From 51b154ed5289682364b830858a4a1ca47fcd04e7 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Wed, 13 Mar 2013 14:59:45 -0700
Subject: [PATCH] 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 | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index 86fa7a71336a1..bb2554f7fbd12 100644
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -62,9 +62,9 @@ struct io_event {
__s64 res2; /* secondary result */
};
-#if defined(__LITTLE_ENDIAN)
+#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
#define PADDED(x,y) x, y
-#elif defined(__BIG_ENDIAN)
+#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
#define PADDED(x,y) y, x
#else
#error edit for your odd byteorder.
--
2.30.2