[PATCH v6 2/3] revocable: Add Kunit test cases

Tzung-Bi Shih
2025-11-06T15:23:51Z

Add Kunit test cases for the revocable API.

The test cases cover the following scenarios:
- Basic: Verifies that a consumer can successfully access the resource
provided via the provider.
- Revocation: Verifies that after the provider revokes the resource,
the consumer correctly receives a NULL pointer on a subsequent access.
- Macro: Same as "Revocation" but uses the REVOCABLE_TRY_ACCESS_WITH()
and REVOCABLE_TRY_ACCESS_SCOPED().

A way to run the test:
$ ./tools/testing/kunit/kunit.py run \
--kconfig_add CONFIG_REVOCABLE_KUNIT_TEST=y \
revocable_test

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
v6:
- Rename REVOCABLE_TRY_ACCESS_WITH() -> REVOCABLE_TRY_ACCESS_SCOPED().
- Add tests for new REVOCABLE_TRY_ACCESS_WITH().

v5: https://lore.kernel.org/chrome-platform/20251016054204.1523139-3-tzungbi@kernel.org
- No changes.

v4: https://lore.kernel.org/chrome-platform/20250923075302.591026-3-tzungbi@kernel.org
- REVOCABLE() -> REVOCABLE_TRY_ACCESS_WITH().
- revocable_release() -> revocable_withdraw_access().

v3: https://lore.kernel.org/chrome-platform/20250912081718.3827390-3-tzungbi@kernel.org
- No changes.

v2: https://lore.kernel.org/chrome-platform/20250820081645.847919-3-tzungbi@kernel.org
- New in the series.

MAINTAINERS | 1 +
drivers/base/Kconfig | 8 ++
drivers/base/Makefile | 3 +
drivers/base/revocable_test.c | 139 ++++++++++++++++++++++++++++++++++
4 files changed, 151 insertions(+)
create mode 100644 drivers/base/revocable_test.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 811ea5f53d2a..63b96b786e7a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22157,6 +22157,7 @@ M: Tzung-Bi Shih <tzungbi@kernel.org>
L: linux-kernel@vger.kernel.org
S: Maintained
F: drivers/base/revocable.c
+F: drivers/base/revocable_test.c
F: include/linux/revocable.h

RFKILL
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 1786d87b29e2..8f7d7b9d81ac 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -250,3 +250,11 @@ config FW_DEVLINK_SYNC_STATE_TIMEOUT
work on.

endmenu
+
+# Kunit test cases
+config REVOCABLE_KUNIT_TEST
+ tristate "Kunit tests for revocable" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ Kunit tests for the revocable API.
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index bdf854694e39..4185aaa9bbb9 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -35,3 +35,6 @@ ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
# define_trace.h needs to know how to find our header
CFLAGS_trace.o := -I$(src)
obj-$(CONFIG_TRACING) += trace.o
+
+# Kunit test cases
+obj-$(CONFIG_REVOCABLE_KUNIT_TEST) += revocable_test.o
diff --git a/drivers/base/revocable_test.c b/drivers/base/revocable_test.c
new file mode 100644
index 000000000000..cc1a9bbe8718
--- /dev/null
+++ b/drivers/base/revocable_test.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Kunit tests for the revocable API.
+ *
+ * The test cases cover the following scenarios:
+ *
+ * - Basic: Verifies that a consumer can successfully access the resource
+ * provided via the provider.
+ *
+ * - Revocation: Verifies that after the provider revokes the resource,
+ * the consumer correctly receives a NULL pointer on a subsequent access.
+ *
+ * - Macro: Same as "Revocation" but uses the REVOCABLE_TRY_ACCESS_WITH()
+ * and REVOCABLE_TRY_ACCESS_SCOPED().
+ */
+
+#include <kunit/test.h>
+#include <linux/revocable.h>
+
+static void revocable_test_basic(struct kunit *test)
+{
+ struct revocable_provider *rp;
+ struct revocable *rev;
+ void *real_res = (void *)0x12345678, *res;
+
+ rp = revocable_provider_alloc(real_res);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rp);
+
+ rev = revocable_alloc(rp);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rev);
+
+ res = revocable_try_access(rev);
+ KUNIT_EXPECT_PTR_EQ(test, res, real_res);
+ revocable_withdraw_access(rev);
+
+ revocable_free(rev);
+ revocable_provider_revoke(rp);
+}
+
+static void revocable_test_revocation(struct kunit *test)
+{
+ struct revocable_provider *rp;
+ struct revocable *rev;
+ void *real_res = (void *)0x12345678, *res;
+
+ rp = revocable_provider_alloc(real_res);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rp);
+
+ rev = revocable_alloc(rp);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rev);
+
+ res = revocable_try_access(rev);
+ KUNIT_EXPECT_PTR_EQ(test, res, real_res);
+ revocable_withdraw_access(rev);
+
+ revocable_provider_revoke(rp);
+
+ res = revocable_try_access(rev);
+ KUNIT_EXPECT_PTR_EQ(test, res, NULL);
+ revocable_withdraw_access(rev);
+
+ revocable_free(rev);
+}
+
+static void revocable_test_macro(struct kunit *test)
+{
+ struct revocable_provider *rp;
+ struct revocable *rev;
+ void *real_res = (void *)0x12345678, *res;
+
+ rp = revocable_provider_alloc(real_res);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rp);
+
+ rev = revocable_alloc(rp);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rev);
+
+ {
+ REVOCABLE_TRY_ACCESS_WITH(rev, res);
+ KUNIT_EXPECT_PTR_EQ(test, res, real_res);
+ }
+
+ revocable_provider_revoke(rp);
+
+ {
+ REVOCABLE_TRY_ACCESS_WITH(rev, res);
+ KUNIT_EXPECT_PTR_EQ(test, res, NULL);
+ }
+
+ revocable_free(rev);
+}
+
+static void revocable_test_macro2(struct kunit *test)
+{
+ struct revocable_provider *rp;
+ struct revocable *rev;
+ void *real_res = (void *)0x12345678, *res;
+ bool accessed;
+
+ rp = revocable_provider_alloc(real_res);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rp);
+
+ rev = revocable_alloc(rp);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, rev);
+
+ accessed = false;
+ REVOCABLE_TRY_ACCESS_SCOPED(rev, res) {
+ KUNIT_EXPECT_PTR_EQ(test, res, real_res);
+ accessed = true;
+ }
+ KUNIT_EXPECT_TRUE(test, accessed);
+
+ revocable_provider_revoke(rp);
+
+ accessed = false;
+ REVOCABLE_TRY_ACCESS_SCOPED(rev, res) {
+ KUNIT_EXPECT_PTR_EQ(test, res, NULL);
+ accessed = true;
+ }
+ KUNIT_EXPECT_TRUE(test, accessed);
+
+ revocable_free(rev);
+}
+
+static struct kunit_case revocable_test_cases[] = {
+ KUNIT_CASE(revocable_test_basic),
+ KUNIT_CASE(revocable_test_revocation),
+ KUNIT_CASE(revocable_test_macro),
+ KUNIT_CASE(revocable_test_macro2),
+ {}
+};
+
+static struct kunit_suite revocable_test_suite = {
+ .name = "revocable_test",
+ .test_cases = revocable_test_cases,
+};
+
+kunit_test_suite(revocable_test_suite);
--
2.48.1