extern void *um_kmalloc(int size);
extern int switcheroo(int fd, int prot, void *from, void *to, int size);
extern void do_exec(int old_pid, int new_pid);
extern void *um_kmalloc(int size);
extern int switcheroo(int fd, int prot, void *from, void *to, int size);
extern void do_exec(int old_pid, int new_pid);