From b9abb19fa5fd2d8a4be61c6cd4b2a48aa1a17f9c Mon Sep 17 00:00:00 2001
From: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Date: Wed, 3 Mar 2021 17:36:11 +0000
Subject: [PATCH] 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: a3a195929d40 ("iommu: Add APIs for multiple domains per device")
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210303173611.520-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/iommu.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d0b0a15dba8413..e10cfa99057cea 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -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)
- return ops->dev_enable_feat(dev, 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)
- return ops->dev_disable_feat(dev, 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)
- return ops->dev_feat_enabled(dev, feat);
+ if (ops->dev_feat_enabled)
+ return ops->dev_feat_enabled(dev, feat);
+ }
return false;
}
--
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