VSLOCK(9) MidnightBSD 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 memory. 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.

MidnightBSD 0.3 August 10, 2004 MidnightBSD 0.3