--- xnu/xnu-517.7.21/iokit/Kernel/IOUserClient.cpp
+++ xnu/xnu-517.7.7/iokit/Kernel/IOUserClient.cpp
@@ -1963,33 +1963,6 @@
 	err = kIOReturnBadArgument;
 
     return( err );
-}
-
-IOMemoryMap * IOUserClient::removeMappingForDescriptor(IOMemoryDescriptor * mem)
-{
-    OSIterator *  iter;
-    IOMemoryMap * map = 0;
-
-    IOLockLock(gIOObjectPortLock);
-
-    iter = OSCollectionIterator::withCollection(mappings);
-    if(iter)
-    {
-        while ((map = OSDynamicCast(IOMemoryMap, iter->getNextObject())))
-        {
-            if(mem == map->getMemoryDescriptor())
-            {
-                map->retain();
-                mappings->removeObject(map);
-                break;
-            }
-        }
-        iter->release();
-    }
-
-    IOLockUnlock(gIOObjectPortLock);
-
-    return (map);
 }
 
 kern_return_t is_io_connect_unmap_memory(