-extern size_t copy_from_user_std_small(size_t, const void __user *, void *);
-extern size_t copy_to_user_std_small(size_t, void __user *, const void *);
-extern size_t strnlen_user_std(size_t, const char __user *);
-extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
-extern int futex_atomic_op(int, int __user *, int, int *);
-extern int futex_atomic_cmpxchg(int __user *, int, int);
+static size_t strnlen_user_mvcos(size_t count, const char __user *src)
+{
+ char buf[256];
+ int rc;
+ size_t done, len, len_str;
+
+ done = 0;
+ do {
+ len = min(count - done, (size_t) 256);
+ rc = uaccess.copy_from_user(len, src + done, buf);
+ if (unlikely(rc == len))
+ return 0;
+ len -= rc;
+ len_str = strnlen(buf, len);
+ done += len_str;
+ } while ((len_str == len) && (done < count));
+ return done + 1;
+}
+
+static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
+ char *dst)
+{
+ int rc;
+ size_t done, len, len_str;
+
+ done = 0;
+ do {
+ len = min(count - done, (size_t) 4096);
+ rc = uaccess.copy_from_user(len, src + done, dst);
+ if (unlikely(rc == len))
+ return -EFAULT;
+ len -= rc;
+ len_str = strnlen(dst, len);
+ done += len_str;
+ } while ((len_str == len) && (done < count));
+ return done;
+}