Commit Graph

133 Commits

Author SHA1 Message Date
Takashi Iwai
bc41a7228c ALSA: pcm: Don't embed device
So far we use the embedded struct device for each PCM substreams in
struct snd_pcm.  This may result in UAF when the delayed kobj release
is used; each corresponding struct device is still accessed at the
(delayed) device release, while the snd_pcm object may be already
gone.

As a workaround, detach the struct device from the snd_pcm object by
allocating via the new snd_device_alloc() helper.

A caveat is that we store the PCM substream pointer to drvdata since
the device resume and others require the access to it.

This patch is based on the fix Curtis posted initially.  In this
patch, the changes are split and use the new helper function instead.

Link: https://lore.kernel.org/r/20230801171928.1460120-1-cujomalainey@chromium.org
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Tested-by: Curtis Malainey <cujomalainey@chromium.org>
Link: https://lore.kernel.org/r/20230816160252.23396-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-08-17 09:23:45 +02:00
Takashi Iwai
192c4cccd0 ALSA: control: Take controls_rwsem lock in snd_ctl_remove()
So far, snd_ctl_remove() requires its caller to take
card->controls_rwsem manually before the call for avoiding possible
races.  However, many callers don't care and miss the locking.

Basically it's cumbersome and error-prone to enforce it to each
caller.  Moreover, card->controls_rwsem is a field that should be used
only by internal or proper helpers, and it's not to be touched at
random external places.

This patch is an attempt to make those calls more consistent: now
snd_ctl_remove() takes the card->controls_rwsem internally, just like
other API functions for kctls.  Since a few callers already take the
controls_rwsem locks, the patch removes those locks at the same time,
too.

Link: https://lore.kernel.org/r/20230718141304.1032-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-07-20 10:01:27 +02:00
Takashi Iwai
f0061c18c1 ALSA: pcm: Avoid reference to status->state
In the PCM core and driver code, there are lots place referring to the
current PCM state via runtime->status->state.  This patch introduced a
local PCM state in runtime itself and replaces those references with
runtime->state.  It has improvements in two aspects:

- The reduction of a indirect access leads to more code optimization

- It avoids a possible (unexpected) modification of the state via mmap
  of the status record

The status->state is updated together with runtime->state, so that
user-space can still read the current state via mmap like before,
too.

This patch touches only the ALSA core code.  The changes in each
driver will follow in later patches.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220926135558.26580-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-09-27 08:44:05 +02:00
Takashi Iwai
01043e3e14 ALSA: pcm: Replace sprintf() with sysfs_emit()
For sysfs outputs, it's safer to use a new helper, sysfs_emit(),
instead of the raw sprintf() & co.  This patch replaces such a
sprintf() call straightforwardly with the new helper.

Link: https://lore.kernel.org/r/20220801165639.26030-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-08-02 16:03:46 +02:00
Takashi Iwai
96b097091c ALSA: pcm: Use deferred fasync helper
For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from timer API.  Note that
it's merely a workaround.

Reported-by: syzbot+8285e973a41b5aa68902@syzkaller.appspotmail.com
Reported-by: syzbot+669c9abf11a6a011dd09@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220728125945.29533-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-07-29 12:57:11 +02:00
Takashi Iwai
4e2b70673f ALSA: pcm: Fix missing return value comments for kernel docs
Each kernel doc comment expects the definition of the return value in
a proper format.  This patch adds or fixes the missing entries for PCM
API.

Link: https://lore.kernel.org/r/20220713104759.4365-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-07-13 13:42:34 +02:00
Takashi Iwai
bc55cfd571 ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock
syzbot caught a potential deadlock between the PCM
runtime->buffer_mutex and the mm->mmap_lock.  It was brought by the
recent fix to cover the racy read/write and other ioctls, and in that
commit, I overlooked a (hopefully only) corner case that may take the
revert lock, namely, the OSS mmap.  The OSS mmap operation
exceptionally allows to re-configure the parameters inside the OSS
mmap syscall, where mm->mmap_mutex is already held.  Meanwhile, the
copy_from/to_user calls at read/write operations also take the
mm->mmap_lock internally, hence it may lead to a AB/BA deadlock.

