On Tue, 6 Dec 2016 23:56:54 +0530
Kirti Wankhede <kwankhede@xxxxxxxxxx> wrote:
> Passing zero for the size to vfio_find_dma() isn't compatible with
> matching the start address of an existing vfio_dma. Doing so triggers a
> corner case. In vfio_find_dma(), when the start address is equal to
> dma->iova and size is 0, check for the end of search range makes it to
> take wrong side of RB-tree. That fails the search even though the address
> is present in mapped dma ranges. Due to this, in vfio_dma_do_unmap(),
> while checking boundary conditions, size should be set to 1 for verifying
> start address of unmap range.
> vfio_find_dma() is also used to verify last address in unmap range with
> size = 0, but in that case address to be searched is calculated with
> size - 1 and so it works correctly.
I think this last sentence should actually read "start + size - 1", or
at least that makes it more understandable for me. I'll make that
change and apply these. Thanks,
Alex
> Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
> ---
> drivers/vfio/vfio_iommu_type1.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index a28fbddb505c..8e9e94ccb2ff 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -826,7 +826,7 @@ again:
> * mappings within the range.
> */
> if (iommu->v2) {
> - dma = vfio_find_dma(iommu, unmap->iova, 0);
> + dma = vfio_find_dma(iommu, unmap->iova, 1);
> if (dma && dma->iova != unmap->iova) {
> ret = -EINVAL;
> goto unlock;
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
