[PATCH] ARM: dma-mapping: add more sanity checks in arm_dma_mmap()
From: m.szyprowski@samsung.com (Marek Szyprowski)
Date: 2012-07-30 08:29:52
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
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> --- arch/arm/mm/dma-mapping.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index f906d5f..a2881c9 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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1.7.1.569.g6f426