Re: [RFC PATCH 2/5] v4l2-compat-ioctl32: add g/s_matrix support.

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

Thanks for the patch.

On Friday 28 June 2013 14:27:31 Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 55 ++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 8f7a6a4..64155b1
> 100644
> --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
> @@ -777,6 +777,44 @@ static int put_v4l2_subdev_edid32(struct
> v4l2_subdev_edid *kp, struct v4l2_subde return 0;
>  }
> 
> +struct v4l2_matrix32 {
> +	__u32 type;
> +	union {
> +		__u32 reserved[4];
> +	} ref;
> +	struct v4l2_rect rect;
> +	compat_caddr_t matrix;
> +	__u32 reserved[12];
> +} __attribute__ ((packed));
> +
> +static int get_v4l2_matrix32(struct v4l2_matrix *kp, struct v4l2_matrix32
> __user *up) +{
> +	u32 tmp;
> +
> +	if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_matrix32)) ||
> +		get_user(kp->type, &up->type) ||
> +		copy_from_user(&kp->ref, &up->ref, sizeof(up->ref)) ||
> +		copy_from_user(&kp->rect, &up->rect, sizeof(up->rect)) ||
> +		get_user(tmp, &up->matrix) ||
> +		copy_from_user(kp->reserved, up->reserved, sizeof(kp->reserved)))
> +			return -EFAULT;

A bit of nit-picking here, the return is aligned too far right according to 
the kernel coding style (same for put_v4l2_matrix32() below).

> +	kp->matrix = compat_ptr(tmp);
> +	return 0;
> +}
> +
> +static int put_v4l2_matrix32(struct v4l2_matrix *kp, struct v4l2_matrix32
> __user *up)
> +{
> +	u32 tmp = (u32)((unsigned long)kp->matrix);
> +
> +	if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_matrix32)) ||
> +		put_user(kp->type, &up->type) ||
> +		copy_to_user(&kp->ref, &up->ref, sizeof(kp->ref)) ||
> +		copy_to_user(&kp->rect, &up->rect, sizeof(kp->rect)) ||
> +		put_user(tmp, &up->matrix) ||

Given that drivers shouldn't be allowed to modify the matrix pointer, could we 
get rid of the put_user() here as a small optimization ? The same could be 
done for all read-only (from a driver point of view) fields in the various 
put_v4l2_* functions.


> +		copy_to_user(kp->reserved, up->reserved, sizeof(kp->reserved)))
> +			return -EFAULT;
> +	return 0;
> +}
> 
>  #define VIDIOC_G_FMT32		_IOWR('V',  4, struct v4l2_format32)
>  #define VIDIOC_S_FMT32		_IOWR('V',  5, struct v4l2_format32)
> @@ -796,6 +834,8 @@ static int put_v4l2_subdev_edid32(struct
> v4l2_subdev_edid *kp, struct v4l2_subde #define	VIDIOC_DQEVENT32	_IOR ('V',
> 89, struct v4l2_event32)
>  #define VIDIOC_CREATE_BUFS32	_IOWR('V', 92, struct v4l2_create_buffers32)
>  #define VIDIOC_PREPARE_BUF32	_IOWR('V', 93, struct v4l2_buffer32)
> +#define VIDIOC_G_MATRIX32	_IOWR('V', 104, struct v4l2_matrix32)
> +#define VIDIOC_S_MATRIX32	_IOWR('V', 105, struct v4l2_matrix32)
> 
>  #define VIDIOC_OVERLAY32	_IOW ('V', 14, s32)
>  #define VIDIOC_STREAMON32	_IOW ('V', 18, s32)
> @@ -817,6 +857,7 @@ static long do_video_ioctl(struct file *file, unsigned
> int cmd, unsigned long ar struct v4l2_event v2ev;
>  		struct v4l2_create_buffers v2crt;
>  		struct v4l2_subdev_edid v2edid;
> +		struct v4l2_matrix v2matrix;
>  		unsigned long vx;
>  		int vi;
>  	} karg;
> @@ -851,6 +892,8 @@ static long do_video_ioctl(struct file *file, unsigned
> int cmd, unsigned long ar case VIDIOC_PREPARE_BUF32: cmd =
> VIDIOC_PREPARE_BUF; break;
>  	case VIDIOC_SUBDEV_G_EDID32: cmd = VIDIOC_SUBDEV_G_EDID; break;
>  	case VIDIOC_SUBDEV_S_EDID32: cmd = VIDIOC_SUBDEV_S_EDID; break;
> +	case VIDIOC_G_MATRIX32: cmd = VIDIOC_G_MATRIX; break;
> +	case VIDIOC_S_MATRIX32: cmd = VIDIOC_S_MATRIX; break;
>  	}
> 
>  	switch (cmd) {
> @@ -922,6 +965,12 @@ static long do_video_ioctl(struct file *file, unsigned
> int cmd, unsigned long ar case VIDIOC_DQEVENT:
>  		compatible_arg = 0;
>  		break;
> +
> +	case VIDIOC_G_MATRIX:
> +	case VIDIOC_S_MATRIX:
> +		err = get_v4l2_matrix32(&karg.v2matrix, up);
> +		compatible_arg = 0;
> +		break;
>  	}
>  	if (err)
>  		return err;
> @@ -994,6 +1043,11 @@ static long do_video_ioctl(struct file *file, unsigned
> int cmd, unsigned long ar case VIDIOC_ENUMINPUT:
>  		err = put_v4l2_input32(&karg.v2i, up);
>  		break;
> +
> +	case VIDIOC_G_MATRIX:
> +	case VIDIOC_S_MATRIX:
> +		err = put_v4l2_matrix32(&karg.v2matrix, up);
> +		break;
>  	}
>  	return err;
>  }
> @@ -1089,6 +1143,7 @@ long v4l2_compat_ioctl32(struct file *file, unsigned
> int cmd, unsigned long arg) case VIDIOC_ENUM_FREQ_BANDS:
>  	case VIDIOC_SUBDEV_G_EDID32:
>  	case VIDIOC_SUBDEV_S_EDID32:
> +	case VIDIOC_QUERY_MATRIX:
>  		ret = do_video_ioctl(file, cmd, arg);
>  		break;
-- 
Regards,

Laurent Pinchart