[alsa-devel] [PATCH v2] ALSA: compress: add support for 32bit calls in a 64bit kernel

[Takashi Iwai]

On Fri, 04 Dec 2015 14:32:33 +0100,
Ravindra Lokhande wrote:
> 
> Compress offload does not support ioctl calls from a 32bit userspace
> in a 64 bit kernel. This patch adds support for ioctls from a 32bit
> userspace in a 64bit kernel
> 
> Signed-off-by: Ravindra Lokhande <rlokhande at nvidia.com>
> ---
> 
> v1 -> v2: use compat_ptr to convert 32 bit address to 64 bit pointer
> 
>  sound/core/compress_offload.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c
> index b123c42..4c156a7 100644
> --- a/sound/core/compress_offload.c
> +++ b/sound/core/compress_offload.c
> @@ -847,6 +847,15 @@ static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
>  	return retval;
>  }
>  
> +/* support of 32bit userspace on 64bit platforms */
> +#ifdef CONFIG_COMPAT
> +static long snd_compr_ioctl_compat(struct file *file, unsigned int cmd,
> +						unsigned long arg)
> +{
> +	return snd_compr_ioctl(file, cmd, (unsigned long)compat_ptr(arg));

You need to include <linux/compat.h> for this macro.


Takashi

> +}
> +#endif
> +
>  static const struct file_operations snd_compr_file_ops = {
>  		.owner =	THIS_MODULE,
>  		.open =		snd_compr_open,
> @@ -854,6 +863,9 @@ static const struct file_operations snd_compr_file_ops = {
>  		.write =	snd_compr_write,
>  		.read =		snd_compr_read,
>  		.unlocked_ioctl = snd_compr_ioctl,
> +#ifdef CONFIG_COMPAT
> +		.compat_ioctl = snd_compr_ioctl_compat,
> +#endif
>  		.mmap =		snd_compr_mmap,
>  		.poll =		snd_compr_poll,
>  };
> -- 
> 2.1.4
> 
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