[PATCH v3 4/7] iommu: Switch gather->end to unsigned long long

[Yong Wu]

Currently gather->end is "unsigned long" which may be overflow in
arch32 in the corner case: 0xfff00000 + 0x100000(iova + size).
Although it doesn't affect the size(end - start), it affects the checking
"gather->end < end"

Fixes: a7d20dc19d9e ("iommu: Introduce struct iommu_iotlb_gather for batching TLB flushes")
Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
 include/linux/iommu.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 794d4085edd3..6e907a95d981 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -178,7 +178,7 @@ enum iommu_dev_features {
  */
 struct iommu_iotlb_gather {
 	unsigned long		start;
-	unsigned long		end;
+	unsigned long long	end;
 	size_t			pgsize;
 };
 
@@ -537,7 +537,8 @@ static inline void iommu_iotlb_gather_add_page(struct iommu_domain *domain,
 					       struct iommu_iotlb_gather *gather,
 					       unsigned long iova, size_t size)
 {
-	unsigned long start = iova, end = start + size;
+	unsigned long start = iova;
+	unsigned long long end = start + size;
 
 	/*
 	 * If the new page is disjoint from the current range or is mapped at
-- 
2.18.0