在 2022/9/26 18:46, Quentin Monnet 写道:
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?
Thanks for your comment. I agree with you. add in v7.
+ } + + 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; +}
