zdtm: Run "ip link set up" after becoming userns root

This allows excluding more userns tests from blacklist.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrew Vagin <avagin@parallels.com>

test/zdtm.sh

@@ -251,13 +251,7 @@ generate_test_list()
 		ns/static/mlock_setuid
 		ns/static/sched_prio00
 		ns/static/sched_policy00
-		ns/static/socket_listen
-		ns/static/socket_listen6
-		ns/static/packet_sock
 		ns/static/packet_sock_mmap
-		ns/static/socket_udp
-		ns/static/socket6_udp
-		ns/static/socket_udplite
 		ns/static/fanotify00
 		ns/static/fifo-ghost
 		ns/static/unlink_fifo

test/zdtm/lib/ns.c

@@ -192,8 +192,6 @@ int ns_exec(void *_arg)
 
 	setsid();
 
-	system("ip link set up dev lo");
-
 	ret = dup2(args->status_pipe[1], STATUS_FD);
 	if (ret < 0) {
 		fprintf(stderr, "dup2() failed: %m\n");
@@ -207,6 +205,8 @@ int ns_exec(void *_arg)
 		return -1;
 	}
 
+	system("ip link set up dev lo");
+
 	if (prepare_mntns())
 		return -1;