1 files changed, 65 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 8a9ba4292109..054ecb6b1e9f 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -7496,6 +7496,71 @@ static struct btf_dedup_test dedup_tests[] = {
 	},
 },
 {
+	.descr = "dedup: recursive typedef",
+	/*
+	 * This test simulates a recursive typedef, which in GO is defined as such:
+	 *
+	 *   type Foo func() Foo
+	 *
+	 * In BTF terms, this is represented as a TYPEDEF referencing
+	 * a FUNC_PROTO that returns the same TYPEDEF.
+	 */
+	.input = {
+		.raw_types = {
+			/*
+			 * [1] typedef Foo -> func() Foo
+			 * [2] func_proto() -> Foo
+			 * [3] typedef Foo -> func() Foo
+			 * [4] func_proto() -> Foo
+			 */
+			BTF_TYPEDEF_ENC(NAME_NTH(1), 2),	/* [1] */
+			BTF_FUNC_PROTO_ENC(1, 0),		/* [2] */
+			BTF_TYPEDEF_ENC(NAME_NTH(1), 4),	/* [3] */
+			BTF_FUNC_PROTO_ENC(3, 0),		/* [4] */
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0Foo"),
+	},
+	.expect = {
+		.raw_types = {
+			BTF_TYPEDEF_ENC(NAME_NTH(1), 2),	/* [1] */
+			BTF_FUNC_PROTO_ENC(1, 0),		/* [2] */
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0Foo"),
+	},
+},
+{
+	.descr = "dedup: typedef",
+    /*
+     * // CU 1:
+     * typedef int foo;
+     *
+     * // CU 2:
+     * typedef int foo;
+     */
+	.input = {
+		.raw_types = {
+			/* CU 1 */
+			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+			BTF_TYPEDEF_ENC(NAME_NTH(1), 1),		/* [2] */
+			/* CU 2 */
+			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [3] */
+			BTF_TYPEDEF_ENC(NAME_NTH(1), 3),		/* [4] */
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0foo"),
+	},
+	.expect = {
+		.raw_types = {
+			BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+			BTF_TYPEDEF_ENC(NAME_NTH(1), 1),		/* [2] */
+			BTF_END_RAW,
+		},
+		BTF_STR_SEC("\0foo"),
+	},
+},
+{
 	.descr = "dedup: typedef tags",
 	.input = {
 		.raw_types = {