On 3/28/23 11:48 PM, Jacob Pan wrote:
On Tue, 28 Mar 2023 14:04:15 +0800, Baolu Lu<baolu.lu@xxxxxxxxxxxxxxx>
wrote:
On 3/28/23 7:21 AM, Jacob Pan wrote:
Devices that use ENQCMDS to submit work needs to retrieve its DMA
domain. It can then attach PASID to the DMA domain for shared mapping
(with RID) established by DMA API.
Signed-off-by: Jacob Pan<jacob.jun.pan@xxxxxxxxxxxxxxx>
---
drivers/iommu/iommu.c | 1 +
include/linux/iommu.h | 5 +++++
2 files changed, 6 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 10db680acaed..c51d343a75d2 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2118,6 +2118,7 @@ struct iommu_domain *iommu_get_dma_domain(struct
device *dev) {
return dev->iommu_group->default_domain;
}
+EXPORT_SYMBOL_GPL(iommu_get_dma_domain);
Directly exporting this function for external use seems unsafe. If the
caller is the kernel driver for this device, it's fine because default
domain remains unchanged during the life cycle of the driver. Otherwise,
using this function may cause UAF. Keep in mind that group's default
domain could be changed through sysfs.
don't you have to unload the driver?
Yes, of cause.
Hence, the getting domain interfaces are only safe to be used in the
driver of the device.
Best regards,
baolu
