VM_PAGE_PROTECT(9) MidnightBSD Kernel Developer’s Manual VM_PAGE_PROTECT(9)

NAME

vm_page_protect — lower a page’s protection

SYNOPSIS

#include <sys/param.h>
#include <vm/vm.h>
#include <vm/vm_page.h>

void

vm_page_protect(vm_page_t mem, int prot);

DESCRIPTION

The vm_page_protect() function lowers a page’s protection. The protection is never raised by this function; therefore, if the page is already at VM_PROT_NONE, the function does nothing.

Its arguments are:

mem

The page whose protection is lowered.

prot

The protection the page should be reduced to. If VM_PROT_NONE is specified, then the PG_WRITABLE and PG_MAPPED flags are cleared and the pmap_page’s protection is set to VM_PROT_NONE. If VM_PROT_READ is specified, then the PG_WRITABLE flag is cleared and the pmap_page’s protection is set to VM_PROT_READ.

Higher protection requests are ignored.

AUTHORS

This manual page was written by Chad David 〈davidc@acns.ab.ca〉.

MidnightBSD 0.3 July 14, 2001 MidnightBSD 0.3