1 files changed, 129 insertions, 93 deletions

diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
index c653ce533430..ce625b1ce9a5 100644
--- a/drivers/usb/usbip/stub_dev.c
+++ b/drivers/usb/usbip/stub_dev.c
@@ -1,20 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2003-2008 Takahiro Hirofuchi
- *
- * This is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
- * USA.
  */
 
 #include <linux/device.h>
@@ -44,7 +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);
 
@@ -53,13 +39,15 @@ static DEVICE_ATTR_RO(usbip_status);
  * is used to transfer usbip requests by kernel threads. -1 is a magic number
  * by which usbip connection is finished.
  */
-static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
+static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
 	struct stub_device *sdev = dev_get_drvdata(dev);
 	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");
@@ -75,6 +63,7 @@ static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
 
 		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) {
@@ -83,25 +72,54 @@ static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
 		}
 
 		socket = sockfd_lookup(sockfd, &err);
-		if (!socket)
+		if (!socket) {
+			dev_err(dev, "failed to lookup sock");
 			goto err;
+		}
 
-		sdev->ud.tcp_socket = socket;
+		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;
@@ -109,48 +127,28 @@ static ssize_t store_sockfd(struct device *dev, struct device_attribute *attr,
 		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(usbip_sockfd, S_IWUSR, NULL, store_sockfd);
-
-static int stub_add_files(struct device *dev)
-{
-	int err = 0;
-
-	err = device_create_file(dev, &dev_attr_usbip_status);
-	if (err)
-		goto err_status;
-
-	err = device_create_file(dev, &dev_attr_usbip_sockfd);
-	if (err)
-		goto err_sockfd;
+static DEVICE_ATTR_WO(usbip_sockfd);
 
-	err = device_create_file(dev, &dev_attr_usbip_debug);
-	if (err)
-		goto err_debug;
-
-	return 0;
-
-err_debug:
-	device_remove_file(dev, &dev_attr_usbip_sockfd);
-err_sockfd:
-	device_remove_file(dev, &dev_attr_usbip_status);
-err_status:
-	return err;
-}
-
-static void stub_remove_files(struct device *dev)
-{
-	device_remove_file(dev, &dev_attr_usbip_status);
-	device_remove_file(dev, &dev_attr_usbip_sockfd);
-	device_remove_file(dev, &dev_attr_usbip_debug);
-}
+static struct attribute *usbip_attrs[] = {
+	&dev_attr_usbip_status.attr,
+	&dev_attr_usbip_sockfd.attr,
+	&dev_attr_usbip_debug.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(usbip);
 
 static void stub_shutdown_connection(struct usbip_device *ud)
 {
@@ -163,8 +161,7 @@ static void stub_shutdown_connection(struct usbip_device *ud)
 	 * step 1?
 	 */
 	if (ud->tcp_socket) {
-		dev_dbg(&sdev->udev->dev, "shutdown tcp_socket %p\n",
-			ud->tcp_socket);
+		dev_dbg(&sdev->udev->dev, "shutdown sockfd %d\n", ud->sockfd);
 		kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
 	}
 
@@ -187,6 +184,7 @@ static void stub_shutdown_connection(struct usbip_device *ud)
 	if (ud->tcp_socket) {
 		sockfd_put(ud->tcp_socket);
 		ud->tcp_socket = NULL;
+		ud->sockfd = -1;
 	}
 
 	/* 3. free used data */
@@ -280,7 +278,9 @@ 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;
 
 	INIT_LIST_HEAD(&sdev->priv_init);
 	INIT_LIST_HEAD(&sdev->priv_tx);
@@ -312,9 +312,17 @@ static int stub_probe(struct usb_device *udev)
 	struct stub_device *sdev = NULL;
 	const char *udev_busid = dev_name(&udev->dev);
 	struct bus_id_priv *busid_priv;
-	int rc;
+	int rc = 0;
+	char save_status;
 
-	dev_dbg(&udev->dev, "Enter\n");
+	dev_dbg(&udev->dev, "Enter probe\n");
+
+	/* Not sure if this is our device. Allocate here to avoid
+	 * calling alloc while holding busid_table lock.
+	 */
+	sdev = stub_device_alloc(udev);
+	if (!sdev)
+		return -ENOMEM;
 
 	/* check we should claim or not by busid_table */
 	busid_priv = get_busid_priv(udev_busid);
@@ -329,13 +337,18 @@ static int stub_probe(struct usb_device *udev)
 		 * other matched drivers by the driver core.
 		 * See driver_probe_device() in driver/base/dd.c
 		 */
-		return -ENODEV;
+		rc = -ENODEV;
+		if (!busid_priv)
+			goto sdev_free;
+
+		goto call_put_busid_priv;
 	}
 
 	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
 		dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
 			 udev_busid);
-		return -ENODEV;
+		rc = -ENODEV;
+		goto call_put_busid_priv;
 	}
 
 	if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
@@ -343,13 +356,10 @@ static int stub_probe(struct usb_device *udev)
 			"%s is attached on vhci_hcd... skip!\n",
 			udev_busid);
 
