--- Gnu-Mach/vm/vm_object.c	2020/09/02 04:47:46	1.1.1.3
+++ Gnu-Mach/vm/vm_object.c	2020/09/02 04:50:01	1.1.1.4
@@ -588,10 +588,6 @@ void vm_object_terminate(
 
 			VM_PAGE_CHECK(p);
 
-			if (p->busy && !p->absent)
-				panic("vm_object_terminate.2 0x%x 0x%x",
-				      object, p);
-
 			VM_PAGE_FREE(p);
 		}
 	} else while (!queue_empty(&object->memq)) {
@@ -599,9 +595,6 @@ void vm_object_terminate(
 
 		VM_PAGE_CHECK(p);
 
-		if (p->busy && !p->absent)
-			panic("vm_object_terminate.3 0x%x 0x%x", object, p);
-
 		vm_page_lock_queues();
 		VM_PAGE_QUEUES_REMOVE(p);
 		vm_page_unlock_queues();
@@ -619,9 +612,6 @@ void vm_object_terminate(
 			goto free_page;
 		}
 
-		if (p->fictitious)
-			panic("vm_object_terminate.4 0x%x 0x%x", object, p);
-
 		if (!p->dirty)
 			p->dirty = pmap_is_modified(p->phys_addr);
 
@@ -1336,16 +1326,6 @@ kern_return_t vm_object_copy_call(
 	vm_page_t	p;
 
 	/*
-	 *	Set the backing object for the new
-	 *	temporary object.
-	 */
-
-	assert(src_object->ref_count > 0);
-	src_object->ref_count++;
-	vm_object_paging_begin(src_object);
-	vm_object_unlock(src_object);
-
-	/*
 	 *	Create a memory object port to be associated
 	 *	with this new vm_object.
 	 *
@@ -1358,10 +1338,18 @@ kern_return_t vm_object_copy_call(
 	 */
 
 	new_memory_object = ipc_port_alloc_kernel();
-	if (new_memory_object == IP_NULL) {
-		panic("vm_object_copy_call: allocate memory object port");
-		/* XXX Shouldn't panic here. */
-	}
+	if (new_memory_object == IP_NULL)
+		return KERN_RESOURCE_SHORTAGE;
+
+	/*
+	 *	Set the backing object for the new
+	 *	temporary object.
+	 */
+
+	assert(src_object->ref_count > 0);
+	src_object->ref_count++;
+	vm_object_paging_begin(src_object);
+	vm_object_unlock(src_object);
 
 	/* we hold a naked receive right for new_memory_object */
 	(void) ipc_port_make_send(new_memory_object);
@@ -2477,34 +2465,9 @@ void vm_object_collapse(
 					VM_PAGE_FREE(p);
 				    }
 				    else {
-					if (pp != VM_PAGE_NULL) {
-					    /*
-					     *	Parent has an absent page...
-					     *	it's not being paged in, so
-					     *	it must really be missing from
-					     *	the parent.
-					     *
-					     *	Throw out the absent page...
-					     *	any faults looking for that
-					     *	page will restart with the new
-					     *	one.
-					     */
-
-					    /*
-					     *	This should never happen -- the
-					     *	parent cannot have ever had an
-					     *	external memory object, and thus
-					     *	cannot have absent pages.
-					     */
-					    panic("vm_object_collapse: bad case");
-
-					    VM_PAGE_FREE(pp);
-
-					    /*
-					     *	Fall through to move the backing
-					     *	object's page up.
-					     */
-					}
+					assert(pp == VM_PAGE_NULL || !
+					       "vm_object_collapse: bad case");
+
 					/*
 					 *	Parent now has no page.
 					 *	Move the backing object's page up.