1 files changed, 53 insertions, 11 deletions

diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
index 2305d425e6c9..ce625b1ce9a5 100644
--- a/drivers/usb/usbip/stub_dev.c
+++ b/drivers/usb/usbip/stub_dev.c
@@ -30,7 +30,7 @@ static ssize_t usbip_status_show(struct device *dev,
 	status = sdev->ud.status;
 	spin_unlock_irq(&sdev->ud.lock);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", status);
+	return sysfs_emit(buf, "%d\n", status);
 }
 static DEVICE_ATTR_RO(usbip_status);
 
@@ -46,6 +46,8 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
 	int sockfd = 0;
 	struct socket *socket;
 	int rv;
+	struct task_struct *tcp_rx = NULL;
+	struct task_struct *tcp_tx = NULL;
 
 	if (!sdev) {
 		dev_err(dev, "sdev is null\n");
@@ -61,6 +63,7 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
 
 		dev_info(dev, "stub up\n");
 
+		mutex_lock(&sdev->ud.sysfs_lock);
 		spin_lock_irq(&sdev->ud.lock);
 
 		if (sdev->ud.status != SDEV_ST_AVAILABLE) {
@@ -69,26 +72,54 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
 		}
 
 		socket = sockfd_lookup(sockfd, &err);
-		if (!socket)
+		if (!socket) {
+			dev_err(dev, "failed to lookup sock");
 			goto err;
+		}
 
-		sdev->ud.tcp_socket = socket;
-		sdev->ud.sockfd = sockfd;
+		if (socket->type != SOCK_STREAM) {
+			dev_err(dev, "Expecting SOCK_STREAM - found %d",
+				socket->type);
+			goto sock_err;
+		}
 
+		/* unlock and create threads and get tasks */
 		spin_unlock_irq(&sdev->ud.lock);
+		tcp_rx = kthread_create(stub_rx_loop, &sdev->ud, "stub_rx");
+		if (IS_ERR(tcp_rx)) {
+			sockfd_put(socket);
+			goto unlock_mutex;
+		}
+		tcp_tx = kthread_create(stub_tx_loop, &sdev->ud, "stub_tx");
+		if (IS_ERR(tcp_tx)) {
+			kthread_stop(tcp_rx);
+			sockfd_put(socket);
+			goto unlock_mutex;
+		}
 
-		sdev->ud.tcp_rx = kthread_get_run(stub_rx_loop, &sdev->ud,
-						  "stub_rx");
-		sdev->ud.tcp_tx = kthread_get_run(stub_tx_loop, &sdev->ud,
-						  "stub_tx");
+		/* get task structs now */
+		get_task_struct(tcp_rx);
+		get_task_struct(tcp_tx);
 
+		/* lock and update sdev->ud state */
 		spin_lock_irq(&sdev->ud.lock);
+		sdev->ud.tcp_socket = socket;
+		sdev->ud.sockfd = sockfd;
+		sdev->ud.tcp_rx = tcp_rx;
+		sdev->ud.tcp_tx = tcp_tx;
 		sdev->ud.status = SDEV_ST_USED;
 		spin_unlock_irq(&sdev->ud.lock);
 
+		wake_up_process(sdev->ud.tcp_rx);
+		wake_up_process(sdev->ud.tcp_tx);
+
+		mutex_unlock(&sdev->ud.sysfs_lock);
+
 	} else {
 		dev_info(dev, "stub down\n");
 
+		mutex_lock(&sdev->ud.sysfs_lock);
+
 		spin_lock_irq(&sdev->ud.lock);
 		if (sdev->ud.status != SDEV_ST_USED)
 			goto err;
@@ -96,12 +127,17 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
 		spin_unlock_irq(&sdev->ud.lock);
 
 		usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
+		mutex_unlock(&sdev->ud.sysfs_lock);
 	}
 
 	return count;
 
+sock_err:
+	sockfd_put(socket);
 err:
 	spin_unlock_irq(&sdev->ud.lock);
+unlock_mutex:
+	mutex_unlock(&sdev->ud.sysfs_lock);
 	return -EINVAL;
 }
 static DEVICE_ATTR_WO(usbip_sockfd);
@@ -242,6 +278,7 @@ static struct stub_device *stub_device_alloc(struct usb_device *udev)
 	sdev->ud.side		= USBIP_STUB;
 	sdev->ud.status		= SDEV_ST_AVAILABLE;
 	spin_lock_init(&sdev->ud.lock);
+	mutex_init(&sdev->ud.sysfs_lock);
 	sdev->ud.tcp_socket	= NULL;
 	sdev->ud.sockfd		= -1;
 
@@ -358,7 +395,6 @@ static int stub_probe(struct usb_device *udev)
 
 err_port:
 	dev_set_drvdata(&udev->dev, NULL);
-	usb_put_dev(udev);
 
 	/* we already have busid_priv, just lock busid_lock */
 	spin_lock(&busid_priv->busid_lock);
@@ -373,6 +409,7 @@ call_put_busid_priv:
 	put_busid_priv(busid_priv);
 
 sdev_free:
+	usb_put_dev(udev);
 	stub_device_free(sdev);
 
 	return rc;
@@ -427,8 +464,13 @@ static void stub_disconnect(struct usb_device *udev)
 	/* release port */
 	rc = usb_hub_release_port(udev->parent, udev->portnum,
 				  (struct usb_dev_state *) udev);
-	if (rc) {
-		dev_dbg(&udev->dev, "unable to release port\n");
+	/*
+	 * NOTE: If a HUB disconnect triggered disconnect of the down stream
+	 * device usb_hub_release_port will return -ENODEV so we can safely ignore
+	 * that error here.
+	 */
+	if (rc && (rc != -ENODEV)) {
+		dev_dbg(&udev->dev, "unable to release port (%i)\n", rc);
 		return;
 	}