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authorMarek Szyprowski <m.szyprowski@samsung.com>2012-07-30 09:35:26 +0200
committerMarek Szyprowski <m.szyprowski@samsung.com>2012-07-30 12:25:45 +0200
commit50262a4bf38dd70486e9fce2b8235d5ae3e0f627 (patch)
treef20c140547bd6d33079143fcc77d81844796609c /arch
parente9da6e9905e639b0f842a244bc770b48ad0523e9 (diff)
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ARM: dma-mapping: add more sanity checks in arm_dma_mmap()
Add some sanity checks and forbid mmaping of buffers into vma areas larger than allocated dma buffer. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mm/dma-mapping.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index f906d5f4cbd8..a2881c98fb03 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -611,16 +611,22 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
{
int ret = -ENXIO;
#ifdef CONFIG_MMU
+ unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = dma_to_pfn(dev, dma_addr);
+ unsigned long off = vma->vm_pgoff;
+
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
- ret = remap_pfn_range(vma, vma->vm_start,
- pfn + vma->vm_pgoff,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
+ if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
+ ret = remap_pfn_range(vma, vma->vm_start,
+ pfn + off,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+ }
#endif /* CONFIG_MMU */
return ret;
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