Commit Graph

111 Commits

Author SHA1 Message Date
Takashi Iwai 84bb065b31 ALSA: rawmidi: Use guard() for locking
We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.

There are a few remaining explicit mutex and spinlock calls, and those
are the places where the temporary unlock/relocking happens -- which
guard() doens't cover well yet.

Only the code refactoring, and no functional changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-10-tiwai@suse.de
2024-02-28 15:01:21 +01:00
Takashi Iwai b2ce0027d7 ALSA: rawmidi: Fix NULL dereference at proc read
At the implementation of the optional proc fs in rawmidi, I forgot
that rmidi->ops itself is optional and can be NULL.
Add the proper NULL check for avoiding the Oops.

Fixes: fa030f666d ("ALSA: ump: Additional proc output")
Reported-and-tested-by: Mark Hills <mark@xwax.org>
Closes: https://lore.kernel.org/r/ef9118c3-a2eb-d0ff-1efa-cc5fb6416bde@xwax.org
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230916060725.11726-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-09-16 08:08:05 +02:00
Takashi Iwai ea29a02fd8 ALSA: rawmidi: Don't embed device
This patch detaches the struct device from the snd_rawmidi object by
allocating via snd_device_alloc(), just like done for other devices.

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/20230816160252.23396-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-08-17 09:24:08 +02:00
Takashi Iwai fa030f666d ALSA: ump: Additional proc output
UMP devices may have more interesting information than the traditional
rawmidi.  Extend the rawmidi_global_ops to allow the optional proc
info output and show some more bits in the proc file for UMP.

Note that the "Groups" field shows the first and the last UMP Groups,
and both numbers are 1-based (i.e. the first group is 1).

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-7-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23 12:10:59 +02:00
Takashi Iwai 30fc139260 ALSA: ump: Add ioctls to inquiry UMP EP and Block info via control API
It'd be convenient to have ioctls to inquiry the UMP Endpoint and UMP
Block information directly via the control API without opening the
rawmidi interface, just like SNDRV_CTL_IOCTL_RAWMIDI_INFO.

This patch extends the rawmidi ioctl handler to support those; new
ioctls, SNDRV_CTL_IOCTL_UMP_ENDPOINT_INFO and
SNDRV_CTL_IOCTL_UMP_BLOCK_INFO, return the snd_ump_endpoint and
snd_ump_block data that is specified by the device field,
respectively.

Suggested-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23 12:10:58 +02:00
Takashi Iwai 127ae6f6da ALSA: rawmidi: Skip UMP devices at SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE
Applications may look for rawmidi devices with the ioctl
SNDRV_CTL_IOCTL_RAWMIDI_NEXT_DEVICE.  Returning a UMP device from this
ioctl may confuse the existing applications that support only the
legacy rawmidi.

This patch changes the code to skip the UMP devices from the lookup
for avoiding the confusion, and introduces a new ioctl to look for the
UMP devices instead.

Along with this change, bump the CTL protocol version to 2.0.9.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23 12:10:57 +02:00
Takashi Iwai e3a8a5b726 ALSA: rawmidi: UMP support
This patch adds the support helpers for UMP (Universal MIDI Packet) in
ALSA core.

The basic design is that a rawmidi instance is assigned to each UMP
Endpoint.  A UMP Endpoint provides a UMP stream, typically
bidirectional (but can be also uni-directional, too), which may hold
up to 16 UMP Groups, where each UMP (input/output) Group corresponds
to the traditional MIDI I/O Endpoint.

Additionally, the ALSA UMP abstraction provides the multiple UMP
Blocks that can be assigned to each UMP Endpoint.  A UMP Block is a
metadata to hold the UMP Group clusters, and can represent the
functions assigned to each UMP Group.  A typical implementation of UMP
Block is the Group Terminal Blocks of USB MIDI 2.0 specification.

For distinguishing from the legacy byte-stream MIDI device, a new
device "umpC*D*" will be created, instead of the standard (MIDI 1.0)
devices "midiC*D*".  The UMP instance can be identified by the new
rawmidi info bit SNDRV_RAWMIDI_INFO_UMP, too.

A UMP rawmidi device reads/writes only in 4-bytes words alignment,
stored in CPU native endianness.

The transmit and receive functions take care of the input/out data
alignment, and may return zero or aligned size, and the params ioctl
may return -EINVAL when the given input/output buffer size isn't
aligned.

