Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio fixes from Rusty Russell:
 "One reversion, a tiny leak fix, and a cc:stable locking fix, in two
  parts"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio: console: add locking around c_ovq operations
  virtio: console: rename cvq_lock to c_ivq_lock
  hw_random: free rng_buffer at module exit
  Revert "virtio_console: Initialize guest_connected=true for rproc_serial"

drivers/char/hw_random/core.c

@@ -380,6 +380,15 @@ void hwrng_unregister(struct hwrng *rng)
 }
 EXPORT_SYMBOL_GPL(hwrng_unregister);
 
+static void __exit hwrng_exit(void)
+{
+	mutex_lock(&rng_mutex);
+	BUG_ON(current_rng);
+	kfree(rng_buffer);
+	mutex_unlock(&rng_mutex);
+}
+
+module_exit(hwrng_exit);
 
 MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver");
 MODULE_LICENSE("GPL");

drivers/char/virtio_console.c

@@ -149,7 +149,8 @@ struct ports_device {
 	spinlock_t ports_lock;
 
 	/* To protect the vq operations for the control channel */
-	spinlock_t cvq_lock;
+	spinlock_t c_ivq_lock;
+	spinlock_t c_ovq_lock;
 
 	/* The current config space is stored here */
 	struct virtio_console_config config;
@@ -569,11 +570,14 @@ static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
 	vq = portdev->c_ovq;
 
 	sg_init_one(sg, &cpkt, sizeof(cpkt));
+
+	spin_lock(&portdev->c_ovq_lock);
 	if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt, GFP_ATOMIC) == 0) {
 		virtqueue_kick(vq);
 		while (!virtqueue_get_buf(vq, &len))
 			cpu_relax();
 	}
+	spin_unlock(&portdev->c_ovq_lock);
 	return 0;
 }
 
@@ -1436,7 +1440,7 @@ static int add_port(struct ports_device *portdev, u32 id)
 		 * rproc_serial does not want the console port, only
 		 * the generic port implementation.
 		 */
-		port->host_connected = port->guest_connected = true;
+		port->host_connected = true;
 	else if (!use_multiport(port->portdev)) {
 		/*
 		 * If we're not using multiport support,
@@ -1709,23 +1713,23 @@ static void control_work_handler(struct work_struct *work)
 	portdev = container_of(work, struct ports_device, control_work);
 	vq = portdev->c_ivq;
 
-	spin_lock(&portdev->cvq_lock);
+	spin_lock(&portdev->c_ivq_lock);
 	while ((buf = virtqueue_get_buf(vq, &len))) {
-		spin_unlock(&portdev->cvq_lock);
+		spin_unlock(&portdev->c_ivq_lock);
 
 		buf->len = len;
 		buf->offset = 0;
 
 		handle_control_message(portdev, buf);
 
-		spin_lock(&portdev->cvq_lock);
+		spin_lock(&portdev->c_ivq_lock);
 		if (add_inbuf(portdev->c_ivq, buf) < 0) {
 			dev_warn(&portdev->vdev->dev,
 				 "Error adding buffer to queue\n");
 			free_buf(buf, false);
 		}
 	}
-	spin_unlock(&portdev->cvq_lock);
+	spin_unlock(&portdev->c_ivq_lock);
 }
 
 static void out_intr(struct virtqueue *vq)
@@ -1752,13 +1756,23 @@ static void in_intr(struct virtqueue *vq)
 	port->inbuf = get_inbuf(port);
 
 	/*
-	 * Don't queue up data when port is closed.  This condition
+	 * Normally the port should not accept data when the port is
+	 * closed. For generic serial ports, the host won't (shouldn't)
+	 * send data till the guest is connected. But this condition
 	 * can be reached when a console port is not yet connected (no
-	 * tty is spawned) and the host sends out data to console
-	 * ports.  For generic serial ports, the host won't
-	 * (shouldn't) send data till the guest is connected.
+	 * tty is spawned) and the other side sends out data over the
+	 * vring, or when a remote devices start sending data before
+	 * the ports are opened.
+	 *
+	 * A generic serial port will discard data if not connected,
+	 * while console ports and rproc-serial ports accepts data at
+	 * any time. rproc-serial is initiated with guest_connected to
+	 * false because port_fops_open expects this. Console ports are
+	 * hooked up with an HVC console and is initialized with
+	 * guest_connected to true.
 	 */
-	if (!port->guest_connected)
+
+	if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
 		discard_port_data(port);
 
 	spin_unlock_irqrestore(&port->inbuf_lock, flags);
@@ -1986,10 +2000,12 @@ static int virtcons_probe(struct virtio_device *vdev)
 	if (multiport) {
 		unsigned int nr_added_bufs;
 
-		spin_lock_init(&portdev->cvq_lock);
+		spin_lock_init(&portdev->c_ivq_lock);
+		spin_lock_init(&portdev->c_ovq_lock);
 		INIT_WORK(&portdev->control_work, &control_work_handler);
 
-		nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+		nr_added_bufs = fill_queue(portdev->c_ivq,
+					   &portdev->c_ivq_lock);
 		if (!nr_added_bufs) {
 			dev_err(&vdev->dev,
 				"Error allocating buffers for control queue\n");
@@ -2140,7 +2156,7 @@ static int virtcons_restore(struct virtio_device *vdev)
 		return ret;
 
 	if (use_multiport(portdev))
-		fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+		fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
 
 	list_for_each_entry(port, &portdev->ports, list) {
 		port->in_vq = portdev->in_vqs[port->id];