Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756512AbaAJCQf (ORCPT ); Thu, 9 Jan 2014 21:16:35 -0500 Received: from mail-ve0-f175.google.com ([209.85.128.175]:59481 "EHLO mail-ve0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751745AbaAJCQb (ORCPT ); Thu, 9 Jan 2014 21:16:31 -0500 MIME-Version: 1.0 In-Reply-To: <20140109120135.GJ29041@8bytes.org> References: <52CE0252.4090106@oracle.com> <20140109120135.GJ29041@8bytes.org> Date: Fri, 10 Jan 2014 10:16:30 +0800 Message-ID: Subject: Re: [PATCH Trivial] intel-iommu: check return value of device_to_iommu() before using it From: Ethan Zhao To: Joerg Roedel Cc: ethan zhao , dwmw2@infradead.org, Yinghai Lu , Bjorn Helgaas , jiang.liu@linux.intel.com, iommu@lists.linux-foundation.org, linux-pci , LKML Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 9, 2014 at 8:01 PM, Joerg Roedel wrote: > On Thu, Jan 09, 2014 at 09:58:42AM +0800, ethan zhao wrote: >> drivers/iommu/intel-iommu.c | 2 ++ >> 1 files changed, 2 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c >> index 40203ad..5b4531a 100644 >> --- a/drivers/iommu/intel-iommu.c >> +++ b/drivers/iommu/intel-iommu.c >> @@ -1105,6 +1105,8 @@ static struct device_domain_info >> *iommu_support_dev_iotlb( >> struct device_domain_info *info; >> struct intel_iommu *iommu = device_to_iommu(segment, bus, devfn); >> >> + if (!iommu) >> + return NULL; >> if (!ecap_dev_iotlb_support(iommu->ecap)) >> return NULL; > > This call can not fail, iommu_support_dev_iotlb() is only called from > domain_context_mapping_one() which does the iommu==NULL check on its > own before the call. > Agree, till now, was checked in domain_context_mapping_one(), but how about if we query information with iommu_support_dev_iotlb() in other code ? Thanks, Ethan > > Joerg > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/