UAPI: fix endianness conditionals in linux/acct.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 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>
diff --git a/include/uapi/linux/acct.h b/include/uapi/linux/acct.h
index 11b6ca3..df2f9a0 100644
--- a/include/uapi/linux/acct.h
+++ b/include/uapi/linux/acct.h
@@ -107,10 +107,12 @@
#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__