iommu/vt-d: Use BUS_NOTIFY_REMOVED_DEVICE in hotplug path
In the PCI hotplug path of the Intel IOMMU driver, replace
the usage of the BUS_NOTIFY_DEL_DEVICE notifier, which is
executed before the driver is unbound from the device, with
BUS_NOTIFY_REMOVED_DEVICE, which runs after that.
This fixes a kernel BUG being triggered in the VT-d code
when the device driver tries to unmap DMA buffers and the
VT-d driver already destroyed all mappings.
Reported-by: Stefani Seibold <stefani@seibold.net>
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index fb092f3..8ffd756 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -329,7 +329,8 @@
/* Only care about add/remove events for physical functions */
if (pdev->is_virtfn)
return NOTIFY_DONE;
- if (action != BUS_NOTIFY_ADD_DEVICE && action != BUS_NOTIFY_DEL_DEVICE)
+ if (action != BUS_NOTIFY_ADD_DEVICE &&
+ action != BUS_NOTIFY_REMOVED_DEVICE)
return NOTIFY_DONE;
info = dmar_alloc_pci_notify_info(pdev, action);
@@ -339,7 +340,7 @@
down_write(&dmar_global_lock);
if (action == BUS_NOTIFY_ADD_DEVICE)
dmar_pci_bus_add_dev(info);
- else if (action == BUS_NOTIFY_DEL_DEVICE)
+ else if (action == BUS_NOTIFY_REMOVED_DEVICE)
dmar_pci_bus_del_dev(info);
up_write(&dmar_global_lock);