--- xnu/xnu-517.7.21/iokit/Kernel/IOWorkLoop.cpp
+++ xnu/xnu-124.1/iokit/Kernel/IOWorkLoop.cpp
@@ -37,8 +37,7 @@
 OSDefineMetaClassAndStructors(IOWorkLoop, OSObject);
 
 // Block of unused functions intended for future use
-OSMetaClassDefineReservedUsed(IOWorkLoop, 0);
-
+OSMetaClassDefineReservedUnused(IOWorkLoop, 0);
 OSMetaClassDefineReservedUnused(IOWorkLoop, 1);
 OSMetaClassDefineReservedUnused(IOWorkLoop, 2);
 OSMetaClassDefineReservedUnused(IOWorkLoop, 3);
@@ -59,6 +58,10 @@
 
 void IOWorkLoop::launchThreadMain(void *self)
 {
+    register thread_t mythread = current_thread();
+
+    // Make sure that this thread always has a kernel stack
+    stack_privilege(mythread);
     thread_set_cont_arg((int) self);
     threadMainContinuation();
 }
@@ -103,7 +106,7 @@
     IOWorkLoop *me = new IOWorkLoop;
 
     if (me && !me->init()) {
-        me->release();
+        me->free();
         return 0;
     }
 
@@ -294,8 +297,13 @@
 	    assert_wait((void *) &workToDo, false);
 	    IOSimpleLockUnlockEnableInterrupt(workToDoLock, is);
 
+#if defined (__i386__)
+	    thread_block(0);
+	    continue;
+#else
 	    thread_set_cont_arg((int) this);
 	    thread_block(&threadMainContinuation);
+#endif
 	    /* NOTREACHED */
 	}
 
@@ -312,7 +320,7 @@
 exitThread:
     workThread = 0;	// Say we don't have a loop and free ourselves
     free();
-    IOExitThread();
+    IOExitThread(0);
 }
 
 IOThread IOWorkLoop::getThread() const
@@ -366,20 +374,6 @@
     IORecursiveLockWakeup(gateLock, event, oneThread);
 }
 
-IOReturn IOWorkLoop::runAction(Action inAction, OSObject *target,
-                                  void *arg0, void *arg1,
-                                  void *arg2, void *arg3)
-{
-    IOReturn res;
-
-    // closeGate is recursive so don't worry if we already hold the lock.
-    closeGate();
-    res = (*inAction)(target, arg0, arg1, arg2, arg3);
-    openGate();
-
-    return res;
-}
-
 IOReturn IOWorkLoop::_maintRequest(void *inC, void *inD, void *, void *)
 {
     maintCommandEnum command = (maintCommandEnum) (vm_address_t) inC;
@@ -389,48 +383,43 @@
     switch (command)
     {
     case mAddEvent:
-        if (!inEvent->getWorkLoop()) {
-            SETP(&fFlags, kLoopRestart);
-
-            inEvent->retain();
-            inEvent->setWorkLoop(this);
-            inEvent->setNext(0);
-    
-            if (!eventChain)
-                eventChain = inEvent;
-            else {
-                IOEventSource *event, *next;
-    
-                for (event = eventChain; (next = event->getNext()); event = next)
-                    ;
-                event->setNext(inEvent);
-            }
+	SETP(&fFlags, kLoopRestart);
+        inEvent->retain();
+        inEvent->setWorkLoop(this);
+        inEvent->setNext(0);
+
+        if (!eventChain)
+            eventChain = inEvent;
+        else {
+            IOEventSource *event, *next;
+
+            for (event = eventChain; (next = event->getNext()); event = next)
+                ;
+            event->setNext(inEvent);
         }
         break;
 
     case mRemoveEvent:
-        if (inEvent->getWorkLoop()) {
-            if (eventChain == inEvent)
-                eventChain = inEvent->getNext();
-            else {
-                IOEventSource *event, *next;
-    
-                event = eventChain;
-                while ((next = event->getNext()) && next != inEvent)
-                    event = next;
-    
-                if (!next) {
-                    res = kIOReturnBadArgument;
-                    break;
-                }
-                event->setNext(inEvent->getNext());
+        if (eventChain == inEvent)
+            eventChain = inEvent->getNext();
+        else {
+            IOEventSource *event, *next;
+
+            event = eventChain;
+            while ((next = event->getNext()) && next != inEvent)
+                event = next;
+
+            if (!next) {
+                res = kIOReturnBadArgument;
+                break;
             }
-    
-            inEvent->setWorkLoop(0);
-            inEvent->setNext(0);
-            inEvent->release();
-            SETP(&fFlags, kLoopRestart);
+            event->setNext(inEvent->getNext());
         }
+
+        inEvent->setWorkLoop(0);
+        inEvent->setNext(0);
+        inEvent->release();
+	SETP(&fFlags, kLoopRestart);
         break;
 
     default: