On Tue October 2 2012 16:27:30 Tomasz Stanislawski wrote:
This patch adds extension to videobuf2-core. It allow to export a mmap buffer as a file descriptor.
Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com
drivers/media/video/videobuf2-core.c | 82 ++++++++++++++++++++++++++++++++++ include/media/videobuf2-core.h | 4 ++ 2 files changed, 86 insertions(+)
diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c index 05da3b4..a97815b 100644 --- a/drivers/media/video/videobuf2-core.c +++ b/drivers/media/video/videobuf2-core.c
<snip>
@@ -2455,6 +2528,15 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) } EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff); +int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p) +{
- struct video_device *vdev = video_devdata(file);
- /* No need to call vb2_queue_is_busy(), anyone can export buffers. */
After thinking about this some more I'm not so sure we should allow this. Exporting a buffer also means that the memory can't be freed as long as the exported filehandle remains open.
That means that it is possible to make a malicious application that exports the buffers and never frees them, which can cause havoc. I think that only the filehandle that called REQBUFS/CREATE_BUFS should be allowed to export buffers.
What do you think?
Regards,
Hans
- return vb2_expbuf(vdev->queue, p);
+} +EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
/* v4l2_file_operations helpers */ int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)