1  /* As default architectures with sizeof (off_t) < sizeof (off64_t) the mmap is
       2     implemented with __SYS_mmap2 syscall and the offset is represented in
       3     multiples of page size.  For offset larger than
       4     '1 << (page_shift + 8 * sizeof (off_t))' (that is, 1<<44 on system with
       5     page size of 4096 bytes) the system call silently truncates the offset.
       6     For this case, glibc mmap implementation returns EINVAL.  */
       7  
       8  /* Return the maximum value expected as offset argument in mmap64 call.  */
       9  static inline uint64_t
      10  mmap64_maximum_offset (long int page_shift)
      11  {
      12    if (sizeof (off_t) < sizeof (off64_t))
      13      return (UINT64_C(1) << (page_shift + (8 * sizeof (off_t)))) - 1;
      14    else
      15      return UINT64_MAX;
      16  }