kunit: allow kunit tests to be loaded as a module

As tests are added to kunit, it will become less feasible to execute
all built tests together.  By supporting modular tests we provide
a simple way to do selective execution on a running system; specifying

CONFIG_KUNIT=y
CONFIG_KUNIT_EXAMPLE_TEST=m

...means we can simply "insmod example-test.ko" to run the tests.

To achieve this we need to do the following:

o export the required symbols in kunit
o string-stream tests utilize non-exported symbols so for now we skip
  building them when CONFIG_KUNIT_TEST=m.
o drivers/base/power/qos-test.c contains a few unexported interface
  references, namely freq_qos_read_value() and freq_constraints_init().
  Both of these could be potentially defined as static inline functions
  in include/linux/pm_qos.h, but for now we simply avoid supporting
  module build for that test suite.
o support a new way of declaring test suites.  Because a module cannot
  do multiple late_initcall()s, we provide a kunit_test_suites() macro
  to declare multiple suites within the same module at once.
o some test module names would have been too general ("test-test"
  and "example-test" for kunit tests, "inode-test" for ext4 tests);
  rename these as appropriate ("kunit-test", "kunit-example-test"
  and "ext4-inode-test" respectively).

Also define kunit_test_suite() via kunit_test_suites()
as callers in other trees may need the old definition.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits
Acked-by: David Gow <davidgow@google.com> # For list-test
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 334 insertions, 0 deletions

diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
new file mode 100644
index 000000000000..ccb8d2e332f7
--- /dev/null
+++ b/lib/kunit/kunit-test.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for core test infrastructure.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+#include <kunit/test.h>
+
+#include "try-catch-impl.h"
+
+struct kunit_try_catch_test_context {
+	struct kunit_try_catch *try_catch;
+	bool function_called;
+};
+
+static void kunit_test_successful_try(void *data)
+{
+	struct kunit *test = data;
+	struct kunit_try_catch_test_context *ctx = test->priv;
+
+	ctx->function_called = true;
+}
+
+static void kunit_test_no_catch(void *data)
+{
+	struct kunit *test = data;
+
+	KUNIT_FAIL(test, "Catch should not be called\n");
+}
+
+static void kunit_test_try_catch_successful_try_no_catch(struct kunit *test)
+{
+	struct kunit_try_catch_test_context *ctx = test->priv;
+	struct kunit_try_catch *try_catch = ctx->try_catch;
+
+	kunit_try_catch_init(try_catch,
+			     test,
+			     kunit_test_successful_try,
+			     kunit_test_no_catch);
+	kunit_try_catch_run(try_catch, test);
+
+	KUNIT_EXPECT_TRUE(test, ctx->function_called);
+}
+
+static void kunit_test_unsuccessful_try(void *data)
+{
+	struct kunit *test = data;
+	struct kunit_try_catch_test_context *ctx = test->priv;
+	struct kunit_try_catch *try_catch = ctx->try_catch;
+
+	kunit_try_catch_throw(try_catch);
+	KUNIT_FAIL(test, "This line should never be reached\n");
+}
+
+static void kunit_test_catch(void *data)
+{
+	struct kunit *test = data;
+	struct kunit_try_catch_test_context *ctx = test->priv;
+
+	ctx->function_called = true;
+}
+
+static void kunit_test_try_catch_unsuccessful_try_does_catch(struct kunit *test)
+{
+	struct kunit_try_catch_test_context *ctx = test->priv;
+	struct kunit_try_catch *try_catch = ctx->try_catch;
+
+	kunit_try_catch_init(try_catch,
+			     test,
+			     kunit_test_unsuccessful_try,
+			     kunit_test_catch);
+	kunit_try_catch_run(try_catch, test);
+
+	KUNIT_EXPECT_TRUE(test, ctx->function_called);
+}
+
+static int kunit_try_catch_test_init(struct kunit *test)
+{
+	struct kunit_try_catch_test_context *ctx;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+	test->priv = ctx;
+
+	ctx->try_catch = kunit_kmalloc(test,
+				       sizeof(*ctx->try_catch),
+				       GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->try_catch);
+
+	return 0;
+}
+
+static struct kunit_case kunit_try_catch_test_cases[] = {
+	KUNIT_CASE(kunit_test_try_catch_successful_try_no_catch),
+	KUNIT_CASE(kunit_test_try_catch_unsuccessful_try_does_catch),
+	{}
+};
+
+static struct kunit_suite kunit_try_catch_test_suite = {
+	.name = "kunit-try-catch-test",
+	.init = kunit_try_catch_test_init,
+	.test_cases = kunit_try_catch_test_cases,
+};
+
+/*
+ * Context for testing test managed resources
+ * is_resource_initialized is used to test arbitrary resources
+ */
+struct kunit_test_resource_context {
+	struct kunit test;
+	bool is_resource_initialized;
+	int allocate_order[2];
+	int free_order[2];
+};
+
+static int fake_resource_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_test_resource_context *ctx = context;
+
+	res->allocation = &ctx->is_resource_initialized;
+	ctx->is_resource_initialized = true;
+	return 0;
+}
+
+static void fake_resource_free(struct kunit_resource *res)
+{
+	bool *is_resource_initialized = res->allocation;
+
+	*is_resource_initialized = false;
+}
+
+static void kunit_resource_test_init_resources(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+
+	kunit_init_test(&ctx->test, "testing_test_init_test");
+
+	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
+}
+
+static void kunit_resource_test_alloc_resource(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+	struct kunit_resource *res;
+	kunit_resource_free_t free = fake_resource_free;
+
+	res = kunit_alloc_and_get_resource(&ctx->test,
+					   fake_resource_init,
+					   fake_resource_free,
+					   GFP_KERNEL,
+					   ctx);
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, res);
+	KUNIT_EXPECT_PTR_EQ(test,
+			    &ctx->is_resource_initialized,
+			    (bool *) res->allocation);
+	KUNIT_EXPECT_TRUE(test, list_is_last(&res->node, &ctx->test.resources));
+	KUNIT_EXPECT_PTR_EQ(test, free, res->free);
+}
+
+static void kunit_resource_test_destroy_resource(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+	struct kunit_resource *res = kunit_alloc_and_get_resource(
+			&ctx->test,
+			fake_resource_init,
+			fake_resource_free,
+			GFP_KERNEL,
+			ctx);
+
+	KUNIT_ASSERT_FALSE(test,
+			   kunit_resource_destroy(&ctx->test,
+						  kunit_resource_instance_match,
+						  res->free,
+						  res->allocation));
+
+	KUNIT_EXPECT_FALSE(test, ctx->is_resource_initialized);
+	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
+}
+
+static void kunit_resource_test_cleanup_resources(struct kunit *test)
+{
+	int i;
+	struct kunit_test_resource_context *ctx = test->priv;
+	struct kunit_resource *resources[5];
+
+	for (i = 0; i < ARRAY_SIZE(resources); i++) {
+		resources[i] = kunit_alloc_and_get_resource(&ctx->test,
+							    fake_resource_init,
+							    fake_resource_free,
+							    GFP_KERNEL,
+							    ctx);
+	}
+
+	kunit_cleanup(&ctx->test);
+
+	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
+}
+
+static void kunit_resource_test_mark_order(int order_array[],
+					   size_t order_size,
+					   int key)
+{
+	int i;
+
+	for (i = 0; i < order_size && order_array[i]; i++)
+		;
+
+	order_array[i] = key;
+}
+
+#define KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, order_field, key)		       \
+		kunit_resource_test_mark_order(ctx->order_field,	       \
+					       ARRAY_SIZE(ctx->order_field),   \
+					       key)
+
+static int fake_resource_2_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_test_resource_context *ctx = context;
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, allocate_order, 2);
+
+	res->allocation = ctx;
+
+	return 0;
+}
+
+static void fake_resource_2_free(struct kunit_resource *res)
+{
+	struct kunit_test_resource_context *ctx = res->allocation;
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, free_order, 2);
+}
+
+static int fake_resource_1_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_test_resource_context *ctx = context;
+
+	kunit_alloc_and_get_resource(&ctx->test,
+				     fake_resource_2_init,
+				     fake_resource_2_free,
+				     GFP_KERNEL,
+				     ctx);
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, allocate_order, 1);
+
+	res->allocation = ctx;
+
+	return 0;
+}
+
+static void fake_resource_1_free(struct kunit_resource *res)
+{
+	struct kunit_test_resource_context *ctx = res->allocation;
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, free_order, 1);
+}
+
+/*
+ * TODO(brendanhiggins@google.com): replace the arrays that keep track of the
+ * order of allocation and freeing with strict mocks using the IN_SEQUENCE macro
+ * to assert allocation and freeing order when the feature becomes available.
+ */
+static void kunit_resource_test_proper_free_ordering(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+
+	/* fake_resource_1 allocates a fake_resource_2 in its init. */
+	kunit_alloc_and_get_resource(&ctx->test,
+				     fake_resource_1_init,
+				     fake_resource_1_free,
+				     GFP_KERNEL,
+				     ctx);
+
+	/*
+	 * Since fake_resource_2_init calls KUNIT_RESOURCE_TEST_MARK_ORDER
+	 * before returning to fake_resource_1_init, it should be the first to
+	 * put its key in the allocate_order array.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->allocate_order[0], 2);
+	KUNIT_EXPECT_EQ(test, ctx->allocate_order[1], 1);
+
+	kunit_cleanup(&ctx->test);
+
+	/*
+	 * Because fake_resource_2 finishes allocation before fake_resource_1,
+	 * fake_resource_1 should be freed first since it could depend on
+	 * fake_resource_2.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->free_order[0], 1);
+	KUNIT_EXPECT_EQ(test, ctx->free_order[1], 2);
+}
+
+static int kunit_resource_test_init(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx =
+			kzalloc(sizeof(*ctx), GFP_KERNEL);
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	test->priv = ctx;
+
+	kunit_init_test(&ctx->test, "test_test_context");
+
+	return 0;
+}
+
+static void kunit_resource_test_exit(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+
+	kunit_cleanup(&ctx->test);
+	kfree(ctx);
+}
+
+static struct kunit_case kunit_resource_test_cases[] = {
+	KUNIT_CASE(kunit_resource_test_init_resources),
+	KUNIT_CASE(kunit_resource_test_alloc_resource),
+	KUNIT_CASE(kunit_resource_test_destroy_resource),
+	KUNIT_CASE(kunit_resource_test_cleanup_resources),
+	KUNIT_CASE(kunit_resource_test_proper_free_ordering),
+	{}
+};
+
+static struct kunit_suite kunit_resource_test_suite = {
+	.name = "kunit-resource-test",
+	.init = kunit_resource_test_init,
+	.exit = kunit_resource_test_exit,
+	.test_cases = kunit_resource_test_cases,
+};
+kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite);
+
+MODULE_LICENSE("GPL v2");