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 <jgg@xxxxxxxxxx>
---
drivers/iommu/io-pgtable-arm-v7s.c | 3 +--
drivers/iommu/io-pgtable-arm.c | 3 +--
drivers/iommu/io-pgtable-dart.c | 3 +--
3 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 75f244a3e12df6..06ffc683b28fee 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -552,9 +552,8 @@ static int arm_v7s_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
paddr >= (1ULL << data->iop.cfg.oas)))
return -ERANGE;
- /* If no access, then nothing to do */
if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
- return 0;
+ return -EINVAL;
while (pgcount--) {
ret = __arm_v7s_map(data, iova, paddr, pgsize, prot, 1, data->pgd,
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index f5d9fd1f45bf49..ff4149ae1751d4 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -515,9 +515,8 @@ static int arm_lpae_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
if (WARN_ON(iaext || paddr >> cfg->oas))
return -ERANGE;
- /* If no access, then nothing to do */
if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
- return 0;
+ return -EINVAL;
prot = arm_lpae_prot_to_pte(data, iommu_prot);
ret = __arm_lpae_map(data, iova, paddr, pgsize, pgcount, prot, lvl,
diff --git a/drivers/iommu/io-pgtable-dart.c b/drivers/iommu/io-pgtable-dart.c
index ad28031e1e93d6..c004640640ee50 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);
--
2.46.0