A few new UMP-specific ioctls are added for obtaining the new UMP
endpoint and block information.

As of this commit, no ALSA sequencer instance is attached to UMP
devices yet.  They will be supported by later patches.

Along with those changes, the protocol version for rawmidi is bumped
to 2.0.3.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23 12:10:54 +02:00
Takashi Iwai fb3bd12159 ALSA: rawmidi: Add ioctl callback to snd_rawmidi_global_ops
A new callback, ioctl, is added to snd_rawmidi_global_ops for allowing
the driver to deal with the own ioctls.  This is another preparation
patch for the upcoming UMP support.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23 12:10:53 +02:00
Takashi Iwai 09b62892dd ALSA: rawmidi: Pass rawmidi directly to snd_rawmidi_kernel_open()
snd_rawmidi_kernel_open() is used only internally from ALSA sequencer,
so far, and parsing the card / device matching table at each open is
redundant, as each sequencer client already gets the rawmidi object
beforehand.

This patch optimizes the path by passing the rawmidi object directly
at snd_rawmidi_kernel_open().  This is also a preparation for the
upcoming UMP rawmidi I/O support.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-23 12:10:52 +02:00
Colin Ian King 72457b3abb ALSA: rawmidi: remove variable dest_frames
Variable dest_frames is just being incremented and it's never used
anywhere else. The variable and the increment are redundant so
remove it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20221024130415.2155860-1-colin.i.king@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-10-24 16:01:05 +02:00
Takashi Iwai a70aef7982 ALSA: rawmidi: Drop register_mutex in snd_rawmidi_free()
The register_mutex taken around the dev_unregister callback call in
snd_rawmidi_free() may potentially lead to a mutex deadlock, when OSS
emulation and a hot unplug are involved.

Since the mutex doesn't protect the actual race (as the registration
itself is already protected by another means), let's drop it.

Link: https://lore.kernel.org/r/CAB7eexJP7w1B0mVgDF0dQ+gWor7UdkiwPczmL7pn91xx8xpzOA@mail.gmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20221011070147.7611-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-10-11 09:02:32 +02:00
Takashi Iwai 3809db6430 ALSA: rawmidi: Take buffer refcount while draining output
Although snd_rawmidi_drain_output() may take some long time, it has no
protection and intrusive operations like the buffer resize may happen
meanwhile.  For making the operation a bit more robust, this patch
takes the buffer refcount for blocking the buffer resize.

Also, as this function is exported, in theory, it might be called
asynchronously from the stream open/close state.  For avoiding the
missing refcount, now the close call checks the buffer refcount, too.

Link: https://lore.kernel.org/r/20220617144051.18985-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-20 09:36:04 +02:00
Takashi Iwai 463a20fd34 ALSA: rawmidi: Check stream state at exported functions
The rawmidi interface provides some exported functions to be called
from outside, and currently there is no state check for those calls
whether the stream is properly opened and running.  Although such an
invalid call shouldn't happen, but who knows.

This patch adds the proper rawmidi stream state checks with spinlocks
for avoiding unexpected accesses when such exported functions are
called in an invalid state.  After this patch, with the
substream->opened and substream->runtime are always tied and
guaranteed to be set under substream->lock.

Link: https://lore.kernel.org/r/20220617144051.18985-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-20 09:36:03 +02:00
Takashi Iwai 94b98194b6 ALSA: rawmidi: Take open_mutex around parameter changes
The input/output parameter changes are pretty intrusive, possibly
involving with the buffer resizing operation.  Hence those should be
performed exclusively; otherwise some ugly race could happen.

This patch puts the existing open_mutex for snd_rawmidi_input_params()
and *_output_params() for protecting the concurrent calls.  Since
those are exported, it's also meant for hardening from the external
calls, too.

Link: https://lore.kernel.org/r/20220617144051.18985-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-20 09:36:02 +02:00
Takashi Iwai f1d4043335 ALSA: rawmidi: Move lock to snd_rawmidi_substream
Having a lock in snd_rawmidi_runtime can be a problem especially when
a substream is accessed from the outside, as the runtime creation
might be racy with the external calls.  As a first step for hardening,
move the spinlock from snd_rawmidi_runtime to snd_rawmidi_substream.

