From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fenghua Yu Date: Tue, 04 Aug 2009 22:10:24 +0000 Subject: [PATCH 2/4] Bug Fix drivers/pci/intel-iommu.c: secure sg_next() calling Message-Id: <20090804221024.GA21406@linux-os.sc.intel.com> List-Id: References: <617E1C2C70743745A92448908E030B2A02AD5AD7@scsmsx411.amr.corp.intel.com> In-Reply-To: <617E1C2C70743745A92448908E030B2A02AD5AD7@scsmsx411.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Woodhouse , Tony Luck Cc: iommu@lists.linux-foundation.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Fenghua Yu sg_next() is called only when sg is not NULL. This solves a kernel panic on some platforms (e.g. ia64). Signed-off-by: Fenghua Yu --- drivers/pci/intel-iommu.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index bec29ed..54ee63d 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -1705,8 +1715,12 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, iov_pfn++; pteval += VTD_PAGE_SIZE; sg_res--; - if (!sg_res) - sg = sg_next(sg); + if (!sg_res) { + if (sg) + sg = sg_next(sg); + else + return 0; + } } return 0; }