Commit 19526e70 authored by Wang Yufen's avatar Wang Yufen Committed by Alexei Starovoitov
Browse files

bpftool: Add autoattach for bpf prog load|loadall 



Add autoattach 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: default avatarWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: default avatarWang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1665736275-28143-2-git-send-email-wangyufen@huawei.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 98af3746

tools/bpf/bpftool/prog.c

+74 −2
Original line number Diff line number Diff line
@@ -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) {

		p_info("Program %s does not support autoattach, falling back to pinning",

		       bpf_program__name(prog));

		return bpf_obj_pin(bpf_program__fd(prog), path);

	}



	err = bpf_link__pin(link, path);

	bpf_link__destroy(link);

	return err;

}



static int pathname_concat(char *buf, size_t buf_sz, const char *path, const char *name)

{

	int len;



	len = snprintf(buf, buf_sz, "%s/%s", path, name);

	if (len < 0)

		return -EINVAL;

	if ((size_t)len >= buf_sz)

		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(buf, sizeof(buf), path, bpf_program__name(prog));

		if (err)

			goto err_unpin_programs;



		err = auto_attach_program(prog, buf);

		if (err)

			goto err_unpin_programs;

	}



	return 0;



err_unpin_programs:

	while ((prog = bpf_object__prev_program(obj, prog))) {

		if (pathname_concat(buf, sizeof(buf), path, bpf_program__name(prog)))

			continue;



		bpf_program__unpin(prog, buf);

	}



	return err;

}



static int load_with_options(int argc, char **argv, bool first_prog_only)

{

	enum bpf_prog_type common_prog_type = BPF_PROG_TYPE_UNSPEC;
@@ -1464,6 +1525,7 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) 
	struct bpf_program *prog = NULL, *pos;

	unsigned int old_map_fds = 0;

	const char *pinmaps = NULL;

	bool auto_attach = false;

	struct bpf_object *obj;

	struct bpf_map *map;

	const char *pinfile;
@@ -1583,6 +1645,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) 
				goto err_free_reuse_maps;



			pinmaps = GET_ARG();

		} else if (is_prefix(*argv, "autoattach")) {

			auto_attach = true;

			NEXT_ARG();

		} else {

			p_err("expected no more arguments, 'type', 'map' or 'dev', got: '%s'?",

			      *argv);
@@ -1692,6 +1757,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) 
			goto err_close_obj;

		}



		if (auto_attach)

			err = auto_attach_program(prog, pinfile);

		else

			err = bpf_obj_pin(bpf_program__fd(prog), pinfile);

		if (err) {

			p_err("failed to pin program %s",
@@ -1699,6 +1767,9 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) 
			goto err_close_obj;

		}

	} else {

		if (auto_attach)

			err = auto_attach_programs(obj, pinfile);

		else

			err = bpf_object__pin_programs(obj, pinfile);

		if (err) {

			p_err("failed to pin all programs");
@@ -2338,6 +2409,7 @@ static int do_help(int argc, char **argv) 
		"                         [type TYPE] [dev NAME] \\\n"

		"                         [map { idx IDX | name NAME } MAP]\\\n"

		"                         [pinmaps MAP_DIR]\n"

		"                         [autoattach]\n"

		"       %1$s %2$s attach PROG ATTACH_TYPE [MAP]\n"

		"       %1$s %2$s detach PROG ATTACH_TYPE [MAP]\n"

		"       %1$s %2$s run PROG \\\n"