1.\" $NetBSD: mprotect.2,v 1.24 2011/04/03 06:54:30 jruoho Exp $ 2.\" 3.\" Copyright (c) 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)mprotect.2 8.1 (Berkeley) 6/9/93 31.\" 32.Dd April 3, 2011 33.Dt MPROTECT 2 34.Os 35.Sh NAME 36.Nm mprotect 37.Nd control the protection of pages 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In sys/mman.h 42.Ft int 43.Fn mprotect "void *addr" "size_t len" "int prot" 44.Sh DESCRIPTION 45The 46.Fn mprotect 47system call 48changes the specified pages to have protection 49.Fa prot . 50Not all implementations will guarantee protection on a page basis; 51the granularity of protection changes may be as large as an entire region. 52.Pp 53The protections (region accessibility) are specified in the 54.Fa prot 55argument by 56.Tn OR Ns 'ing 57the following values: 58.Pp 59.Bl -tag -width MAP_FIXEDX -offset indent 60.It Dv PROT_EXEC 61Pages may be executed. 62.It Dv PROT_READ 63Pages may be read. 64.It Dv PROT_WRITE 65Pages may be written. 66.It Dv PROT_NONE 67No permissions. 68.El 69.Sh RETURN VALUES 70Upon successful completion, 71a value of 0 is returned. 72Otherwise, a value of \-1 is returned and 73.Va errno 74is set to indicate the error. 75.Sh ERRORS 76.Bl -tag -width Er 77.It Bq Er EACCES 78A memory protection violation occurred, or the 79.Dv PROT_EXEC 80flag was attempted on pages which belong to a filesystem mounted with the 81.Dv NOEXEC 82flag. 83.It Bq Er EINVAL 84An invalid memory range, or invalid parameters were provided. 85.It Bq Er ENOMEM 86A resource shortage occurred while internally calling 87.Xr uvm_map_protect 9 . 88.El 89.Sh SEE ALSO 90.Xr madvise 2 , 91.Xr mincore 2 , 92.Xr msync 2 , 93.Xr munmap 2 94.Sh HISTORY 95The 96.Fn mprotect 97function first appeared in 98.Bx 4.4 . 99