1.\" 2.\" Copyright (c) 2008 Apple Inc. All rights reserved. 3.\" 4.\" @APPLE_LICENSE_HEADER_START@ 5.\" 6.\" This file contains Original Code and/or Modifications of Original Code 7.\" as defined in and that are subject to the Apple Public Source License 8.\" Version 2.0 (the 'License'). You may not use this file except in 9.\" compliance with the License. Please obtain a copy of the License at 10.\" http://www.opensource.apple.com/apsl/ and read it before using this 11.\" file. 12.\" 13.\" The Original Code and all software distributed under the License are 14.\" distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15.\" EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16.\" INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17.\" FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18.\" Please see the License for the specific language governing rights and 19.\" limitations under the License. 20.\" 21.\" @APPLE_LICENSE_HEADER_END@ 22.\" 23.\" 24.\" $NetBSD: mprotect.2,v 1.6 1995/10/12 15:41:08 jtc Exp $ 25.\" 26.\" Copyright (c) 1991, 1993 27.\" The Regents of the University of California. All rights reserved. 28.\" 29.\" Redistribution and use in source and binary forms, with or without 30.\" modification, are permitted provided that the following conditions 31.\" are met: 32.\" 1. Redistributions of source code must retain the above copyright 33.\" notice, this list of conditions and the following disclaimer. 34.\" 2. Redistributions in binary form must reproduce the above copyright 35.\" notice, this list of conditions and the following disclaimer in the 36.\" documentation and/or other materials provided with the distribution. 37.\" 3. All advertising materials mentioning features or use of this software 38.\" must display the following acknowledgement: 39.\" This product includes software developed by the University of 40.\" California, Berkeley and its contributors. 41.\" 4. Neither the name of the University nor the names of its contributors 42.\" may be used to endorse or promote products derived from this software 43.\" without specific prior written permission. 44.\" 45.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 46.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 49.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55.\" SUCH DAMAGE. 56.\" 57.\" @(#)mprotect.2 8.1 (Berkeley) 6/9/93 58.\" $FreeBSD: src/lib/libc/sys/mprotect.2,v 1.18 2007/01/09 00:28:15 imp Exp $ 59.\" 60.Dd October 16, 2008 61.Dt MPROTECT 2 62.Os 63.Sh NAME 64.Nm mprotect 65.Nd control the protection of pages 66.Sh SYNOPSIS 67.Fd #include <sys/mman.h> 68.Ft int 69.Fo mprotect 70.Fa "void *addr" 71.Fa "size_t len" 72.Fa "int prot" 73.Fc 74.Sh DESCRIPTION 75The 76.Fn mprotect 77system call 78changes the specified pages to have protection 79.Fa prot . 80Not all implementations will guarantee protection on a page basis but Mac OS X's 81current implementation does. 82.Pp 83When a program violates the protections of a page, it gets a SIGBUS or SIGSEGV signal. 84.Pp 85Currently 86.Fa prot 87can be one or more of the following: 88.Pp 89.Bl -tag -width ".Dv PROT_WRITE" -compact 90.It Dv PROT_NONE 91No permissions at all. 92.It Dv PROT_READ 93The pages can be read. 94.It Dv PROT_WRITE 95The pages can be written. 96.It Dv PROT_EXEC 97The pages can be executed. 98.El 99.Sh RETURN VALUES 100Upon successful completion, 101a value of 0 is returned. 102Otherwise, a value of -1 is returned and 103.Va errno 104is set to indicate the error. 105.Sh ERRORS 106.Fn mprotect 107will fail if: 108.Bl -tag -width Er 109.\" =========== 110.It Bq Er EACCES 111The requested protection conflicts with 112the access permissions of the process 113on the specified address range. 114.\" =========== 115.\" .It Bq Er EAGAIN 116.\" Insufficient memory resources exist to allow locking a private page 117.\" under PROT_WRITE. 118.\" =========== 119.It Bq Er EINVAL 120.Fa addr 121is not a multiple of the page size (i.e. 122.Fa addr 123is not page-aligned). 124.\" =========== 125.It Bq Er ENOMEM 126The specified address range is outside of the address range 127of the process or includes an unmapped page. 128.\" =========== 129.It Bq Er ENOTSUP 130The combination of accesses requested in 131.Fa prot 132is not supported. 133.El 134.Sh LEGACY SYNOPSIS 135.Fd #include <sys/types.h> 136.Fd #include <sys/mman.h> 137.Pp 138The include file 139.In sys/types.h 140is necessary. 141.Pp 142.Ft int 143.br 144.Fo mprotect 145.Fa "caddr_t addr" 146.Fa "size_t len" 147.Fa "int prot" 148.Fc ; 149.Pp 150The type of 151.Fa addr 152has changed. 153.Sh SEE ALSO 154.Xr madvise 2 , 155.Xr mincore 2 , 156.Xr msync 2 , 157.Xr munmap 2 , 158.Xr compat 5 159.Sh HISTORY 160The 161.Fn mprotect 162function first appeared in 4.4BSD. 163