UFFDIO_POISON(2const) - Linux manual page (original) (raw)
UFFDIOPOISON(2const) UFFDIOPOISON(2const)
NAME top
UFFDIO_POISON - mark an address range as "poisoned"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_**, UFFDIO_POISON, ...);**
**#include <linux/userfaultfd.h>**
**struct uffdio_poison {**
**struct uffdio_range range;**
/* Range to install poison PTE markers in */
**__u64 mode;** /* Flags controlling the behavior of poison */
**__s64 updated;** /* Number of bytes poisoned, or negated error */
**};**DESCRIPTION top
Mark an address range as "poisoned". Future accesses to these
addresses will raise a **SIGBUS** signal. Unlike **MADV_HWPOISON** this
works by installing page table entries, rather than "really"
poisoning the underlying physical pages. This means it only
affects this particular address space.
The following value may be bitwise ORed in _mode_ to change the
behavior of the **UFFDIO_POISON** operation:
**UFFDIO_POISON_MODE_DONTWAKE**
Do not wake up the thread that waits for page-fault
resolution.
The _updated_ field is used by the kernel to return the number of
bytes that were actually poisoned, or an error in the same manner
as **UFFDIO_COPY**. If the value returned in the _updated_ field
doesn't match the value that was specified in _range.len_, the
operation fails with the error **EAGAIN**. The _updated_ field is
output-only; it is not read by the **UFFDIO_POISON** operation.RETURN VALUE top
On success, 0 is returned. In this case, the entire area was
poisoned.
On error, -1 is returned and _[errno](../man3/errno.3.html)_ is set to indicate the error.ERRORS top
**EAGAIN** The number of bytes mapped (i.e., the value returned in the
_updated_ field) does not equal the value that was specified
in the _range.len_ field.
**EINVAL** Either _range.start_ or _range.len_ was not a multiple of the
system page size; or _range.len_ was zero; or the range
specified was invalid.
**EINVAL** An invalid bit was specified in the _mode_ field.
**EEXIST** One or more pages were already mapped in the given range.
**ENOENT** The faulting process has changed its virtual memory layout
simultaneously with an outstanding **UFFDIO_POISON** operation.
**ENOMEM** Allocating memory for page table entries failed.
**ESRCH** The faulting process has exited at the time of a
**UFFDIO_POISON** operation.STANDARDS top
Linux.HISTORY top
Linux 6.6.EXAMPLES top
See [userfaultfd(2)](../man2/userfaultfd.2.html).SEE ALSO top
[ioctl(2)](../man2/ioctl.2.html), [ioctl_userfaultfd(2)](../man2/ioctl%5Fuserfaultfd.2.html), [userfaultfd(2)](../man2/userfaultfd.2.html)
_linux.git/Documentation/admin-guide/mm/userfaultfd.rst_COLOPHON top
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man-pages@man7.orgLinux man-pages 6.10 2024-07-23 UFFDIOPOISON(2const)
Pages that refer to this page:ioctl_userfaultfd(2)