A similar problem was already seen in the past and we fixed it with a
refcount (in commit b248371628).  The former fix covered only the
call paths with OSS read/write and OSS ioctls, while we need to cover
the concurrent access via both ALSA and OSS APIs now.

This patch addresses the problem above by replacing the buffer_mutex
lock in the read/write operations with a refcount similar as we've
used for OSS.  The new field, runtime->buffer_accessing, keeps the
number of concurrent read/write operations.  Unlike the former
buffer_mutex protection, this protects only around the
copy_from/to_user() calls; the other codes are basically protected by
the PCM stream lock.  The refcount can be a negative, meaning blocked
by the ioctls.  If a negative value is seen, the read/write aborts
with -EBUSY.  In the ioctl side, OTOH, they check this refcount, too,
and set to a negative value for blocking unless it's already being
accessed.

Reported-by: syzbot+6e5c88838328e99c7e1c@syzkaller.appspotmail.com
Fixes: dca947d4d2 ("ALSA: pcm: Fix races among concurrent read/write and buffer changes")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/000000000000381a0d05db622a81@google.com
Link: https://lore.kernel.org/r/20220330120903.4738-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-03-30 14:29:49 +02:00
Takashi Iwai
92ee3c60ec ALSA: pcm: Fix races among concurrent hw_params and hw_free calls
Currently we have neither proper check nor protection against the
concurrent calls of PCM hw_params and hw_free ioctls, which may result
in a UAF.  Since the existing PCM stream lock can't be used for
protecting the whole ioctl operations, we need a new mutex to protect
those racy calls.

This patch introduced a new mutex, runtime->buffer_mutex, and applies
it to both hw_params and hw_free ioctl code paths.  Along with it, the
both functions are slightly modified (the mmap_count check is moved
into the state-check block) for code simplicity.

Reported-by: Hu Jiahui <kirin.say@gmail.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220322170720.3529-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-03-22 20:56:07 +01:00
Takashi Iwai
5471e9762e ALSA: PCM: Add missing rwsem around snd_ctl_remove() calls
snd_ctl_remove() has to be called with card->controls_rwsem held (when
called after the card instantiation).  This patch add the missing
rwsem calls around it.

Fixes: a8ff48cb70 ("ALSA: pcm: Free chmap at PCM free callback, too")
Link: https://lore.kernel.org/r/20211116071314.15065-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-11-16 08:13:55 +01:00
YueHaibing
e1dc219af7 ALSA: pcm: use DEVICE_ATTR_RO macro
Use DEVICE_ATTR_RO() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20210524120007.39728-1-yuehaibing@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-25 09:00:04 +02:00
Takashi Iwai
8d19b4e0b3 ALSA: pcm: Use for_each_pcm_substream() macro
There are a few places doing the same loop iterating all PCM
substreams belonging to the PCM object.  Introduce a local helper
macro, for_each_pcm_substream(), to simplify the code.

Link: https://lore.kernel.org/r/20210206203656.15959-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-02-08 16:01:01 +01:00
Takashi Iwai
29bb274e94 ALSA: pcm: Call sync_stop at disconnection
The PCM core should perform the sync for the pending stop operations
at disconnection.  Otherwise it may lead to unexpected access.

Currently the old user of sync_stop, USB-audio driver, has its own
sync, so this isn't needed, but it's better to guarantee the sync in
the PCM core level.

This patch adds the missing sync_stop call at PCM disconnection
callback.  It also assures the IRQ sync if it's specified in the
card.  snd_pcm_sync_stop() is slightly modified to be called also for
any PCM substream object now.

