--- old/src/hotspot/share/runtime/javaCalls.hpp	2018-09-28 11:53:55.000000000 -0700
+++ new/src/hotspot/share/runtime/javaCalls.hpp	2018-09-28 11:53:55.000000000 -0700
@@ -163,34 +163,44 @@
     value_state_limit
   };
 
+  void size_check(int words = 1) {
+    assert(_size + (words-1) < _max_size, "oob: increase max_size argument to JavaCallArguments");
+  }
+
   inline void push_oop(Handle h) {
+    size_check();
     _value_state[_size] = value_state_handle;
     _size = push_oop_impl(h.raw_value(), _size);
   }
 
   inline void push_jobject(jobject h) {
+    size_check();
     _value_state[_size] = value_state_jobject;
     _size = push_oop_impl(h, _size);
   }
 
   inline void push_int(int i) {
+    size_check();
     _value_state[_size] = value_state_primitive;
     JNITypes::put_int(i, _value, _size);
   }
 
   inline void push_double(double d) {
+    size_check(2);
     _value_state[_size] = value_state_primitive;
     _value_state[_size + 1] = value_state_primitive;
     JNITypes::put_double(d, _value, _size);
   }
 
   inline void push_long(jlong l) {
+    size_check(2);
     _value_state[_size] = value_state_primitive;
     _value_state[_size + 1] = value_state_primitive;
     JNITypes::put_long(l, _value, _size);
   }
 
   inline void push_float(float f) {
+    size_check();
     _value_state[_size] = value_state_primitive;
     JNITypes::put_float(f, _value, _size);
   }
@@ -210,6 +220,7 @@
     _value_state--;
     _value--;
     _size++;
+    DEBUG_ONLY(_max_size++);
     _value_state[0] = value_state_handle;
     push_oop_impl(h.raw_value(), 0);
   }