Now that non-LFS stat function is implemented on to on LFS, it will
use statx when available. It allows to check for nanosecond timestamp
if the kernel supports __NR_statx.
Checked on s390-linux-gnu with 4.12.14 kernel.
Both new tests io/tst-stat and io/tst-stat-lfs (_FILE_OFFSET_BITS=64)
are comparing the nanosecond fields with the statx result. Unfortunately
on s390(31bit) those fields are always zero if old KABI with non-LFS
support is used. With _FILE_OFFSET_BITS=64 stat is using statx internally.
As suggested by Adhemerval this patch disables the nanosecond check for
s390(31bit).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Now that fstat is implemented on top fstatat we need to handle negative
inputs. The implementation now rejects AT_FDCWD, which would otherwise
be accepted by the kernel.
Checked on x86_64-linux-gnu and on i686-linux-gnu.
