Index: generic/include/proc/thread.h
===================================================================
--- generic/include/proc/thread.h	(revision df0103f7b38d6ac53512fd7880952c2d3a01c7d1)
+++ generic/include/proc/thread.h	(revision f6a0f065313f80577feb532b149596c25b7b3866)
@@ -92,4 +92,10 @@
 	volatile int timeout_pending;		/**< Flag signalling sleep timeout in progress. */
 
+	/** True if this thread is executing copy_from_uspace(). False otherwise. */
+	bool in_copy_from_uspace;
+	/** True if this thread is executing copy_to_uspace(). False otherwise. */
+	bool in_copy_to_uspace;
+
+
 	fpu_context_t *saved_fpu_context;
 	int fpu_context_exists;