Hello,

On 2014-04-21 08:47, Ritesh Harjani wrote:
68efd7d2fb("arm: dma-mapping: remove order parameter from
arm_iommu_create_mapping()") is causing kernel panic
because it wrongly sets the value of mapping->size:

Unable to handle kernel NULL pointer dereference at virtual
address 000000a0
pgd = e7a84000
[000000a0] *pgd=00000000
...
PC is at bitmap_clear+0x48/0xd0
LR is at __iommu_remove_mapping+0x130/0x164

Fix it by correcting mapping->size value.

Signed-off-by: Ritesh Harjani <[email protected]>
Acked-by: Laurent Pinchart <[email protected]>

Thanks for spotting this issue! I'm really sorry for introducing it. I will push it to the fixes branch asap.

---
  arch/arm/mm/dma-mapping.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index f62aa06..6b00be1 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1963,8 +1963,8 @@ arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t 
base, size_t size)
        mapping->nr_bitmaps = 1;
        mapping->extensions = extensions;
        mapping->base = base;
-       mapping->size = bitmap_size << PAGE_SHIFT;
        mapping->bits = BITS_PER_BYTE * bitmap_size;
+       mapping->size = mapping->bits << PAGE_SHIFT;
spin_lock_init(&mapping->lock);

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland

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