[PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size
Murali Karicheri
m-karicheri2 at ti.com
Fri Jan 23 14:32:39 PST 2015
Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.
Also arm_iommu_create_mapping() has size parameter of size_t and
arm_setup_iommu_dma_ops() can take a value higher than that. So
limit the size to SIZE_MAX.
Signed-off-by: Murali Karicheri <m-karicheri2 at ti.com>
---
arch/arm/mm/dma-mapping.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797..a1f9030 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
if (!iommu)
return false;
+ /*
+ * currently arm_iommu_create_mapping() takes a max of size_t
+ * for size param. So check this limit for now.
+ */
+ if (size > SIZE_MAX)
+ return false;
+
mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
if (IS_ERR(mapping)) {
pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
@@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
{
struct dma_map_ops *dma_ops;
+ /* limit dma_mask to the lower of the two values */
+ *dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
+
dev->archdata.dma_coherent = coherent;
if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
dma_ops = arm_get_iommu_dma_map_ops(coherent);
--
1.7.9.5
More information about the linux-arm-kernel
mailing list