[libcamera-devel] [PATCH] libcamera: camera: Ensure requests belong to the camera

[Kieran Bingham]

Quoting Kieran Bingham (2022-03-17 13:17:26)
> Requests are created by a Camera, and can only be queued
> to that specific Camera. Enforce this during the public API
> to prevent mis-use by incorrect applications.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> ---
>  src/libcamera/camera.cpp | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
> index bb856d606f4a..dd6552e83eee 100644
> --- a/src/libcamera/camera.cpp
> +++ b/src/libcamera/camera.cpp
> @@ -23,6 +23,7 @@
>  #include "libcamera/internal/camera_controls.h"
>  #include "libcamera/internal/formats.h"
>  #include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/request.h"
>  
>  /**
>   * \file libcamera/camera.h
> @@ -1119,6 +1120,12 @@ int Camera::queueRequest(Request *request)
>         if (ret < 0)
>                 return ret;
>  
> +       /* Requests can only be queued to the camera that created them.*/
> +       if (request->_d()->camera() != this) {
> +               LOG(Camera, Error) << "Request was not created by this camera";
> +               return -EINVAL;

I have two tags so I'm ready to merge this but ...  I'm tempted to make
this a distinct return code:

  EXDEV 18 Invalid cross-device link

Adding 
+ * \retval -EXDEV The request does not belong to this camera

to the doxygen accordingly.

Any comments, either a +1 or a -1 on whether I should or should not post
a v2 with this?

--
Kieran


> +       }
> +
>         /*
>          * The camera state may change until the end of the function. No locking
>          * is however needed as PipelineHandler::queueRequest() will handle
> -- 
> 2.32.0
>