[PATCH bpf-next v2 5/5] selftests/bpf: Test duplicate bpf_refcount fields

[Kumar Kartikeya Dwivedi <memxor@gmail.com>]

Add a raw BTF test with two bpf_refcount fields. The duplicate must be
rejected during BTF loading instead of reaching the duplicate-field
invariant in btf_parse_fields().

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 21 ++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 2100400d896b..67b9015cbd98 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -4277,6 +4277,27 @@ static struct btf_raw_test raw_tests[] = {
 	.btf_load_err = true,
 },
 
+/*
+ * struct value {
+ *     struct bpf_refcount a;
+ *     struct bpf_refcount b;
+ * };
+ */
+{
+	.descr = "struct test duplicate bpf_refcount fields",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_STRUCT_ENC(NAME_TBD, 1, 4),				/* [2] */
+		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
+		BTF_STRUCT_ENC(NAME_TBD, 2, 8),				/* [3] */
+		BTF_MEMBER_ENC(NAME_TBD, 2, 0),
+		BTF_MEMBER_ENC(NAME_TBD, 2, 32),
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0int\0bpf_refcount\0refs\0value\0a\0b"),
+	.btf_load_err = true,
+},
+
 {
 	.descr = "struct test repeated fields count overflow",
 	.raw_types = {
-- 
2.53.0