From cb216b84d6ea24fa10f1e7aac35de77246841041 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Wed, 21 Nov 2018 16:00:51 +0000 Subject: [PATCH] swiotlb: Skip cache maintenance on map error If swiotlb_bounce_page() failed, calling arch_sync_dma_for_device() may lead to such delights as performing cache maintenance on whatever address phys_to_virt(SWIOTLB_MAP_ERROR) looks like, which is typically outside the kernel memory map and goes about as well as expected. Don't do that. Fixes: a4a4330db46a ("swiotlb: add support for non-coherent DMA") Tested-by: John Stultz Signed-off-by: Robin Murphy Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 5731daa09a32..045930e32c0e 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -679,7 +679,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, } if (!dev_is_dma_coherent(dev) && - (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0) + (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0 && + dev_addr != DIRECT_MAPPING_ERROR) arch_sync_dma_for_device(dev, phys, size, dir); return dev_addr; -- 2.20.1