Re: [PATCH] bpf: export btf_find_by_name_kind and bpf_base_func_proto

[Yonghong Song <yonghong.song@linux.dev>]

On 7/24/24 2:13 AM, Ming Lei wrote:
> On Tue, Jul 23, 2024 at 09:43:12PM -0700, Kui-Feng Lee wrote:
>>
>> On 7/23/24 20:19, Ming Lei wrote:
>>> Export btf_find_by_name_kind and bpf_base_func_proto, so that kernel
>>> module can use them.
>>>
>>> Almost all existed struct_ops users(hid, sched_ext, ...) need the two APIs.
>>>
>>> Without this change, hid-bpf can't be built as module.
>> Could you give me more context?
>> Give me a link of an example code or something?
>> Or explain the use case?
> The merged patchset "Registrating struct_ops types from modules" is
> trying to allow module to register struct_ops, which often needs
> bpf_base_func_proto()(for allowing generic helpers available in
> prog) and btf_find_by_name_kind() (for implementing .btf_struct_access).
>
> One example is hid-bpf, which is a driver and supposed to build as module,
> but it can't be done because the two APIs aren't exported.

Could you give more specific examples about where these two APIs are
used in hid-bpf?

>
> I am working on ublk bpf support, which needs bpf_base_func_proto() at
> least, and might require btf_find_by_name_kind() in future.
>
>
> Thanks,
> Ming
>
>