--- xnu/xnu-792/iokit/Kernel/IOWorkLoop.cpp
+++ xnu/xnu-517.7.21/iokit/Kernel/IOWorkLoop.cpp
@@ -57,6 +57,12 @@
 
 #define fFlags loopRestart
 
+void IOWorkLoop::launchThreadMain(void *self)
+{
+    thread_set_cont_arg((int) self);
+    threadMainContinuation();
+}
+
 bool IOWorkLoop::init()
 {
     // The super init and gateLock allocation MUST be done first
@@ -84,7 +90,7 @@
     if (addEventSource(controlG) != kIOReturnSuccess)
         return false;
 
-    workThread = IOCreateThread((thread_continue_t)threadMainContinuation, this);
+    workThread = IOCreateThread(launchThreadMain, (void *) this);
     if (!workThread)
         return false;
 
@@ -240,9 +246,12 @@
 
 #endif /* KDEBUG */
 
-void IOWorkLoop::threadMainContinuation(IOWorkLoop *self)
-{
-	self->threadMain();
+void IOWorkLoop::threadMainContinuation()
+{
+  IOWorkLoop* self;
+  self = (IOWorkLoop *) thread_get_cont_arg();
+
+  self->threadMain();
 }
 
 void IOWorkLoop::threadMain()
@@ -285,7 +294,8 @@
 	    assert_wait((void *) &workToDo, false);
 	    IOSimpleLockUnlockEnableInterrupt(workToDoLock, is);
 
-	    thread_block_parameter((thread_continue_t)threadMainContinuation, this);
+	    thread_set_cont_arg((int) this);
+	    thread_block(&threadMainContinuation);
 	    /* NOTREACHED */
 	}