создать файловый дескриптор для обработки ошибок страниц в пользовательском пространстве (create a file descriptor for handling page faults in user space)
Ошибки (Error)
See descriptions of the individual operations, above. In
addition, the following general errors can occur for all of the
operations described above:
EFAULT argp does not point to a valid memory address.
EINVAL (For all operations except UFFDIO_API.) The userfaultfd
object has not yet been enabled (via the UFFDIO_API
operation).
