From patchwork Mon Mar 6 14:21:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9606687 X-Patchwork-Delegate: bhelgaas@google.com 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 7B3066046A for ; Mon, 6 Mar 2017 14:34:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7004726224 for ; Mon, 6 Mar 2017 14:34:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6442028285; Mon, 6 Mar 2017 14:34:21 +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 9A90126E69 for ; Mon, 6 Mar 2017 14:34:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754626AbdCFOdD (ORCPT ); Mon, 6 Mar 2017 09:33:03 -0500 Received: from mga09.intel.com ([134.134.136.24]:47009 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753503AbdCFO3s (ORCPT ); Mon, 6 Mar 2017 09:29:48 -0500 Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Mar 2017 06:22:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,254,1484035200"; d="scan'208";a="72746201" 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 06:22:47 -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 14/29] drivers, media: convert vb2_dc_buf.refcount from atomic_t to refcount_t Date: Mon, 6 Mar 2017 16:21:01 +0200 Message-Id: <1488810076-3754-15-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 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/media/v4l2-core/videobuf2-dma-contig.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index fb6a177..d29a07f 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -12,6 +12,7 @@ #include #include +#include #include #include #include @@ -34,7 +35,7 @@ struct vb2_dc_buf { /* MMAP related */ struct vb2_vmarea_handler handler; - atomic_t refcount; + refcount_t refcount; struct sg_table *sgt_base; /* DMABUF related */ @@ -86,7 +87,7 @@ static unsigned int vb2_dc_num_users(void *buf_priv) { struct vb2_dc_buf *buf = buf_priv; - return atomic_read(&buf->refcount); + return refcount_read(&buf->refcount); } static void vb2_dc_prepare(void *buf_priv) @@ -122,7 +123,7 @@ static void vb2_dc_put(void *buf_priv) { struct vb2_dc_buf *buf = buf_priv; - if (!atomic_dec_and_test(&buf->refcount)) + if (!refcount_dec_and_test(&buf->refcount)) return; if (buf->sgt_base) { @@ -170,7 +171,7 @@ static void *vb2_dc_alloc(struct device *dev, unsigned long attrs, buf->handler.put = vb2_dc_put; buf->handler.arg = buf; - atomic_inc(&buf->refcount); + refcount_set(&buf->refcount, 1); return buf; } @@ -407,7 +408,7 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags) return NULL; /* dmabuf keeps reference to vb2 buffer */ - atomic_inc(&buf->refcount); + refcount_inc(&buf->refcount); return dbuf; }