From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 25 Nov 2016 11:01:32 +0000 (+0300)
Subject: sparc64: move dereference after check for NULL
X-Git-Tag: Ubuntu-5.0.0-8.9~5966^2~5
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=efca4885b5dea6af906d27b3516f68e0bc1ff9c3;p=mirror_ubuntu-disco-kernel.git

sparc64: move dereference after check for NULL

We shouldn't dereference "iommu" until after we have checked that it is
non-NULL.

Fixes: f08978b0fdbf ("sparc64: Enable sun4v dma ops to use IOMMU v2 APIs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 06981cc716b6..cabb609fedcc 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -478,11 +478,10 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist,
 	BUG_ON(direction == DMA_NONE);
 
 	iommu = dev->archdata.iommu;
-	atu = iommu->atu;
-
 	if (nelems == 0 || !iommu)
 		return 0;
-	
+	atu = iommu->atu;
+
 	prot = HV_PCI_MAP_ATTR_READ;
 	if (direction != DMA_TO_DEVICE)
 		prot |= HV_PCI_MAP_ATTR_WRITE;