From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933423AbZHDWKj (ORCPT ); Tue, 4 Aug 2009 18:10:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933288AbZHDWKi (ORCPT ); Tue, 4 Aug 2009 18:10:38 -0400 Received: from mga02.intel.com ([134.134.136.20]:35338 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933111AbZHDWKh (ORCPT ); Tue, 4 Aug 2009 18:10:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.43,324,1246863600"; d="scan'208";a="538605525" Date: Tue, 4 Aug 2009 15:10:24 -0700 From: Fenghua Yu To: David Woodhouse , Tony Luck Cc: iommu@lists.linux-foundation.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, Fenghua Yu Subject: [PATCH 2/4] Bug Fix drivers/pci/intel-iommu.c: secure sg_next() calling Message-ID: <20090804221024.GA21406@linux-os.sc.intel.com> References: <617E1C2C70743745A92448908E030B2A02AD5AD7@scsmsx411.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <617E1C2C70743745A92448908E030B2A02AD5AD7@scsmsx411.amr.corp.intel.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; }