| Message ID | 20200923160156.80814-1-lmb@cloudflare.com |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [bpf-next] bpf: explicitly size compatible_reg_types | expand |
On Wed, Sep 23, 2020 at 9:03 AM Lorenz Bauer <lmb@cloudflare.com> 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 <lmb@cloudflare.com> > Suggested-by: Alexei Starovoitov <ast@kernel.org> > --- I like this more as well. Acked-by: Andrii Nakryiko <andriin@fb.com> > 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 >
On Wed, Sep 23, 2020 at 9:05 AM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Wed, Sep 23, 2020 at 9:03 AM Lorenz Bauer <lmb@cloudflare.com> 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 <lmb@cloudflare.com> > > Suggested-by: Alexei Starovoitov <ast@kernel.org> > > --- > > I like this more as well. > > Acked-by: Andrii Nakryiko <andriin@fb.com> Applied. Thanks
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,
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 <lmb@cloudflare.com> Suggested-by: Alexei Starovoitov <ast@kernel.org> --- kernel/bpf/verifier.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)