- enable ipc warnings by default

- ipc checking code in kernel didn't properly catch the
   sendrec() to self case; added special case check
 - triggered by PM using stock panic() - needs its own _exit()

reported by Joren l'Ami.

kernel/debug.h

@@ -19,7 +19,7 @@
  * Of course the call still fails, but nothing is printed if these warnings
  * are disabled.
  */
-#define DEBUG_ENABLE_IPC_WARNINGS	0
+#define DEBUG_ENABLE_IPC_WARNINGS	1
 #define DEBUG_STACKTRACE		1
 #define DEBUG_VMASSERT			1
 #define DEBUG_SCHED_CHECK		1

kernel/proc.c

@@ -201,6 +201,13 @@ long bit_map;			/* notification event set or flags */
   }
   else
   {
+	if(caller_ptr->p_endpoint == src_dst_e) {
+#if DEBUG_ENABLE_IPC_WARNINGS
+		kprintf("sys_call: trap %d by %d with self %d\n", 
+			call_nr, proc_nr(caller_ptr), src_dst_e);
+#endif
+		return EINVAL;
+	}
 	/* Require a valid source and/or destination process. */
 	if(!isokendpt(src_dst_e, &src_dst_p)) {
 #if DEBUG_ENABLE_IPC_WARNINGS

servers/pm/forkexit.c

@@ -417,3 +417,13 @@ register struct mproc *rmp;	/* tells which process is exiting */
   rmp->mp_child_stime = 0;
   procs_in_use--;
 }
+
+PUBLIC void _exit(int code)
+{
+	sys_exit(SELF);
+}
+
+PUBLIC void __exit(int code)
+{
+	sys_exit(SELF);
+}