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| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2018-06-12 13:08:40 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-24 13:09:01 +0200 |
| commit | a929f067a88f0f9a2b02e328f746007f645fa920 (patch) | |
| tree | a0d3a59e4d5f144afd2a8b920ea9d67ba5782db2 | |
| parent | 2e62d135dd530d7144f55c6ce84e2ec29f48596a (diff) | |
| download | linux-a929f067a88f0f9a2b02e328f746007f645fa920.tar.gz | |
arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag
[ Upstream commit dd65a941f6ba473a5cb9d013d57fa43b48450a04 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 614af886b7ef4f..58470b151bc3fa 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -629,13 +629,14 @@ 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); |