File: /usr/src/servers/pm/table.c This file seems to contain the map of the integers for system calls to the function that implements the call. call_vec is an array of pointers to functions of type int (*)(void) Entry 29 is do_pause, /* 29 = pause */ Entry 30 is no_sys, /* 30 = utime */ Entry 31 is no_sys, /* 31 = (stty) */ The no_sys function is defined in several different places: - /usr/src/servers/pm/utility.c - /usr/src/servers/vfs/utility.c - /usr/src/servers/mfs/utility.c In each of these places the function just returns an error code: