Following arm64-support to development branch

This includes the following fixes:
* fix build of arch/arm64/kernel/vdso

Change-Id: I73b05034d29f7f8731ac17f9736edbba4fb2c639

executer/user/arch/arm64/archdep.S

@@ -1,16 +1,39 @@
 /* archdep.S COPYRIGHT FUJITSU LIMITED 2017-2018 */
-/* TODO: skeleton for UTI */
+
+#include <sys/syscall.h>
+
+/*
+ * int switch_ctx(int fd, unsigned long cmd, void **param, void *lctx,
+ *		  void *rctx);
+ *   <register> : <argument>
+ *     x0 : int fd
+ *     x1 : unsigned long cmd
+ *     x2 : void **param
+ *     x3 : void *lctx
+ *     x4 : void *rctx
+ */
 .global switch_ctx
 switch_ctx:
+	/* send ioctl(fd, cmd, param) */
+	mov	w8, #__NR_ioctl
+	svc	#0x0
+
+	/* if (syscall_ret < 0 && -4095(-MAX_ERRNO) <= syscall_ret) goto 1f; */
+	cmp	x0, #0xfffffffffffff000
+	b.hi	1f
+
+	/* if (syscall_ret != 0) goto 2f; */
+	cmp	x0, #0x0
+	b.ne	2f
+
+	/* function_ret = 0 */
+	mov	x0, #0x0
 	ret
 
-/* TODO: skeleton for UTI */
-.global compare_and_swap
-compare_and_swap:
-	ret
-
-/* TODO: skeleton for UTI */
-.global compare_and_swap_int
-compare_and_swap_int:
+	/* error case */
+1:
+	/* function_ret = -1 */
+	mov	x0, #0xffffffffffffffff
+2:
 	ret