Accoding to safe_mode.h, php_checkuid() has six modes.

main/safe_mode.c

@@ -35,12 +35,14 @@
 /*
  * php_checkuid
  *
- * This function has four modes:
+ * This function has six modes:
  * 
  * 0 - return invalid (0) if file does not exist
  * 1 - return valid (1)  if file does not exist
  * 2 - if file does not exist, check directory
  * 3 - only check directory (needed for mkdir)
+ * 4 - check mode and param
+ * 5 - only check file
  */
 
 PHPAPI int php_checkuid(const char *filename, char *fopen_mode, int mode)