Merge branch 'fix resolving VAR after DATASEC'

Lorenz Bauer says:

====================

See the first patch for a detailed explanation.

v2:
- Move RESOLVE_TBD assignment out of the loop (Martin)
====================

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

kernel/bpf/btf.c

@@ -4569,6 +4569,7 @@ static int btf_datasec_resolve(struct btf_verifier_env *env,
 	struct btf *btf = env->btf;
 	u16 i;
 
+	env->resolve_mode = RESOLVE_TBD;
 	for_each_vsi_from(i, v->next_member, v->t, vsi) {
 		u32 var_type_id = vsi->type, type_id, type_size = 0;
 		const struct btf_type *var_type = btf_type_by_id(env->btf,

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 {