| Message ID | 20200916023005.26414-1-yan.y.zhao@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] vfio/type1: fix dirty bitmap calculation in vfio_dma_rw | expand |
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 5fbf0c1f7433..d0438388feeb 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2933,7 +2933,8 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, * size */ bitmap_set(dma->bitmap, offset >> pgshift, - *copied >> pgshift); + ((offset + *copied - 1) >> pgshift) - + (offset >> pgshift) + 1); } } else *copied = copy_from_user(data, (void __user *)vaddr,
the count of dirtied pages is not only determined by count of copied pages, but also by the start offset. e.g. if offset = PAGE_SIZE - 1, and *copied=2, the dirty pages count is 2, instead of 1 or 0. Fixes: d6a4c185660c ("vfio iommu: Implementation of ioctl for dirty pages tracking") Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> --- v2: updated the format of the Fixes: line. --- drivers/vfio/vfio_iommu_type1.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)