From: Jason Gunthorpe Date: Mon, 2 Mar 2026 22:22:53 +0000 (-0400) Subject: iommupt: Fix short gather if the unmap goes into a large mapping X-Git-Tag: v7.0-rc7~29^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ee6e69d032550687a3422504bfca3f834c7b5061;p=thirdparty%2Fkernel%2Flinux.git iommupt: Fix short gather if the unmap goes into a large mapping unmap has the odd behavior that it can unmap more than requested if the ending point lands within the middle of a large or contiguous IOPTE. In this case the gather should flush everything unmapped which can be larger than what was requested to be unmapped. The gather was only flushing the range requested to be unmapped, not extending to the extra range, resulting in a short invalidation if the caller hits this special condition. This was found by the new invalidation/gather test I am adding in preparation for ARMv8. Claude deduced the root cause. As far as I remember nothing relies on unmapping a large entry, so this is likely not a triggerable bug. Cc: stable@vger.kernel.org Fixes: 7c53f4238aa8 ("iommupt: Add unmap_pages op") Signed-off-by: Jason Gunthorpe Reviewed-by: Lu Baolu Reviewed-by: Samiullah Khawaja Reviewed-by: Vasant Hegde Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/generic_pt/iommu_pt.h b/drivers/iommu/generic_pt/iommu_pt.h index 3e33fe64feab..7e7a6e7abdee 100644 --- a/drivers/iommu/generic_pt/iommu_pt.h +++ b/drivers/iommu/generic_pt/iommu_pt.h @@ -1057,7 +1057,7 @@ size_t DOMAIN_NS(unmap_pages)(struct iommu_domain *domain, unsigned long iova, pt_walk_range(&range, __unmap_range, &unmap); - gather_range_pages(iotlb_gather, iommu_table, iova, len, + gather_range_pages(iotlb_gather, iommu_table, iova, unmap.unmapped, &unmap.free_list); return unmap.unmapped;