This patch just replaces the lock calls, no real functional change is
put yet.

Link: https://lore.kernel.org/r/20220617144051.18985-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-20 09:36:02 +02:00
Takashi Iwai cd76175a2b ALSA: rawmidi: Make internal functions local static
__snd_rawmidi_transmit_peek() and __snd_rawmidi_transmit_ack() are
never called from the outside.  Let's make them local static and
unexport them.

Link: https://lore.kernel.org/r/20220617144051.18985-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-06-20 09:36:01 +02:00
Jaroslav Kysela 39a8fc4971 ALSA: rawmidi - fix the uninitalized user_pversion
The user_pversion was uninitialized for the user space file structure
in the open function, because the file private structure use
kmalloc for the allocation.

The kernel ALSA sequencer code clears the file structure, so no additional
fixes are required.

Cc: stable@kernel.org
Cc: broonie@kernel.org
BugLink: https://github.com/alsa-project/alsa-lib/issues/178
Fixes: 09d2317440 ("ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION")
Reported-by: syzbot+88412ee8811832b00dbe@syzkaller.appspotmail.com
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20211218123925.2583847-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-12-22 20:18:27 +01:00
Jaroslav Kysela 09d2317440 ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION
The new framing mode causes the user space regression, because
the alsa-lib code does not initialize the reserved space in
the params structure when the device is opened.

This change adds SNDRV_RAWMIDI_IOCTL_USER_PVERSION like we
do for the PCM interface for the protocol acknowledgment.

Cc: David Henningsson <coding@diwic.se>
Cc: <stable@vger.kernel.org>
Fixes: 08fdced60c ("ALSA: rawmidi: Add framing mode")
BugLink: https://github.com/alsa-project/alsa-lib/issues/178
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210920171850.154186-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-09-23 09:26:40 +02:00
Colin Ian King a6de7b32b6 ALSA: rawmidi: fix incorrect array bounds check on clock_names
The array bounds check on clock_names is currently checking the size
of the entire array rather than the number of elements in the array
leading to a potential array bounds read error. Fix this by using
the ARRAY_SIZE macro instead of sizeof.

Addresses-Coverity: ("Out-of-bounds read")
Fixes: 08fdced60c ("ALSA: rawmidi: Add framing mode")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210519105424.55221-1-colin.king@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-19 16:20:25 +02:00
David Henningsson 08fdced60c ALSA: rawmidi: Add framing mode
This commit adds a new framing mode that frames all MIDI data into
32-byte frames with a timestamp.

The main benefit is that we can get accurate timestamps even if
userspace wakeup and processing is not immediate.

Testing on a Celeron N3150 with this mode has a max jitter of 2.8 ms,
compared to the in-kernel seq implementation which has a max jitter
of 5 ms during idle and much worse when running scheduler stress tests
in parallel.

Signed-off-by: David Henningsson <coding@diwic.se>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210515071533.55332-1-coding@diwic.se
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-05-17 16:02:44 +02:00
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
Takashi Iwai 88a06d6fd6 ALSA: rawmidi: Access runtime->avail always in spinlock
The runtime->avail field may be accessed concurrently while some
places refer to it without taking the runtime->lock spinlock, as
detected by KCSAN.  Usually this isn't a big problem, but for
consistency and safety, we should take the spinlock at each place
referencing this field.

Reported-by: syzbot+a23a6f1215c84756577c@syzkaller.appspotmail.com
Reported-by: syzbot+3d367d1df1d2b67f5c19@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20201206083527.21163-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-12-06 09:36:10 +01:00
Pierre-Louis Bossart 93fcef86ca ALSA: rawmidi: (cosmetic) align function parameters
fix cppcheck:

sound/core/rawmidi.c:1711:49: style:inconclusive: Function
'snd_rawmidi_free' argument 1 names different: declaration 'rawmidi'
definition 'rmidi'. [funcArgNamesDifferent]

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200902212133.30964-16-pierre-louis.bossart@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-09-03 09:27:44 +02:00
Takashi Iwai c1f6e3c818 ALSA: rawmidi: Fix racy buffer resize under concurrent accesses
The rawmidi core allows user to resize the runtime buffer via ioctl,
and this may lead to UAF when performed during concurrent reads or
writes: the read/write functions unlock the runtime lock temporarily
during copying form/to user-space, and that's the race window.

