Re: [PATCH bpf-next] bpf: explicitly size compatible_reg_types
From: Andrii Nakryiko <hidden>
Date: 2020-09-23 16:05:52
Also in:
bpf, lkml
On Wed, Sep 23, 2020 at 9:03 AM Lorenz Bauer [off-list ref] wrote:
Arrays with designated initializers have an implicit length of the highest initialized value plus one. I used this to ensure that newly added entries in enum bpf_reg_type get a NULL entry in compatible_reg_types. This is difficult to understand since it requires knowledge of the peculiarities of designated initializers. Use __BPF_ARG_TYPE_MAX to size the array instead. Signed-off-by: Lorenz Bauer <redacted> Suggested-by: Alexei Starovoitov <ast@kernel.org> ---
I like this more as well. Acked-by: Andrii Nakryiko <redacted>
quoted hunk ↗ jump to hunk
kernel/bpf/verifier.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 15ab889b0a3f..d7c993ded26a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c@@ -4002,7 +4002,7 @@ static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_T static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } }; static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } }; -static const struct bpf_reg_types *compatible_reg_types[] = { +static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_MAP_KEY] = &map_key_value_types, [ARG_PTR_TO_MAP_VALUE] = &map_key_value_types, [ARG_PTR_TO_UNINIT_MAP_VALUE] = &map_key_value_types,@@ -4025,7 +4025,6 @@ static const struct bpf_reg_types *compatible_reg_types[] = { [ARG_PTR_TO_ALLOC_MEM_OR_NULL] = &alloc_mem_types, [ARG_PTR_TO_INT] = &int_ptr_types, [ARG_PTR_TO_LONG] = &int_ptr_types, - [__BPF_ARG_TYPE_MAX] = NULL, }; static int check_reg_type(struct bpf_verifier_env *env, u32 regno, --2.25.1