[PATCH 4/4] iommupt: Return zero for invalid iova_to_phys() ranges

[Shuai Xue]

DOMAIN_NS(iova_to_phys) returns a phys_addr_t and follows the IOMMU
iova_to_phys() convention of returning 0 when there is no valid
translation.

make_range() returns a negative errno if the input IOVA cannot be
represented by this page table format. Returning that errno directly
casts it to phys_addr_t. Callers treat zero as no translation and use
non-zero values as physical addresses, so this can make them consume a
bogus physical address instead of seeing a failed translation.

Match the page-table walk failure path and return 0 for range validation
failures too.

Fixes: 9d4c274cd7d5 ("iommupt: Add iova_to_phys op")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: Qoder:Qwen-3.8-MAX-Preview
Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
---
 drivers/iommu/generic_pt/iommu_pt.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/generic_pt/iommu_pt.h b/drivers/iommu/generic_pt/iommu_pt.h
index c2752151c80a..07ec2b3ab986 100644
--- a/drivers/iommu/generic_pt/iommu_pt.h
+++ b/drivers/iommu/generic_pt/iommu_pt.h
@@ -224,7 +224,7 @@ phys_addr_t DOMAIN_NS(iova_to_phys)(struct iommu_domain *domain,
 
 	ret = make_range(common_from_iommu(iommu_table), &range, iova, 1);
 	if (ret)
-		return ret;
+		return 0;
 
 	ret = pt_walk_range(&range, __iova_to_phys, &res);
 	/* PHYS_ADDR_MAX would be a better error code */
-- 
2.39.3