This patch fixes the hole by introducing a reference counter for the
runtime buffer read/write access and returns -EBUSY error when the
resize is performed concurrently against read/write.

Note that the ref count field is a simple integer instead of
refcount_t here, since the all contexts accessing the buffer is
basically protected with a spinlock, hence we need no expensive atomic
ops.  Also, note that this busy check is needed only against read /
write functions, and not in receive/transmit callbacks; the race can
happen only at the spinlock hole mentioned in the above, while the
whole function is protected for receive / transmit callbacks.

Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/CAFcO6XMWpUVK_yzzCpp8_XP7+=oUpQvuBeCbMffEDkpe8jWrfg@mail.gmail.com
Link: https://lore.kernel.org/r/s5heerw3r5z.wl-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-05-07 22:29:14 +02:00
Takashi Iwai edb87ed5f9 ALSA: rawmidi: More constification
Apply const prefix to the static flag info table.

Just for minor optimization and no functional changes.

Link: https://lore.kernel.org/r/20200105144823.29547-42-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-05 16:14:58 +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 d9e5582c4b ALSA: Avoid using timespec for struct snd_rawmidi_status
The struct snd_rawmidi_status will use 'timespec' type variables to record
timestamp, which is not year 2038 safe on 32bits system.

Thus we introduced 'struct snd_rawmidi_status32' and 'struct snd_rawmidi_status64'
to handle 32bit time_t and 64bit time_t in native mode, which replace
timespec with s64 type.

In compat mode, we renamed or introduced new structures to handle 32bit/64bit
time_t in compatible mode. The 'struct snd_rawmidi_status32' and
snd_rawmidi_ioctl_status32() are used to handle 32bit time_t in compat mode.
'struct compat_snd_rawmidi_status64' is used to handle 64bit time_t.

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 22:06:16 +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
Kirill Smelkov c5bf68fe0c *: convert stream-like files from nonseekable_open -> stream_open
Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af34
("fs: stream_open - opener for stream-like files so that read and write
can run simultaneously without deadlock"), search and convert to
stream_open all in-kernel nonseekable_open users for which read and
write actually do not depend on ppos and where there is no other methods
in file_operations which assume @offset access.

I've verified each generated change manually - that it is correct to convert -
and each other nonseekable_open instance left - that it is either not correct
to convert there, or that it is not converted due to current stream_open.cocci
limitations. The script also does not convert files that should be valid to
convert, but that currently have .llseek = noop_llseek or generic_file_llseek
for unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Among cases converted 14 were potentially vulnerable to read vs write deadlock
(see details in 10dce8af34):

	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.

and the rest were just safe to convert to stream_open because their read and
write do not use ppos at all and corresponding file_operations do not
have methods that assume @offset file access(*):

	arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.

One can also recheck/review the patch via generating it with explanation comments included via

	$ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain"

(*) This second group also contains cases with read/write deadlocks that
stream_open.cocci don't yet detect, but which are still valid to convert to
stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c
calls wait_for_completion_interruptible() in its .read, but stream_open.cocci
currently detects only "wait_event*" as blocking.

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Harald Welte <laforge@gnumonks.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs]
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: David Herrmann <dh.herrmann@googlemail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Jean Delvare <jdelvare@suse.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>	[watchdog/* hwmon/*]
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec]
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec]
Cc: Benson Leung <bleung@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome]
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*]
Cc: Mark Brown <broonie@kernel.org>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Zwane Mwaikambo <zwanem@gmail.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-05-06 17:46:41 +03:00
Gustavo A. R. Silva 2b1d9c8f87 ALSA: rawmidi: Fix potential Spectre v1 vulnerability
info->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/rawmidi.c:604 __snd_rawmidi_info_select() warn: potential spectre issue 'rmidi->streams' [r] (local cap)

Fix this by sanitizing info->stream before using it to index
rmidi->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://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-03-21 13:21:15 +01:00
Takashi Iwai 6aea5702e2 ALSA: rawmidi: A lightweight function to discard pending bytes
For discarding the pending bytes on rawmidi, we process with a loop of
snd_rawmidi_transmit() which is just a waste of CPU power.
Implement a lightweight API function to discard the pending bytes and
the proceed the ring buffer instantly, and use it instead of open
codes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-10-04 20:13:17 +02:00
Takashi Iwai 5a7b44a8df ALSA: rawmidi: Initialize allocated buffers
syzbot reported the uninitialized value exposure in certain situations
using virmidi loop.  It's likely a very small race at writing and
reading, and the influence is almost negligible.  But it's safer to
paper over this just by replacing the existing kvmalloc() with
kvzalloc().

