Re: [PATCH bpf-next v2 04/28] libbpf: add HID program type and API

Andrii Nakryiko
2022-03-08T05:52:21Z

On Mon, Mar 7, 2022 at 5:38 PM Song Liu <songliubraving@fb.com> wrote:
>
>
>
> > On Mar 7, 2022, at 5:30 PM, Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> >
> > On Fri, Mar 4, 2022 at 9:31 AM Benjamin Tissoires
> > <benjamin.tissoires@redhat.com> wrote:
> >>
> >> HID-bpf program type are needing a new SEC.
> >> To bind a hid-bpf program, we can rely on bpf_program__attach_fd()
> >> so export a new function to the API.
> >>
> >> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> >>
> >> ---
> >>
> >> changes in v2:
> >> - split the series by bpf/libbpf/hid/selftests and samples
> >> ---
> >> tools/lib/bpf/libbpf.c | 7 +++++++
> >> tools/lib/bpf/libbpf.h | 2 ++
> >> tools/lib/bpf/libbpf.map | 1 +
> >> 3 files changed, 10 insertions(+)
> >>
> >> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> >> index 81bf01d67671..356bbd3ad2c7 100644
> >> --- a/tools/lib/bpf/libbpf.c
> >> +++ b/tools/lib/bpf/libbpf.c
> >> @@ -8680,6 +8680,7 @@ static const struct bpf_sec_def section_defs[] = {
> >> SEC_DEF("cgroup/setsockopt", CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
> >> SEC_DEF("struct_ops+", STRUCT_OPS, 0, SEC_NONE),
> >> SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
> >> + SEC_DEF("hid/device_event", HID, BPF_HID_DEVICE_EVENT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
> >
> > no SEC_SLOPPY_PFX for any new program type, please
> >
> >
> >> };
> >>
> >> #define MAX_TYPE_NAME_SIZE 32
> >> @@ -10659,6 +10660,12 @@ static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie)
> >> return bpf_program__attach_iter(prog, NULL);
> >> }
> >>
> >> +struct bpf_link *
> >> +bpf_program__attach_hid(const struct bpf_program *prog, int hid_fd)
> >> +{
> >> + return bpf_program__attach_fd(prog, hid_fd, 0, "hid");
> >> +}
> >> +
> >> struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
> >> {
> >> if (!prog->sec_def || !prog->sec_def->attach_fn)
> >> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> >> index c8d8daad212e..f677ac0a9ede 100644
> >> --- a/tools/lib/bpf/libbpf.h
> >> +++ b/tools/lib/bpf/libbpf.h
> >> @@ -529,6 +529,8 @@ struct bpf_iter_attach_opts {
> >> LIBBPF_API struct bpf_link *
> >> bpf_program__attach_iter(const struct bpf_program *prog,
> >> const struct bpf_iter_attach_opts *opts);
> >> +LIBBPF_API struct bpf_link *
> >> +bpf_program__attach_hid(const struct bpf_program *prog, int hid_fd);
> >>
> >> /*
> >> * Libbpf allows callers to adjust BPF programs before being loaded
> >> diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
> >> index 47e70c9058d9..fdc6fa743953 100644
> >> --- a/tools/lib/bpf/libbpf.map
> >> +++ b/tools/lib/bpf/libbpf.map
> >> @@ -424,6 +424,7 @@ LIBBPF_0.6.0 {
> >> LIBBPF_0.7.0 {
> >> global:
> >> bpf_btf_load;
> >> + bpf_program__attach_hid;
> >
> > should go into 0.8.0
>
> Ah, I missed this one.
>
> btw, bpf_xdp_attach and buddies should also go into 0.8.0, no?

not really, they were released in libbpf v0.7, it's just any new
incoming API that should go into 0.8.0

>
> >
> >> bpf_program__expected_attach_type;
> >> bpf_program__log_buf;
> >> bpf_program__log_level;
> >> --
> >> 2.35.1
> >>
>