Function nix::sys::mman::mmap

pub unsafe fn mmap(addr: *mut c_void,
                   length: size_t,
                   prot: ProtFlags,
                   flags: MapFlags,
                   fd: RawFd,
                   offset: off_t)
                   -> Result<*mut c_void>

Calls to mmap are inherently unsafe, so they must be made in an unsafe block. Typically a higher-level abstraction will hide the unsafe interactions with the mmap'd region.