12 unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)  in copy_from_user()  argument
14 	if (likely(access_ok(VERIFY_READ, from, n)))  in copy_from_user()
15 		n = __copy_from_user(to, from, n);  in copy_from_user()
17 		memset(to, 0, n);  in copy_from_user()
18 	return n;  in copy_from_user()
21 unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)  in copy_to_user()  argument
23 	if (likely(access_ok(VERIFY_WRITE, to, n)))  in copy_to_user()
24 		n = __copy_to_user(to, from, n);  in copy_to_user()
25 	return n;  in copy_to_user()
29 			   unsigned long n)  in copy_in_user()  argument
32 	if (likely(access_ok(VERIFY_READ, from, n) &&  in copy_in_user()
33 	    access_ok(VERIFY_WRITE, to, n)))  in copy_in_user()
34 		n =__copy_tofrom_user(to, from, n);  in copy_in_user()
35 	return n;  in copy_in_user()