ioctl_userfaultfd(2) - Linux manual page (original) (raw)

ioctluserfaultfd(2) System Calls Manual ioctluserfaultfd(2)

NAME top

   ioctl_userfaultfd - create a file descriptor for handling page
   faults in user space

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#include <linux/userfaultfd.h>** /* Definition of **UFFD*** constants */
   **#include <sys/ioctl.h>**

   **int ioctl(int** _fd_**, int** _op_**, ...);**

DESCRIPTION top

   Various [ioctl(2)](../man2/ioctl.2.html) operations can be performed on a userfaultfd
   object (created by a call to [userfaultfd(2)](../man2/userfaultfd.2.html)) using calls of the
   form:

       ioctl(fd, op, argp);

   In the above, _fd_ is a file descriptor referring to a userfaultfd
   object, _op_ is one of the operations listed below, and _argp_ is a
   pointer to a data structure that is specific to _op_.

   The various [ioctl(2)](../man2/ioctl.2.html) operations are described below.  The
   **UFFDIO_API**, **UFFDIO_REGISTER**, and **UFFDIO_UNREGISTER** operations are
   used to _configure_ userfaultfd behavior.  These operations allow
   the caller to choose what features will be enabled and what kinds
   of events will be delivered to the application.  The remaining
   operations are _range_ operations.  These operations enable the
   calling application to resolve page-fault events.

   [UFFDIO_API(2const)](../man2/UFFDIO%5FAPI.2const.html)
   [UFFDIO_REGISTER(2const)](../man2/UFFDIO%5FREGISTER.2const.html)
   [UFFDIO_UNREGISTER(2const)](../man2/UFFDIO%5FUNREGISTER.2const.html)
   [UFFDIO_COPY(2const)](../man2/UFFDIO%5FCOPY.2const.html)
   [UFFDIO_ZEROPAGE(2const)](../man2/UFFDIO%5FZEROPAGE.2const.html)
   [UFFDIO_WAKE(2const)](../man2/UFFDIO%5FWAKE.2const.html)
   [UFFDIO_WRITEPROTECT(2const)](../man2/UFFDIO%5FWRITEPROTECT.2const.html)
   [UFFDIO_CONTINUE(2const)](../man2/UFFDIO%5FCONTINUE.2const.html)
   [UFFDIO_POISON(2const)](../man2/UFFDIO%5FPOISON.2const.html)

RETURN VALUE top

   On success, 0 is returned.  On error, -1 is returned, and _[errno](../man3/errno.3.html)_ is
   set to indicate the error.

ERRORS top

   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).

STANDARDS top

   Linux.

EXAMPLES top

   See [userfaultfd(2)](../man2/userfaultfd.2.html).

SEE ALSO top

   [ioctl(2)](../man2/ioctl.2.html), [mmap(2)](../man2/mmap.2.html), [userfaultfd(2)](../man2/userfaultfd.2.html)

   _linux.git/Documentation/admin-guide/mm/userfaultfd.rst_

COLOPHON top

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Linux man-pages 6.10 2024-07-23 ioctluserfaultfd(2)

Pages that refer to this page:ioctl(2), UFFDIO_API(2const), UFFDIO_CONTINUE(2const), UFFDIO_COPY(2const), UFFDIO_POISON(2const), UFFDIO_REGISTER(2const), UFFDIO_UNREGISTER(2const), UFFDIO_WAKE(2const), UFFDIO_WRITEPROTECT(2const), UFFDIO_ZEROPAGE(2const), userfaultfd(2)