As described in BZ#22457 an interpose malloc can free an invalid
pointer for fallback preadv implementation. Fortunately this is
just and issue on microblaze-linux-gnu running kernels older than
3.15. This patch fixes it by calling mmap/unmap instead of
posix_memalign/ free.
Checked on microblaze-linux-gnu check with run-built-tests=no and
by using the sysdeps/posix implementation on x86_64-linux-gnu (just
for sanity test where it shown no regression).
[BZ #22457]
* sysdeps/posix/preadv_common.c (PREADV): Use mmap/munmap instead of
posix_memalign/free.
* sysdeps/posix/pwritev_common.c (PWRITEV): Likewise.
c45d78aac4