Sat Sep 24 2022 11:13:48 GMT+0100 (British Summer Time) ~ Wang Yufen <wangyufen@xxxxxxxxxx> > Add auto_attach optional to support one-step load-attach-pin_link. > > For example, > $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach > > $ bpftool link > 26: tracing name test1 tag f0da7d0058c00236 gpl > loaded_at 2022-09-09T21:39:49+0800 uid 0 > xlated 88B jited 55B memlock 4096B map_ids 3 > btf_id 55 > 28: kprobe name test3 tag 002ef1bef0723833 gpl > loaded_at 2022-09-09T21:39:49+0800 uid 0 > xlated 88B jited 56B memlock 4096B map_ids 3 > btf_id 55 > 57: tracepoint name oncpu tag 7aa55dfbdcb78941 gpl > loaded_at 2022-09-09T21:41:32+0800 uid 0 > xlated 456B jited 265B memlock 4096B map_ids 17,13,14,15 > btf_id 82 > > $ bpftool link > 1: tracing prog 26 > prog_type tracing attach_type trace_fentry > 3: perf_event prog 28 > 10: perf_event prog 57 > > The autoattach optional can support tracepoints, k(ret)probes, > u(ret)probes. > > Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx> > Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx> > --- > v5 -> v6: skip the programs not supporting auto-attach, > and change optional name from "auto_attach" to "autoattach" > v4 -> v5: some formatting nits of doc > v3 -> v4: rename functions, update doc, bash and do_help() > v2 -> v3: switch to extend prog load command instead of extend perf > v2: https://patchwork.kernel.org/project/netdevbpf/patch/20220824033837.458197-1-weiyongjun1@xxxxxxxxxx/ > v1: https://patchwork.kernel.org/project/netdevbpf/patch/20220816151725.153343-1-weiyongjun1@xxxxxxxxxx/ > tools/bpf/bpftool/prog.c | 76 ++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 74 insertions(+), 2 deletions(-) > > diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c > index c81362a001ba..b1cbd06dee19 100644 > --- a/tools/bpf/bpftool/prog.c > +++ b/tools/bpf/bpftool/prog.c > @@ -1453,6 +1453,67 @@ get_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, > return ret; > } > > +static int > +auto_attach_program(struct bpf_program *prog, const char *path) > +{ > + struct bpf_link *link; > + int err; > + > + link = bpf_program__attach(prog); > + if (!link) > + return -1; > + > + err = bpf_link__pin(link, path); > + if (err) { > + bpf_link__destroy(link); > + return err; > + } > + return 0; > +} > + > +static int pathname_concat(const char *path, const char *name, char *buf) > +{ > + int len; > + > + len = snprintf(buf, PATH_MAX, "%s/%s", path, name); > + if (len < 0) > + return -EINVAL; > + if (len >= PATH_MAX) > + return -ENAMETOOLONG; > + > + return 0; > +} > + > +static int > +auto_attach_programs(struct bpf_object *obj, const char *path) > +{ > + struct bpf_program *prog; > + char buf[PATH_MAX]; > + int err; > + > + bpf_object__for_each_program(prog, obj) { > + err = pathname_concat(path, bpf_program__name(prog), buf); > + if (err) > + goto err_unpin_programs; > + > + err = auto_attach_program(prog, buf); > + if (err && errno != EOPNOTSUPP) > + goto err_unpin_programs; If I read the above correctly, we skip entirely programs that couldn't be auto-attached. I'm not sure what Andrii had in mind exactly, but it would make sense to me to fallback to regular program pinning if the program couldn't be attached/linked, so we still keep it loaded in the kernel after bpftool exits. Probably with a p_info() message to let users know? > + } > + > + return 0; > + > +err_unpin_programs: > + while ((prog = bpf_object__prev_program(obj, prog))) { > + if (pathname_concat(path, bpf_program__name(prog), buf)) > + continue; > + > + bpf_program__unpin(prog, buf); > + } > + > + return err; > +}
