return -ENOTTY;
if ( _IOC_DIR(cmd) & _IOC_READ )
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,0,0)
ret = !access_ok(arg, _IOC_SIZE(cmd));
-#else
- ret = !access_ok(VERIFY_WRITE, arg, _IOC_SIZE(cmd));
-#endif
else if ( _IOC_DIR(cmd) & _IOC_WRITE )
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,0,0)
ret = !access_ok(arg, _IOC_SIZE(cmd));
-#else
- ret = !access_ok(VERIFY_READ, arg, _IOC_SIZE(cmd));
-#endif
if ( ret )
return -EFAULT;