On Sun, Jun 28, 2020 at 01:59:54PM -0700, Yonghong Song wrote: SNIP > > > > > > The corresponding BTF_ID definition here is: > > > BTF_ID_LIST(bpf_skb_output_btf_ids) > > > BTF_ID(struct, sk_buff) > > > > > > The bpf helper writer needs to ensure proper declarations > > > of BTF_IDs like the above matching helpers definition. > > > Support we have arg1 and arg3 as BTF_ID. then the list > > > definition may be > > > > > > BTF_ID_LIST(bpf_skb_output_btf_ids) > > > BTF_ID(struct, sk_buff) > > > BTF_ID(struct, __unused) > > > BTF_ID(struct, task_struct) > > > > > > This probably okay, I guess. > > > > right, AFAIK we don't have such case yet, but would be good > > to be ready and have something like > > > > BTF_ID(struct, __unused) > > > > maybe adding new type for that will be better: > > > > BTF_ID(none, unused) > > Maybe we can have a separate macro BTF_ID_UNUSED macro > which simply adds 4 bytes hole in the .btf_ids* section. right, we don't need symbols for that jirka
