Re: [PATCH 07/10] ALSA: rme96: Return error code in PCM copy ops

[Knut Petersen <Knut_Petersen@t-online.de>]

On 29.10.2013 17:00, Takashi Iwai wrote:
> Just pass the error code returned from copy_from_user_toio() and
> copy_to_user_fromio() helpers.
>
> Spotted by coverity CID 114119.
>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>   sound/pci/rme96.c | 10 ++++------
>   1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/sound/pci/rme96.c b/sound/pci/rme96.c
> index bb9ebc5543d7..0236363c301f 100644
> --- a/sound/pci/rme96.c
> +++ b/sound/pci/rme96.c
> @@ -350,9 +350,8 @@ snd_rme96_playback_copy(struct snd_pcm_substream *substream,
>   	struct rme96 *rme96 = snd_pcm_substream_chip(substream);
>   	count <<= rme96->playback_frlog;
>   	pos <<= rme96->playback_frlog;
> -	copy_from_user_toio(rme96->iobase + RME96_IO_PLAY_BUFFER + pos, src,
> -			    count);
> -	return 0;
> +	return copy_from_user_toio(rme96->iobase + RME96_IO_PLAY_BUFFER + pos, src,
> +				   count);

Under which circumstances could copy_from_user_toio() fail?
>   }
>   
>   static int
> @@ -365,9 +364,8 @@ snd_rme96_capture_copy(struct snd_pcm_substream *substream,
>   	struct rme96 *rme96 = snd_pcm_substream_chip(substream);
>   	count <<= rme96->capture_frlog;
>   	pos <<= rme96->capture_frlog;
> -	copy_to_user_fromio(dst, rme96->iobase + RME96_IO_REC_BUFFER + pos,
> -			    count);
> -        return 0;
> +	return copy_to_user_fromio(dst, rme96->iobase + RME96_IO_REC_BUFFER + pos,
> +				   count);
When will copy_to_user_fromio() fail?


cu,
  Knut
>   }
>   
>   /*