Fixes: 1e850beea2 ("ALSA: pcm: Add the support for sync-stop operation")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210206203656.15959-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-02-08 16:00:28 +01:00
Joe Perches
75b1a8f9d6 ALSA: Convert strlcpy to strscpy when return value is unused
strlcpy is deprecated.  see: Documentation/process/deprecated.rst

Change the calls that do not use the strlcpy return value to the
preferred strscpy.

Done with cocci script:

@@
expression e1, e2, e3;
@@

-	strlcpy(
+	strscpy(
	e1, e2, e3);

This cocci script leaves the instances where the return value is
used unchanged.

After this patch, sound/ has 3 uses of strlcpy() that need to be
manually inspected for conversion and changed one day.

$ git grep -w strlcpy sound/
sound/usb/card.c:               len = strlcpy(card->longname, s, sizeof(card->longname));
sound/usb/mixer.c:      return strlcpy(buf, p->name, buflen);
sound/usb/mixer.c:                      return strlcpy(buf, p->names[index], buflen);

Miscellenea:

o Remove trailing whitespace in conversion of sound/core/hwdep.c

Link: https://lore.kernel.org/lkml/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/22b393d1790bb268769d0bab7bacf0866dcb0c14.camel@perches.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-01-08 09:30:05 +01:00
Pierre-Louis Bossart
931522b908 ALSA: core: pcm: simplify locking for timers
Fix sparse warning:

sound/core/pcm.c:999:9: warning: context imbalance in
'snd_pcm_detach_substream' - different lock contexts for basic block

There's no real reason to test the same thing twice, and it's simpler
have linear sequences.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200902212133.30964-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-09-03 09:24:33 +02:00
Takashi Iwai
296a37fd02 ALSA: pcm: Fix superfluous snprintf() usage
show_pcm_class() returns obviously a short string that can't overflow
PAGE_SIZE.  And even if it were to overflow, using snprintf() there is
just wrong, as it doesn't return the correct size.
So simplify with sprintf() instead.

Link: https://lore.kernel.org/r/20200313130223.8908-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-13 15:58:35 +01:00
Takashi Iwai
d03af9b8ea ALSA: pcm: More constifications
Apply const prefix to more possible places: the string tables for PCM
format and co, the table for the PCM type helpers, etc.

Just for minor optimization and no functional changes.

Link: https://lore.kernel.org/r/20200105144823.29547-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-05 16:14:29 +01:00
Takashi Iwai
f15ee210cd ALSA: core: Constify snd_device_ops definitions
Now we may declare const for snd_device_ops definitions, so let's do
it for optimization.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-03 09:23:51 +01:00
Baolin Wang
3ddee7f88a ALSA: Avoid using timespec for struct snd_pcm_status
The struct snd_pcm_status will use 'timespec' type variables to record
timestamp, which is not year 2038 safe on 32bits system.

Userspace will use SNDRV_PCM_IOCTL_STATUS and SNDRV_PCM_IOCTL_STATUS_EXT
as commands to issue ioctl() to fill the 'snd_pcm_status' structure in
userspace. The command number is always defined through _IOR/_IOW/IORW,
so when userspace changes the definition of 'struct timespec' to use
64-bit types, the command number also changes.

Thus in the kernel, we now need to define two versions of each such ioctl
and corresponding ioctl commands to handle 32bit time_t and 64bit time_t
in native mode:
struct snd_pcm_status32 {
	......

	s32 trigger_tstamp_sec;
	s32 trigger_tstamp_nsec;

	......

	s32 audio_tstamp_sec;
	s32 audio_tstamp_nsec;

	......
};

struct snd_pcm_status64 {
	......

	s32 trigger_tstamp_sec;
	s32 trigger_tstamp_nsec;

	......

	s32 audio_tstamp_sec;
	s32 audio_tstamp_nsec;

	......
};

Moreover in compat file, we renamed or introduced new structures to handle
32bit/64bit time_t in compatible mode. The 'struct snd_pcm_status32' and
snd_pcm_status_user32() are used to handle 32bit time_t in compat mode.
'struct compat_snd_pcm_status64' and snd_pcm_status_user_compat64() are used
to handle 64bit time_t.

The implicit padding before timespec is made explicit to avoid incompatible
structure layout between 32-bit and 64-bit x86 due to the different
alignment requirements, and the snd_pcm_status structure is now hidden
from the kernel to avoid relying on the timespec definitio definitionn

Finally we can replace SNDRV_PCM_IOCTL_STATUS and SNDRV_PCM_IOCTL_STATUS_EXT
with new commands and introduce new functions to fill new 'struct snd_pcm_status64'
instead of using unsafe 'struct snd_pcm_status'. Then in future, the new
commands can be matched when userspace changes 'timespec' to 64bit type
to make a size change of 'struct snd_pcm_status'. When glibc changes time_t
to 64-bit, any recompiled program will issue ioctl commands that the kernel
does not understand without this patch.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-12-11 22:06:15 +01:00
Thomas Gleixner
1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00
Takashi Iwai
734b5a0bbd ALSA: Replace snd_malloc_pages() and snd_free_pages() with standard helpers, take#2
snd_malloc_pages() and snd_free_pages() are merely thin wrappers of
the standard page allocator / free functions.  Even the arguments are
compatible with some standard helpers, so there is little merit of
keeping these wrappers.

This patch replaces the all existing callers of snd_malloc_pages() and
snd_free_pages() with the direct calls of the standard helper
functions.  In this version, we use a recently introduced one,
alloc_pages_exact(), which suits better than the old
snd_malloc_pages() implementation for our purposes.  Then we can avoid
the waste of pages by alignment to power-of-two.

Since alloc_pages_exact() does split pages, we need no longer
__GFP_COMP flag; or better to say, we must not pass __GFP_COMP to
alloc_pages_exact().  So the former unconditional addition of
__GFP_COMP flag in snd_malloc_pages() is dropped, as well as in most
other places.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-03-27 17:15:01 +01:00
Takashi Iwai
a8d149813b ALSA: pcm: Remove superfluous snd_info_register() calls
The calls of snd_info_register() are superfluous and should be avoided
at the procfs creation time.  They are called at the end of the whole
initialization via snd_card_register().  This patch drops such
superfluous calls, as well as cleaning up the calls of substream proc
entries with a common helper.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-02-06 18:11:54 +01:00
Takashi Iwai
205d6bcf9b Merge branch 'topic/pcm-lock-refactor' into for-next
Pull PCM lock refactoring.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-01-24 14:46:21 +01:00
Takashi Iwai
480e32ebd5 ALSA: pcm: Simplify proc file destruction
The proc files are recursively freed by calling with the root
snd_info_entry object, so we don't have to keep each object for
releasing one by one.  Move the release of the PCM stream proc root at
the beginning, so that we can remove the redundant code and resource.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-01-24 14:40:25 +01:00
Takashi Iwai
73365cb10b ALSA: pcm: Unify snd_pcm_group initialization
There are multiple open codes that initialize the same object.
Create a common helper function instead.

Also, use kzalloc() to be safer at creating a group object, and move
the initialization out of the critical section.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-01-21 16:39:35 +01:00
Takashi Iwai
3d21ef0b49 ALSA: pcm: Suspend streams globally via device type PM ops
Until now we rely on each driver calling snd_pcm_suspend*() explicitly
at its own PM handling.  However, this can be done far more easily by
setting the PM ops to each actual snd_pcm device object.

This patch adds the device_type object for PCM stream and assigns to
each PCM stream object.  The type contains only the PM ops for system
suspend; we don't need to deal with the resume in general.

The suspend hook simply calls snd_pcm_suspend_all() for the given PCM
streams.  This implies that the PM order is correctly put, i.e. PCM is
suspended before the main (or codec) driver, which should be true in
general.  If a special ordering is needed, you'd need to adjust the
device PM order manually later.

