diff options
| author | Dave Marchevsky <davemarchevsky@fb.com> | 2022-10-20 09:07:19 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-10-21 19:23:28 -0700 |
| commit | d1673304097c1f5b04e062cf62fb40200ef1546b (patch) | |
| tree | 95079f88a1bb8802c8f8bc57eb9814dfb9e06993 | |
| parent | 9ef40974a82a474321a4c2dd75d395943930c638 (diff) | |
bpf: Consider all mem_types compatible for map_{key,value} args
After the previous patch, which added PTR_TO_MEM | MEM_ALLOC type
map_key_value_types, the only difference between map_key_value_types and
mem_types sets is PTR_TO_BUF and PTR_TO_MEM, which are in the latter set
but not the former.
Helpers which expect ARG_PTR_TO_MAP_KEY or ARG_PTR_TO_MAP_VALUE
already effectively expect a valid blob of arbitrary memory that isn't
necessarily explicitly associated with a map. When validating a
PTR_TO_MAP_{KEY,VALUE} arg, the verifier expects meta->map_ptr to have
already been set, either by an earlier ARG_CONST_MAP_PTR arg, or custom
logic like that in process_timer_func or process_kptr_func.
So let's get rid of map_key_value_types and just use mem_types for those
args.
This has the effect of adding PTR_TO_BUF and PTR_TO_MEM to the set of
compatible types for ARG_PTR_TO_MAP_KEY and ARG_PTR_TO_MAP_VALUE.
PTR_TO_BUF is used by various bpf_iter implementations to represent a
chunk of valid r/w memory in ctx args for iter prog.
PTR_TO_MEM is used by networking, tracing, and ringbuf helpers to
represent a chunk of valid memory. The PTR_TO_MEM | MEM_ALLOC
type added in previous commit is specific to ringbuf helpers.
Presence or absence of MEM_ALLOC doesn't change the validity of using
PTR_TO_MEM as a map_{key,val} input.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221020160721.4030492-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/verifier.c | 15 |
1 files changed, 2 insertions, 13 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 97351ae3e7a7..ddc1452cf023 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5634,17 +5634,6 @@ struct bpf_reg_types { u32 *btf_id; }; -static const struct bpf_reg_types map_key_value_types = { - .types = { - PTR_TO_STACK, - PTR_TO_PACKET, - PTR_TO_PACKET_META, - PTR_TO_MAP_KEY, - PTR_TO_MAP_VALUE, - PTR_TO_MEM | MEM_ALLOC, - }, -}; - static const struct bpf_reg_types sock_types = { .types = { PTR_TO_SOCK_COMMON, @@ -5711,8 +5700,8 @@ static const struct bpf_reg_types dynptr_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_MAP_KEY] = &mem_types, + [ARG_PTR_TO_MAP_VALUE] = &mem_types, [ARG_CONST_SIZE] = &scalar_types, [ARG_CONST_SIZE_OR_ZERO] = &scalar_types, [ARG_CONST_ALLOC_SIZE_OR_ZERO] = &scalar_types, |