VSLOCK(9) BSD Kernel Developer's Manual VSLOCK(9)NAME
vslock, vsunlock — lock/unlock user space addresses in memory
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 process into mem‐
ory. The actual amount of memory locked is a multiple of the machine's
page size. The starting page number is computed by truncating 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 operation 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 faulting/mapping a
page.
BSD August 10, 2004 BSD
