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


vslock, vsunlock — lock/unlock user space addresses in memory


#include <sys/param.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>


vslock(void *addr, size_t len);


vsunlock(void *addr, size_t len);


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.


The vslock() function will return 0 on success, otherwise it will return one of the errors listed below.


The vslock() function will fail if:


The addr and len parameters specify a memory range that wraps around the end of the machine address space.


The size of the specified address range exceeds the system limit on locked memory.


Locking the requested address range would cause the process to exceed its per-process locked memory limit.


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