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authorJoerg Roedel <joerg.roedel@amd.com>2012-09-28 16:14:44 +0200
committerJoerg Roedel <joerg.roedel@amd.com>2012-09-28 16:14:44 +0200
commit0774e392555a128cff7a94929b9ce957927fef49 (patch)
tree2dd8b9d9156e8c276c9ee2a7f37a62447184d2c9 /drivers
parentbef83de5a0e3031ff6ff9584b458611a7ac01b85 (diff)
downloadlinux-0774e392555a128cff7a94929b9ce957927fef49.tar.gz
iommu/amd: Fix wrong assumption in iommu-group specific code
The new IOMMU groups code in the AMD IOMMU driver makes the assumption that there is a pci_dev struct available for all device-ids listed in the IVRS ACPI table. Unfortunatly this assumption is not true and so this code causes a NULL pointer dereference at boot on some systems. Fix it by making sure the given pointer is never NULL when passed to the group specific code. The real fix is larger and will be queued for v3.7. Reported-by: Florian Dazinger <florian@dazinger.net> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/amd_iommu.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index b64502dfa9f..e89daf1b21b 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -266,7 +266,7 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to)
static int iommu_init_device(struct device *dev)
{
- struct pci_dev *dma_pdev, *pdev = to_pci_dev(dev);
+ struct pci_dev *dma_pdev = NULL, *pdev = to_pci_dev(dev);
struct iommu_dev_data *dev_data;
struct iommu_group *group;
u16 alias;
@@ -293,7 +293,9 @@ static int iommu_init_device(struct device *dev)
dev_data->alias_data = alias_data;
dma_pdev = pci_get_bus_and_slot(alias >> 8, alias & 0xff);
- } else
+ }
+
+ if (dma_pdev == NULL)
dma_pdev = pci_dev_get(pdev);
/* Account for quirked devices */