iommu/io-pgtable-arm: Fix IOVA validation for 32-bit

Since we ony support the TTB1 quirk for AArch64 contexts, and
consequently only for 64-bit builds, the sign-extension aspect of the
"are all bits above IAS consistent?" check should implicitly only apply
to 64-bit IOVAs. Change the type of the cast to ensure that 32-bit longs
don't inadvertently get sign-extended, and thus considered invalid, if
they happen to be above 2GB in the TTB0 region.

Reported-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Acked-by: Will Deacon <will@kernel.org>
Fixes: db6903010aa5 ("iommu/io-pgtable-arm: Prepare for TTBR1 usage")
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 983b084..04fbd4b 100644 (file)
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -468,7 +468,7 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
        arm_lpae_iopte *ptep = data->pgd;
        int ret, lvl = data->start_level;
        arm_lpae_iopte prot;
-       long iaext = (long)iova >> cfg->ias;
+       long iaext = (s64)iova >> cfg->ias;
 
        /* If no access, then nothing to do */
        if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
@@ -645,7 +645,7 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
        struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
        struct io_pgtable_cfg *cfg = &data->iop.cfg;
        arm_lpae_iopte *ptep = data->pgd;
-       long iaext = (long)iova >> cfg->ias;
+       long iaext = (s64)iova >> cfg->ias;
 
        if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
                return 0;