On 7/25/24 8:45 PM, Ming Lei wrote:
On Fri, Jul 26, 2024 at 11:21 AM Yonghong Song <yonghong.song@xxxxxxxxx> wrote:
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?
Sure, hid-bpf struct_ops has been merged to linus tree already.
However, it can't be built as module because the two APIs aren't exported:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/hid/bpf/hid_bpf_struct_ops.c
Okay, From the above hid_bpf_struct_ops.c, I do see bpf_base_func_proto() and
btf_find_by_name_kind() are used.
Your change looks good to me. Please add more details in the commit message and resubmit.
Your subject
[PATCH] bpf: export btf_find_by_name_kind and bpf_base_func_proto
please change to
[PATCH bpf-next] bpf: export btf_find_by_name_kind and bpf_base_func_proto
The above 'bpf-next' ensures CI to test your patch.
Thanks,
Ming
