propagate error code for prepare image

executer/kernel/control.c

@@ -87,8 +87,8 @@ static long mcexec_prepare_image(ihk_os_t os,
 
 	wait_event_interruptible(usrdata->wq_prepare, pdesc->status);
 
-	if(pdesc->err == -1){
-		ret = -EFAULT;	
+	if(pdesc->err < 0){
+		ret = pdesc->err;	
 		goto free_out;
 	}
 

executer/kernel/ikc.c

@@ -35,7 +35,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
 		break;
 
 	case SCD_MSG_PREPARE_PROCESS_NACKED:
-		mcexec_prepare_ack(__os, pisp->arg, -1);
+		mcexec_prepare_ack(__os, pisp->arg, pisp->err);
 		break;
 
 	case SCD_MSG_SYSCALL_ONESIDE:

executer/kernel/mcctrl.h

@@ -24,6 +24,7 @@
 struct ikc_scd_packet {
 	int msg;
 	int ref;
+	int err;
 	unsigned long arg;
 };