.BR UFFDIO_WRITEPROTECT (2const)
.TQ
.BR UFFDIO_CONTINUE (2const)
-.SS UFFDIO_POISON
-(Since Linux 6.6.)
-Mark an address range as "poisoned".
-Future accesses to these addresses will raise a
-.B SIGBUS
-signal.
-Unlike
-.B 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.
-.P
-The
-.I argp
-argument is a pointer to a
-.I uffdio_poison
-structure as shown below:
-.P
-.in +4n
-.EX
-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 */
-};
-.EE
-.in
-.P
-The following value may be bitwise ORed in
-.I mode
-to change the behavior of the
-.B UFFDIO_POISON
-operation:
-.TP
-.B UFFDIO_POISON_MODE_DONTWAKE
-Do not wake up the thread that waits for page-fault resolution.
-.P
-The
-.I 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
-.BR UFFDIO_COPY .
-If the value returned in the
-.I updated
-field doesn't match the value that was specified in
-.IR range.len ,
-the operation fails with the error
-.BR EAGAIN .
-The
-.I updated
-field is output-only;
-it is not read by the
-.B UFFDIO_POISON
-operation.
-.P
-This
-.BR ioctl (2)
-operation returns 0 on success.
-In this case,
-the entire area was poisoned.
-On error, \-1 is returned and
-.I errno
-is set to indicate the error.
-Possible errors include:
-.TP
-.B EAGAIN
-The number of bytes mapped
-(i.e., the value returned in the
-.I updated
-field)
-does not equal the value that was specified in the
-.I range.len
-field.
-.TP
-.B EINVAL
-Either
-.I range.start
-or
-.I range.len
-was not a multiple of the system page size; or
-.I range.len
-was zero; or the range specified was invalid.
-.TP
-.B EINVAL
-An invalid bit was specified in the
-.I mode
-field.
-.TP
-.B EEXIST
-One or more pages were already mapped in the given range.
-.TP
-.B ENOENT
-The faulting process has changed its virtual memory layout simultaneously with
-an outstanding
-.B UFFDIO_POISON
-operation.
-.TP
-.B ENOMEM
-Allocating memory for page table entries failed.
-.TP
-.B ESRCH
-The faulting process has exited at the time of a
-.B UFFDIO_POISON
-operation.
-.\"
+.TQ
+.BR UFFDIO_POISON (2const)
.SH RETURN VALUE
See descriptions of the individual operations, above.
.SH ERRORS
--- /dev/null
+.\" Copyright 2016, IBM Corporation.
+.\" Written by Mike Rapoport <rppt@linux.vnet.ibm.com>
+.\" Copyright 2016, Michael Kerrisk <mtk.manpages@gmail.com>
+.\" Copyright 2024, Alejandro Colomar <alx@kernel.org>
+.\"
+.\" SPDX-License-Identifier: Linux-man-pages-copyleft
+.\"
+.TH UFFDIO_POISON 2const (date) "Linux man-pages (unreleased)"
+.SH NAME
+UFFDIO_POISON
+\-
+mark an address range as "poisoned"
+.SH LIBRARY
+Standard C library
+.RI ( libc ", " \-lc )
+.SH SYNOPSIS
+.nf
+.BR "#include <linux/userfaultfd.h>" " /* Definition of " UFFD* " constants */"
+.B #include <sys/ioctl.h>
+.P
+.BI "int ioctl(int " fd ", UFFDIO_POISON, ...);"
+.fi
+.SH DESCRIPTION
+(Since Linux 6.6.)
+Mark an address range as "poisoned".
+Future accesses to these addresses will raise a
+.B SIGBUS
+signal.
+Unlike
+.B 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.
+.P
+The
+.I argp
+argument is a pointer to a
+.I uffdio_poison
+structure as shown below:
+.P
+.in +4n
+.EX
+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 */
+};
+.EE
+.in
+.P
+The following value may be bitwise ORed in
+.I mode
+to change the behavior of the
+.B UFFDIO_POISON
+operation:
+.TP
+.B UFFDIO_POISON_MODE_DONTWAKE
+Do not wake up the thread that waits for page-fault resolution.
+.P
+The
+.I 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
+.BR UFFDIO_COPY .
+If the value returned in the
+.I updated
+field doesn't match the value that was specified in
+.IR range.len ,
+the operation fails with the error
+.BR EAGAIN .
+The
+.I updated
+field is output-only;
+it is not read by the
+.B UFFDIO_POISON
+operation.
+.SH RETURN VALUE
+This
+.BR ioctl (2)
+operation returns 0 on success.
+In this case,
+the entire area was poisoned.
+On error, \-1 is returned and
+.I errno
+is set to indicate the error.
+.SH ERRORS
+.TP
+.B EAGAIN
+The number of bytes mapped
+(i.e., the value returned in the
+.I updated
+field)
+does not equal the value that was specified in the
+.I range.len
+field.
+.TP
+.B EINVAL
+Either
+.I range.start
+or
+.I range.len
+was not a multiple of the system page size; or
+.I range.len
+was zero; or the range specified was invalid.
+.TP
+.B EINVAL
+An invalid bit was specified in the
+.I mode
+field.
+.TP
+.B EEXIST
+One or more pages were already mapped in the given range.
+.TP
+.B ENOENT
+The faulting process has changed its virtual memory layout simultaneously with
+an outstanding
+.B UFFDIO_POISON
+operation.
+.TP
+.B ENOMEM
+Allocating memory for page table entries failed.
+.TP
+.B ESRCH
+The faulting process has exited at the time of a
+.B UFFDIO_POISON
+operation.
+.SH STANDARDS
+Linux.
+.SH HISTORY
+.SH EXAMPLES
+See
+.BR userfaultfd (2).
+.SH SEE ALSO
+.BR ioctl (2),
+.BR ioctl_userfaultfd (2),
+.BR userfaultfd (2)
+.P
+.I Documentation/admin\-guide/mm/userfaultfd.rst
+in the Linux kernel source tree
projects / thirdparty / man-pages.git / commitdiff
