2019-11-18 19:40:37

by Jacob Pan

Subject: [PATCH v2 06/10] iommu/vt-d: Fix off-by-one in PASID allocation

PASID allocator uses IDR which is exclusive for the end of the
allocation range. There is no need to decrement pasid_max.

Fixes: af39507305fb ("iommu/vt-d: Apply global PASID in SVA")
Reported-by: Eric Auger <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
Acked-by: Lu Baolu <[email protected]>
---
drivers/iommu/intel-svm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 74df10a39dfc..e90d0b914afe 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -338,7 +338,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
/* Do not use PASID 0 in caching mode (virtualised IOMMU) */
ret = intel_pasid_alloc_id(svm,
!!cap_caching_mode(iommu->cap),
- pasid_max - 1, GFP_KERNEL);
+ pasid_max, GFP_KERNEL);
if (ret < 0) {
kfree(svm);
kfree(sdev);
--
2.7.4

2019-11-18 21:03:10

by Eric Auger

Subject: Re: [PATCH v2 06/10] iommu/vt-d: Fix off-by-one in PASID allocation

Hi Jacob,

On 11/18/19 8:42 PM, Jacob Pan wrote:
> PASID allocator uses IDR which is exclusive for the end of the
> allocation range. There is no need to decrement pasid_max.
>
> Fixes: af39507305fb ("iommu/vt-d: Apply global PASID in SVA")
> Reported-by: Eric Auger <[email protected]>
> Signed-off-by: Jacob Pan <[email protected]>
> Acked-by: Lu Baolu <[email protected]>
> ---
> drivers/iommu/intel-svm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> index 74df10a39dfc..e90d0b914afe 100644
> --- a/drivers/iommu/intel-svm.c
> +++ b/drivers/iommu/intel-svm.c
> @@ -338,7 +338,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
> /* Do not use PASID 0 in caching mode (virtualised IOMMU) */
> ret = intel_pasid_alloc_id(svm,
> !!cap_caching_mode(iommu->cap),
> - pasid_max - 1, GFP_KERNEL);
> + pasid_max, GFP_KERNEL);
> if (ret < 0) {
> kfree(svm);
> kfree(sdev);
>
Reviewed-by: Eric Auger <[email protected]>

Thanks

Eric