selftests/bpf: check that modifier resolves after pointer

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>
Link: https://lore.kernel.org/r/20230306112138.155352-3-lmb@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index cbb600b..210d643 100644 (file)
--- 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 {