UAPI: fix endianness conditionals in linux/aio_abi.h
authorDavid Howells <dhowells@redhat.com>
Wed, 13 Mar 2013 21:59:45 +0000 (14:59 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 13 Mar 2013 22:21:48 +0000 (15:21 -0700)
commit51b154ed5289682364b830858a4a1ca47fcd04e7
treea7e3ae9ad1047db6cedd5701df4b2f33f6386cd1
parent97da55fcec6e3898f50010a6847dfa64f7c085e6
UAPI: fix endianness conditionals in linux/aio_abi.h

In the UAPI header files, __BIG_ENDIAN and __LITTLE_ENDIAN must be
compared against __BYTE_ORDER in preprocessor conditionals where these are
exposed to userspace (that is they're not inside __KERNEL__ conditionals).

However, in the main kernel the norm is to check for
"defined(__XXX_ENDIAN)" rather than comparing against __BYTE_ORDER and
this has incorrectly leaked into the userspace headers.

The definition of PADDED() in linux/aio_abi.h is wrong in this way.  Note
that userspace will likely interpret this and thus the order of fields in
struct iocb incorrectly as the little-endian variant on big-endian
machines - depending on header inclusion order.

[!!!] NOTE [!!!]  This patch may adversely change the userspace API.  It might
be better to fix the ordering of aio_key and aio_reserved1 in struct iocb.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/uapi/linux/aio_abi.h