fix compat futex code for private futexes

When the private futex support was added the compat code wasn't changed.
The result is that code using compat code which fail, e.g., because the
timeout values are not correctly passed.  The following patch should fix
that.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/futex_compat.c

@@ -144,20 +144,21 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
 	struct timespec ts;
 	ktime_t t, *tp = NULL;
 	int val2 = 0;
+	int cmd = op & FUTEX_CMD_MASK;
 
-	if (utime && (op == FUTEX_WAIT || op == FUTEX_LOCK_PI)) {
+	if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) {
 		if (get_compat_timespec(&ts, utime))
 			return -EFAULT;
 		if (!timespec_valid(&ts))
 			return -EINVAL;
 
 		t = timespec_to_ktime(ts);
-		if (op == FUTEX_WAIT)
+		if (cmd == FUTEX_WAIT)
 			t = ktime_add(ktime_get(), t);
 		tp = &t;
 	}
-	if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE
+	if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE
-	    || op == FUTEX_CMP_REQUEUE_PI)
+	    || cmd == FUTEX_CMP_REQUEUE_PI)
 		val2 = (int) (unsigned long) utime;
 
 	return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);