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