From patchwork Mon Mar 6 14:20:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9606503 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B0EB76046A for ; Mon, 6 Mar 2017 14:26:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A5C8B2842C for ; Mon, 6 Mar 2017 14:26:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 99ABF28433; Mon, 6 Mar 2017 14:26:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 53B5E2842C for ; Mon, 6 Mar 2017 14:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753775AbdCFO0F (ORCPT ); Mon, 6 Mar 2017 09:26:05 -0500 Received: from mga14.intel.com ([192.55.52.115]:37943 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752768AbdCFOZj (ORCPT ); Mon, 6 Mar 2017 09:25:39 -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 06:22:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,254,1484035200"; d="scan'208";a="72745989" 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 06:22:10 -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 08/29] drivers, md: convert mddev.active from atomic_t to refcount_t Date: Mon, 6 Mar 2017 16:20:55 +0200 Message-Id: <1488810076-3754-9-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-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- drivers/md/md.c | 6 +++--- drivers/md/md.h | 3 ++- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 985374f..94c8ebf 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -449,7 +449,7 @@ EXPORT_SYMBOL(md_unplug); static inline struct mddev *mddev_get(struct mddev *mddev) { - atomic_inc(&mddev->active); + refcount_inc(&mddev->active); return mddev; } @@ -459,7 +459,7 @@ static void mddev_put(struct mddev *mddev) { struct bio_set *bs = NULL; - if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) + if (!refcount_dec_and_lock(&mddev->active, &all_mddevs_lock)) return; if (!mddev->raid_disks && list_empty(&mddev->disks) && mddev->ctime == 0 && !mddev->hold_active) { @@ -495,7 +495,7 @@ void mddev_init(struct mddev *mddev) INIT_LIST_HEAD(&mddev->all_mddevs); setup_timer(&mddev->safemode_timer, md_safemode_timeout, (unsigned long) mddev); - atomic_set(&mddev->active, 1); + refcount_set(&mddev->active, 1); atomic_set(&mddev->openers, 0); atomic_set(&mddev->active_io, 0); spin_lock_init(&mddev->lock); diff --git a/drivers/md/md.h b/drivers/md/md.h index b8859cb..4811663 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -360,7 +361,7 @@ struct mddev { */ struct mutex open_mutex; struct mutex reconfig_mutex; - atomic_t active; /* general refcount */ + refcount_t active; /* general refcount */ atomic_t openers; /* number of active opens */ int changed; /* True if we might need to