-		return -ENODEV;
+		rc = -ENODEV;
+		goto call_put_busid_priv;
 	}
 
-	/* ok, this is my device */
-	sdev = stub_device_alloc(udev);
-	if (!sdev)
-		return -ENOMEM;
 
 	dev_info(&udev->dev,
 		"usbip-host: register new device (bus %u dev %u)\n",
@@ -359,9 +369,16 @@ static int stub_probe(struct usb_device *udev)
 
 	/* set private data to usb_device */
 	dev_set_drvdata(&udev->dev, sdev);
+
 	busid_priv->sdev = sdev;
 	busid_priv->udev = udev;
 
+	save_status = busid_priv->status;
+	busid_priv->status = STUB_BUSID_ALLOC;
+
+	/* release the busid_lock */
+	put_busid_priv(busid_priv);
+
 	/*
 	 * Claim this hub port.
 	 * It doesn't matter what value we pass as owner
@@ -374,35 +391,36 @@ static int stub_probe(struct usb_device *udev)
 		goto err_port;
 	}
 
-	rc = stub_add_files(&udev->dev);
-	if (rc) {
-		dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid);
-		goto err_files;
-	}
-	busid_priv->status = STUB_BUSID_ALLOC;
-
 	return 0;
-err_files:
-	usb_hub_release_port(udev->parent, udev->portnum,
-			     (struct usb_dev_state *) 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);
 	busid_priv->sdev = NULL;
+	busid_priv->status = save_status;
+	spin_unlock(&busid_priv->busid_lock);
+	/* lock is released - go to free */
+	goto sdev_free;
+
+call_put_busid_priv:
+	/* release the busid_lock */
+	put_busid_priv(busid_priv);
+
+sdev_free:
+	usb_put_dev(udev);
 	stub_device_free(sdev);
+
 	return rc;
 }
 
 static void shutdown_busid(struct bus_id_priv *busid_priv)
 {
-	if (busid_priv->sdev && !busid_priv->shutdown_busid) {
-		busid_priv->shutdown_busid = 1;
-		usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
+	usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
 
-		/* wait for the stop of the event handler */
-		usbip_stop_eh(&busid_priv->sdev->ud);
-	}
+	/* wait for the stop of the event handler */
+	usbip_stop_eh(&busid_priv->sdev->ud);
 }
 
 /*
@@ -416,7 +434,7 @@ static void stub_disconnect(struct usb_device *udev)
 	struct bus_id_priv *busid_priv;
 	int rc;
 
-	dev_dbg(&udev->dev, "Enter\n");
+	dev_dbg(&udev->dev, "Enter disconnect\n");
 
 	busid_priv = get_busid_priv(udev_busid);
 	if (!busid_priv) {
@@ -429,21 +447,30 @@ static void stub_disconnect(struct usb_device *udev)
 	/* get stub_device */
 	if (!sdev) {
 		dev_err(&udev->dev, "could not get device");
+		/* release busid_lock */
+		put_busid_priv(busid_priv);
 		return;
 	}
 
 	dev_set_drvdata(&udev->dev, NULL);
 
+	/* release busid_lock before call to remove device files */
+	put_busid_priv(busid_priv);
+
 	/*
 	 * NOTE: rx/tx threads are invoked for each usb_device.
 	 */
-	stub_remove_files(&udev->dev);
 
 	/* 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;
 	}
 
@@ -451,21 +478,29 @@ static void stub_disconnect(struct usb_device *udev)
 	if (usbip_in_eh(current))
 		return;
 
+	/* we already have busid_priv, just lock busid_lock */
+	spin_lock(&busid_priv->busid_lock);
+	if (!busid_priv->shutdown_busid)
+		busid_priv->shutdown_busid = 1;
+	/* release busid_lock */
+	spin_unlock(&busid_priv->busid_lock);
+
 	/* shutdown the current connection */
 	shutdown_busid(busid_priv);
 
 	usb_put_dev(sdev->udev);
 
+	/* we already have busid_priv, just lock busid_lock */
+	spin_lock(&busid_priv->busid_lock);
 	/* free sdev */
 	busid_priv->sdev = NULL;
 	stub_device_free(sdev);
 
-	if (busid_priv->status == STUB_BUSID_ALLOC) {
+	if (busid_priv->status == STUB_BUSID_ALLOC)
 		busid_priv->status = STUB_BUSID_ADDED;
-	} else {
-		busid_priv->status = STUB_BUSID_OTHER;
-		del_match_busid((char *)udev_busid);
-	}
+	/* release busid_lock */
+	spin_unlock(&busid_priv->busid_lock);
+	return;
 }
 
 #ifdef CONFIG_PM
@@ -498,4 +533,5 @@ struct usb_device_driver stub_driver = {
 	.resume		= stub_resume,
 #endif
 	.supports_autosuspend	=	0,
+	.dev_groups	= usbip_groups,
 };