Function map_memory_anywhere 

pub fn map_memory_anywhere<L>(
    locked: &mut Locked<L>,
    current_task: &CurrentTask,
    len: u64,
) -> UserAddress
where
    L: LockEqualOrBefore<FileOpsCore> + LockBefore<ThreadGroupLimits>,

Maps a region of mery at least len bytes long with PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, returning the mapped address.