On Sat, May 7, 2022 at 8:21 PM Kui-Feng Lee <kuifeng@xxxxxx> wrote:
>
> Add a cookie field to the attributes of bpf_link_create().
> Add bpf_program__attach_trace_opts() to attach a cookie to a link.
>
> Signed-off-by: Kui-Feng Lee <kuifeng@xxxxxx>
> ---
> tools/lib/bpf/bpf.c | 8 ++++++++
> tools/lib/bpf/bpf.h | 3 +++
> tools/lib/bpf/libbpf.c | 32 ++++++++++++++++++++++++++++++++
> tools/lib/bpf/libbpf.h | 12 ++++++++++++
> tools/lib/bpf/libbpf.map | 1 +
> 5 files changed, 56 insertions(+)
>
I have a gripe with better code reuse, but that's internal change so
we can do it in a follow up.
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 73a5192defb3..df9be47d67bc 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -11440,6 +11440,38 @@ struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog)
> return bpf_program__attach_btf_id(prog);
> }
>
> +struct bpf_link *bpf_program__attach_trace_opts(const struct bpf_program *prog,
> + const struct bpf_trace_opts *opts)
there is bpf_program__attach_btf_id() that does all of this except for
the cookie. It would be nicer to extend bpf_program__attach_btf_id(),
which won't break any API because it's an internal helper, add
optional bpf_trace_opts to it and then just redirect
bpf_program__attach_trace_opts() to bpf_program__attach_btf_id and
update all the existing callers with just passing NULL for opts.
We can do that as a follow up, given your patch set seems to be pretty
much ready to be landed.
> +{
> + char errmsg[STRERR_BUFSIZE];
> + struct bpf_link *link;
> + int prog_fd, pfd;
> + LIBBPF_OPTS(bpf_link_create_opts, link_opts);
> +
[...]
