From patchwork Fri Dec 6 03:21:06 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 3292951 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6CA809F373 for ; Fri, 6 Dec 2013 03:25:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AA14620173 for ; Fri, 6 Dec 2013 03:25:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7625200CA for ; Fri, 6 Dec 2013 03:25:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753824Ab3LFDZd (ORCPT ); Thu, 5 Dec 2013 22:25:33 -0500 Received: from mga03.intel.com ([143.182.124.21]:56623 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752828Ab3LFDUj (ORCPT ); Thu, 5 Dec 2013 22:20:39 -0500 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga101.ch.intel.com with ESMTP; 05 Dec 2013 19:20:39 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,838,1378882800"; d="scan'208";a="325986886" Received: from gerry-dev.bj.intel.com ([10.238.158.74]) by AZSMGA002.ch.intel.com with ESMTP; 05 Dec 2013 19:20:35 -0800 From: Jiang Liu To: Joerg Roedel , David Woodhouse , Dan Williams , Vinod Koul , Ashok Raj , Yijing Wang , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: Jiang Liu , Tony Luck , Yinghai Lu , linux-pci@vger.kernel.org, dmaengine@vger.kernel.org Subject: [Patch Part1 V2 03/20] iommu/vt-d: fix a race window in allocating domain ID for virtual machines Date: Fri, 6 Dec 2013 11:21:06 +0800 Message-Id: <1386300083-6882-4-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1386300083-6882-1-git-send-email-jiang.liu@linux.intel.com> References: <1386300083-6882-1-git-send-email-jiang.liu@linux.intel.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Function intel_iommu_domain_init() may be concurrently called by upper layer without serialization, so use atomic_t to protect domain id allocation. Signed-off-by: Jiang Liu --- drivers/iommu/intel-iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 43b9bfe..b8e3b48 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3877,7 +3877,7 @@ static void vm_domain_remove_all_dev_info(struct dmar_domain *domain) } /* domain id for virtual machine, it won't be set in context */ -static unsigned long vm_domid; +static atomic_t vm_domid = ATOMIC_INIT(0); static struct dmar_domain *iommu_alloc_vm_domain(void) { @@ -3887,7 +3887,7 @@ static struct dmar_domain *iommu_alloc_vm_domain(void) if (!domain) return NULL; - domain->id = vm_domid++; + domain->id = atomic_inc_return(&vm_domid); domain->nid = -1; memset(domain->iommu_bmp, 0, sizeof(domain->iommu_bmp)); domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;