From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elena Reshetova 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> References: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" To: gregkh@linuxfoundation.org Cc: peterz@infradead.org, linux-pci@vger.kernel.org, target-devel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, Elena Reshetova , devel@driverdev.osuosl.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-serial@vger.kernel.org, fcoe-devel@open-fcoe.org, xen-devel@lists.xenproject.org, open-iscsi@googlegroups.com, linux-media@vger.kernel.org, Kees Cook , linux-raid@vger.kernel.org, linux-bcache@vger.kernel.org, Hans Liljestrand , David Windsor , netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org List-Id: linux-raid.ids 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; } -- 2.7.4