From 40edba667959559aa4385a5ec047420fcfeb5f03 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 7 Nov 2012 12:44:12 +0100 Subject: ALSA: Add a reference counter to card instance commit a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 upstream. 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 Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/rawmidi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'sound/core/rawmidi.c') diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index cbbed0d..69935c0 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -394,8 +394,10 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) if (rmidi == NULL) return -ENODEV; - if (!try_module_get(rmidi->card->module)) + if (!try_module_get(rmidi->card->module)) { + snd_card_unref(rmidi->card); return -ENXIO; + } mutex_lock(&rmidi->open_mutex); card = rmidi->card; @@ -455,6 +457,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) #endif file->private_data = rawmidi_file; mutex_unlock(&rmidi->open_mutex); + snd_card_unref(rmidi->card); return 0; __error: @@ -462,6 +465,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) __error_card: mutex_unlock(&rmidi->open_mutex); module_put(rmidi->card->module); + snd_card_unref(rmidi->card); return err; } -- cgit v1.1 From 8a7173c58c8a1e25d7b2d572f045da837bb373bf Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 7 Nov 2012 12:44:13 +0100 Subject: ALSA: Avoid endless sleep after disconnect commit 0914f7961babbf28aaa2f19b453951fb4841c03f upstream. 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. Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/rawmidi.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'sound/core/rawmidi.c') diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index 69935c0..cd2c134 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -439,6 +439,10 @@ 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; @@ -1010,6 +1014,8 @@ 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) @@ -1253,6 +1259,8 @@ 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) @@ -1628,9 +1636,20 @@ 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]) { @@ -1645,6 +1664,7 @@ 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 v1.1