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UAPI: fix endianness conditionals in linux/acct.h

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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 ACCT_BYTEORDER in linux/acct.h is wrong in this way.
Note that userspace will likely interpret this 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 value of ACCT_BYTEORDER.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Howells 2013-03-13 14:59:46 -07:00 committed by Linus Torvalds
parent 51b154ed52
commit 29ba06b9ed
1 changed files with 4 additions and 2 deletions
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6
include/uapi/linux/acct.h
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@ -107,10 +107,12 @@ struct acct_v3
#define ACORE 0x08 /* ... dumped core */
#define AXSIG 0x10 /* ... was killed by a signal */
#ifdef __BIG_ENDIAN
#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
#define ACCT_BYTEORDER 0x80 /* accounting file is big endian */
#else
#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
#define ACCT_BYTEORDER 0x00 /* accounting file is little endian */
#else
#error unspecified endianness
#endif
#ifndef __KERNEL__