2 files changed, 27 insertions, 6 deletions

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 131342280b46..a57698985f9c 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -491,10 +491,10 @@ static int uio_open(struct inode *inode, struct file *filep)
 	if (!idev->info) {
 		mutex_unlock(&idev->info_lock);
 		ret = -EINVAL;
-		goto err_alloc_listener;
+		goto err_infoopen;
 	}
 
-	if (idev->info && idev->info->open)
+	if (idev->info->open)
 		ret = idev->info->open(idev->info, inode);
 	mutex_unlock(&idev->info_lock);
 	if (ret)
@@ -635,7 +635,7 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
 		goto out;
 	}
 
-	if (!idev->info || !idev->info->irq) {
+	if (!idev->info->irq) {
 		retval = -EIO;
 		goto out;
 	}
@@ -940,9 +940,12 @@ int __uio_register_device(struct module *owner,
 	atomic_set(&idev->event, 0);
 
 	ret = uio_get_minor(idev);
-	if (ret)
+	if (ret) {
+		kfree(idev);
 		return ret;
+	}
 
+	device_initialize(&idev->dev);
 	idev->dev.devt = MKDEV(uio_major, idev->minor);
 	idev->dev.class = &uio_class;
 	idev->dev.parent = parent;
@@ -953,7 +956,7 @@ int __uio_register_device(struct module *owner,
 	if (ret)
 		goto err_device_create;
 
-	ret = device_register(&idev->dev);
+	ret = device_add(&idev->dev);
 	if (ret)
 		goto err_device_create;
 
@@ -985,9 +988,10 @@ int __uio_register_device(struct module *owner,
 err_request_irq:
 	uio_dev_del_attributes(idev);
 err_uio_dev_add_attributes:
-	device_unregister(&idev->dev);
+	device_del(&idev->dev);
 err_device_create:
 	uio_free_minor(idev);
+	put_device(&idev->dev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(__uio_register_device);
diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c
index 8773e373ffe5..dde5cbb27178 100644
--- a/drivers/uio/uio_pci_generic.c
+++ b/drivers/uio/uio_pci_generic.c
@@ -39,6 +39,22 @@ to_uio_pci_generic_dev(struct uio_info *info)
 	return container_of(info, struct uio_pci_generic_dev, info);
 }
 
+static int release(struct uio_info *info, struct inode *inode)
+{
+	struct uio_pci_generic_dev *gdev = to_uio_pci_generic_dev(info);
+
+	/*
+	 * This driver is insecure when used with devices doing DMA, but some
+	 * people (mis)use it with such devices.
+	 * Let's at least make sure DMA isn't left enabled after the userspace
+	 * driver closes the fd.
+	 * Note that there's a non-zero chance doing this will wedge the device
+	 * at least until reset.
+	 */
+	pci_clear_master(gdev->pdev);
+	return 0;
+}
+
 /* Interrupt handler. Read/modify/write the command register to disable
  * the interrupt. */
 static irqreturn_t irqhandler(int irq, struct uio_info *info)
@@ -78,6 +94,7 @@ static int probe(struct pci_dev *pdev,
 
 	gdev->info.name = "uio_pci_generic";
 	gdev->info.version = DRIVER_VERSION;
+	gdev->info.release = release;
 	gdev->pdev = pdev;
 	if (pdev->irq) {
 		gdev->info.irq = pdev->irq;