mirror of
https://github.com/freebsd/freebsd-src
synced 2024-07-09 04:36:31 +00:00
8269e7673c
Remove core system call implementations and documentation to lib/libsys and lib/libsys/<arch> from lib/libc/sys and lib/libc/<arch>/<sys>. Update paths to allow libc to find them in their new home. Reviewed by: kib, emaste, imp Pull Request: https://github.com/freebsd/freebsd-src/pull/908
129 lines
3.3 KiB
Groff
129 lines
3.3 KiB
Groff
.\" Copyright (c) 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd September 7, 2021
|
|
.Dt MPROTECT 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mprotect
|
|
.Nd control the protection of pages
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/mman.h
|
|
.Ft int
|
|
.Fn mprotect "void *addr" "size_t len" "int prot"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn mprotect
|
|
system call
|
|
changes the specified pages to have protection
|
|
.Fa prot .
|
|
.Pp
|
|
The
|
|
.Fa prot
|
|
argument shall be
|
|
.Dv PROT_NONE
|
|
(no permissions at all)
|
|
or the bitwise
|
|
.Em or
|
|
of one or more of the following values:
|
|
.Pp
|
|
.Bl -tag -width ".Dv PROT_WRITE" -compact
|
|
.It Dv PROT_READ
|
|
The pages can be read.
|
|
.It Dv PROT_WRITE
|
|
The pages can be written.
|
|
.It Dv PROT_EXEC
|
|
The pages can be executed.
|
|
.El
|
|
.Pp
|
|
In addition to these standard protection flags,
|
|
the
|
|
.Fx
|
|
implementation of
|
|
.Fn mprotect
|
|
provides the ability to set the maximum protection of a region
|
|
(which prevents
|
|
.Nm
|
|
from adding to the permissions later).
|
|
This is accomplished by bitwise
|
|
.Em or Ns 'ing
|
|
one or more
|
|
.Dv PROT_
|
|
values wrapped in the
|
|
.Dv PROT_MAX()
|
|
macro into the
|
|
.Fa prot
|
|
argument.
|
|
.Sh RETURN VALUES
|
|
.Rv -std mprotect
|
|
.Sh ERRORS
|
|
The
|
|
.Fn mprotect
|
|
system call will fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EACCES
|
|
The calling process was not allowed to change
|
|
the protection to the value specified by
|
|
the
|
|
.Fa prot
|
|
argument.
|
|
.It Bq Er EINVAL
|
|
The virtual address range specified by the
|
|
.Fa addr
|
|
and
|
|
.Fa len
|
|
arguments is not valid.
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa prot
|
|
argument contains unhandled bits.
|
|
.It Bq Er ENOTSUP
|
|
The
|
|
.Fa prot
|
|
argument contains permissions which are not a subset of the specified
|
|
maximum permissions.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr madvise 2 ,
|
|
.Xr mincore 2 ,
|
|
.Xr msync 2 ,
|
|
.Xr munmap 2
|
|
.Sh HISTORY
|
|
The
|
|
.Fn mprotect
|
|
system call was first documented in
|
|
.Bx 4.2
|
|
and first appeared in
|
|
.Bx 4.4 .
|
|
.Pp
|
|
The
|
|
.Dv PROT_MAX
|
|
functionality was introduced in
|
|
.Fx 13 .
|