Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932235Ab2EGUkv (ORCPT ); Mon, 7 May 2012 16:40:51 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:35219 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757676Ab2EGUku (ORCPT ); Mon, 7 May 2012 16:40:50 -0400 From: =?UTF-8?q?Tomasz=20Mo=C5=84?= To: Mauro Carvalho Chehab , Marek Szyprowski , Guennadi Liakhovetski , Kyungmin Park , linux-media@vger.kernel.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Tomasz=20Mo=C5=84?= Subject: [PATCH 1/1] v4l: mem2mem_testdev: Fix race conditions in driver. Date: Mon, 7 May 2012 22:39:01 +0200 Message-Id: <1336423141-10956-1-git-send-email-desowin@gmail.com> X-Mailer: git-send-email 1.7.10 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4053 Lines: 140 The mem2mem_testdev allows multiple instances to be opened in parallel. Source and destination queue data are being shared between all instances, which can lead to kernel oops due to race conditions (most likely to happen inside device_run()). Attached patch fixes mentioned problem by storing queue data per device context. Signed-off-by: Tomasz Moń --- drivers/media/video/mem2mem_testdev.c | 50 +++++++++++++++++---------------- 1 file changed, 26 insertions(+), 24 deletions(-) diff --git a/drivers/media/video/mem2mem_testdev.c b/drivers/media/video/mem2mem_testdev.c index 12897e8..ae7ca12 100644 --- a/drivers/media/video/mem2mem_testdev.c +++ b/drivers/media/video/mem2mem_testdev.c @@ -110,22 +110,6 @@ enum { V4L2_M2M_DST = 1, }; -/* Source and destination queue data */ -static struct m2mtest_q_data q_data[2]; - -static struct m2mtest_q_data *get_q_data(enum v4l2_buf_type type) -{ - switch (type) { - case V4L2_BUF_TYPE_VIDEO_OUTPUT: - return &q_data[V4L2_M2M_SRC]; - case V4L2_BUF_TYPE_VIDEO_CAPTURE: - return &q_data[V4L2_M2M_DST]; - default: - BUG(); - } - return NULL; -} - #define V4L2_CID_TRANS_TIME_MSEC V4L2_CID_PRIVATE_BASE #define V4L2_CID_TRANS_NUM_BUFS (V4L2_CID_PRIVATE_BASE + 1) @@ -198,8 +182,26 @@ struct m2mtest_ctx { int aborting; struct v4l2_m2m_ctx *m2m_ctx; + + /* Source and destination queue data */ + struct m2mtest_q_data q_data[2]; }; +static struct m2mtest_q_data *get_q_data(struct m2mtest_ctx *ctx, + enum v4l2_buf_type type) +{ + switch (type) { + case V4L2_BUF_TYPE_VIDEO_OUTPUT: + return &ctx->q_data[V4L2_M2M_SRC]; + case V4L2_BUF_TYPE_VIDEO_CAPTURE: + return &ctx->q_data[V4L2_M2M_DST]; + default: + BUG(); + } + return NULL; +} + + static struct v4l2_queryctrl *get_ctrl(int id) { int i; @@ -223,7 +225,7 @@ static int device_process(struct m2mtest_ctx *ctx, int tile_w, bytes_left; int width, height, bytesperline; - q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_OUTPUT); + q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT); width = q_data->width; height = q_data->height; @@ -436,7 +438,7 @@ static int vidioc_g_fmt(struct m2mtest_ctx *ctx, struct v4l2_format *f) if (!vq) return -EINVAL; - q_data = get_q_data(f->type); + q_data = get_q_data(ctx, f->type); f->fmt.pix.width = q_data->width; f->fmt.pix.height = q_data->height; @@ -535,7 +537,7 @@ static int vidioc_s_fmt(struct m2mtest_ctx *ctx, struct v4l2_format *f) if (!vq) return -EINVAL; - q_data = get_q_data(f->type); + q_data = get_q_data(ctx, f->type); if (!q_data) return -EINVAL; @@ -747,7 +749,7 @@ static int m2mtest_queue_setup(struct vb2_queue *vq, struct m2mtest_q_data *q_data; unsigned int size, count = *nbuffers; - q_data = get_q_data(vq->type); + q_data = get_q_data(ctx, vq->type); size = q_data->width * q_data->height * q_data->fmt->depth >> 3; @@ -775,7 +777,7 @@ static int m2mtest_buf_prepare(struct vb2_buffer *vb) dprintk(ctx->dev, "type: %d\n", vb->vb2_queue->type); - q_data = get_q_data(vb->vb2_queue->type); + q_data = get_q_data(ctx, vb->vb2_queue->type); if (vb2_plane_size(vb, 0) < q_data->sizeimage) { dprintk(ctx->dev, "%s data will not fit into plane (%lu < %lu)\n", @@ -860,6 +862,9 @@ static int m2mtest_open(struct file *file) ctx->transtime = MEM2MEM_DEF_TRANSTIME; ctx->num_processed = 0; + ctx->q_data[V4L2_M2M_SRC].fmt = &formats[0]; + ctx->q_data[V4L2_M2M_DST].fmt = &formats[0]; + ctx->m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &queue_init); if (IS_ERR(ctx->m2m_ctx)) { @@ -982,9 +987,6 @@ static int m2mtest_probe(struct platform_device *pdev) goto err_m2m; } - q_data[V4L2_M2M_SRC].fmt = &formats[0]; - q_data[V4L2_M2M_DST].fmt = &formats[0]; - return 0; v4l2_m2m_release(dev->m2m_dev); -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/