From: Joerg Roedel Date: Fri, 28 Sep 2012 14:14:44 +0000 (+0200) Subject: iommu/amd: Fix wrong assumption in iommu-group specific code X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0774e392555a128cff7a94929b9ce957927fef49;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git 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 Signed-off-by: Joerg Roedel --- 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 */