linux.git/sound/core/seq/seq_clientmgr.c, branch v4.9

ALSA: seq: fix to copy from/to user space

2016-09-13T13:45:29+00:00

When checking value of request for copy operation, current implementation
compares shifted value to macros, while these macros are already shifted.
As a result, it never performs to copy from/to user space.

This commit fixes the bug.

Fixes: 8ce8eb601c71('ALSA: seq: add an alternative way to handle ioctl requests'
Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: seq: initialize whole fields of automatic variable with union type

2016-08-31T12:09:05+00:00

Currently, automatic variable of 'union ioctl_arg' type is initialized
by designated initialization. Although, the actual effect is interpretation
of early element of int type and initialization of 'int pversion'.
Therefore the first field corresponding to int type is initialized to zero.
This is against my expectation to initialize whole fields.

This commit uses memset() to initialize the variable, instead of designated
initialization.

Fixes: 04a56dd8ed0d ('ALSA: seq: change ioctl command operation to get data in kernel space')
Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: seq: obsolete change of address limit

2016-08-22T09:11:05+00:00

Former commits change existent functions so that they don't handle data in
kernel space. Copying from/to userspace is done outside of the functions,
thus no need to change address limit of running task.

This commit obsoletes get_fs()/set_fs() and applies corresponding changes.

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

ALSA: seq: change ioctl command operation to get data in kernel space

2016-08-22T09:11:04+00:00

In previous commit, a new table for functions with data in kernel space
is added to replace current table.

This commit changes existent functions to fit the table. These functions
are added to the new table and removed from the old table.

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

ALSA: seq: add an alternative way to handle ioctl requests

2016-08-22T09:11:03+00:00

ALSA sequencer is designed with two types of clients; application and
kernel. Operations for each ioctl command should handle data in both of
user space and kernel space, while current implementation just allows them
to handle data in user space. Data in kernel space is handled with change
of address limit of running tasks.

This commit adds a new table to map ioctl commands to corresponding
functions. The functions get data in kernel space. Helper functions to
operate kernel and application clients seek entries from the table.
Especially, the helper function for application is responsible for coping
from user space to kernel space or vise versa.

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

ALSA: seq: add documentation for snd_seq_kernel_client_ctl

2016-08-22T09:11:02+00:00

This kernel API is used by kernel implementation. Currently, it's used for
kernel clients of ALSA sequencer, while it can be used for application
clients. The difference is just on address spaces of argument. In short,
this kernel API can be available for application client with data in kernel
space.

This commit adds a document about this.

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

ALSA: seq: Provide card number / PID via sequencer client info

2016-03-08T09:52:52+00:00

rawmidi devices expose the card number via IOCTLs, which allows to
find the corresponding device in sysfs.

The sequencer provides no identifing data. Chromium works around this
issue by scanning rawmidi as well as sequencer devices and matching
them by using assumtions, how the kernel register sequencer devices.

This changes adds support for exposing the card number for kernel clients
as well as the PID for user client.

The minor of the API version is changed to distinguish between the zero
initialised reserved field and card number 0.

[minor coding style fixes by tiwai]

Signed-off-by: Martin Koegler 
Acked-by: Clemens Ladisch 
Signed-off-by: Takashi Iwai

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

2016-02-03T13:51:51+00:00

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 
Cc: 
Signed-off-by: Takashi Iwai

ALSA: seq: Fix missing NULL check at remove_events ioctl

2016-01-12T16:21:48+00:00

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 
Cc: 
Signed-off-by: Takashi Iwai

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