Re: [PATCH 07/10] libbpf: Add bpf_link_create support for multi kprobes

Jiri Olsa
2022-03-06T17:29:28Z

On Fri, Mar 04, 2022 at 03:11:16PM -0800, Andrii Nakryiko wrote:
> On Tue, Feb 22, 2022 at 9:07 AM Jiri Olsa <jolsa@kernel.org> wrote:
> >
> > Adding new kprobe_multi struct to bpf_link_create_opts object
> > to pass multiple kprobe data to link_create attr uapi.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> > tools/lib/bpf/bpf.c | 7 +++++++
> > tools/lib/bpf/bpf.h | 9 ++++++++-
> > 2 files changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> > index 418b259166f8..5e180def2cef 100644
> > --- a/tools/lib/bpf/bpf.c
> > +++ b/tools/lib/bpf/bpf.c
> > @@ -853,6 +853,13 @@ int bpf_link_create(int prog_fd, int target_fd,
> > if (!OPTS_ZEROED(opts, perf_event))
> > return libbpf_err(-EINVAL);
> > break;
> > + case BPF_TRACE_KPROBE_MULTI:
> > + attr.link_create.kprobe_multi.syms = OPTS_GET(opts, kprobe_multi.syms, 0);
> > + attr.link_create.kprobe_multi.addrs = OPTS_GET(opts, kprobe_multi.addrs, 0);
> > + attr.link_create.kprobe_multi.cookies = OPTS_GET(opts, kprobe_multi.cookies, 0);
> > + attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0);
> > + attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0);
> > + break;
> > default:
> > if (!OPTS_ZEROED(opts, flags))
> > return libbpf_err(-EINVAL);
> > diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> > index 16b21757b8bf..bd285a8f3420 100644
> > --- a/tools/lib/bpf/bpf.h
> > +++ b/tools/lib/bpf/bpf.h
> > @@ -413,10 +413,17 @@ struct bpf_link_create_opts {
> > struct {
> > __u64 bpf_cookie;
> > } perf_event;
> > + struct {
> > + __u64 syms;
> > + __u64 addrs;
> > + __u64 cookies;
>
> hm, I think we can and should use proper types here, no?
>
> const char **syms;
> const void **addrs;
> const __u64 *cookies;
>
> ?

right, will change

thanks,
jirka