Reported-by: syzbot+194dffdb8b22fc5d207a@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-09-03 15:16:43 +02:00
Takashi Iwai ef4db239cd ALSA: rawmidi: Use kvmalloc() for buffers
The size of in-kernel rawmidi buffers may be big up to 1MB, and it can
be specified freely by user-space; which implies that user-space may
trigger kmalloc() errors frequently.

This patch replaces the buffer allocation via kvmalloc() for dealing
with bigger buffers gracefully.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-18 07:47:57 +02:00
Takashi Iwai f5beb598b0 ALSA: rawmidi: Minor code refactoring
Unify a few open codes with helper functions to improve the
readability.  Minor behavior changes (rather fixes) are:
- runtime->drain clearance is done within lock
- active_sensing is updated before resizing buffer in
  SNDRV_RAWMIDI_IOCTL_PARAMS ioctl.
Other than that, simply code cleanups.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-17 23:07:29 +02:00
Takashi Iwai 7fdc9b0807 ALSA: rawmidi: Simplify error paths
Apply the standard idiom: rewrite the multiple unlocks in error paths
in the goto-error-and-single-unlock way.

Just a code refactoring, and no functional changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-17 22:48:38 +02:00
Takashi Iwai 5bed913972 ALSA: rawmidi: Tidy up coding styles
Just minor coding style fixes like removal of superfluous white space,
adding missing blank lines, etc.  No actual code changes at all.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-17 22:37:07 +02:00
Takashi Iwai 39675f7a7c ALSA: rawmidi: Change resized buffers atomically
The SNDRV_RAWMIDI_IOCTL_PARAMS ioctl may resize the buffers and the
current code is racy.  For example, the sequencer client may write to
buffer while it being resized.

As a simple workaround, let's switch to the resized buffer inside the
stream runtime lock.

Reported-by: syzbot+52f83f0ea8df16932f7f@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-17 17:33:17 +02:00
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Linus Torvalds 168fe32a07 Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull poll annotations from Al Viro:
 "This introduces a __bitwise type for POLL### bitmap, and propagates
  the annotations through the tree. Most of that stuff is as simple as
  'make ->poll() instances return __poll_t and do the same to local
  variables used to hold the future return value'.

  Some of the obvious brainos found in process are fixed (e.g. POLLIN
  misspelled as POLL_IN). At that point the amount of sparse warnings is
  low and most of them are for genuine bugs - e.g. ->poll() instance
  deciding to return -EINVAL instead of a bitmap. I hadn't touched those
  in this series - it's large enough as it is.

  Another problem it has caught was eventpoll() ABI mess; select.c and
  eventpoll.c assumed that corresponding POLL### and EPOLL### were
  equal. That's true for some, but not all of them - EPOLL### are
  arch-independent, but POLL### are not.

  The last commit in this series separates userland POLL### values from
  the (now arch-independent) kernel-side ones, converting between them
  in the few places where they are copied to/from userland. AFAICS, this
  is the least disruptive fix preserving poll(2) ABI and making epoll()
  work on all architectures.

  As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and
  it will trigger only on what would've triggered EPOLLWRBAND on other
  architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered
  at all on sparc. With this patch they should work consistently on all
  architectures"

* 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  make kernel-side POLL... arch-independent
  eventpoll: no need to mask the result of epi_item_poll() again
  eventpoll: constify struct epoll_event pointers
  debugging printk in sg_poll() uses %x to print POLL... bitmap
  annotate poll(2) guts
  9p: untangle ->poll() mess
  ->si_band gets POLL... bitmap stored into a user-visible long field
  ring_buffer_poll_wait() return value used as return value of ->poll()
  the rest of drivers/*: annotate ->poll() instances
  media: annotate ->poll() instances
  fs: annotate ->poll() instances
  ipc, kernel, mm: annotate ->poll() instances
  net: annotate ->poll() instances
  apparmor: annotate ->poll() instances
  tomoyo: annotate ->poll() instances
  sound: annotate ->poll() instances
  acpi: annotate ->poll() instances
  crypto: annotate ->poll() instances
  block: annotate ->poll() instances
  x86: annotate ->poll() instances
  ...
2018-01-30 17:58:07 -08:00
Takashi Iwai c1cfd9025c ALSA: rawmidi: Avoid racy info ioctl via ctl device
The rawmidi also allows to obtaining the information via ioctl of ctl
API.  It means that user can issue an ioctl to the rawmidi device even
when it's being removed as long as the control device is present.
Although the code has some protection via the global register_mutex,
its range is limited to the search of the corresponding rawmidi
object, and the mutex is already unlocked at accessing the rawmidi
object.  This may lead to a use-after-free.

