On Thu, Nov 3, 2022 at 12:11 PM Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> wrote: > > Introduce local kptrs, i.e. PTR_TO_BTF_ID that point to a type in > program BTF. This is indicated by the presence of MEM_TYPE_LOCAL type > tag in reg->type to avoid having to check btf_is_kernel when trying to > match argument types in helpers. ... > > + /* MEM is of a type from program BTF, not kernel BTF. This is used to > + * tag PTR_TO_BTF_ID allocated using bpf_kptr_alloc. > + */ > + MEM_TYPE_LOCAL = BIT(11 + BPF_BASE_TYPE_BITS), > + I know we have bpf_core_type_id_local. It sort-of makes sense in the context of the program. type_id_local -> inside the program type_id_kernel -> kernel but in the context of the verifier "local kptr" doesn't read right. Especially in MEM_TYPE_LOCAL. Also, since it applies to PTR_TO_BTF_ID, should it prefix with PTR_? Probably MEM_ is actually cleaner. And we're not consistent already with MEM_PERCPU. We can live with this inconsistency for now. So how about we rename MEM_ALLOC to MEM_RINGBUF, since it's special bpf_ringbuf_reserve() memory and use MEM_ALLOC to indicate the memory that came from bpf_obj_new ? ... which made me realize that the comment above should s/bpf_kptr_alloc/bpf_obj_new/
