vslock, vsunlock — lock/unlock user space addresses in memory
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:
[EINVAL] The addr and len parameters specify a memory range
that wraps around the end of the machine address
[ENOMEM] The size of the specified address range exceeds the
system limit on locked memory.
[EFAULT] Some portion of the indicated address range is not
allocated. There was an error faulting/mapping a