diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0c1ab43f667257970dcaeb8296dc6b64d66ca1f1..225ffdc3c4caaf7d1ef05d53012aaf6aa56d392d 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -539,6 +539,12 @@ static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
 		BUG();
 }
 
+static inline bool desc_equal(const struct desc_struct *d1,
+			      const struct desc_struct *d2)
+{
+	return d1->a == d2->a && d1->b == d2->b;
+}
+
 static void load_TLS_descriptor(struct thread_struct *t,
 				unsigned int cpu, unsigned int i)
 {