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Commit e6a8c9b3 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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: default avatarStefani Seibold <stefani@seibold.net>
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent b6809ee5

drivers/iommu/dmar.c

+3 −2
Original line number Diff line number Diff line
@@ -329,7 +329,8 @@ static int dmar_pci_bus_notifier(struct notifier_block *nb, 
	/* 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 @@ static int dmar_pci_bus_notifier(struct notifier_block *nb, 
	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);

drivers/iommu/intel-iommu.c

+2 −2
Original line number Diff line number Diff line
@@ -4367,7 +4367,7 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) 
				rmrru->devices_cnt);

			if(ret < 0)

				return ret;

		} else if (info->event == BUS_NOTIFY_DEL_DEVICE) {

		} else if (info->event == BUS_NOTIFY_REMOVED_DEVICE) {

			dmar_remove_dev_scope(info, rmrr->segment,

				rmrru->devices, rmrru->devices_cnt);

		}
@@ -4387,7 +4387,7 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) 
				break;

			else if(ret < 0)

				return ret;

		} else if (info->event == BUS_NOTIFY_DEL_DEVICE) {

		} else if (info->event == BUS_NOTIFY_REMOVED_DEVICE) {

			if (dmar_remove_dev_scope(info, atsr->segment,

					atsru->devices, atsru->devices_cnt))

				break;