[PATCH 4/4] UAPI: Fix endianness conditionals in M32R's asm/stat.h

From: David Howells
Date: Wed Mar 06 2013 - 15:48:29 EST


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 struct stat64 in M32R's asm/stat.h is wrong in this way.
Note that userspace will likely interpret the field order incorrectly as the
big-endian variant on little-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 st_blocks and __pad4 in struct stat64.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Hirokazu Takata <takata@xxxxxxxxxxxxxx>
cc: linux-m32r@xxxxxxxxxxxxxxxxx
cc: linux-m32r-ja@xxxxxxxxxxxxxxxxx
---

arch/m32r/include/uapi/asm/stat.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/m32r/include/uapi/asm/stat.h b/arch/m32r/include/uapi/asm/stat.h
index da4518f..98470fe 100644
--- a/arch/m32r/include/uapi/asm/stat.h
+++ b/arch/m32r/include/uapi/asm/stat.h
@@ -63,10 +63,10 @@ struct stat64 {
long long st_size;
unsigned long st_blksize;

-#if defined(__BIG_ENDIAN)
+#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
unsigned long __pad4; /* future possible st_blocks high bits */
unsigned long st_blocks; /* Number 512-byte blocks allocated. */
-#elif defined(__LITTLE_ENDIAN)
+#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
unsigned long st_blocks; /* Number 512-byte blocks allocated. */
unsigned long __pad4; /* future possible st_blocks high bits */
#else

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