linux-toradex.git/sound/core/seq/seq_clientmgr.c, branch v4.4.2

ALSA: seq: Fix lockdep warnings due to double mutex locks

2016-02-17T20:30:59+00:00

commit 7f0973e973cd74aa40747c9d38844560cd184ee8 upstream.

The port subscription code uses double mutex locks for source and
destination ports, and this may become racy once when wrongly set up.
It leads to lockdep warning splat, typically triggered by fuzzer like
syzkaller, although the actual deadlock hasn't been seen, so far.

This patch simplifies the handling by reducing to two single locks, so
that no lockdep warning will be trigger any longer.

By splitting to two actions, a still-in-progress element shall be
added in one list while handling another.  For ignoring this element,
a new check is added in deliver_to_subscribers().

Along with it, the code to add/remove the subscribers list element was
cleaned up and refactored.

BugLink: http://lkml.kernel.org/r/CACT4Y+aKQXV7xkBW9hpQbzaDO7LrUvohxWh-UwMxXjDy-yBD=A@mail.gmail.com
Reported-by: Dmitry Vyukov 
Tested-by: Dmitry Vyukov 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: seq: Fix missing NULL check at remove_events ioctl

2016-01-31T19:28:55+00:00

commit 030e2c78d3a91dd0d27fef37e91950dde333eba1 upstream.

snd_seq_ioctl_remove_events() calls snd_seq_fifo_clear()
unconditionally even if there is no FIFO assigned, and this leads to
an Oops due to NULL dereference.  The fix is just to add a proper NULL
check.

Reported-by: Dmitry Vyukov 
Tested-by: Dmitry Vyukov 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: replace CONFIG_PROC_FS with CONFIG_SND_PROC_FS

2015-05-27T19:25:19+00:00

We may disable proc fs only for sound part, to reduce ALSA
memory footprint. So add CONFIG_SND_PROC_FS and replace the
old CONFIG_PROC_FSs in alsa code.

With sound proc fs disabled, we can save about 9KB memory
size on X86_64 platform.

Signed-off-by: Jie Yang 
Reviewed-by: Mark Brown 
Signed-off-by: Takashi Iwai

ALSA: seq: fill client ID in return value of pool operation

2015-04-11T07:11:19+00:00

The returned value of 'get/seq client pool' operation has zeroed value
for its client ID, against requested client ID.

This commit fix the bug by filling it with index value of referred
client object.

Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

Merge branch 'topic/snd-device' into for-next

2015-02-03T16:57:16+00:00

ALSA: Simplify snd_device_register() variants

2015-02-02T16:01:26+00:00

Now that all callers have been replaced with
snd_device_register_for_dev(), let's drop the obsolete device
registration code and concentrate only on the code handling struct
device directly.  That said,

- remove the old snd_device_register(),
- rename snd_device_register_for_dev() with snd_device_register(),
- drop superfluous arguments from snd_device_register(),
- change snd_unregister_device() to pass the device pointer directly

Reviewed-by: Jaroslav Kysela 
Signed-off-by: Takashi Iwai

ALSA: seq: Handle the device directly

2015-02-02T13:42:45+00:00

Like the previous change for the timer device, this patch changes the
device management for the ALSA sequencer device using the struct
device directly.

Reviewed-by: Jaroslav Kysela 
Signed-off-by: Takashi Iwai

ALSA: seq: remove unused callback_all field

2015-01-26T12:56:58+00:00

Signed-off-by: Clemens Ladisch 
Signed-off-by: Takashi Iwai

ALSA: seq: correctly report maximum number of ports

2015-01-26T12:54:39+00:00

Due to SNDRV_SEQ_ADDRESS_BROADCAST, not all 256 port number values can
be used.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Takashi Iwai

ALSA: seq: Continue broadcasting events to ports if one of them fails

2014-06-04T15:30:58+00:00

Sometimes PORT_EXIT messages are lost when a process is exiting.
This happens if you subscribe to the announce port with client A,
then subscribe to the announce port with client B, then kill client A.
Client B will not see the PORT_EXIT message because client A's port is
closing and is earlier in the announce port subscription list. The
for each loop will try to send the announcement to client A and fail,
then will stop trying to broadcast to other ports. Killing B works fine
since the announcement will already have gone to A. The CLIENT_EXIT
message does not get lost.

How to reproduce problem:

*** termA
$ aseqdump -p 0:1
  0:1   Port subscribed            0:1 -> 128:0

*** termB
$ aseqdump -p 0:1

*** termA
  0:1   Client start               client 129
  0:1   Port start                 129:0
  0:1   Port subscribed            0:1 -> 129:0

*** termB
  0:1   Port subscribed            0:1 -> 129:0

*** termA
^C

*** termB
  0:1   Client exit                client 128
   <--- expected Port exit as well (before client exit)

Signed-off-by: Adam Goode 
Signed-off-by: Takashi Iwai