> I think this is horrid; why can't we have it return something different > then -EFAULT instead? I did consider this ... but it appears that architectures aren't unified in the return value from get_user() Here's another function involved in the futex call chain leading to this: static int get_futex_value_locked(u32 *dest, u32 __user *from) { int ret; pagefault_disable(); ret = __get_user(*dest, from); pagefault_enable(); return ret ? -EFAULT : 0; } It seems like the expectation here is just "zero or not" and we don't care what the "not" value is ... just turn it into -EFAULT. -Tony