Implement a bi-arch and bi-endian version of load_unaligned_zeropad.
Since the fallback case is so rare, a userspace test harness was used
to test this on ppc64le, ppc64 and ppc32:
http://ozlabs.org/~anton/junkcode/test_load_unaligned_zeropad.c
It uses mprotect to force a SEGV across a page boundary, and a SEGV
handler to lookup the exception tables and run the fixup routine.
It also compares the result against a normal load.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
de5946c035