[PATCH bpf v2 2/2] selftests/bpf: check that modifier resolves after pointer

[Lorenz Bauer <lorenz.bauer@isovalent.com>]

Add a regression test that ensures that a VAR pointing at a
modifier which follows a PTR (or STRUCT or ARRAY) is resolved
correctly by the datasec validator.

Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
---
 tools/testing/selftests/bpf/prog_tests/btf.c | 28 ++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index cbb600be943d..210d643fda6c 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -879,6 +879,34 @@ static struct btf_raw_test raw_tests[] = {
 	.btf_load_err = true,
 	.err_str = "Invalid elem",
 },
+{
+	.descr = "var after datasec, ptr followed by modifier",
+	.raw_types = {
+		/* .bss section */				/* [1] */
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 2),
+			sizeof(void*)+4),
+		BTF_VAR_SECINFO_ENC(4, 0, sizeof(void*)),
+		BTF_VAR_SECINFO_ENC(6, sizeof(void*), 4),
+		/* int */					/* [2] */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),
+		/* int* */					/* [3] */
+		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2),
+		BTF_VAR_ENC(NAME_TBD, 3, 0),			/* [4] */
+		/* const int */					/* [5] */
+		BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_CONST, 0, 0), 2),
+		BTF_VAR_ENC(NAME_TBD, 5, 0),			/* [6] */
+		BTF_END_RAW,
+	},
+	.str_sec = "\0a\0b\0c\0",
+	.str_sec_size = sizeof("\0a\0b\0c\0"),
+	.map_type = BPF_MAP_TYPE_ARRAY,
+	.map_name = ".bss",
+	.key_size = sizeof(int),
+	.value_size = sizeof(void*)+4,
+	.key_type_id = 0,
+	.value_type_id = 1,
+	.max_entries = 1,
+},
 /* Test member exceeds the size of struct.
  *
  * struct A {
-- 
2.39.2