vslock(9)

NAME

vslock, vsunlock - lock/unlock user space addresses in memo

ry

SYNOPSIS

#include <sys/param.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
int
vslock(void *addr, size_t len);
void
vsunlock(void *addr, size_t len);

DESCRIPTION

The vslock() and vsunlock() functions respectively lock and

unlock a
range of addresses belonging to the currently running pro

cess into memory. The actual amount of memory locked is a multiple of

the machine's
page size. The starting page number is computed by truncat

ing addr to
the nearest preceding page boundary, and by rounding up addr

+ len to the
next page boundary. The process context to use for this op

eration is
taken from the global variable curproc.

RETURN VALUES

The vslock() function will return 0 on success, otherwise it

will return
one of the errors listed below.

ERRORS

The vslock() function will fail if:

[EINVAL] The addr and len parameters specify a

memory range

that wraps around the end of the machine

address
space.

[ENOMEM] The size of the specified address range

exceeds the

system limit on locked memory.

[ENOMEM] Locking the requested address range would

cause the

process to exceed its per-process locked

memory limit.

[EFAULT] Some portion of the indicated address

range is not

allocated. There was an error fault

ing/mapping a
page.

BSD August 10, 2004

BSD