path: root/drivers/xen
diff options
authorJoe Jin <joe.jin@oracle.com>2018-10-16 15:21:16 -0700
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2018-10-18 23:51:39 +0000
commit7250f422da0480d8512b756640f131b9b893ccda (patch)
treeddaacea5ceed2d431e2c552c301323d9ece97737 /drivers/xen
parent35a7f35ad1b150ddf59a41dcac7b2fa32982be0e (diff)
xen-swiotlb: use actually allocated size on check physical continuous
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 <joe.jin@oracle.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Christoph Helwig <hch@lst.de> Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: John Sobecki <john.sobecki@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index a6f9ba85dc4b..aa081f806728 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -303,6 +303,9 @@ 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
@@ -351,6 +354,9 @@ 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);

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