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path: root/drivers/uio/uio_pci_generic.c
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Diffstat (limited to 'drivers/uio/uio_pci_generic.c')
-rw-r--r--drivers/uio/uio_pci_generic.c17
1 files changed, 17 insertions, 0 deletions
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;