linux/x86: dma_map_sg(): BUG_ON() before use

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff --git a/arch/i386/kernel/pci-dma-xen.c b/arch/i386/kernel/pci-dma-xen.c
index 7fe2e6dd7e0e0eae3830ccd4f9437f3db1235da5..9c8b6435a4d17ed7bff870331c088819037c4cb8 100644 (file)
--- a/arch/i386/kernel/pci-dma-xen.c
+++ b/arch/i386/kernel/pci-dma-xen.c
@@ -91,10 +91,10 @@ dma_map_sg(struct device *hwdev, struct scatterlist *sg, int nents,
                rc = swiotlb_map_sg(hwdev, sg, nents, direction);
        } else {
                for (i = 0; i < nents; i++ ) {
+                       BUG_ON(!sg[i].page);
                        sg[i].dma_address =
                                gnttab_dma_map_page(sg[i].page) + sg[i].offset;
                        sg[i].dma_length  = sg[i].length;
-                       BUG_ON(!sg[i].page);
                        IOMMU_BUG_ON(address_needs_mapping(
                                hwdev, sg[i].dma_address));
                        IOMMU_BUG_ON(range_straddles_page_boundary(