From patchwork Tue Feb 21 15:49:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9584909 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 7655A600CA for ; Tue, 21 Feb 2017 15:49:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 621812003F for ; Tue, 21 Feb 2017 15:49:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 56952288F2; Tue, 21 Feb 2017 15:49:33 +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=ham 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 F3B782003F for ; Tue, 21 Feb 2017 15:49:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752652AbdBUPt3 (ORCPT ); Tue, 21 Feb 2017 10:49:29 -0500 Received: from mga02.intel.com ([134.134.136.20]:30014 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752374AbdBUPt1 (ORCPT ); Tue, 21 Feb 2017 10:49:27 -0500 Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Feb 2017 07:49:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,190,1484035200"; d="scan'208";a="67318704" Received: from michalrx-mobl.ger.corp.intel.com (HELO elena-ThinkPad-X230.ger.corp.intel.com) ([10.249.39.9]) by orsmga005.jf.intel.com with ESMTP; 21 Feb 2017 07:49:24 -0800 From: Elena Reshetova To: linux-kernel@vger.kernel.org Cc: linux-xfs@vger.kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org, darrick.wong@oracle.com, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 5/7] fs, xfs: convert xlog_ticket.t_ref from atomic_t to refcount_t Date: Tue, 21 Feb 2017 17:49:05 +0200 Message-Id: <1487692147-17066-6-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487692147-17066-1-git-send-email-elena.reshetova@intel.com> References: <1487692147-17066-1-git-send-email-elena.reshetova@intel.com> Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@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 --- fs/xfs/xfs_log.c | 10 +++++----- fs/xfs/xfs_log_priv.h | 4 +++- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index b1469f0..c127fa0 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -3500,8 +3500,8 @@ void xfs_log_ticket_put( xlog_ticket_t *ticket) { - ASSERT(atomic_read(&ticket->t_ref) > 0); - if (atomic_dec_and_test(&ticket->t_ref)) + ASSERT(refcount_read(&ticket->t_ref) > 0); + if (refcount_dec_and_test(&ticket->t_ref)) kmem_zone_free(xfs_log_ticket_zone, ticket); } @@ -3509,8 +3509,8 @@ xlog_ticket_t * xfs_log_ticket_get( xlog_ticket_t *ticket) { - ASSERT(atomic_read(&ticket->t_ref) > 0); - atomic_inc(&ticket->t_ref); + ASSERT(refcount_read(&ticket->t_ref) > 0); + refcount_inc(&ticket->t_ref); return ticket; } @@ -3632,7 +3632,7 @@ xlog_ticket_alloc( unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes); - atomic_set(&tic->t_ref, 1); + refcount_set(&tic->t_ref, 1); tic->t_task = current; INIT_LIST_HEAD(&tic->t_queue); tic->t_unit_res = unit_res; diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index c2604a5..279afce 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -18,6 +18,8 @@ #ifndef __XFS_LOG_PRIV_H__ #define __XFS_LOG_PRIV_H__ +#include + struct xfs_buf; struct xlog; struct xlog_ticket; @@ -168,7 +170,7 @@ typedef struct xlog_ticket { struct list_head t_queue; /* reserve/write queue */ struct task_struct *t_task; /* task that owns this ticket */ xlog_tid_t t_tid; /* transaction identifier : 4 */ - atomic_t t_ref; /* ticket reference count : 4 */ + refcount_t t_ref; /* ticket reference count : 4 */ int t_curr_res; /* current reservation in bytes : 4 */ int t_unit_res; /* unit reservation in bytes : 4 */ char t_ocnt; /* original count : 1 */