Merge tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - fix race with device reference versus driver release (Alex Williamson)

 - add reset hooks and Calxeda xgmac reset for vfio-platform (Eric Auger)

 - enable vfio-platform for ARM64 (Eric Auger)

 - tag Baptiste Reynal as vfio-platform sub-maintainer (Alex Williamson)

* tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio:
  MAINTAINERS: Add vfio-platform sub-maintainer
  VFIO: platform: enable ARM64 build
  VFIO: platform: Calxeda xgmac reset module
  VFIO: platform: populate the reset function on probe
  VFIO: platform: add reset callback
  VFIO: platform: add reset struct and lookup table
  vfio/pci: Fix racy vfio_device_get_from_dev() call

1 files changed, 9 insertions, 7 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;
 }