Commit b9abb19f authored by Shameer Kolothum's avatar Shameer Kolothum Committed by Joerg Roedel
Browse files

iommu: Check dev->iommu in iommu_dev_xxx functions 



The device iommu probe/attach might have failed leaving dev->iommu
to NULL and device drivers may still invoke these functions resulting
in a crash in iommu vendor driver code.

Hence make sure we check that.

Fixes: a3a19592 ("iommu: Add APIs for multiple domains per device")
Signed-off-by: default avatarShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210303173611.520-1-shameerali.kolothum.thodi@huawei.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 1e28eed1

drivers/iommu/iommu.c

+15 −9
Original line number Diff line number Diff line
@@ -2878,10 +2878,12 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); 
 */

int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)

{

	const struct iommu_ops *ops = dev->bus->iommu_ops;

	if (dev->iommu && dev->iommu->iommu_dev) {

		const struct iommu_ops *ops = dev->iommu->iommu_dev->ops;



	if (ops && ops->dev_enable_feat)

		if (ops->dev_enable_feat)

			return ops->dev_enable_feat(dev, feat);

	}



	return -ENODEV;

}
@@ -2894,10 +2896,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); 
 */

int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)

{

	const struct iommu_ops *ops = dev->bus->iommu_ops;

	if (dev->iommu && dev->iommu->iommu_dev) {

		const struct iommu_ops *ops = dev->iommu->iommu_dev->ops;



	if (ops && ops->dev_disable_feat)

		if (ops->dev_disable_feat)

			return ops->dev_disable_feat(dev, feat);

	}



	return -EBUSY;

}
@@ -2905,10 +2909,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); 


bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)

{

	const struct iommu_ops *ops = dev->bus->iommu_ops;

	if (dev->iommu && dev->iommu->iommu_dev) {

		const struct iommu_ops *ops = dev->iommu->iommu_dev->ops;



	if (ops && ops->dev_feat_enabled)

		if (ops->dev_feat_enabled)

			return ops->dev_feat_enabled(dev, feat);

	}



	return false;

}