For avoiding it, this patch widens the application of register_mutex
to the whole snd_rawmidi_info_select() function.  We have another
mutex per rawmidi object, but this operation isn't very hot path, so
it shouldn't matter from the performance POV.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-12-14 16:52:31 +01:00
Al Viro 680ef72abd sound: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27 16:20:02 -05:00
Linus Torvalds 920f2ecdf6 sound updates for 4.13-rc1
This development cycle resulted in a fair amount of changes in both
 core and driver sides.  The most significant change in ALSA core is
 about PCM.  Also the support of of-graph card and the new DAPM widget
 for DSP are noteworthy changes in ASoC core.  And there're lots of
 small changes splat over the tree, as you can see in diffstat.
 
 Below are a few highlights:
 
 ALSA core:
 - Removal of set_fs() hackery from PCM core stuff, and the code
   reorganization / optimization thereafter
 - Improved support of PCM ack ops, and a new ABI for improved
   control/status mmap handling
 - Lots of constifications in various codes
 
 ASoC core:
 - The support of of-graph card, which may work as a better generic
   device for a replacement of simple-card
 - New widget types intended mainly for use with DSPs
 
 ASoC drivers:
 - New drivers for Allwinner V3s SoCs
 - Ensonic ES8316 codec support
 - More Intel SKL and KBL works
 - More device support for Intel SST Atom (mostly for cheap tablets and
   2-in-1 devices)
 - Support for Rockchip PDM controllers
 - Support for STM32 I2S and S/PDIF controllers
 - Support for ZTE AUD96P22 codecs
 
 HD-audio:
 - Support of new Realtek codecs (ALC215/ALC285/ALC289), more quirks
   for HP and Dell machines
 - A few more fixes for i915 component binding
 
 Note that of-graph change may bring the conflicts with a later pull
 request of devicetree, as currently found in linux-next.
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Merge tag 'sound-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound updates from Takashi Iwai:
 "This development cycle resulted in a fair amount of changes in both
  core and driver sides. The most significant change in ALSA core is
  about PCM. Also the support of of-graph card and the new DAPM widget
  for DSP are noteworthy changes in ASoC core. And there're lots of
  small changes splat over the tree, as you can see in diffstat.

  Below are a few highlights:

  ALSA core:
   - Removal of set_fs() hackery from PCM core stuff, and the code
     reorganization / optimization thereafter
   - Improved support of PCM ack ops, and a new ABI for improved
     control/status mmap handling
   - Lots of constifications in various codes

  ASoC core:
   - The support of of-graph card, which may work as a better generic
     device for a replacement of simple-card
   - New widget types intended mainly for use with DSPs

  ASoC drivers:
   - New drivers for Allwinner V3s SoCs
   - Ensonic ES8316 codec support
   - More Intel SKL and KBL works
   - More device support for Intel SST Atom (mostly for cheap tablets
     and 2-in-1 devices)
   - Support for Rockchip PDM controllers
   - Support for STM32 I2S and S/PDIF controllers
   - Support for ZTE AUD96P22 codecs

  HD-audio:
   - Support of new Realtek codecs (ALC215/ALC285/ALC289), more quirks
     for HP and Dell machines
   - A few more fixes for i915 component binding"

