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
mmap64_maximum_offset(long int page_shift)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 }
17