[PATCH] Fix BSD accounting cross-platform compatibility

BSD accounting cross-platform compatibility is a new feature of 2.6.8 and
thus not crucial, but it'd be nice not to have kernels writing wrong file
formats out in the wild.

The endianness detection logic I wanted to suppose for userspace turned out
to be bogus.  So just do it the simple way and store endianness info
together with the version number.
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/acct.h

@@ -17,6 +17,7 @@
 
 #include <linux/types.h>
 #include <asm/param.h>
+#include <asm/byteorder.h>
 
 /* 
  *  comp_t is a 16-bit "floating" point number with a 3-bit base 8
@@ -104,7 +105,12 @@ struct acct_v3
 #define ACOMPAT		0x04	/* ... used compatibility mode (VAX only not used) */
 #define ACORE		0x08	/* ... dumped core */
 #define AXSIG		0x10	/* ... was killed by a signal */
-#define ABYTESEX	0x80	/* always set, allows to detect byteorder */
+
+#ifdef __BIG_ENDIAN
+#define ACCT_BYTEORDER	0x80	/* accounting file is big endian */
+#else
+#define ACCT_BYTEORDER	0x00	/* accounting file is little endian */
+#endif
 
 #ifdef __KERNEL__
 

kernel/acct.c

@@ -398,7 +398,7 @@ static void do_acct_process(long exitcode, struct file *file)
 	 */
 	memset((caddr_t)&ac, 0, sizeof(acct_t));
 
-	ac.ac_version = ACCT_VERSION;
+	ac.ac_version = ACCT_VERSION | ACCT_BYTEORDER;
 	strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));
 
 	elapsed = jiffies_64_to_AHZ(get_jiffies_64() - current->start_time);
@@ -441,8 +441,7 @@ static void do_acct_process(long exitcode, struct file *file)
 		old_encode_dev(tty_devnum(current->signal->tty)) : 0;
 	read_unlock(&tasklist_lock);
 
-	/* ABYTESEX is always set to allow byte order detection */
-	ac.ac_flag = ABYTESEX;
+	ac.ac_flag = 0;
 	if (current->flags & PF_FORKNOEXEC)
 		ac.ac_flag |= AFORK;
 	if (current->flags & PF_SUPERPRIV)