Fix races at PCM disconnection: - while a PCM device is being opened or closed - while the PCM state is being changed without lock in prepare, hw_params, hw_free ops
Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/core/pcm.c | 7 ++++++- sound/core/pcm_native.c | 16 ++++++++++++---- 2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/sound/core/pcm.c b/sound/core/pcm.c index f299194..993b240 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -1086,11 +1086,15 @@ static int snd_pcm_dev_disconnect(struct snd_device *device) if (list_empty(&pcm->list)) goto unlock;
+ mutex_lock(&pcm->open_mutex); list_del_init(&pcm->list); for (cidx = 0; cidx < 2; cidx++) - for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) + for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) { + snd_pcm_stream_lock_irq(substream); if (substream->runtime) substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED; + snd_pcm_stream_unlock_irq(substream); + } list_for_each_entry(notify, &snd_pcm_notify_list, list) { notify->n_disconnect(pcm); } @@ -1110,6 +1114,7 @@ static int snd_pcm_dev_disconnect(struct snd_device *device) pcm->streams[cidx].chmap_kctl = NULL; } } + mutex_unlock(&pcm->open_mutex); unlock: mutex_unlock(®ister_mutex); return 0; diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 53b5ada..f030643 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -369,6 +369,14 @@ static int period_to_usecs(struct snd_pcm_runtime *runtime) return usecs; }
+static void snd_pcm_set_state(struct snd_pcm_substream *substream, int state) +{ + snd_pcm_stream_lock_irq(substream); + if (substream->runtime->status->state != SNDRV_PCM_STATE_DISCONNECTED) + substream->runtime->status->state = state; + snd_pcm_stream_unlock_irq(substream); +} + static int snd_pcm_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { @@ -452,7 +460,7 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, runtime->boundary *= 2;
snd_pcm_timer_resolution_change(substream); - runtime->status->state = SNDRV_PCM_STATE_SETUP; + snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);
if (pm_qos_request_active(&substream->latency_pm_qos_req)) pm_qos_remove_request(&substream->latency_pm_qos_req); @@ -464,7 +472,7 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, /* hardware might be unusable from this time, so we force application to retry to set the correct hardware parameter settings */ - runtime->status->state = SNDRV_PCM_STATE_OPEN; + snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN); if (substream->ops->hw_free != NULL) substream->ops->hw_free(substream); return err; @@ -512,7 +520,7 @@ static int snd_pcm_hw_free(struct snd_pcm_substream *substream) return -EBADFD; if (substream->ops->hw_free) result = substream->ops->hw_free(substream); - runtime->status->state = SNDRV_PCM_STATE_OPEN; + snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN); pm_qos_remove_request(&substream->latency_pm_qos_req); return result; } @@ -1320,7 +1328,7 @@ static void snd_pcm_post_prepare(struct snd_pcm_substream *substream, int state) { struct snd_pcm_runtime *runtime = substream->runtime; runtime->control->appl_ptr = runtime->status->hw_ptr; - runtime->status->state = SNDRV_PCM_STATE_PREPARED; + snd_pcm_set_state(substream, SNDRV_PCM_STATE_PREPARED); }
static struct action_ops snd_pcm_action_prepare = {