Re: [PATCH v1 1/3] iommu/vt-d: Fix prq reporting issues

Lu Baolu
2020-10-28T04:57:28Z

Hi Yi,

On 10/28/20 9:36 AM, Yi Sun wrote:
> From: Liu Yi L <yi.l.liu@intel.com>
>
> Should get correct sid and set it into sdev. Because we execute
> 'sdev->sid != req->rid' in the loop of prq_event_thread().

How about making the title more accurate, how about something like:

iommu/vt-d: Fix use before set issue in intel_svm_bind_gpasid()

>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
> ---
> drivers/iommu/intel/svm.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index f1861fa..75d9dc9 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -277,6 +277,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
> struct iommu_gpasid_bind_data *data)
> {
> struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
> + struct device_domain_info *info;
> struct intel_svm_dev *sdev = NULL;
> struct dmar_domain *dmar_domain;
> struct intel_svm *svm = NULL;
> @@ -357,6 +358,8 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
> goto out;
> }
> sdev->dev = dev;
> + info = get_domain_info(dev);
> + sdev->sid = PCI_DEVID(info->bus, info->devfn);
>
> /* Only count users if device has aux domains */
> if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
>

How about moving get_domain_info() up to the sanity check part?

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index f1861fa3d0e4..75846692f2f2 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -279,6 +279,7 @@ int intel_svm_bind_gpasid(struct iommu_domain
*domain, struct device *dev,
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct intel_svm_dev *sdev = NULL;
struct dmar_domain *dmar_domain;
+ struct device_domain_info *info;
struct intel_svm *svm = NULL;
int ret = 0;

@@ -310,6 +311,10 @@ int intel_svm_bind_gpasid(struct iommu_domain
*domain, struct device *dev,
if (data->hpasid <= 0 || data->hpasid >= PASID_MAX)
return -EINVAL;

+ info = get_domain_info(dev);
+ if (!info)
+ return -EINVAL;
+
dmar_domain = to_dmar_domain(domain);

mutex_lock(&pasid_mutex);
@@ -357,6 +362,7 @@ int intel_svm_bind_gpasid(struct iommu_domain
*domain, struct device *dev,
goto out;
}
sdev->dev = dev;
+ sdev->sid = PCI_DEVID(info->bus, info->devfn);

/* Only count users if device has aux domains */
if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))

Best regards,
baolu