From 87d143de94e24bc209b10750b1937d7b5b9ee648 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 10 Dec 2018 19:33:31 +0000 Subject: [PATCH] arm64: dma-mapping: Fix FORCE_CONTIGUOUS buffer clearing commit 3238c359acee4ab57f15abb5a82b8ab38a661ee7 upstream. We need to invalidate the caches *before* clearing the buffer via the non-cacheable alias, else in the worst case __dma_flush_area() may write back dirty lines over the top of our nice new zeros. Fixes: dd65a941f6ba ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag") Cc: # 4.18.x- Acked-by: Will Deacon Signed-off-by: Robin Murphy Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/dma-mapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 58470b151bc3..ba88b5b68db6 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -633,9 +633,9 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, prot, __builtin_return_address(0)); if (addr) { - memset(addr, 0, size); if (!coherent) __dma_flush_area(page_to_virt(page), iosize); + memset(addr, 0, size); } else { iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs); dma_release_from_contiguous(dev, page, -- 2.20.1