diff options
| -rw-r--r-- | include/linux/btf.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/arraymap.c | 15 | ||||
| -rw-r--r-- | kernel/bpf/btf.c | 2 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 15 |
4 files changed, 27 insertions, 6 deletions
diff --git a/include/linux/btf.h b/include/linux/btf.h index 455d31b55828..64cdf2a23d42 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -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); diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 217b10bd9f48..584636c9e2eb 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -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; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 0cecf6bab61b..cad09858a5f2 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -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; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 198c9680bf0d..438199e2eca4 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -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; } |