This patch introduces a new flag, snd_pcm.no_device_suspend, too.
With this flag set, the PCM device object won't invoke
snd_pcm_suspend_all() by itself.  This is needed for ASoC who wants to
manage the PM call orders in its serialized way, and the flag is set
in soc_new_pcm() as default.

For the non-ASoC world, we can get rid of the manual snd_pcm_suspend
calls.  This will be done in the later patches.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-01-15 17:46:36 +01:00
Gustavo A. R. Silva
94ffb030b6 ALSA: pcm: Fix potential Spectre v1 vulnerability
stream is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

sound/core/pcm.c:140 snd_pcm_control_ioctl() warn: potential spectre issue 'pcm->streams' [r] (local cap)

Fix this by sanitizing stream before using it to index pcm->streams

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: stable@vger.kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-12-13 09:14:33 +01:00
Takashi Iwai
e647f5a5c5 ALSA: pcm: Use snd_pcm_stop_xrun() for xrun injection
Basically the xrun injection routine can simply call the standard
helper snd_pcm_stop_xrun(), but with one exception: it may be called
even when the stream is closed.

Make snd_pcm_stop_xrun() more robust and check the NULL runtime state,
and simplify xrun injection code by calling it.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-04 15:34:59 +02:00
Takashi Iwai
9cd641ed31 ALSA: pcm: trace XRUN event at injection, too
The PCM xrun injection triggers directly snd_pcm_stop() without the
standard xrun handler, hence it's not recorded on the event buffer.
Ditto for snd_pcm_stop_xrun() call and SNDRV_PCM_IOCTL_XRUN ioctl.
They are inconvenient from the debugging POV.

Let's make them to trigger XRUN via the standard helper more
consistently.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-04 15:34:57 +02:00
Joe Perches
6a73cf46ce sound: Use octal not symbolic permissions
Convert the S_<FOO> symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...>

Miscellanea:

o Wrapped one multi-line call to a single line

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-28 11:27:20 +02:00
Takashi Iwai
a820ccbe21 ALSA: pcm: Fix UAF at PCM release via PCM timer access
The PCM runtime object is created and freed dynamically at PCM stream
open / close time.  This is tracked via substream->runtime, and it's
cleared at snd_pcm_detach_substream().

The runtime object assignment is protected by PCM open_mutex, so for
all PCM operations, it's safely handled.  However, each PCM substream
provides also an ALSA timer interface, and user-space can access to
this while closing a PCM substream.  This may eventually lead to a
UAF, as snd_pcm_timer_resolution() tries to access the runtime while
clearing it in other side.

Fortunately, it's the only concurrent access from the PCM timer, and
it merely reads runtime->timer_resolution field.  So, we can avoid the
race by reordering kfree() and wrapping the substream->runtime
clearance with the corresponding timer lock.

Reported-by: syzbot+8e62ff4e07aa2ce87826@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-03 08:36:40 +02:00
Robb Glasser
362bca57f5 ALSA: pcm: prevent UAF in snd_pcm_info
When the device descriptor is closed, the `substream->runtime` pointer
is freed. But another thread may be in the ioctl handler, case
SNDRV_CTL_IOCTL_PCM_INFO. This case calls snd_pcm_info_user() which
calls snd_pcm_info() which accesses the now freed `substream->runtime`.

Note: this fixes CVE-2017-0861

Signed-off-by: Robb Glasser <rglasser@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-12-05 23:28:08 +01:00
Takashi Iwai
6ca73de7eb ALSA: pcm: Forcibly stop at disconnect callback
So far we assumed that each driver implements the hotplug PCM handling
properly, e.g. dealing with the pending PCM stream at disconnect
callback.  But most codes don't care, and it eventually leaves the PCM
stream inconsistent state when an abrupt disconnection like sysfs
unbind happens.

This patch is simple but a big-hammer solution: invoke snd_pcm_stop()
at the common PCM disconnect callback always when the stream is
running.

Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-18 08:05:46 +02:00
Takashi Iwai
8b645e4a40 ALSA: pcm: Don't call register and disconnect callbacks for internal PCM
The internal PCM (aka DPCM backend PCM) doesn't need any registration
procedure, thus currently we bail out immediately at dev_register
callback.  Similarly, its counterpart, dev_disconnect callback, is
superfluous for the internal PCM.  For simplifying and avoiding the
conflicting disconnect call for internal PCM objects, this patch drops
dev_register and dev_disconnect callbacks for the internal ops.

The only uncertain thing by this action is whether skipping the PCM
state change to SNDRV_PCM_STATE_DISCONNECT for the internal PCM is
mandatory.  Looking through the current implementations, this doesn't
look so, hence dropping the whole dev_disconnect would make more
sense.

Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-10-18 08:05:34 +02:00
Takashi Iwai
e6b4c525d9 ALSA: pcm: Correct broken procfs set up
The commit c8da9be4a7 ("ALSA: pcm: Adjust nine function calls
together with a variable assignment") contained a badly incorrect
conversion, a "status" PCM procfs creation was replaced with the next
one.  Luckily, this could be spotted easily by the kernel runtime
warning.

Fixes: c8da9be4a7 ("ALSA: pcm: Adjust nine function calls together...")
Reported-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-08-25 00:05:16 +02:00
Markus Elfring
c8da9be4a7 ALSA: pcm: Adjust nine function calls together with a variable assignment
The script "checkpatch.pl" pointed information out like the following.

ERROR: do not use assignment in if condition

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-08-23 10:36:18 +02:00
Markus Elfring
97d15a141f ALSA: pcm: Use common error handling code in _snd_pcm_new()
Add a jump target so that a bit of exception handling can be better reused
at the end of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-08-23 10:35:50 +02:00
Arvind Yadav
343fe85066 ALSA: pcm: constify attribute_group structures.
attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/device.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
   text	   data	    bss	    dec	    hex	filename
   9781	    240	      8	  10029	   272d	sound/core/pcm.o

File size After adding 'const':
   text	   data	    bss	    dec	    hex	filename
   9813	    176	      8	   9997	   270d	sound/core/pcm.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-29 18:20:15 +02:00
Takashi Sakamoto
2c4842d3b6 ALSA: pcm: add local header file for snd-pcm module
Several files are used to construct PCM core module, a.k.a snd-pcm.
Although available APIs are described in 'include/sound/pcm.h', some of
them are not exported as symbols in kernel space. Such APIs are just for
module local usage.

This commit adds module local header file and move some function prototypes
into it so that scopes of them are controlled properly and developers
get no confusion from unavailable symbols.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-05-26 08:38:14 +02:00
Arnd Bergmann
9aee03f39c ALSA: pcm: use "do {} while (0)" for empty macro
Recent compilers produce a harmless warning for the new pcm_call_notify()
macro when CONFIG_SND_PCM_OSS is disabled:

sound/core/pcm.c: In function 'snd_pcm_free':
sound/core/pcm.c:905:37: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]

This turns the empty macro into a 'do {} while (0)' statement to avoid
the warning.

Fixes: 58f30d650c ("ALSA: pcm: Build pcm notifier code conditionally")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-05-18 16:38:49 +02:00
Takashi Iwai
58f30d650c ALSA: pcm: Build pcm notifier code conditionally
The PCM notifier code is used only by OSS emulation layer, so we can
build it conditionally for reducing the size.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-05-17 07:13:03 +02:00
Takashi Iwai
a8ff48cb70 ALSA: pcm: Free chmap at PCM free callback, too
The chmap ctls assigned to PCM streams are freed in the PCM disconnect
callback.  However, since the disconnect callback isn't called when
the card gets freed before registering, the chmap ctls may still be
left assigned.  They are eventually freed together with other ctls,
but it may cause an Oops at pcm_chmap_ctl_private_free(), as the
function refers to the assigned PCM stream, while the PCM objects have
been already freed beforehand.

