From 9b4cb632e1af21d1fe02047e13b1022d50747a73 Mon Sep 17 00:00:00 2001 From: Joe Jin Date: Tue, 16 Oct 2018 15:21:16 -0700 Subject: xen-swiotlb: use actually allocated size on check physical continuous commit 7250f422da0480d8512b756640f131b9b893ccda upstream. xen_swiotlb_{alloc,free}_coherent() allocate/free memory based on the order of the pages and not size argument (bytes). This is inconsistent with range_straddles_page_boundary and memset which use the 'size' value, which may lead to not exchanging memory with Xen (range_straddles_page_boundary() returned true). And then the call to xen_swiotlb_free_coherent() would actually try to exchange the memory with Xen, leading to the kernel hitting an BUG (as the hypercall returned an error). This patch fixes it by making the 'size' variable be of the same size as the amount of memory allocated. CC: stable@vger.kernel.org Signed-off-by: Joe Jin Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: Christoph Helwig Cc: Dongli Zhang Cc: John Sobecki Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- drivers/xen/swiotlb-xen.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/xen') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 2fe7353ab720..5d04b362837d 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -310,6 +310,9 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, */ flags &= ~(__GFP_DMA | __GFP_HIGHMEM); + /* Convert the size to actually allocated. */ + size = 1UL << (order + XEN_PAGE_SHIFT); + /* On ARM this function returns an ioremap'ped virtual address for * which virt_to_phys doesn't return the corresponding physical * address. In fact on ARM virt_to_phys only works for kernel direct @@ -359,6 +362,9 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, * physical address */ phys = xen_bus_to_phys(dev_addr); + /* Convert the size to actually allocated. */ + size = 1UL << (order + XEN_PAGE_SHIFT); + if (((dev_addr + size - 1 <= dma_mask)) || range_straddles_page_boundary(phys, size)) xen_destroy_contiguous_region(phys, order); -- cgit v1.2.3