no match");
}

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),
+ KUNIT_CASE(filter_suites_test_glob_test),
+ KUNIT_CASE(filter_suites_to_empty_test),
{}
};

@@ -190,20 +143,6 @@ 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_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,
struct kunit_case *test_cases)
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 3052526b9b89..b6495c7f9a7e 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -582,11 +582,11 @@ static void kunit_init_suite(struct kunit_suite *suite)
suite->suite_init_err = 0;
}

-int __kunit_test_suites_init(struct kunit_suite * const * const suites)
+int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites)
{
unsigned int i;

- for (i = 0; suites[i] != NULL; i++) {
+ for (i = 0; i < num_suites; i++) {
kunit_init_suite(suites[i]);
kunit_run_tests(suites[i]);
}
@@ -599,11 +599,11 @@ static void kunit_exit_suite(struct kunit_suite *suite)
kunit_debugfs_destroy_suite(suite);
}

-void __kunit_test_suites_exit(struct kunit_suite **suites)
+void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites)
{
unsigned int i;

- for (i = 0; suites[i] != NULL; i++)
+ for (i = 0; i < num_suites; i++)
kunit_exit_suite(suites[i]);

kunit_suite_counter = 1;
@@ -613,18 +613,12 @@ EXPORT_SYMBOL_GPL(__kunit_test_suites_exit);
#ifdef CONFIG_MODULES
static void kunit_module_init(struct module *mod)
{
- unsigned int i;
-
- for (i = 0; i < mod->num_kunit_suites; i++)
- __kunit_test_suites_init(mod->kunit_suites[i]);
+ __kunit_test_suites_init(mod->kunit_suites, mod->num_kunit_suites);
}

static void kunit_module_exit(struct module *mod)
{
- unsigned int i;
-
- for (i = 0; i < mod->num_kunit_suites; i++)
- __kunit_test_suites_exit(mod->kunit_suites[i]);
+ __kunit_test_suites_exit(mod->kunit_suites, mod->num_kunit_suites);
}

static int kunit_module_notify(struct notifier_block *nb, unsigned long val,
--
2.36.1.476.g0c4daa206d-goog