libbpf: Add bpf_link_create support for multi uprobes

Adding new uprobe_multi struct to bpf_link_create_opts object
to pass multiple uprobe data to link_create attr uapi.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-14-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: olsajiri

tools/lib/bpf/bpf.c

@@ -767,6 +767,17 @@ int bpf_link_create(int prog_fd, int target_fd,
 		if (!OPTS_ZEROED(opts, kprobe_multi))
 			return libbpf_err(-EINVAL);
 		break;
+	case BPF_TRACE_UPROBE_MULTI:
+		attr.link_create.uprobe_multi.flags = OPTS_GET(opts, uprobe_multi.flags, 0);
+		attr.link_create.uprobe_multi.cnt = OPTS_GET(opts, uprobe_multi.cnt, 0);
+		attr.link_create.uprobe_multi.path = ptr_to_u64(OPTS_GET(opts, uprobe_multi.path, 0));
+		attr.link_create.uprobe_multi.offsets = ptr_to_u64(OPTS_GET(opts, uprobe_multi.offsets, 0));
+		attr.link_create.uprobe_multi.ref_ctr_offsets = ptr_to_u64(OPTS_GET(opts, uprobe_multi.ref_ctr_offsets, 0));
+		attr.link_create.uprobe_multi.cookies = ptr_to_u64(OPTS_GET(opts, uprobe_multi.cookies, 0));
+		attr.link_create.uprobe_multi.pid = OPTS_GET(opts, uprobe_multi.pid, 0);
+		if (!OPTS_ZEROED(opts, uprobe_multi))
+			return libbpf_err(-EINVAL);
+		break;
 	case BPF_TRACE_FENTRY:
 	case BPF_TRACE_FEXIT:
 	case BPF_MODIFY_RETURN:

tools/lib/bpf/bpf.h

@@ -392,6 +392,15 @@ struct bpf_link_create_opts {
 			const unsigned long *addrs;
 			const __u64 *cookies;
 		} kprobe_multi;
+		struct {
+			__u32 flags;
+			__u32 cnt;
+			const char *path;
+			const unsigned long *offsets;
+			const unsigned long *ref_ctr_offsets;
+			const __u64 *cookies;
+			__u32 pid;
+		} uprobe_multi;
 		struct {
 			__u64 cookie;
 		} tracing;
@@ -409,7 +418,7 @@ struct bpf_link_create_opts {
 	};
 	size_t :0;
 };
-#define bpf_link_create_opts__last_field kprobe_multi.cookies
+#define bpf_link_create_opts__last_field uprobe_multi.pid
 
 LIBBPF_API int bpf_link_create(int prog_fd, int target_fd,
 			       enum bpf_attach_type attach_type,