NOVA: Use everywhere same value for a invalid cap

base-nova/include/base/ipc_msgbuf.h

@@ -183,7 +183,7 @@ namespace Genode {
 				if (_rcv_pt_sel_cnt < _rcv_pt_sel_max)
 					return _rcv_pt_sel[_rcv_pt_sel_cnt++].sel;
 				else
-					return 0;
+					return ~0UL;
 			}
 
 			/**
@@ -294,7 +294,8 @@ namespace Genode {
 					if (!item) break;
 					if (_rcv_pt_sel_max >= MAX_CAP_ARGS) break;
 
-					_rcv_pt_sel[_rcv_pt_sel_max].sel   = item->crd >> 12;
+					Nova::Crd cap = Nova::Crd(item->crd);
+					_rcv_pt_sel[_rcv_pt_sel_max].sel   = cap.is_null() ? ~0UL : cap.base();
 					_rcv_pt_sel[_rcv_pt_sel_max++].del = item->is_del();
 				}
 			}

base-nova/include/base/native_types.h

@@ -26,8 +26,13 @@ namespace Genode {
 
 	struct Native_thread
 	{
+		enum { INVALID_INDEX = ~0UL };
+
 		addr_t ec_sel;    /* NOVA cap selector for execution context */
 		addr_t exc_pt_sel; /* base of event portal window */
+
+		Native_thread() : ec_sel(INVALID_INDEX),
+		                  exc_pt_sel (INVALID_INDEX) { }
 	};
 
 	typedef Native_thread Native_thread_id;
@@ -92,6 +97,7 @@ namespace Genode {
 			bool   _trans_map;
 			void * _ptr;
 
+			enum { INVALID_INDEX = ~0UL };
 		protected:
 
 			explicit
@@ -123,18 +129,24 @@ namespace Genode {
 			bool valid() const
 			{
 				 return !_cap.dst.is_null() &&
-					 _cap.dst.base() != ~0UL;
+					 _cap.dst.base() != INVALID_INDEX;
 			 }
 
 			Dst dst()   const { return _cap.dst; }
 			void * local() const { return _ptr; }
-			addr_t local_name() const { return _cap.dst.base(); }
+
+			addr_t local_name() const {
+				if (valid())
+					return _cap.dst.base();
+				else
+					return INVALID_INDEX;
+			}
 
 			static Dst invalid() { return Dst(); }
 
 			static Native_capability invalid_cap()
 			{
-				return Native_capability(~0UL);
+				return Native_capability(INVALID_INDEX);
 			}
 
 			/** Invoke map syscall instead of translate_map call */

base-nova/src/base/lock/lock_helper.h

@@ -63,7 +63,9 @@ static inline Genode::Native_thread_id thread_get_my_native_id()
 	Genode::Thread_base *myself = Genode::Thread_base::myself();
 
 	if (myself == 0) {
-		Genode::Native_thread_id main_tid = { 0, 0 };
+		Genode::Native_thread_id main_tid;
+		main_tid.ec_sel     = 0;
+		main_tid.exc_pt_sel = 0;
 		return main_tid;
 	} else
 		return myself->tid();
@@ -72,7 +74,7 @@ static inline Genode::Native_thread_id thread_get_my_native_id()
 
 static inline Genode::Native_thread_id thread_invalid_id()
 {
-	Genode::Native_thread_id tid = { ~0UL, ~0UL };
+	Genode::Native_thread_id tid;
 	return tid;
 }
 

base-nova/src/core/cpu_session_extension.cc

@@ -24,7 +24,7 @@ Cpu_session_component::native_cap(Thread_capability thread_cap)
 {
 	Cpu_thread_component *thread = _lookup_thread(thread_cap);
 	if (!thread)
-		return Native_capability(0, 0);
+		return Native_capability::invalid_cap();
 
 	return thread->platform_thread()->native_cap();
 }