4.19-stable review patch. If anyone has any objections, please let me know.
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From: Robin Murphy robin.murphy@arm.com
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: stable@vger.kernel.org # 4.18.x- Acked-by: Will Deacon will.deacon@arm.com Signed-off-by: Robin Murphy robin.murphy@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/mm/dma-mapping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -587,9 +587,9 @@ static void *__iommu_alloc_attrs(struct 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,