.\"
.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved.
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.\" $FreeBSD$
.\"
.Dd July 14, 2001
.Dt VM_PAGE_PROTECT 9
.Os
.Sh NAME
.Nm vm_page_protect
.Nd "lower a page's protection"
.Sh SYNOPSIS
.In sys/param.h
.In vm/vm.h
.In vm/vm_page.h
.Ft void
.Fn vm_page_protect "vm_page_t mem" "int prot"
.Sh DESCRIPTION
The
.Fn vm_page_protect
function lowers a page's protection.
The protection is never raised by this function; therefore, if the page is
already at
.Dv VM_PROT_NONE ,
the function does nothing.
.Pp
Its arguments are:
.Bl -tag -width ".Fa prot"
.It Fa mem
The page whose protection is lowered.
.It Fa prot
The protection the page should be reduced to.
If
.Dv VM_PROT_NONE
is specified, then the
.Dv PG_WRITABLE
and
.Dv PG_MAPPED
flags are cleared and the pmap_page's protection is set to
.Dv VM_PROT_NONE .
If
.Dv VM_PROT_READ
is specified, then the
.Dv PG_WRITABLE
flag is cleared and the pmap_page's protection is set to
.Dv VM_PROT_READ .
.El
.Pp
Higher protection requests are ignored.
.Sh AUTHORS
This manual page was written by
.An Chad David Aq davidc@acns.ab.ca .