Re: [PATCH v2 1/5] media: Determine early whether an IOCTL is supported

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

Hi Sakari,

Thank you for the patch.

On Wednesday 04 May 2016 14:20:51 Sakari Ailus wrote:
> Preparation for refactoring media IOCTL handling to unify common parts.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/media/media-device.c | 52 ++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 49 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 898a3cf..c24149d 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -419,13 +419,33 @@ static long media_device_get_topology(struct
> media_device *mdev, return 0;
>  }
> 
> -static long media_device_ioctl(struct file *filp, unsigned int cmd,
> -			       unsigned long arg)
> +#define MEDIA_IOC(__cmd) \
> +	[_IOC_NR(MEDIA_IOC_##__cmd)] = { .cmd = MEDIA_IOC_##__cmd }
> +
> +/* the table is indexed by _IOC_NR(cmd) */
> +struct media_ioctl_info {
> +	unsigned int cmd;
> +};
> +
> +static inline long is_valid_ioctl(const struct media_ioctl_info *info,
> +				  unsigned int len, unsigned int cmd)
> +{
> +	return (_IOC_NR(cmd) >= len
> +		|| info[_IOC_NR(cmd)].cmd != cmd) ? -ENOIOCTLCMD : 0;
> +}
> +
> +static long __media_device_ioctl(
> +	struct file *filp, unsigned int cmd, void __user *arg,
> +	const struct media_ioctl_info *info_array, unsigned int info_array_len)
>  {
>  	struct media_devnode *devnode = media_devnode_data(filp);
>  	struct media_device *dev = to_media_device(devnode);
>  	long ret;
> 
> +	ret = is_valid_ioctl(info_array, info_array_len, cmd);
> +	if (ret)
> +		return ret;
> +
>  	mutex_lock(&dev->graph_mutex);
>  	switch (cmd) {
>  	case MEDIA_IOC_DEVICE_INFO:
> @@ -461,6 +481,22 @@ static long media_device_ioctl(struct file *filp,
> unsigned int cmd, return ret;
>  }
> 
> +static const struct media_ioctl_info ioctl_info[] = {
> +	MEDIA_IOC(DEVICE_INFO),
> +	MEDIA_IOC(ENUM_ENTITIES),
> +	MEDIA_IOC(ENUM_LINKS),
> +	MEDIA_IOC(SETUP_LINK),
> +	MEDIA_IOC(G_TOPOLOGY),
> +};
> +
> +static long media_device_ioctl(struct file *filp, unsigned int cmd,
> +			       unsigned long arg)
> +{
> +	return __media_device_ioctl(
> +		filp, cmd, (void __user *)arg,
> +		ioctl_info, ARRAY_SIZE(ioctl_info));
> +}
> +
>  #ifdef CONFIG_COMPAT
> 
>  struct media_links_enum32 {
> @@ -491,6 +527,14 @@ static long media_device_enum_links32(struct
> media_device *mdev,
> 
>  #define MEDIA_IOC_ENUM_LINKS32		_IOWR('|', 0x02, struct 
media_links_enum32)
> 
> +static const struct media_ioctl_info compat_ioctl_info[] = {
> +	MEDIA_IOC(DEVICE_INFO),
> +	MEDIA_IOC(ENUM_ENTITIES),
> +	MEDIA_IOC(ENUM_LINKS32),
> +	MEDIA_IOC(SETUP_LINK),
> +	MEDIA_IOC(G_TOPOLOGY),
> +};
> +
>  static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
>  				      unsigned long arg)
>  {
> @@ -503,7 +547,9 @@ static long media_device_compat_ioctl(struct file *filp,
> unsigned int cmd, case MEDIA_IOC_ENUM_ENTITIES:
>  	case MEDIA_IOC_SETUP_LINK:
>  	case MEDIA_IOC_G_TOPOLOGY:
> -		return media_device_ioctl(filp, cmd, arg);
> +		return __media_device_ioctl(
> +			filp, cmd, (void __user *)arg,
> +			compat_ioctl_info, ARRAY_SIZE(compat_ioctl_info));
> 
>  	case MEDIA_IOC_ENUM_LINKS32:
>  		mutex_lock(&dev->graph_mutex);

-- 
Regards,

Laurent Pinchart