iommu: Improve error handling when setting bus iommu
When some part of bus_set_iommu fails it should undo any made changes
and not simply leave everything as is.
This includes unregistering the bus notifier in iommu_bus_init when
add_iommu_group fails and also setting the bus->iommu_ops back to NULL.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 08c53c5..02e4313 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -818,7 +818,15 @@
kfree(nb);
return err;
}
- return bus_for_each_dev(bus, NULL, &cb, add_iommu_group);
+
+ err = bus_for_each_dev(bus, NULL, &cb, add_iommu_group);
+ if (err) {
+ bus_unregister_notifier(bus, nb);
+ kfree(nb);
+ return err;
+ }
+
+ return 0;
}
/**
@@ -836,13 +844,19 @@
*/
int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
{
+ int err;
+
if (bus->iommu_ops != NULL)
return -EBUSY;
bus->iommu_ops = ops;
/* Do IOMMU specific setup for this bus-type */
- return iommu_bus_init(bus, ops);
+ err = iommu_bus_init(bus, ops);
+ if (err)
+ bus->iommu_ops = NULL;
+
+ return err;
}
EXPORT_SYMBOL_GPL(bus_set_iommu);