.\" $NetBSD: mprotect.2,v 1.6 1995/10/12 15:41:08 jtc Exp $ .\" .\" 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. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. 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. .\" .\" @(#)mprotect.2 8.1 (Berkeley) 6/9/93 .\" .Dd June 9, 1993 .Dt MPROTECT 2 .Os .Sh NAME .Nm mprotect .Nd control the protection of pages .Sh SYNOPSIS .Fd #include <sys/mman.h> .Ft int .Fo mprotect .Fa "void *addr" .Fa "size_t len" .Fa "int prot" .Fc .Sh DESCRIPTION The .Fn mprotect system call changes the specified pages to have protection .Fa prot . Not all implementations will guarantee protection on a page basis; the granularity of protection changes may be as large as an entire region. .Sh RETURN VALUES Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and .Va errno is set to indicate the error. .Sh ERRORS .Fn mprotect will fail if: .Bl -tag -width Er .\" =========== .It Bq Er EACCES The requested protection conflicts with the access permissions of the process on the specified address range. .\" =========== .\" .It Bq Er EAGAIN .\" Insufficient memory resources exist to allow locking a private page .\" under PROT_WRITE. .\" =========== .It Bq Er EINVAL .Fa addr is not a multiple of the page size. .\" =========== .\" .It Bq Er ENOMEM .\" The specified address range is outside of the address range .\" of the process or includes an unmapped page. .\" =========== .It Bq Er ENOTSUP The combination of accesses requested in .Fa prot is not supported. .El .Sh LEGACY SYNOPSIS .Fd #include <sys/types.h> .Fd #include <sys/mman.h> .Pp The include file .In sys/types.h is necessary. .Pp .Ft int .br .Fo mprotect .Fa "caddr_t addr" .Fa "size_t len" .Fa "int prot" .Fc ; .Pp The type of .Fa addr has changed. .Sh SEE ALSO .Xr madvise 2 , .Xr mincore 2 , .Xr msync 2 , .Xr munmap 2 , .Xr compat 5 .Sh HISTORY The .Fn mprotect function first appeared in 4.4BSD.