ALSA: core: pass audio tstamp config from userspace

Let userspace select audio timestamp config when the
STATUS_EXT ioctl is used, ignore and zero all
other fields
No change for the existing STATUS ioctl, parameters
are treated as read-only.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 14 insertions, 3 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index b03a638b420c..72323a8c35c8 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -753,12 +753,21 @@ int snd_pcm_status(struct snd_pcm_substream *substream,
 }
 
 static int snd_pcm_status_user(struct snd_pcm_substream *substream,
-                               struct snd_pcm_status __user * _status)
+                               struct snd_pcm_status __user * _status,
+                               bool ext)
 {
         struct snd_pcm_status status;
         int res;
-        
+
         memset(&status, 0, sizeof(status));
+        /*
+         * with extension, parameters are read/write,
+         * get audio_tstamp_data from user,
+         * ignore rest of status structure
+         */
+        if (ext && get_user(status.audio_tstamp_data,
+                                (u32 __user *)(&_status->audio_tstamp_data)))
+                return -EFAULT;
         res = snd_pcm_status(substream, &status);
         if (res < 0)
                 return res;
@@ -2723,7 +2732,9 @@ static int snd_pcm_common_ioctl1(struct file *file,
         case SNDRV_PCM_IOCTL_SW_PARAMS:
                 return snd_pcm_sw_params_user(substream, arg);
         case SNDRV_PCM_IOCTL_STATUS:
-                return snd_pcm_status_user(substream, arg);
+                return snd_pcm_status_user(substream, arg, false);
+        case SNDRV_PCM_IOCTL_STATUS_EXT:
+                return snd_pcm_status_user(substream, arg, true);
         case SNDRV_PCM_IOCTL_CHANNEL_INFO:
                 return snd_pcm_channel_info_user(substream, arg);
         case SNDRV_PCM_IOCTL_PREPARE: