diff options
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 16 | ||||
| -rw-r--r-- | drivers/vfio/vfio.c | 27 |
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; } |
