@@ -51,6 +51,7 @@ bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
const struct btf_member *m,
u32 expected_offset, u32 expected_size);
int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
+bool btf_type_is_void(const struct btf_type *t);
#ifdef CONFIG_BPF_SYSCALL
const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
@@ -391,7 +391,8 @@ static void array_map_seq_show_elem(struct bpf_map *map, void *key,
return;
}
- seq_printf(m, "%u: ", *(u32 *)key);
+ if (map->btf_key_type_id)
+ seq_printf(m, "%u: ", *(u32 *)key);
btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
seq_puts(m, "\n");
@@ -428,6 +429,18 @@ static int array_map_check_btf(const struct bpf_map *map,
{
u32 int_data;
+ /* One exception for keyless BTF: .bss/.data/.rodata map */
+ if (btf_type_is_void(key_type)) {
+ if (map->map_type != BPF_MAP_TYPE_ARRAY ||
+ map->max_entries != 1)
+ return -EINVAL;
+
+ if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC)
+ return -EINVAL;
+
+ return 0;
+ }
+
if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
return -EINVAL;
@@ -326,7 +326,7 @@ static bool btf_type_is_modifier(const struct btf_type *t)
return false;
}
-static bool btf_type_is_void(const struct btf_type *t)
+bool btf_type_is_void(const struct btf_type *t)
{
return t == &btf_void;
}
@@ -504,9 +504,16 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
u32 key_size, value_size;
int ret = 0;
- key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
- if (!key_type || key_size != map->key_size)
- return -EINVAL;
+ /* Some maps allow key to be unspecified. */
+ if (btf_key_id) {
+ key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
+ if (!key_type || key_size != map->key_size)
+ return -EINVAL;
+ } else {
+ key_type = btf_type_by_id(btf, 0);
+ if (!map->ops->map_check_btf)
+ return -EINVAL;
+ }
value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
if (!value_type || value_size != map->value_size)
@@ -573,7 +580,7 @@ static int map_create(union bpf_attr *attr)
if (attr->btf_key_type_id || attr->btf_value_type_id) {
struct btf *btf;
- if (!attr->btf_key_type_id || !attr->btf_value_type_id) {
+ if (!attr->btf_value_type_id) {
err = -EINVAL;
goto free_map_nouncharge;
}