diff options
| author | Takashi Iwai <tiwai@suse.de> | 2012-12-03 11:12:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-11 09:03:36 -0800 |
| commit | 5a6400c991f269eaab5a175d8b7c656155a74129 (patch) | |
| tree | 98bd2050b1f3c827fc464ba198699117aa87a394 | |
| parent | 51afc625ccd2e38f76f690ccce93e11a21d9543b (diff) | |
ALSA: usb-audio: Avoid autopm calls after disconnection
commit 59866da9e4ae54819e3c4e0a8f426bdb0c2ef993 upstream.
Add a similar protection against the disconnection race and the
invalid use of usb instance after disconnection, as well as we've done
for the USB audio PCM.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=51201
Reviewd-by: Clemens Ladisch <clemens@ladisch.de>
Tested-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | sound/usb/midi.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/sound/usb/midi.c b/sound/usb/midi.c index a0fe5dd3057..0ee3d39627a 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -115,6 +115,7 @@ struct snd_usb_midi { struct list_head list; struct timer_list error_timer; spinlock_t disc_lock; + struct rw_semaphore disc_rwsem; struct mutex mutex; u32 usb_id; int next_midi_device; @@ -1021,6 +1022,12 @@ static void substream_open(struct snd_rawmidi_substream *substream, int open) struct snd_usb_midi* umidi = substream->rmidi->private_data; struct snd_kcontrol *ctl; + down_read(&umidi->disc_rwsem); + if (umidi->disconnected) { + up_read(&umidi->disc_rwsem); + return; + } + mutex_lock(&umidi->mutex); if (open) { if (umidi->opened++ == 0 && umidi->roland_load_ctl) { @@ -1039,6 +1046,7 @@ static void substream_open(struct snd_rawmidi_substream *substream, int open) } } mutex_unlock(&umidi->mutex); + up_read(&umidi->disc_rwsem); } static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream) @@ -1059,8 +1067,15 @@ static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream) snd_BUG(); return -ENXIO; } + + down_read(&umidi->disc_rwsem); + if (umidi->disconnected) { + up_read(&umidi->disc_rwsem); + return -ENODEV; + } err = usb_autopm_get_interface(umidi->iface); port->autopm_reference = err >= 0; + up_read(&umidi->disc_rwsem); if (err < 0 && err != -EACCES) return -EIO; substream->runtime->private_data = port; @@ -1075,8 +1090,10 @@ static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream) struct usbmidi_out_port *port = substream->runtime->private_data; substream_open(substream, 0); - if (port->autopm_reference) + down_read(&umidi->disc_rwsem); + if (!umidi->disconnected && port->autopm_reference) usb_autopm_put_interface(umidi->iface); + up_read(&umidi->disc_rwsem); return 0; } @@ -1386,9 +1403,12 @@ void snd_usbmidi_disconnect(struct list_head* p) * a timer may submit an URB. To reliably break the cycle * a flag under lock must be used */ + down_write(&umidi->disc_rwsem); spin_lock_irq(&umidi->disc_lock); umidi->disconnected = 1; spin_unlock_irq(&umidi->disc_lock); + up_write(&umidi->disc_rwsem); + for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) { struct snd_usb_midi_endpoint* ep = &umidi->endpoints[i]; if (ep->out) @@ -2100,6 +2120,7 @@ int snd_usbmidi_create(struct snd_card *card, umidi->usb_protocol_ops = &snd_usbmidi_standard_ops; init_timer(&umidi->error_timer); spin_lock_init(&umidi->disc_lock); + init_rwsem(&umidi->disc_rwsem); mutex_init(&umidi->mutex); umidi->usb_id = USB_ID(le16_to_cpu(umidi->dev->descriptor.idVendor), le16_to_cpu(umidi->dev->descriptor.idProduct)); |