From: Robin Murphy <robin.murphy@arm.com>
To: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: <linux-kernel@vger.kernel.org>,
<iommu@lists.linux-foundation.org>,
jean-philippe@linaro.org, will@kernel.org,
linuxarm@openeuler.org, prime.zeng@hisilicon.com
Subject: Re: [PATCH] iommu: Check dev->iommu in iommu_dev_xxx functions
Date: Tue, 26 Jan 2021 13:50:40 +0000 [thread overview]
Message-ID: <20210126135039.000039a0@arm.com> (raw)
In-Reply-To: <20210126130629.8928-1-shameerali.kolothum.thodi@huawei.com>
On Tue, 26 Jan 2021 13:06:29 +0000
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> 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 <shameerali.kolothum.thodi@huawei.com>
> ---
> 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()
Robin.
> return false;
> @@ -2878,7 +2878,7 @@ int iommu_dev_enable_feature(struct device
> *dev, enum iommu_dev_features feat) {
> const struct iommu_ops *ops = dev->bus->iommu_ops;
>
> - if (ops && ops->dev_enable_feat)
> + if (dev->iommu && ops && ops->dev_enable_feat)
> return ops->dev_enable_feat(dev, feat);
>
> return -ENODEV;
> @@ -2894,7 +2894,7 @@ int iommu_dev_disable_feature(struct device
> *dev, enum iommu_dev_features feat) {
> const struct iommu_ops *ops = dev->bus->iommu_ops;
>
> - if (ops && ops->dev_disable_feat)
> + if (dev->iommu && ops && ops->dev_disable_feat)
> return ops->dev_disable_feat(dev, feat);
>
> return -EBUSY;
> @@ -2905,7 +2905,7 @@ bool iommu_dev_feature_enabled(struct device
> *dev, enum iommu_dev_features feat) {
> const struct iommu_ops *ops = dev->bus->iommu_ops;
>
> - if (ops && ops->dev_feat_enabled)
> + if (dev->iommu && ops && ops->dev_feat_enabled)
> return ops->dev_feat_enabled(dev, feat);
>
> return false;
next prev parent reply other threads:[~2021-01-26 13:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 13:06 [PATCH] iommu: Check dev->iommu in iommu_dev_xxx functions Shameer Kolothum
2021-01-26 13:50 ` Robin Murphy [this message]
2021-01-26 16:40 ` Shameerali Kolothum Thodi
2021-01-26 17:24 ` Robin Murphy
2021-01-28 12:54 ` Joerg Roedel
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