iommu: Fix bus notifier breakage (fb3e3065) · Commits · 戴 / test

iommu_bus_init() registers a bus notifier on the given bus by using a statically defined notifier block: static struct notifier_block iommu_bus_nb = { .notifier_call = iommu_bus_notifier, }; This same notifier block is used for all busses. This causes a problem for notifiers registered after iommu has registered this callback on multiple busses. The problem is that a subsequent notifier being registered on a bus which has this iommu notifier will also get linked in to the notifier list of all other busses which have this iommu notifier. This patch fixes this by allocating the notifier_block at runtime. Some error checking is also added to catch any allocation failure or notifier registration error. Signed-off-by:

Mark Salter <msalter@redhat.com> Signed-off-by:

Joerg Roedel <jroedel@suse.de>

drivers/iommu/iommu.c

+16 −10

Original line number	Diff line number	Diff line
		@@ -799,18 +799,26 @@ static int iommu_bus_notifier(struct notifier_block *nb,
		return 0;
		}

		static struct notifier_block iommu_bus_nb = {
		.notifier_call = iommu_bus_notifier,
		};

		static void iommu_bus_init(struct bus_type bus, const struct iommu_ops ops)
		static int iommu_bus_init(struct bus_type bus, const struct iommu_ops ops)
		{
		int err;
		struct notifier_block *nb;
		struct iommu_callback_data cb = {
		.ops = ops,
		};

		bus_register_notifier(bus, &iommu_bus_nb);
		bus_for_each_dev(bus, NULL, &cb, add_iommu_group);
		nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
		if (!nb)
		return -ENOMEM;

		nb->notifier_call = iommu_bus_notifier;

		err = bus_register_notifier(bus, nb);
		if (err) {
		kfree(nb);
		return err;
		}
		return bus_for_each_dev(bus, NULL, &cb, add_iommu_group);
		}

		/**
		@@ -834,9 +842,7 @@ int bus_set_iommu(struct bus_type bus, const struct iommu_ops ops)
		bus->iommu_ops = ops;

		/* Do IOMMU specific setup for this bus-type */
		iommu_bus_init(bus, ops);

		return 0;
		return iommu_bus_init(bus, ops);
		}
		EXPORT_SYMBOL_GPL(bus_set_iommu);

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