From a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 16 Oct 2012 13:05:59 +0200 Subject: ALSA: Add a reference counter to card instance For more strict protection for wild disconnections, a refcount is introduced to the card instance, and let it up/down when an object is referred via snd_lookup_*() in the open ops. The free-after-last-close check is also changed to check this refcount instead of the empty list, too. Reported-by: Matthieu CASTET Cc: Signed-off-by: Takashi Iwai --- sound/core/oss/pcm_oss.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'sound/core/oss/pcm_oss.c') diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index 08fde0060fd..2529e01538e 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -2457,6 +2457,8 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file) __error2: snd_card_file_remove(pcm->card, file); __error1: + if (pcm) + snd_card_unref(pcm->card); return err; } -- cgit v1.2.3-70-g09d2 From 0914f7961babbf28aaa2f19b453951fb4841c03f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 16 Oct 2012 16:43:39 +0200 Subject: ALSA: Avoid endless sleep after disconnect When disconnect callback is called, each component should wake up sleepers and check card->shutdown flag for avoiding the endless sleep blocking the proper resource release. Cc: Signed-off-by: Takashi Iwai --- sound/core/control.c | 2 ++ sound/core/hwdep.c | 7 +++++++ sound/core/oss/pcm_oss.c | 4 ++++ sound/core/pcm.c | 6 +++++- sound/core/pcm_native.c | 8 ++++++++ sound/core/rawmidi.c | 20 ++++++++++++++++++++ 6 files changed, 46 insertions(+), 1 deletion(-) (limited to 'sound/core/oss/pcm_oss.c') diff --git a/sound/core/control.c b/sound/core/control.c index 9768a3963c8..8c7c2c9bba6 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -1437,6 +1437,8 @@ static ssize_t snd_ctl_read(struct file *file, char __user *buffer, spin_unlock_irq(&ctl->read_lock); schedule(); remove_wait_queue(&ctl->change_sleep, &wait); + if (ctl->card->shutdown) + return -ENODEV; if (signal_pending(current)) return -ERESTARTSYS; spin_lock_irq(&ctl->read_lock); diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c index 53a6ba5ad61..3f7f6628cf7 100644 --- a/sound/core/hwdep.c +++ b/sound/core/hwdep.c @@ -131,6 +131,10 @@ static int snd_hwdep_open(struct inode *inode, struct file * file) mutex_unlock(&hw->open_mutex); schedule(); mutex_lock(&hw->open_mutex); + if (hw->card->shutdown) { + err = -ENODEV; + break; + } if (signal_pending(current)) { err = -ERESTARTSYS; break; @@ -462,12 +466,15 @@ static int snd_hwdep_dev_disconnect(struct snd_device *device) mutex_unlock(®ister_mutex); return -EINVAL; } + mutex_lock(&hwdep->open_mutex); + wake_up(&hwdep->open_wait); #ifdef CONFIG_SND_OSSEMUL if (hwdep->ossreg) snd_unregister_oss_device(hwdep->oss_type, hwdep->card, hwdep->device); #endif snd_unregister_device(SNDRV_DEVICE_TYPE_HWDEP, hwdep->card, hwdep->device); list_del_init(&hwdep->list); + mutex_unlock(&hwdep->open_mutex); mutex_unlock(®ister_mutex); return 0; } diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index 2529e01538e..f337b66a020 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -2441,6 +2441,10 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file) mutex_unlock(&pcm->open_mutex); schedule(); mutex_lock(&pcm->open_mutex); + if (pcm->card->shutdown) { + err = -ENODEV; + break; + } if (signal_pending(current)) { err = -ERESTARTSYS; break; diff --git a/sound/core/pcm.c b/sound/core/pcm.c index 993b2405fdf..030102caeee 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -1087,12 +1087,16 @@ static int snd_pcm_dev_disconnect(struct snd_device *device) goto unlock; mutex_lock(&pcm->open_mutex); + wake_up(&pcm->open_wait); list_del_init(&pcm->list); for (cidx = 0; cidx < 2; cidx++) for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) { snd_pcm_stream_lock_irq(substream); - if (substream->runtime) + if (substream->runtime) { substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED; + wake_up(&substream->runtime->sleep); + wake_up(&substream->runtime->tsleep); + } snd_pcm_stream_unlock_irq(substream); } list_for_each_entry(notify, &snd_pcm_notify_list, list) { diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 48c6a70ad69..6e8872de5ba 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1518,6 +1518,10 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream, down_read(&snd_pcm_link_rwsem); snd_pcm_stream_lock_irq(substream); remove_wait_queue(&to_check->sleep, &wait); + if (card->shutdown) { + result = -ENODEV; + break; + } if (tout == 0) { if (substream->runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) result = -ESTRPIPE; @@ -2169,6 +2173,10 @@ static int snd_pcm_open(struct file *file, struct snd_pcm *pcm, int stream) mutex_unlock(&pcm->open_mutex); schedule(); mutex_lock(&pcm->open_mutex); + if (pcm->card->shutdown) { + err = -ENODEV; + break; + } if (signal_pending(current)) { err = -ERESTARTSYS; break; diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index 7d4f62ab671..1bb95aeea08 