2 files changed, 102 insertions, 0 deletions
diff --git a/kernel/tests/.kunitconfig b/kernel/tests/.kunitconfig
new file mode 100644
index 000000000000..b3d1206fd81a
--- /dev/null
+++ b/kernel/tests/.kunitconfig
@@ -0,0 +1,4 @@
+CONFIG_KUNIT=y
+CONFIG_NAMESPACES=y
+CONFIG_USER_NS=y
+CONFIG_USER_NS_MAP_KUNIT_TEST=y
diff --git a/kernel/tests/user_ns_map_kunit.c b/kernel/tests/user_ns_map_kunit.c
new file mode 100644
index 000000000000..033dccc6a535
--- /dev/null
+++ b/kernel/tests/user_ns_map_kunit.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for user namespace map insertion and sorting.
+ */
+
+#define pr_fmt(fmt) "user_namespace: " fmt
+
+#include <kunit/test.h>
+#include <linux/user_namespace.h>
+
+#define NR_EXTENTS (UID_GID_MAP_MAX_BASE_EXTENTS + 5)
+
+static void user_ns_map_insert(struct kunit *test)
+{
+	struct uid_gid_map map;
+	struct uid_gid_extent extent;
+	int i, ret;
+
+	memset(&map, 0, sizeof(map));
+
+	/* Insert up to UID_GID_MAP_MAX_BASE_EXTENTS elements */
+	for (i = 0; i < UID_GID_MAP_MAX_BASE_EXTENTS; i++) {
+		extent.first = i * 10;
+		extent.lower_first = i * 100;
+		extent.count = 5;
+
+		ret = uid_gid_map_insert_extent(&map, &extent);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+	}
+
+	KUNIT_EXPECT_EQ(test, map.nr_extents, UID_GID_MAP_MAX_BASE_EXTENTS);
+
+	/* Verify the elements ended up in the 'extent' array */
+	for (i = 0; i < UID_GID_MAP_MAX_BASE_EXTENTS; i++) {
+		KUNIT_EXPECT_EQ(test, map.extent[i].first, i * 10);
+		KUNIT_EXPECT_EQ(test, map.extent[i].lower_first, i * 100);
+		KUNIT_EXPECT_EQ(test, map.extent[i].count, 5);
+	}
+}
+
+static void user_ns_map_insert_extended(struct kunit *test)
+{
+	struct uid_gid_map map;
+	struct uid_gid_extent extent;
+	int i, ret;
+
+	memset(&map, 0, sizeof(map));
+
+	/* Insert more than UID_GID_MAP_MAX_BASE_EXTENTS elements */
+	for (i = 0; i < NR_EXTENTS; i++) {
+		int value = 9 - i;
+
+		extent.first = value * 10;
+		extent.lower_first = value * 100;
+		extent.count = 5;
+
+		ret = uid_gid_map_insert_extent(&map, &extent);
+		KUNIT_ASSERT_EQ(test, ret, 0);
+	}
+
+	KUNIT_EXPECT_EQ(test, map.nr_extents, NR_EXTENTS);
+
+	/* Now sort the map to set up reverse mapping */
+	ret = uid_gid_map_sort(&map);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, map.reverse);
+
+	/* Verify the elements are in 'forward' and that sorting is correct */
+	for (i = 0; i < map.nr_extents; i++) {
+		KUNIT_EXPECT_EQ(test, map.forward[i].first, i * 10);
+		KUNIT_EXPECT_EQ(test, map.forward[i].lower_first, i * 100);
+		KUNIT_EXPECT_EQ(test, map.forward[i].count, 5);
+
+		KUNIT_EXPECT_EQ(test, map.reverse[i].first, i * 10);
+		KUNIT_EXPECT_EQ(test, map.reverse[i].lower_first, i * 100);
+		KUNIT_EXPECT_EQ(test, map.reverse[i].count, 5);
+	}
+
+	kfree(map.forward);
+	kfree(map.reverse);
+}
+
+static struct kunit_case user_ns_map_test_cases[] = {
+	KUNIT_CASE(user_ns_map_insert),
+	KUNIT_CASE(user_ns_map_insert_extended),
+	{}
+};
+
+static struct kunit_suite user_ns_map_test_suite = {
+	.name = "user_ns_map",
+	.test_cases = user_ns_map_test_cases,
+};
+
+kunit_test_suite(user_ns_map_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("KUnit test for user namespace map insertion");
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");