From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 31 Jan 2022 14:05:24 -0800
Subject: libbpf: Open code raw_tp_open and link_create commands.
Patch-mainline: v5.18-rc1
Git-commit: c69f94a33d12a9c49f1800c54838ee19447ac176
References: jsc#PED-1377

Open code raw_tracepoint_open and link_create used by light skeleton
to be able to avoid full libbpf eventually.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 tools/bpf/bpftool/gen.c       |    6 +++---
 tools/lib/bpf/skel_internal.h |   26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -381,13 +381,13 @@ static void codegen_attach_detach(struct
 		switch (bpf_program__type(prog)) {
 		case BPF_PROG_TYPE_RAW_TRACEPOINT:
 			tp_name = strchr(bpf_program__section_name(prog), '/') + 1;
-			printf("\tint fd = bpf_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name);
+			printf("\tint fd = skel_raw_tracepoint_open(\"%s\", prog_fd);\n", tp_name);
 			break;
 		case BPF_PROG_TYPE_TRACING:
 			if (bpf_program__expected_attach_type(prog) == BPF_TRACE_ITER)
-				printf("\tint fd = bpf_link_create(prog_fd, 0, BPF_TRACE_ITER, NULL);\n");
+				printf("\tint fd = skel_link_create(prog_fd, 0, BPF_TRACE_ITER);\n");
 			else
-				printf("\tint fd = bpf_raw_tracepoint_open(NULL, prog_fd);\n");
+				printf("\tint fd = skel_raw_tracepoint_open(NULL, prog_fd);\n");
 			break;
 		default:
 			printf("\tint fd = ((void)prog_fd, 0); /* auto-attach not supported */\n");
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -110,6 +110,32 @@ static inline int skel_map_update_elem(i
 	return skel_sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, attr_sz);
 }
 
+static inline int skel_raw_tracepoint_open(const char *name, int prog_fd)
+{
+	const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint.prog_fd);
+	union bpf_attr attr;
+
+	memset(&attr, 0, attr_sz);
+	attr.raw_tracepoint.name = (long) name;
+	attr.raw_tracepoint.prog_fd = prog_fd;
+
+	return skel_sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz);
+}
+
+static inline int skel_link_create(int prog_fd, int target_fd,
+				   enum bpf_attach_type attach_type)
+{
+	const size_t attr_sz = offsetofend(union bpf_attr, link_create.iter_info_len);
+	union bpf_attr attr;
+
+	memset(&attr, 0, attr_sz);
+	attr.link_create.prog_fd = prog_fd;
+	attr.link_create.target_fd = target_fd;
+	attr.link_create.attach_type = attach_type;
+
+	return skel_sys_bpf(BPF_LINK_CREATE, &attr, attr_sz);
+}
+
 static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 {
 	int map_fd = -1, prog_fd = -1, key = 0, err;