--- xnu/xnu-344.23/iokit/Kernel/IOUserClient.cpp
+++ xnu/xnu-201.19/iokit/Kernel/IOUserClient.cpp
@@ -65,9 +65,6 @@
 
 extern ipc_port_t master_device_port;
 
-extern void iokit_retain_port( ipc_port_t port );
-extern void iokit_release_port( ipc_port_t port );
-
 #include <vm/vm_map.h>
 
 } /* extern "C" */
@@ -83,12 +80,9 @@
 public:
     OSObject *	object;
     ipc_port_t	port;
-    UInt32      mscount;
 
     static IOMachPort * portForObject( OSObject * obj,
 				ipc_kobject_type_t type );
-    static bool noMoreSendersForObject( OSObject * obj,
-				ipc_kobject_type_t type, mach_port_mscount_t * mscount );
     static void releasePortForObject( OSObject * obj,
 				ipc_kobject_type_t type );
     static OSDictionary * dictForType( ipc_kobject_type_t type );
@@ -142,11 +136,8 @@
 	    continue;
 
         if( (inst = (IOMachPort *)
-                dict->getObject( (const OSSymbol *) obj ))) {
-	    inst->mscount++;
-	    inst->retain();
+                dict->getObject( (const OSSymbol *) obj )))
             continue;
-	}
 
         inst = new IOMachPort;
         if( inst && !inst->init()) {
@@ -158,7 +149,7 @@
         if( inst->port) {
 	    // retains obj
             dict->setObject( (const OSSymbol *) obj, inst );
-	    inst->mscount++;
+            inst->release();	// one more to free port => release obj
 
         } else {
             inst->release();
@@ -170,34 +161,6 @@
     IOUnlock( gIOObjectPortLock);
 
     return( inst );
-}
-
-bool IOMachPort::noMoreSendersForObject( OSObject * obj,
-				ipc_kobject_type_t type, mach_port_mscount_t * mscount )
-{
-    OSDictionary *	dict;
-    IOMachPort *	machPort;
-    bool		destroyed = true;
-
-    IOTakeLock( gIOObjectPortLock);
-
-    if( (dict = dictForType( type ))) {
-        obj->retain();
-
-	machPort = (IOMachPort *) dict->getObject( (const OSSymbol *) obj );
-	if( machPort) {
-	    destroyed = (machPort->mscount == *mscount);
-	    if( destroyed)
-		dict->removeObject( (const OSSymbol *) obj );
-	    else
-		*mscount = machPort->mscount;
-	}
-	obj->release();
-    }
-
-    IOUnlock( gIOObjectPortLock);
-
-    return( destroyed );
 }
 
 void IOMachPort::releasePortForObject( OSObject * obj,
@@ -259,31 +222,19 @@
 iokit_port_for_object( io_object_t obj, ipc_kobject_type_t type )
 {
     IOMachPort * machPort;
-    ipc_port_t	 port;
-
-    if( (machPort = IOMachPort::portForObject( obj, type ))) {
-
-	port = machPort->port;
-	if( port)
-	    iokit_retain_port( port );
-
-	machPort->release();
-
-    } else
-	port = NULL;
-
-    return( port );
+
+    if( (machPort = IOMachPort::portForObject( obj, type )))
+	return( machPort->port );
+    else
+	return( 0 );
 }
 
 kern_return_t
 iokit_client_died( io_object_t obj, ipc_port_t /* port */,
-			ipc_kobject_type_t type, mach_port_mscount_t * mscount )
+			ipc_kobject_type_t type )
 {
     IOUserClient *	client;
     IOMemoryMap *	map;
-
-    if( !IOMachPort::noMoreSendersForObject( obj, type, mscount ))
-	return( kIOReturnNotReady );
 
     if( (IKOT_IOKIT_CONNECT == type)
      && (client = OSDynamicCast( IOUserClient, obj )))
@@ -292,7 +243,9 @@
      && (map = OSDynamicCast( IOMemoryMap, obj )))
 	map->taskDied();
 
-    return( kIOReturnSuccess );
+    IOMachPort::releasePortForObject( obj, type );
+
+    return( kIOReturnSuccess);
 }
 
 };	/* extern "C" */
@@ -398,7 +351,7 @@
     pingMsg->msgHdr.msgh_remote_port	= port;
     pingMsg->msgHdr.msgh_bits 		= MACH_MSGH_BITS(
                                             MACH_MSG_TYPE_COPY_SEND,
-                                            MACH_MSG_TYPE_MAKE_SEND );
+                                            MACH_MSG_TYPE_COPY_SEND );
     pingMsg->msgHdr.msgh_size 		= msgSize;
     pingMsg->msgHdr.msgh_id		= kOSNotificationMessageID;
 
