From 6093cd582f8e027117a8d4ad5d129a1aacdc53d2 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 22 Aug 2024 11:45:55 -0300 Subject: iommu: Do not return 0 from map_pages if it doesn't do anything These three implementations of map_pages() all succeed if a mapping is requested with no read or write. Since they return back to __iommu_map() leaving the mapped output as 0 it triggers an infinite loop. Therefore nothing is using no-access protection bits. Further, VFIO and iommufd rely on iommu_iova_to_phys() to get back PFNs stored by map, if iommu_map() succeeds but iommu_iova_to_phys() fails that will create serious bugs. Thus remove this never used "nothing to do" concept and just fail map immediately. Fixes: e5fc9753b1a8 ("iommu/io-pgtable: Add ARMv7 short descriptor support") Fixes: e1d3c0fd701d ("iommu: add ARM LPAE page table allocator") Fixes: 745ef1092bcf ("iommu/io-pgtable: Move Apple DART support to its own file") Signed-off-by: Jason Gunthorpe Acked-by: Will Deacon Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/2-v1-1211e1294c27+4b1-iommu_no_prot_jgg@nvidia.com Signed-off-by: Joerg Roedel --- drivers/iommu/io-pgtable-dart.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/iommu/io-pgtable-dart.c') diff --git a/drivers/iommu/io-pgtable-dart.c b/drivers/iommu/io-pgtable-dart.c index ad28031e1e93..c004640640ee 100644 --- a/drivers/iommu/io-pgtable-dart.c +++ b/drivers/iommu/io-pgtable-dart.c @@ -245,9 +245,8 @@ static int dart_map_pages(struct io_pgtable_ops *ops, unsigned long iova, if (WARN_ON(paddr >> cfg->oas)) return -ERANGE; - /* If no access, then nothing to do */ if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE))) - return 0; + return -EINVAL; tbl = dart_get_table(data, iova); -- cgit v1.2.3-70-g09d2