|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | HISTORY | EXAMPLES | SEE ALSO | COLOPHON |
|
|
|
UFFDIO_WRITEPROTECT(2const) UFFDIO_WRITEPROTECT(2const)
UFFDIO_WRITEPROTECT - write-protect or write-unprotect a
userfaultfd-registered memory range
Standard C library (libc, -lc)
#include <linux/userfaultfd.h> /* Definition of UFFD* constants */
#include <sys/ioctl.h>
int ioctl(int fd, UFFDIO_WRITEPROTECT, ...);
#include <linux/userfaultfd.h>
struct uffdio_writeprotect {
struct uffdio_range range; /* Range to change write permission*/
__u64 mode; /* Mode to change write permission */
};
Write-protect or write-unprotect a userfaultfd-registered memory
range registered with mode UFFDIO_REGISTER_MODE_WP.
There are two mode bits that are supported in this structure:
UFFDIO_WRITEPROTECT_MODE_WP
When this mode bit is set, the ioctl will be a write-
protect operation upon the memory range specified by range.
Otherwise it will be a write-unprotect operation upon the
specified range, which can be used to resolve a userfaultfd
write-protect page fault.
UFFDIO_WRITEPROTECT_MODE_DONTWAKE
When this mode bit is set, do not wake up any thread that
waits for page-fault resolution after the operation. This
can be specified only if UFFDIO_WRITEPROTECT_MODE_WP is not
specified.
On success, 0 is returned. On error, -1 is returned and errno is
set to indicate the error.
EINVAL The start or the len field of the ufdio_range structure was
not a multiple of the system page size; or len was zero; or
the specified range was otherwise invalid.
EAGAIN The process was interrupted; retry this call.
ENOENT The range specified in range is not valid. For example,
the virtual address does not exist, or not registered with
userfaultfd write-protect mode.
EFAULT Encountered a generic fault during processing.
Linux.
Linux 5.7.
See userfaultfd(2).
ioctl(2), ioctl_userfaultfd(2), userfaultfd(2)
Documentation/admin-guide/mm/userfaultfd.rst in the Linux kernel
source tree
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.15.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2025-08-11. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.15 2025-05-17 UFFDIO_WRITEPROTECT(2const)
Pages that refer to this page: ioctl_userfaultfd(2)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|