@@ -483,7 +436,7 @@
 {
     unsigned int	count;
     kern_return_t	kr;
-    ipc_port_t		port = NULL;
+    IOMachPort *	machPort;
     bool		sendPing = false;
 
     IOTakeLock( lock );
@@ -499,16 +452,12 @@
     IOUnlock( lock );
 
     if( sendPing) {
-	if( (port = iokit_port_for_object( this, IKOT_IOKIT_OBJECT ) ))
-            pingMsg->msgHdr.msgh_local_port = port;
-	else
-            pingMsg->msgHdr.msgh_local_port = NULL;
+        if( (0 == pingMsg->msgHdr.msgh_local_port)
+         && (machPort = IOMachPort::portForObject( this, IKOT_IOKIT_OBJECT ) ))
+            pingMsg->msgHdr.msgh_local_port = machPort->port;
 
         kr = mach_msg_send_from_kernel( &pingMsg->msgHdr,
                                         pingMsg->msgHdr.msgh_size);
-	if( port)
-	    iokit_release_port( port );
-
         if( KERN_SUCCESS != kr)
             IOLog("%s: mach_msg_send_from_kernel {%x}\n", __FILE__, kr );
     }
@@ -573,7 +522,7 @@
                                     void * messageArgument, vm_size_t argSize )
 {
     kern_return_t		kr;
-    ipc_port_t 			port;
+    IOMachPort *		machPort;
     IOServiceInterestContent * 	data = (IOServiceInterestContent *)
                                        pingMsg->notifyHeader.content;
 
@@ -591,17 +540,13 @@
         - sizeof( data->messageArgument)
         + argSize;
 
-    if( (port = iokit_port_for_object( provider, IKOT_IOKIT_OBJECT ) ))
-	pingMsg->msgHdr.msgh_local_port = port;
+    if( (machPort = IOMachPort::portForObject( provider, IKOT_IOKIT_OBJECT ) ))
+        pingMsg->msgHdr.msgh_local_port = machPort->port;
     else
-	pingMsg->msgHdr.msgh_local_port = NULL;
+        pingMsg->msgHdr.msgh_local_port = MACH_PORT_NULL;
     
     kr = mach_msg_send_from_kernel( &pingMsg->msgHdr,
                                     pingMsg->msgHdr.msgh_size);
-
-    if( port)
-	iokit_release_port( port );
-
     if( KERN_SUCCESS != kr)
         IOLog("%s: mach_msg_send_from_kernel {%x}\n", __FILE__, kr );
 
@@ -730,8 +675,8 @@
 IOMemoryMap * IOUserClient::mapClientMemory( 
 	IOOptionBits		type,
 	task_t			task,
-	IOOptionBits		mapFlags,
-	IOVirtualAddress	atAddress )
+	IOOptionBits		mapFlags = kIOMapAnywhere,
+	IOVirtualAddress	atAddress = 0 )
 {
     IOReturn		err;
     IOOptionBits	options = 0;
@@ -1366,7 +1311,14 @@
 
     CHECK( IORegistryEntry, registry_entry, entry );
 
+#if 0
+    // need virtual
     obj = entry->copyProperty(property_name);
+#else
+    obj = entry->getProperty(property_name);
+    if( obj)
+        obj->retain();
+#endif
     if( !obj)
         return( kIOReturnNoResources );
 
@@ -1422,7 +1374,14 @@
 
     CHECK( IORegistryEntry, registry_entry, entry );
 
+#if 0
+    // need virtual
     obj = entry->copyProperty(property_name);
+#else
+    obj = entry->getProperty(property_name);
+    if( obj)
+        obj->retain();
+#endif
     if( !obj)
         return( kIOReturnNotFound );
 
@@ -1462,8 +1421,15 @@
 
     CHECK( IORegistryEntry, registry_entry, entry );
 
+#if 0
     obj = entry->copyProperty( property_name,
                                IORegistryEntry::getPlane( plane ), options);
+#else
+    obj = entry->getProperty( property_name,
+                               IORegistryEntry::getPlane( plane ), options);
+    if( obj)
+        obj->retain();
+#endif
     if( !obj)
         return( kIOReturnNotFound );
 
@@ -2501,8 +2467,6 @@
         case kIOCatalogRemoveKernelLinker: {
                 if (gIOCatalogue->removeKernelLinker() != KERN_SUCCESS) {
                     kr = kIOReturnError;
-                } else {
-                    kr = kIOReturnSuccess;
                 }
             }
             break;