On Sun, Jun 25, 2023 at 10:18:16AM +0800, Jackie Liu wrote: > From: Jackie Liu <liuyun01@xxxxxxxxxx> > > When tracking functions through kprobe.multi, the number of tracked > functions cannot be directly obtained. Sometimes in order to calculate > this value, it is necessary to recalculate according to the pattern in > the program. This is unnecessary. It is calculated by libbpf feedback > through opts.cnt value, which can save resources. Example at [1]. > > [1] https://github.com/JackieLiu1/ketones/blob/master/src/funccount/funccount.c#L317 > > Signed-off-by: Jackie Liu <liuyun01@xxxxxxxxxx> > --- > tools/lib/bpf/libbpf.c | 3 ++- > tools/lib/bpf/libbpf.h | 2 +- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index fca5d2e412c5..ed3f1202c570 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -10506,7 +10506,7 @@ static void kprobe_multi_resolve_reinit(struct kprobe_multi_resolve *res) > struct bpf_link * > bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > const char *pattern, > - const struct bpf_kprobe_multi_opts *opts) > + struct bpf_kprobe_multi_opts *opts) > { > LIBBPF_OPTS(bpf_link_create_opts, lopts); > struct kprobe_multi_resolve res = { > @@ -10582,6 +10582,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > } > link->fd = link_fd; > free(res.addrs); > + OPTS_SET(opts, cnt, res.cnt); hum I'm not sure it's good idea to use opts for output values there's ongoing patchset adding possibility to get this info/value via BPF_OBJ_GET_INFO_BY_FD syscall [1] jirka [1] https://lore.kernel.org/bpf/20230623141546.3751-1-laoar.shao@xxxxxxxxx/ > return link; > > error: > diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h > index 0b7362397ea3..f860dacc6add 100644 > --- a/tools/lib/bpf/libbpf.h > +++ b/tools/lib/bpf/libbpf.h > @@ -527,7 +527,7 @@ struct bpf_kprobe_multi_opts { > LIBBPF_API struct bpf_link * > bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, > const char *pattern, > - const struct bpf_kprobe_multi_opts *opts); > + struct bpf_kprobe_multi_opts *opts); > > struct bpf_ksyscall_opts { > /* size of this struct, for forward/backward compatibility */ > -- > 2.25.1 >
