PERFORCE change 92280 for review

[Todd Miller]

http://perforce.freebsd.org/chv.cgi?CH=92280

Change 92280 by millert at millert_g4tower on 2006/02/23 19:02:58

	Fix long-standing panic.  io_free() calls mac_destroy_port_label()
	on a potentially-uninitialized port label.  To fix, be sure
	to always intialized a port's label after its creation by
	io_alloc().  The best place for this is right after the
	ipc_port_t is bzero()d.

Affected files ...

.. //depot/projects/trustedbsd/sedarwin7/src/darwin/xnu/osfmk/ipc/ipc_object.c#8 edit

Differences ...

==== //depot/projects/trustedbsd/sedarwin7/src/darwin/xnu/osfmk/ipc/ipc_object.c#8 (text+ko) ====

@@ -336,6 +336,9 @@
 		ipc_port_t port = (ipc_port_t)object;
 
 		bzero((char *)port, sizeof(*port));
+#ifdef MAC
+		mac_init_port_label(&port->ip_label);
+#endif
 	} else if (otype == IOT_PORT_SET) {
 		ipc_pset_t pset = (ipc_pset_t)object;
 
@@ -404,6 +407,9 @@
 		ipc_port_t port = (ipc_port_t)object;
 
 		bzero((char *)port, sizeof(*port));
+#ifdef MAC
+		mac_init_port_label(&port->ip_label);
+#endif
 	} else if (otype == IOT_PORT_SET) {
 		ipc_pset_t pset = (ipc_pset_t)object;
 
@@ -999,7 +1005,8 @@
  * User allocated label handles can never be modified.
  */
 
-struct label *io_getlabel (ipc_object_t objp)
+struct label *io_getlabel(
+	ipc_object_t	objp)
 {
 	ipc_port_t port = (ipc_port_t) objp;
 
@@ -1030,10 +1037,8 @@
 #endif	/* MACH_ASSERT */
 
 #ifdef MAC
-		/* XXX: This was never getting called before,
-		   and calling it now causes problems. */
-
-		mac_destroy_port_label (&port->ip_label);
+		/* Port label should have been initialized after creation. */
+		mac_destroy_port_label(&port->ip_label);
 #endif	  
 	}
 	zfree(ipc_object_zones[otype], (vm_offset_t) object);