[PATCH 1/5] bcm2835-camera: Correct port_parameter_get return value

[Michael Zoran]

On Tue, 2017-03-21 at 08:27 +0100, Greg KH wrote:
> On Fri, Mar 17, 2017 at 02:56:42PM -0700, Michael Zoran wrote:
> > From: Dave Stevenson <dave.stevenson at raspberrypi.org>
> > 
> > The API for port_parameter_get() requires that the
> > filled length is returned, or if insufficient space
> > that the required space is returned.
> > 
> > Signed-off-by: Dave Stevenson <dave.stevenson at raspberrypi.org>
> > 
> > Changed path:
> > From: drivers/media/platform/bcm2835/mmal-vchiq.c
> > To:   drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> > 
> > Signed-off-by: Michael Zoran <mzoran at crowfest.net>
> > ---
> >  .../vc04_services/bcm2835-camera/mmal-vchiq.c        | 20
> > ++++++++++++++++----
> >  1 file changed, 16 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/staging/vc04_services/bcm2835-camera/mmal-
> > vchiq.c b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> > index fc1076db0f82..4f4499dfe0c3 100644
> > --- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> > +++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> > @@ -1422,6 +1422,7 @@ static int port_parameter_get(struct
> > vchiq_mmal_instance *instance,
> >  	struct mmal_msg m;
> >  	struct mmal_msg *rmsg;
> >  	VCHI_HELD_MSG_T rmsg_handle;
> > +	u32 reply_size;
> >  
> >  	m.h.type = MMAL_MSG_TYPE_PORT_PARAMETER_GET;
> >  
> > @@ -1445,19 +1446,30 @@ static int port_parameter_get(struct
> > vchiq_mmal_instance *instance,
> >  	}
> >  
> >  	ret = -rmsg->u.port_parameter_get_reply.status;
> > -	if (ret || (rmsg->u.port_parameter_get_reply.size >
> > *value_size)) {
> > +	/*
> > +	 * port_parameter_get_reply.size includes the header,
> > +	 * whilst *value_size doesn't.
> > +	 */
> > +	reply_size = rmsg->u.port_parameter_get_reply.size - (2 *
> > sizeof(u32));
> > +
> > +	if (ret || (reply_size > *value_size)) {
> >  		/* Copy only as much as we have space for
> >  		 * but report true size of parameter
> >  		 */
> >  		memcpy(value, &rmsg-
> > >u.port_parameter_get_reply.value,
> >  		       *value_size);
> > -		*value_size = rmsg-
> > >u.port_parameter_get_reply.size;
> >  	} else
> >  		memcpy(value, &rmsg-
> > >u.port_parameter_get_reply.value,
> > -		       rmsg->u.port_parameter_get_reply.size);
> > +		       reply_size);
> > +
> > +	/*
> > +	 * Return amount of data copied if big enough,
> > +	 * or wanted if not big enough.
> > +	 */
> > +	*value_size = reply_size;
> >  
> >  	pr_debug("%s:result:%d component:0x%x port:%d
> > parameter:%d\n", __func__,
> > -		 ret, port->component->handle, port->handle,
> > parameter_id);
> > +	        ret, port->component->handle, port->handle,
> > parameter_id);
> 
> Why did you change this last line?  It was previously correct.
> 
> thanks,
> 
> greg k-h

Hi Greg,

No I didn't, it should be an exact copy of the original with the the
paths changed.

I'm not happen with this code block in general.  I think this
particular block needs to be written.  I'll see what I can do.