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| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2018-06-12 13:08:40 +0200 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-06-19 15:19:21 +0200 |
| commit | dd65a941f6ba473a5cb9d013d57fa43b48450a04 (patch) | |
| tree | 3239077195d29ca00d83dffe4d3097128444055e /arch | |
| parent | Linux 4.18-rc1 (diff) | |
| download | linux-dd65a941f6ba473a5cb9d013d57fa43b48450a04.tar.xz linux-dd65a941f6ba473a5cb9d013d57fa43b48450a04.zip | |
arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag
dma_alloc_*() buffers might be exposed to userspace via mmap() call, so
they should be cleared on allocation. In case of IOMMU-based dma-mapping
implementation such buffer clearing was missing in the code path for
DMA_ATTR_FORCE_CONTIGUOUS flag handling, because dma_alloc_from_contiguous()
doesn't honor __GFP_ZERO flag. This patch fixes this issue. For more
information on clearing buffers allocated by dma_alloc_* functions,
see commit 6829e274a623 ("arm64: dma-mapping: always clear allocated
buffers").
Fixes: 44176bb38fa4 ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/mm/dma-mapping.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 49e217ac7e1e..61e93f0b5482 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -583,13 +583,14 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, size >> PAGE_SHIFT); return NULL; } - if (!coherent) - __dma_flush_area(page_to_virt(page), iosize); - addr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot, __builtin_return_address(0)); - if (!addr) { + if (addr) { + memset(addr, 0, size); + if (!coherent) + __dma_flush_area(page_to_virt(page), iosize); + } else { iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs); dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT); |