Hi Tomasz,
On Monday, May 07, 2012 10:39 PM Tomasz Moń wrote:
> 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 <desowin@xxxxxxxxx>
Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Thanks for fixing this bug!
> ---
> 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
Best regards
--
Marek Szyprowski
Samsung Poland R&D Center
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