The fix is to free the chmap ctls also at PCM free callback, not only
at PCM disconnect.

Reported-by: Laxminath Kasam <b_lkasam@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-07-08 09:15:44 +02:00
Takashi Sakamoto
0052b7dcf9 ALSA: pcm: remove structure member of 'struct snd_pcm_hwptr_log *' type because this structure had been removed
This structure was added by 4d96eb255c ('ALSA: pcm_lib - add possibility
to log last 10 DMA ring buffer positions') to store PCM pointers
information of latest 10 pointer movements (=XRUN_LOG_CNT). When
CONFIG_SND_PCM_XRUN_DEBUG is configured, 'struct snd_pcm_runtime' has
'hwptr_log' member with a pointer to the structure. When calling
xrun_log() in pcm_lib.c, the structure was allocated to the pointer.
When calling snd_pcm_detach_substream() in pcm.c, the allocated pointer
is released.

In f5914908a5 ('ALSA: pcm: Replace PCM hwptr tracking with tracepoints'),
the pointer logging is replaced with using Linux Kernel Tracepoints. The
structure was also removed, while it's just declared. The member and kfree
still remains.

This commit removes the member and related codes. I think this was
overlooked because it brings no errors/warnings to C compilers.

Fixes: f5914908a5 ('ALSA: pcm: Replace PCM hwptr tracking with tracepoints')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-09-13 12:03:15 +02:00
Takashi Iwai
60b93030b4 ALSA: pcm: Fix pcm_class sysfs output
The pcm_class sysfs of each PCM substream gives only "none" since the
recent code change to embed the struct device.  Fix the code to point
directly to the embedded device object properly.

Fixes: ef46c7af93 ('ALSA: pcm: Embed struct device')
Cc: <stable@vger.kernel.org> # v4.0+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-06-23 11:56:22 +02:00
Jie Yang
cd6a65036f ALSA: replace CONFIG_PROC_FS with CONFIG_SND_PROC_FS
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 <yang.jie@intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-05-27 21:25:19 +02:00
Takashi Iwai
ec0e9937aa ALSA: core: Drop superfluous error/debug messages after malloc failures
The kernel memory allocators already report the errors when the
requested allocation fails, thus we don't need to warn it again in
each caller side.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-10 15:42:14 +01:00
Takashi Iwai
b20221385c ALSA: pcm: Don't ignore internal PCMs in snd_pcm_dev_disconnect()
Some codes in snd_pcm_dev_disconnect() are still valid even for
internal PCMs, but they are skipped because of the check of
list_empty(&pcm->list) at the beginning.  Remove this check and put
pcm->internal checks appropriately for internal PCM object to process
through this function.

Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-20 19:52:04 +01:00
Takashi Iwai
646e1dd8f9 ALSA: pcm: Don't notify internal PCMs
Notifier shouldn't listen to the changes of internal PCMs.

Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-20 19:51:50 +01:00
Takashi Iwai
b95bd3a454 ALSA: pcm: Don't add internal PCMs to PCM device list
An internal PCM object shouldn't be added to the PCM device list, as
it's never accessed directly from the user-space, and it has no proc
or any similar accesses.  Currently, it's excluded in snd_pcm_get()
and snd_pcm_next(), but it's easier not to add such an object to the
list.

Actually, the whole snd_pcm_dev_register() can be skipped for an
internal PCM.  So this patch changes the code there, but also
addresses the uninitialized list_head access.

Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-20 19:51:42 +01:00
Takashi Iwai
ad876c8622 ALSA: pcm: Minor refactoring in snd_pcm_attach_substream()
No functional changes at all.

Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-20 19:51:04 +01:00
Takashi Iwai
40a4b26385 ALSA: Simplify snd_device_register() variants
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 <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02 17:01:26 +01:00