Re: [PATCH v4 1/7] iommu: Prevent pasid attach if no ops->remove_dev_pasid

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2024/11/10 11:59, Baolu Lu wrote:
On 11/8/24 20:04, Yi Liu wrote:
driver should implement both set_dev_pasid and remove_dev_pasid op, otherwise
it is a problem how to detach pasid. In reality, it is impossible that an
iommu driver implements set_dev_pasid() but no remove_dev_pasid() op. However,
it is better to check it.

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
  drivers/iommu/iommu.c | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 13fcd9d8f2df..1c689e57928e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3352,17 +3352,19 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
                    struct iommu_attach_handle *handle)
  {
      /* Caller must be a probed driver on dev */
+    const struct iommu_ops *ops = dev_iommu_ops(dev);
      struct iommu_group *group = dev->iommu_group;
      struct group_device *device;
      int ret;
-    if (!domain->ops->set_dev_pasid)
+    if (!domain->ops->set_dev_pasid ||
+        !ops->remove_dev_pasid)
          return -EOPNOTSUPP;
      if (!group)
          return -ENODEV;

If group is NULL, calling dev_iommu_ops() will trigger a kernel NULL
pointer reference warning, which is unintended. If you need to check
ops->remove_dev_pasid, it should be done after the group check.


good catch. Let me fix it.

--
Regards,
Yi Liu




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux