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authorJoe Jin <joe.jin@oracle.com>2018-10-16 15:21:16 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-21 09:27:33 +0100
commitcf9e0f77f54a18775516de808195cb57439be98a (patch)
tree38f885628c7d857c9f2f390e97beb83ec5c8505b /drivers/xen
parenta9d21a73909f3bce076ecdaed589640d001bc5b2 (diff)
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 <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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/swiotlb-xen.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 1889e928a0da..a8a388382347 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);