1 files changed, 11 insertions, 2 deletions
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index 169d7604eb80..3bcfdeb01395 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -41,8 +41,17 @@ struct vdso_data {
 struct vdso_per_cpu_data {
 	__u64 ectg_timer_base;
 	__u64 ectg_user_time;
-	__u32 cpu_nr;
-	__u32 node_id;
+	/*
+	 * Note: node_id and cpu_nr must be at adjacent memory locations.
+	 * VDSO userspace must read both values with a single instruction.
+	 */
+	union {
+		__u64 getcpu_val;
+		struct {
+			__u32 node_id;
+			__u32 cpu_nr;
+		};
+	};
 };
 
 extern struct vdso_data *vdso_data;