Index: kernel/generic/src/ipc/sysipc.c
===================================================================
--- kernel/generic/src/ipc/sysipc.c	(revision b74959bd4f5b3c25215165e16f18a594cc56d741)
+++ kernel/generic/src/ipc/sysipc.c	(revision 8498915fcb2cf4aa2a0cc399866d4191c963b740)
@@ -378,4 +378,10 @@
 	IPC_SET_ARG2(call.data, arg2);
 	IPC_SET_ARG3(call.data, arg3);
+	/*
+	 * To achieve deterministic behavior, zero out arguments that are beyond
+	 * the limits of the fast version.
+	 */
+	IPC_SET_ARG4(call.data, 0);
+	IPC_SET_ARG5(call.data, 0);
 
 	if (!(res = request_preprocess(&call))) {
@@ -478,4 +484,9 @@
 	IPC_SET_ARG3(call->data, arg3);
 	IPC_SET_ARG4(call->data, arg4);
+	/*
+	 * To achieve deterministic behavior, zero out arguments that are beyond
+	 * the limits of the fast version.
+	 */
+	IPC_SET_ARG5(call->data, 0);
 
 	if (!(res = request_preprocess(call)))
@@ -624,4 +635,9 @@
 	IPC_SET_ARG3(call->data, arg3);
 	IPC_SET_ARG4(call->data, arg4);
+	/*
+	 * To achieve deterministic behavior, zero out arguments that are beyond
+	 * the limits of the fast version.
+	 */
+	IPC_SET_ARG5(call->data, 0);
 	rc = answer_preprocess(call, saveddata ? &saved_data : NULL);