Index: head/sys/kern/kern_mutex.c
===================================================================
--- head/sys/kern/kern_mutex.c
+++ head/sys/kern/kern_mutex.c
@@ -176,6 +176,21 @@
 assert_mtx(const struct lock_object *lock, int what)
 {
 
+	/*
+	 * Treat LA_LOCKED as if LA_XLOCKED was asserted.
+	 *
+	 * Some callers of lc_assert uses LA_LOCKED to indicate that either
+	 * a shared lock or write lock was held, while other callers uses
+	 * the more strict LA_XLOCKED (used as MA_OWNED).
+	 *
+	 * Mutex is the only lock class that can not be shared, as a result,
+	 * we can reasonably consider the caller really intends to assert
+	 * LA_XLOCKED when they are asserting LA_LOCKED on a mutex object.
+	 */
+	if (what & LA_LOCKED) {
+		what &= ~LA_LOCKED;
+		what |= LA_XLOCKED;
+	}
 	mtx_assert((const struct mtx *)lock, what);
 }