Hi Robin,
> -----Original Message-----
> From: Robin Murphy [mailto:[email protected]]
> Sent: 26 January 2021 13:51
> To: Shameerali Kolothum Thodi <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; Zengtao
> (B) <[email protected]>
> Subject: Re: [PATCH] iommu: Check dev->iommu in iommu_dev_xxx functions
>
> On Tue, 26 Jan 2021 13:06:29 +0000
> Shameer Kolothum <[email protected]> wrote:
>
> > The device iommu probe/attach might have failed leaving dev->iommu to
> > NULL and device drivers may still invoke these functions resulting a
> > crash in iommu vendor driver code. Hence make sure we check that.
> >
> > Signed-off-by: Shameer Kolothum <[email protected]>
> > ---
> > drivers/iommu/iommu.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index
> > ffeebda8d6de..cb68153c5cc0 100644
> > --- a/drivers/iommu/iommu.c
> > +++ b/drivers/iommu/iommu.c
> > @@ -2867,7 +2867,7 @@ bool iommu_dev_has_feature(struct device *dev,
> > enum iommu_dev_features feat) {
> > const struct iommu_ops *ops = dev->bus->iommu_ops;
> >
> > - if (ops && ops->dev_has_feat)
> > + if (dev->iommu && ops && ops->dev_has_feat)
> > return ops->dev_has_feat(dev, feat);
>
> Might make sense to make these more self-contained, e.g.:
>
> if (dev->iommu && dev->iommu->ops->foo)
> dev->iommu->ops->foo()
Right. Does that mean adding ops to "struct dev_iommu" or retrieve ops like
below,
if (dev->iommu && dev->iommu->iommu_dev->ops->foo)
dev->iommu->iommu_dev->ops->foo()
Sorry, not clear to me.
Thanks,
Shameer
