From patchwork Mon Mar 6 14:21:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 735794 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vcMpP6Jg1z9sNB for ; Tue, 7 Mar 2017 01:38:05 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932505AbdCFOgb (ORCPT ); Mon, 6 Mar 2017 09:36:31 -0500 Received: from mga14.intel.com ([192.55.52.115]:3818 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932479AbdCFOgO (ORCPT ); Mon, 6 Mar 2017 09:36:14 -0500 Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Mar 2017 06:23:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,254,1484035200"; d="scan'208";a="72746297" Received: from rzetikx-mobl.ger.corp.intel.com (HELO elena-ThinkPad-X230.ger.corp.intel.com) ([10.249.41.1]) by fmsmga005.fm.intel.com with ESMTP; 06 Mar 2017 06:23:06 -0800 From: Elena Reshetova To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org, linux-media@vger.kernel.org, devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-s390@vger.kernel.org, fcoe-devel@open-fcoe.org, linux-scsi@vger.kernel.org, open-iscsi@googlegroups.com, devel@driverdev.osuosl.org, target-devel@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, peterz@infradead.org, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 17/29] drivers, pci: convert hv_pci_dev.refs from atomic_t to refcount_t Date: Mon, 6 Mar 2017 16:21:04 +0200 Message-Id: <1488810076-3754-18-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> References: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Reviewed-by: Stephen Hemminger --- drivers/pci/host/pci-hyperv.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index cd114c6..870deed 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -56,6 +56,7 @@ #include #include #include +#include #include /* @@ -421,7 +422,7 @@ enum hv_pcidev_ref_reason { struct hv_pci_dev { /* List protected by pci_rescan_remove_lock */ struct list_head list_entry; - atomic_t refs; + refcount_t refs; enum hv_pcichild_state state; struct pci_function_description desc; bool reported_missing; @@ -1254,13 +1255,13 @@ static void q_resource_requirements(void *context, struct pci_response *resp, static void get_pcichild(struct hv_pci_dev *hpdev, enum hv_pcidev_ref_reason reason) { - atomic_inc(&hpdev->refs); + refcount_inc(&hpdev->refs); } static void put_pcichild(struct hv_pci_dev *hpdev, enum hv_pcidev_ref_reason reason) { - if (atomic_dec_and_test(&hpdev->refs)) + if (refcount_dec_and_test(&hpdev->refs)) kfree(hpdev); } @@ -1314,7 +1315,7 @@ static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus, wait_for_completion(&comp_pkt.host_event); hpdev->desc = *desc; - get_pcichild(hpdev, hv_pcidev_ref_initial); + refcount_set(&hpdev->refs, 1); get_pcichild(hpdev, hv_pcidev_ref_childlist); spin_lock_irqsave(&hbus->device_list_lock, flags); list_add_tail(&hpdev->list_entry, &hbus->children);