diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h
@@ -134,7 +134,7 @@
  * @bitset:	Bitset for the optional bitmasked wakeup
  */
 struct futex_wait_block {
-	__u32 __user *uaddr;
+	__aligned_u64 uaddr;
 	__u32 val;
 	__u32 bitset;
 };
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -198,7 +198,8 @@
  * initialize the fields) and then, for each futex_wait_block element from
  * userspace, fill a futex_q element with proper values.
  */
-static inline struct futex_vector *futex_read_wait_block(u32 __user *uaddr, u32 count)
+static inline struct futex_vector *futex_read_wait_block(u32 __user *uaddr, u32 count,
+							  unsigned int flags)
 {
 	unsigned int i;
 	struct futex_vector *futexv;
@@ -219,10 +220,17 @@
 			return ERR_PTR(-EFAULT);
 		}
 
-		futexv[i].w.flags = FUTEX_32;
+		if (!fwb.bitset) {
+			kfree(futexv);
+			return ERR_PTR(-EINVAL);
+		}
+
+		futexv[i].w.flags = flags;
 		futexv[i].w.val = fwb.val;
-		futexv[i].w.uaddr = (uintptr_t) (fwb.uaddr);
+		futexv[i].w.uaddr = fwb.uaddr;
 		futexv[i].q = futex_q_init;
+		futexv[i].q.bitset = fwb.bitset;
+		futexv[i].q.wake = futex_wake_mark;
 	}
 
 	return futexv;
@@ -231,17 +239,21 @@
 int futex_wait_multiple(struct futex_vector *vs, unsigned int count,
 			struct hrtimer_sleeper *to);
 
-static int futex_opcode_31(ktime_t *abs_time, u32 __user *uaddr, int count)
+static int futex_opcode_31(ktime_t *abs_time, u32 __user *uaddr, int count, int op)
 {
 	int ret;
 	struct futex_vector *vs;
 	struct hrtimer_sleeper *to = NULL, timeout;
+	unsigned int flags = futex_to_flags(op);
+
+	if (flags & FLAGS_CLOCKRT)
+		return -ENOSYS;
 
-	vs = futex_read_wait_block(uaddr, count);
+	vs = futex_read_wait_block(uaddr, count, flags);
 	if (IS_ERR(vs))
 		return PTR_ERR(vs);
 
-	to = futex_setup_timer(abs_time, &timeout, 0, 0);
+	to = futex_setup_timer(abs_time, &timeout, flags, current->timer_slack_ns);
 
 	ret = futex_wait_multiple(vs, count, abs_time ? to : NULL);
 	kfree(vs);
@@ -274,7 +286,7 @@
 	}
 
 	if (cmd == FUTEX_WAIT_MULTIPLE)
-		return futex_opcode_31(tp, uaddr, val);
+		return futex_opcode_31(tp, uaddr, val, op);
 
 	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
 }
@@ -591,7 +603,7 @@
 	}
 
 	if (cmd == FUTEX_WAIT_MULTIPLE)
-		return futex_opcode_31(tp, uaddr, val);
+		return futex_opcode_31(tp, uaddr, val, op);
 
 	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
 }