Messages in this thread | | | Subject | Re: [PATCH v3] iommu: Check dev->iommu in iommu_dev_xxx functions | From | Robin Murphy <> | Date | Tue, 9 Mar 2021 12:50:29 +0000 |
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On 2021-03-03 17:36, Shameer Kolothum wrote: > 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.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> Fixes: a3a195929d40 ("iommu: Add APIs for multiple domains per device") > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> > --- > v2 --> v3 > -Removed iommu_ops from struct dev_iommu. > v1 --> v2: > -Added iommu_ops to struct dev_iommu based on the discussion with Robin. > -Rebased against iommu-tree core branch. > --- > 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 d0b0a15dba84..e10cfa99057c 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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