From 4855c92dbb7b3b85c23e88ab7ca04f99b9677b41 Mon Sep 17 00:00:00 2001 From: Joe Jin Date: Thu, 17 May 2018 12:33:28 -0700 Subject: [PATCH] xen-swiotlb: fix the check condition for xen_swiotlb_free_coherent When run raidconfig from Dom0 we found that the Xen DMA heap is reduced, but Dom Heap is increased by the same size. Tracing raidconfig we found that the related ioctl() in megaraid_sas will call dma_alloc_coherent() to apply memory. If the memory allocated by Dom0 is not in the DMA area, it will exchange memory with Xen to meet the requiment. Later drivers call dma_free_coherent() to free the memory, on xen_swiotlb_free_coherent() the check condition (dev_addr + size - 1 <= dma_mask) is always false, it prevents calling xen_destroy_contiguous_region() to return the memory to the Xen DMA heap. This issue introduced by commit 6810df88dcfc2 "xen-swiotlb: When doing coherent alloc/dealloc check before swizzling the MFNs.". Signed-off-by: Joe Jin Tested-by: John Sobecki Reviewed-by: Rzeszutek Wilk Cc: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/swiotlb-xen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index e1c60899fdbc..a6f9ba85dc4b 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -351,7 +351,7 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, * physical address */ phys = xen_bus_to_phys(dev_addr); - if (((dev_addr + size - 1 > dma_mask)) || + if (((dev_addr + size - 1 <= dma_mask)) || range_straddles_page_boundary(phys, size)) xen_destroy_contiguous_region(phys, order);