Hi Laurent,

On 15/05/15 00:00, Laurent Pinchart wrote:
The arm_iommu_create_mapping() function takes the IOMMU mapping size as
a size_t, limiting the size to 4GB - 1 on 32 bit platforms while most
bus masters would support the full 32 bits range. Fix this by passing
the size as a 64 bits integer, and limiting it to 4GB for now.

FYI there's already an almost-identical patch in -rc3 from Marek fixing this: 1424532b2163 ("ARM: 8347/1: dma-mapping: fix off-by-one check in arm_setup_iommu_dma_ops").

Robin.


Signed-off-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
---
  arch/arm/include/asm/dma-iommu.h |  2 +-
  arch/arm/mm/dma-mapping.c        | 12 +++---------
  2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h
index 8e3fcb924db6..2ef282f96651 100644
--- a/arch/arm/include/asm/dma-iommu.h
+++ b/arch/arm/include/asm/dma-iommu.h
@@ -25,7 +25,7 @@ struct dma_iommu_mapping {
  };

  struct dma_iommu_mapping *
-arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size);
+arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, u64 size);

  void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping);

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7aa5e339a596..c69e216a0cf9 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1878,7 +1878,7 @@ struct dma_map_ops iommu_coherent_ops = {
   * arm_iommu_attach_device function.
   */
  struct dma_iommu_mapping *
-arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size)
+arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, u64 size)
  {
        unsigned int bits = size >> PAGE_SHIFT;
        unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long);
@@ -1886,7 +1886,8 @@ arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t 
base, size_t size)
        int extensions = 1;
        int err = -ENOMEM;

-       if (!bitmap_size)
+       /* Limit the size to 4GB for now. */
+       if (!size || size > (1ULL << 32))
                return ERR_PTR(-EINVAL);

        if (bitmap_size > PAGE_SIZE) {
@@ -2057,13 +2058,6 @@ 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",


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