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -424,6 +424,10 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) mutex_unlock(&rmidi->open_mutex); schedule(); mutex_lock(&rmidi->open_mutex); + if (rmidi->card->shutdown) { + err = -ENODEV; + break; + } if (signal_pending(current)) { err = -ERESTARTSYS; break; @@ -995,6 +999,8 @@ static ssize_t snd_rawmidi_read(struct file *file, char __user *buf, size_t coun spin_unlock_irq(&runtime->lock); schedule(); remove_wait_queue(&runtime->sleep, &wait); + if (rfile->rmidi->card->shutdown) + return -ENODEV; if (signal_pending(current)) return result > 0 ? result : -ERESTARTSYS; if (!runtime->avail) @@ -1238,6 +1244,8 @@ static ssize_t snd_rawmidi_write(struct file *file, const char __user *buf, spin_unlock_irq(&runtime->lock); timeout = schedule_timeout(30 * HZ); remove_wait_queue(&runtime->sleep, &wait); + if (rfile->rmidi->card->shutdown) + return -ENODEV; if (signal_pending(current)) return result > 0 ? result : -ERESTARTSYS; if (!runtime->avail && !timeout) @@ -1613,9 +1621,20 @@ static int snd_rawmidi_dev_register(struct snd_device *device) static int snd_rawmidi_dev_disconnect(struct snd_device *device) { struct snd_rawmidi *rmidi = device->device_data; + int dir; mutex_lock(®ister_mutex); + mutex_lock(&rmidi->open_mutex); + wake_up(&rmidi->open_wait); list_del_init(&rmidi->list); + for (dir = 0; dir < 2; dir++) { + struct snd_rawmidi_substream *s; + list_for_each_entry(s, &rmidi->streams[dir].substreams, list) { + if (s->runtime) + wake_up(&s->runtime->sleep); + } + } + #ifdef CONFIG_SND_OSSEMUL if (rmidi->ossreg) { if ((int)rmidi->device == midi_map[rmidi->card->number]) { @@ -1630,6 +1649,7 @@ static int snd_rawmidi_dev_disconnect(struct snd_device *device) } #endif /* CONFIG_SND_OSSEMUL */ snd_unregister_device(SNDRV_DEVICE_TYPE_RAWMIDI, rmidi->card, rmidi->device); + mutex_unlock(&rmidi->open_mutex); mutex_unlock(®ister_mutex); return 0; } -- cgit v1.2.3-70-g09d2 From 8bb4d9ce08b0a92ca174e41d92c180328f86173f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 8 Nov 2012 14:36:18 +0100 Subject: ALSA: Fix card refcount unbalance There are uncovered cases whether the card refcount introduced by the commit a0830dbd isn't properly increased or decreased: - OSS PCM and mixer success paths - When lookup function gets NULL This patch fixes these places. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=50251 Cc: Signed-off-by: Takashi Iwai --- sound/core/oss/mixer_oss.c | 1 + sound/core/oss/pcm_oss.c | 1 + sound/core/pcm_native.c | 6 ++++-- sound/core/sound.c | 2 +- sound/core/sound_oss.c | 2 +- 5 files changed, 8 insertions(+), 4 deletions(-) (limited to 'sound/core/oss/pcm_oss.c') diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c index a9a2e63c022..e8a1d18774b 100644 --- a/sound/core/oss/mixer_oss.c +++ b/sound/core/oss/mixer_oss.c @@ -76,6 +76,7 @@ static int snd_mixer_oss_open(struct inode *inode, struct file *file) snd_card_unref(card); return -EFAULT; } + snd_card_unref(card); return 0; } diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index f337b66a020..4c1cc51772e 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -2454,6 +2454,7 @@ static int snd_pcm_oss_open(struct inode *inode, struct file *file) mutex_unlock(&pcm->open_mutex); if (err < 0) goto __error; + snd_card_unref(pcm->card); return err; __error: diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 6e8872de5ba..f9ddecf2f4c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -2122,7 +2122,8 @@ static int snd_pcm_playback_open(struct inode *inode, struct file *file) pcm = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_PCM_PLAYBACK); err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_PLAYBACK); - snd_card_unref(pcm->card); + if (pcm) + snd_card_unref(pcm->card); return err; } @@ -2135,7 +2136,8 @@ static int snd_pcm_capture_open(struct inode *inode, struct file *file) pcm = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_PCM_CAPTURE); err = snd_pcm_open(file, pcm, SNDRV_PCM_STREAM_CAPTURE); - snd_card_unref(pcm->card); + if (pcm) + snd_card_unref(pcm->card); return err; } diff --git a/sound/core/sound.c b/sound/core/sound.c index 89780c323f1..70ccdab7415 100644 --- a/sound/core/sound.c +++ b/sound/core/sound.c @@ -114,7 +114,7 @@ void *snd_lookup_minor_data(unsigned int minor, int type) mreg = snd_minors[minor]; if (mreg && mreg->type == type) { private_data = mreg->private_data; - if (mreg->card_ptr) + if (private_data && mreg->card_ptr) atomic_inc(&mreg->card_ptr->refcount); } else private_data = NULL; diff --git a/sound/core/sound_oss.c b/sound/core/sound_oss.c index e1d79ee3590..726a49ac972 100644 --- a/sound/core/sound_oss.c +++ b/sound/core/sound_oss.c @@ -54,7 +54,7 @@ void *snd_lookup_oss_minor_data(unsigned int minor, int type) mreg = snd_oss_minors[minor]; if (mreg && mreg->type == type) { private_data = mreg->private_data; - if (mreg->card_ptr) + if (private_data && mreg->card_ptr) atomic_inc(&mreg->card_ptr->refcount); } else private_data = NULL; -- cgit v1.2.3-70-g09d2