[PATCH bpf-next v1 2/2] selftests/bpf: Add tests for type tag order validation

[Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>]

Add a few test cases that ensure we catch cases of badly ordered type
tags in modifier chains.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 77 ++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index ec823561b912..fc18f0936925 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -3974,6 +3974,83 @@ static struct btf_raw_test raw_tests[] = {
 	.value_type_id = 1,
 	.max_entries = 1,
 },
+{
+	.descr = "type_tag test #2, type tag order",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_CONST_ENC(3),				/* [2] */
+		BTF_TYPE_TAG_ENC(NAME_TBD, 1),			/* [3] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0tag"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "tag_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Type tags don't precede modifiers",
+},
+{
+	.descr = "type_tag test #3, type tag order",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_TYPE_TAG_ENC(NAME_TBD, 3),			/* [2] */
+		BTF_CONST_ENC(4),				/* [3] */
+		BTF_TYPE_TAG_ENC(NAME_TBD, 1),			/* [4] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0tag\0tag"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "tag_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Type tags don't precede modifiers",
+},
+{
+	.descr = "type_tag test #4, type tag order",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_TYPEDEF_ENC(NAME_TBD, 3),			/* [2] */
+		BTF_CONST_ENC(4),				/* [3] */
+		BTF_TYPE_TAG_ENC(NAME_TBD, 1),			/* [4] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0tag\0tag"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "tag_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 1,
+	.btf_load_err = true,
+	.err_str = "Type tags don't precede modifiers",
+},
+{
+	.descr = "type_tag test #5, type tag order",
+	.raw_types = {
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
+		BTF_TYPE_TAG_ENC(NAME_TBD, 3),			/* [2] */
+		BTF_CONST_ENC(1),				/* [3] */
+		BTF_TYPE_TAG_ENC(NAME_TBD, 2),			/* [4] */
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0tag\0tag"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = "tag_type_check_btf",
+	.key_size = sizeof(int),
+	.value_size = 4,
+	.key_type_id = 1,
+	.value_type_id = 1,
+	.max_entries = 1,
+},
 
 }; /* struct btf_raw_test raw_tests[] */
 
-- 
2.35.1