Index: sys/kern/vfs_lookup.c
===================================================================
--- sys/kern/vfs_lookup.c
+++ sys/kern/vfs_lookup.c
@@ -98,8 +98,8 @@
 {
 	struct vnode *vp;
 	struct lock *lk __diagused;
-	const char *file __diagused;
-	int flags, line __diagused;
+	const char *file __witness_used;
+	int flags, line __witness_used;
 
 	vp = ap->a_vp;
 	lk = vp->v_vnlock;
@@ -115,7 +115,7 @@
 	WITNESS_LOCK(&lk->lock_object, 0, file, line);
 	if ((flags & LK_INTERLOCK) != 0)
 		VI_UNLOCK(vp);
-	LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, ap->a_file, line);
+	LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, ap->a_file, ap->a_line);
 	return (0);
 }
 
Index: sys/sys/systm.h
===================================================================
--- sys/sys/systm.h
+++ sys/sys/systm.h
@@ -554,13 +554,16 @@
 #define gone_in(major, msg)		__gone_ok(major, msg) _gone_in(major, msg)
 #define gone_in_dev(dev, major, msg)	__gone_ok(major, msg) _gone_in_dev(dev, major, msg)
 
-#if !defined(INVARIANTS) && !defined(WITNESS)
-#define	__diagused	__unused
-#elif ((defined(INVARIANTS) && !defined(WITNESS)) || \
-	(!defined(INVARIANTS) && defined(WITNESS)))
-#define	__diagused	__unused
-#else
+#ifdef INVARIANTS
 #define	__diagused
+#else
+#define	__diagused	__unused
+#endif
+
+#ifdef WITNESS
+#define	__witness_used
+#else
+#define	__witness_used	__unused
 #endif
 
 #endif /* _KERNEL */