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

[Umang Jain]

Hi Kieran,

On 4/11/22 01:54, Kieran Bingham via libcamera-devel wrote:
> 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?


-1 (i.e. shouldn't need a v2 on the list).

I am okay returning with EXDEV as the error code.

>
> --
> 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
>>