.\" Copyright (c) 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" %sccs.include.redist.roff% .\" .\" @(#)mprotect.2 8.1 (Berkeley) 06/09/93 .\" .Dd .Dt MPROTECT 2 .Os .Sh NAME .Nm mprotect .Nd control the protection of pages .Sh SYNOPSIS .Fn mprotect "caddr_t addr" "int len" "int prot" .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 SEE ALSO .Xr msync 2 , .Xr munmap 2 , .Xr madvise 2 , .Xr mincore 2 .Sh HISTORY The .Fn mprotect function first appeared in 4.4BSD.