[PATCH v2 3/3] drivers: base: test: Add ...find_device_by...(... NULL) tests

[Brian Norris]

We recently updated these device_match*() (and therefore, various
*find_device_by*()) functions to return a consistent 'false' value when
trying to match a NULL handle. Add tests for this.

This provides regression-testing coverage for the sorts of bugs that
underly commit 5c8418cf4025 ("PCI/pwrctrl: Unregister platform device
only if one actually exists").

Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
---

Changes in v2:
 * Keep "devm" and "match" tests in separate suites

 drivers/base/test/platform-device-test.c | 42 +++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/base/test/platform-device-test.c b/drivers/base/test/platform-device-test.c
index ea05b8785743..c8d4b0a385f2 100644
--- a/drivers/base/test/platform-device-test.c
+++ b/drivers/base/test/platform-device-test.c
@@ -3,6 +3,8 @@
 #include <kunit/resource.h>
 
 #include <linux/device.h>
+#include <linux/device/bus.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 
 #define DEVICE_NAME "test"
@@ -217,7 +219,45 @@ static struct kunit_suite platform_device_devm_test_suite = {
 	.test_cases = platform_device_devm_tests,
 };
 
-kunit_test_suite(platform_device_devm_test_suite);
+static void platform_device_find_by_null_test(struct kunit *test)
+{
+	struct platform_device *pdev;
+	int ret;
+
+	pdev = platform_device_alloc(DEVICE_NAME, PLATFORM_DEVID_NONE);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	ret = platform_device_add(pdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_PTR_EQ(test, of_find_device_by_node(NULL), NULL);
+
+	KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_of_node(&platform_bus_type, NULL), NULL);
+	KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_fwnode(&platform_bus_type, NULL), NULL);
+	KUNIT_EXPECT_PTR_EQ(test, bus_find_device_by_acpi_dev(&platform_bus_type, NULL), NULL);
+
+	KUNIT_EXPECT_FALSE(test, device_match_of_node(&pdev->dev, NULL));
+	KUNIT_EXPECT_FALSE(test, device_match_fwnode(&pdev->dev, NULL));
+	KUNIT_EXPECT_FALSE(test, device_match_acpi_dev(&pdev->dev, NULL));
+	KUNIT_EXPECT_FALSE(test, device_match_acpi_handle(&pdev->dev, NULL));
+
+	platform_device_unregister(pdev);
+}
+
+static struct kunit_case platform_device_match_tests[] = {
+	KUNIT_CASE(platform_device_find_by_null_test),
+	{}
+};
+
+static struct kunit_suite platform_device_match_test_suite = {
+	.name = "platform-device-match",
+	.test_cases = platform_device_match_tests,
+};
+
+kunit_test_suites(
+	&platform_device_devm_test_suite,
+	&platform_device_match_test_suite,
+);
 
 MODULE_DESCRIPTION("Test module for platform devices");
 MODULE_AUTHOR("Maxime Ripard <mripard@xxxxxxxxxx>");
-- 
2.47.0.338.g60cca15819-goog