* tag 'sound-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (418 commits)
  ALSA: hda - Fix unbalance of i915 module refcount
  ASoC: Intel: Skylake: Remove driver debugfs exit
  ASoC: Intel: Skylake: explicitly add the headers sst-dsp.h
  ALSA: hda/realtek - Remove GPIO_MASK
  ALSA: hda/realtek - Fix typo of pincfg for Dell quirk
  ALSA: pcm: add a documentation for tracepoints
  ALSA: atmel: ac97c: fix error return code in atmel_ac97c_probe()
  ALSA: x86: fix error return code in hdmi_lpe_audio_probe()
  ASoC: Intel: Skylake: Add support to read firmware registers
  ASoC: Intel: Skylake: Add sram address to sst_addr structure
  ASoC: Intel: Skylake: Debugfs facility to dump module config
  ASoC: Intel: Skylake: Add debugfs support
  ASoC: fix semicolon.cocci warnings
  ASoC: rt5645: Add quirk override by module option
  ASoC: rsnd: make arrays path and cmd_case static const
  ASoC: audio-graph-card: add widgets and routing for external amplifier support
  ASoC: audio-graph-card: update bindings for amplifier support
  ASoC: rt5665: calibration should be done before jack detection
  ASoC: rsnd: constify dev_pm_ops structures.
  ASoC: nau8825: change crosstalk-bypass property to bool type
  ...
2017-07-06 10:56:51 -07:00
Ingo Molnar ac6424b981 sched/wait: Rename wait_queue_t => wait_queue_entry_t
Rename:

	wait_queue_t		=>	wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:18:27 +02:00
Takashi Iwai 111b0cdb97 ALSA: seq: Allow the modular sequencer registration
Many drivers bind the sequencer stuff in off-load by another driver
module, so that it's loaded only on demand.  In the current code, this
mechanism doesn't work when the driver is built-in while the sequencer
is module.  We check with IS_REACHABLE() and enable only when the
sequencer is in the same level of build.

However, this is basically a overshoot.  The binder code
(snd-seq-device) is an individual module from the sequencer core
(snd-seq), and we just have to make the former a built-in while
keeping the latter a module for allowing the scenario like the above.

This patch achieves that by rewriting Kconfig slightly.  Now, a driver
that provides the manual sequencer device binding should select
CONFIG_SND_SEQ_DEVICE in a way as
	select SND_SEQ_DEVICE if SND_SEQUENCER != n

Note that the "!=n" is needed here to avoid the influence of the
sequencer core is module while the driver is built-in.

Also, since rawmidi.o may be linked with snd_seq_device.o when
built-in, we have to shuffle the code to make the linker happy.
(the kernel linker isn't smart enough yet to handle such a case.)
That is, snd_seq_device.c is moved to sound/core from sound/core/seq,
as well as Makefile.

Last but not least, the patch replaces the code using IS_REACHABLE()
with IS_ENABLED(), since now the condition meets always when enabled.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-12 08:43:33 +02:00
Ingo Molnar 174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Takashi Iwai 6ba79b8532 ALSA: rawmidi: Add const to snd_rawmidi_ops
Make snd_rawmidi_substream.ops to be a const pointer to be safer and
allow more optimization.  The patches to constify each rawmidi ops
will follow.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-01-12 12:49:36 +01:00
Fabian Frederick 7e1b23b078 ALSA: rawmidi: don't opencode IS_REACHABLE()
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-11-12 10:11:52 +01:00
Takashi Iwai 816f318b23 ALSA: rawmidi: Fix possible deadlock with virmidi registration
When a seq-virmidi driver is initialized, it registers a rawmidi
instance with its callback to create an associated seq kernel client.
Currently it's done throughly in rawmidi's register_mutex context.
Recently it was found that this may lead to a deadlock another rawmidi
device that is being attached with the sequencer is accessed, as both
open with the same register_mutex.  This was actually triggered by
syzkaller, as Dmitry Vyukov reported:

======================================================
 [ INFO: possible circular locking dependency detected ]
 4.8.0-rc1+ #11 Not tainted
 -------------------------------------------------------
 syz-executor/7154 is trying to acquire lock:
  (register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341

 but task is already holding lock:
  (&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&grp->list_mutex){++++.+}:
    [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<ffffffff863f6199>] down_read+0x49/0xc0 kernel/locking/rwsem.c:22
    [<     inline     >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681
    [<ffffffff85005c5e>] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822
    [<ffffffff85006e96>] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418
    [<ffffffff85012c52>] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101
    [<ffffffff84fff70a>] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297
    [<     inline     >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383
    [<ffffffff8502d29f>] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450
    [<ffffffff84fd208c>] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645
    [<ffffffff84f816d3>] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164
    [<     inline     >] __snd_device_register sound/core/device.c:162
    [<ffffffff84f8235d>] snd_device_register_all+0xad/0x110 sound/core/device.c:212
    [<ffffffff84f7546f>] snd_card_register+0xef/0x6c0 sound/core/init.c:749
    [<ffffffff85040b7f>] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123
    [<ffffffff833ebf7b>] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564
    ......

