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-rw-r--r--drivers/vfio/pci/vfio_pci.c16
-rw-r--r--drivers/vfio/vfio.c27
2 files changed, 28 insertions, 15 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index e9851add6f4e..964ad572aaee 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1056,19 +1056,21 @@ struct vfio_devices {
static int vfio_pci_get_devs(struct pci_dev *pdev, void *data)
{
struct vfio_devices *devs = data;
- struct pci_driver *pci_drv = ACCESS_ONCE(pdev->driver);
-
- if (pci_drv != &vfio_pci_driver)
- return -EBUSY;
+ struct vfio_device *device;
if (devs->cur_index == devs->max_index)
return -ENOSPC;
- devs->devices[devs->cur_index] = vfio_device_get_from_dev(&pdev->dev);
- if (!devs->devices[devs->cur_index])
+ device = vfio_device_get_from_dev(&pdev->dev);
+ if (!device)
return -EINVAL;
- devs->cur_index++;
+ if (pci_dev_driver(pdev) != &vfio_pci_driver) {
+ vfio_device_put(device);
+ return -EBUSY;
+ }
+
+ devs->devices[devs->cur_index++] = device;
return 0;
}
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index e1278fe04b1e..2fb29dfeffbd 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -661,18 +661,29 @@ int vfio_add_group_dev(struct device *dev,
EXPORT_SYMBOL_GPL(vfio_add_group_dev);
/**
- * Get a reference to the vfio_device for a device that is known to
- * be bound to a vfio driver. The driver implicitly holds a
- * vfio_device reference between vfio_add_group_dev and
- * vfio_del_group_dev. We can therefore use drvdata to increment
- * that reference from the struct device. This additional
- * reference must be released by calling vfio_device_put.
+ * Get a reference to the vfio_device for a device. Even if the
+ * caller thinks they own the device, they could be racing with a
+ * release call path, so we can't trust drvdata for the shortcut.
+ * Go the long way around, from the iommu_group to the vfio_group
+ * to the vfio_device.
*/
struct vfio_device *vfio_device_get_from_dev(struct device *dev)
{
- struct vfio_device *device = dev_get_drvdata(dev);
+ struct iommu_group *iommu_group;
+ struct vfio_group *group;
+ struct vfio_device *device;
+
+ iommu_group = iommu_group_get(dev);
+ if (!iommu_group)
+ return NULL;
- vfio_device_get(device);
+ group = vfio_group_get_from_iommu(iommu_group);
+ iommu_group_put(iommu_group);
+ if (!group)
+ return NULL;
+
+ device = vfio_group_get_device(group, dev);
+ vfio_group_put(group);
return device;
}