diff options
| -rw-r--r-- | sound/core/oss/pcm_oss.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index 0e73d03b30e3..ebc9fdfe64df 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -835,7 +835,8 @@ static int choose_rate(struct snd_pcm_substream *substream, return snd_pcm_hw_param_near(substream, params, SNDRV_PCM_HW_PARAM_RATE, best_rate, NULL); } -static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream) +static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream, + bool trylock) { struct snd_pcm_runtime *runtime = substream->runtime; struct snd_pcm_hw_params *params, *sparams; @@ -849,7 +850,10 @@ static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream) struct snd_mask sformat_mask; struct snd_mask mask; - if (mutex_lock_interruptible(&runtime->oss.params_lock)) + if (trylock) { + if (!(mutex_trylock(&runtime->oss.params_lock))) + return -EAGAIN; + } else if (mutex_lock_interruptible(&runtime->oss.params_lock)) return -EINTR; sw_params = kzalloc(sizeof(*sw_params), GFP_KERNEL); params = kmalloc(sizeof(*params), GFP_KERNEL); @@ -1092,7 +1096,7 @@ static int snd_pcm_oss_get_active_substream(struct snd_pcm_oss_file *pcm_oss_fil if (asubstream == NULL) asubstream = substream; if (substream->runtime->oss.params) { - err = snd_pcm_oss_change_params(substream); + err = snd_pcm_oss_change_params(substream, false); if (err < 0) return err; } @@ -1132,7 +1136,7 @@ static int snd_pcm_oss_make_ready(struct snd_pcm_substream *substream) return 0; runtime = substream->runtime; if (runtime->oss.params) { - err = snd_pcm_oss_change_params(substream); + err = snd_pcm_oss_change_params(substream, false); if (err < 0) return err; } @@ -2163,7 +2167,7 @@ static int snd_pcm_oss_get_space(struct snd_pcm_oss_file *pcm_oss_file, int stre runtime = substream->runtime; if (runtime->oss.params && - (err = snd_pcm_oss_change_params(substream)) < 0) + (err = snd_pcm_oss_change_params(substream, false)) < 0) return err; info.fragsize = runtime->oss.period_bytes; @@ -2804,7 +2808,12 @@ static int snd_pcm_oss_mmap(struct file *file, struct vm_area_struct *area) return -EIO; if (runtime->oss.params) { - if ((err = snd_pcm_oss_change_params(substream)) < 0) + /* use mutex_trylock() for params_lock for avoiding a deadlock + * between mmap_sem and params_lock taken by + * copy_from/to_user() in snd_pcm_oss_write/read() + */ + err = snd_pcm_oss_change_params(substream, true); + if (err < 0) return err; } #ifdef CONFIG_SND_PCM_OSS_PLUGINS |