libbpf: Support exclusive map creation

Implement setters and getters that allow map to be registered as
exclusive to the specified program. The registration should be done
before the exclusive program is loaded.

Signed-off-by: KP Singh <kpsingh@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-5-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

src/bpf.c

@@ -172,7 +172,7 @@ int bpf_map_create(enum bpf_map_type map_type,
 		   __u32 max_entries,
 		   const struct bpf_map_create_opts *opts)
 {
-	const size_t attr_sz = offsetofend(union bpf_attr, map_token_fd);
+	const size_t attr_sz = offsetofend(union bpf_attr, excl_prog_hash_size);
 	union bpf_attr attr;
 	int fd;
 
@@ -203,6 +203,8 @@ int bpf_map_create(enum bpf_map_type map_type,
 	attr.map_ifindex = OPTS_GET(opts, map_ifindex, 0);
 
 	attr.map_token_fd = OPTS_GET(opts, token_fd, 0);
+	attr.excl_prog_hash = ptr_to_u64(OPTS_GET(opts, excl_prog_hash, NULL));
+	attr.excl_prog_hash_size = OPTS_GET(opts, excl_prog_hash_size, 0);
 
 	fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz);
 	return libbpf_err_errno(fd);