 -> #0 (register_mutex#5){+.+.+.}:
    [<     inline     >] check_prev_add kernel/locking/lockdep.c:1829
    [<     inline     >] check_prevs_add kernel/locking/lockdep.c:1939
    [<     inline     >] validate_chain kernel/locking/lockdep.c:2266
    [<ffffffff814791f4>] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335
    [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
    [<ffffffff863f0ef1>] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621
    [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341
    [<ffffffff8502e7c7>] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188
    [<     inline     >] subscribe_port sound/core/seq/seq_ports.c:427
    [<ffffffff85013cc7>] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510
    [<ffffffff85015da9>] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579
    [<ffffffff850079b8>] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480
    [<ffffffff84ffe9e4>] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225
    [<ffffffff84ffeae8>] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440
    [<ffffffff85027664>] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375
    [<ffffffff85023d67>] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281
    [<ffffffff8501b0a8>] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274
    [<ffffffff85019d8a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138
    [<ffffffff84f7040f>] soundcore_open+0x30f/0x640 sound/sound_core.c:639
    ......

 other info that might help us debug this:

 Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&grp->list_mutex);
                                lock(register_mutex#5);
                                lock(&grp->list_mutex);
   lock(register_mutex#5);

 *** DEADLOCK ***
======================================================

The fix is to simply move the registration parts in
snd_rawmidi_dev_register() to the outside of the register_mutex lock.
The lock is needed only to manage the linked list, and it's not
necessarily to cover the whole initialization process.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-08 10:45:20 +02:00
Takashi Iwai 81f577542a ALSA: rawmidi: Fix race at copying & updating the position
The rawmidi read and write functions manage runtime stream status
such as runtime->appl_ptr and runtime->avail.  These point where to
copy the new data and how many bytes have been copied (or to be
read).  The problem is that rawmidi read/write call copy_from_user()
or copy_to_user(), and the runtime spinlock is temporarily unlocked
and relocked while copying user-space.  Since the current code
advances and updates the runtime status after the spin unlock/relock,
the copy and the update may be asynchronous, and eventually
runtime->avail might go to a negative value when many concurrent
accesses are done.  This may lead to memory corruption in the end.

For fixing this race, in this patch, the status update code is
performed in the same lock before the temporary unlock.  Also, the
spinlock is now taken more widely in snd_rawmidi_kernel_read1() for
protecting more properly during the whole operation.

BugLink: http://lkml.kernel.org/r/CACT4Y+b-dCmNf1GpgPKfDO0ih+uZCL2JV4__j-r1kdhPLSgQCQ@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-03 14:51:42 +01:00
Takashi Iwai 06ab30034e ALSA: rawmidi: Make snd_rawmidi_transmit() race-free
A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by
syzkaller fuzzer:
  WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136
 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163
 [<     inline     >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150
 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223
 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273
 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528
 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577
 [<     inline     >] SYSC_write fs/read_write.c:624
 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616
 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185

Also a similar warning is found but in another path:
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133
 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163
 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185
 [<     inline     >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150
 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252
 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302
 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528
 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577
 [<     inline     >] SYSC_write fs/read_write.c:624
 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616
 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185

In the former case, the reason is that virmidi has an open code
calling snd_rawmidi_transmit_ack() with the value calculated outside
the spinlock.   We may use snd_rawmidi_transmit() in a loop just for
consuming the input data, but even there, there is a race between
snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack().

Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and
snd_rawmidi_tranmit_ack() separately without protection, so they are
racy as well.

The patch tries to address these issues by the following ways:
- Introduce the unlocked versions of snd_rawmidi_transmit_peek() and
  snd_rawmidi_transmit_ack() to be called inside the explicit lock.
- Rewrite snd_rawmidi_transmit() to be race-free (the former case).
- Make the split calls (the latter case) protected in the rawmidi spin
  lock.

BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com
BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-03 14:51:28 +01:00