- case JSIOCGAXMAP:
- return copy_to_user(argp, joydev->abspam,
- sizeof(__u8) * (ABS_MAX + 1)) ? -EFAULT : 0;
-
- case JSIOCSBTNMAP:
- if (copy_from_user(joydev->keypam, argp,
- sizeof(__u16) * (KEY_MAX - BTN_MISC + 1)))
+ case (JSIOCGAXMAP & ~IOCSIZE_MASK):
+ len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->abspam));
+ return copy_to_user(argp, joydev->abspam, len) ? -EFAULT : 0;
+
+ case (JSIOCSBTNMAP & ~IOCSIZE_MASK):
+ len = min_t(size_t, _IOC_SIZE(cmd), sizeof(joydev->keypam));
+ /*
+ * FIXME: we should not copy into our keymap before
+ * validating the data.
+ */
+ if (copy_from_user(joydev->keypam, argp, len))