kernel/linux.git/sound/core/seq/oss/seq_oss.c, branch v7.1

ALSA: seq: oss: Convert to snd_seq bus probe mechanism

2025-12-14T10:08:09+00:00

The snd_seq bus got a dedicated probe function. Make use of that. This fixes a runtime warning about the driver needing to be converted to the bus probe method. Note that the remove callback returns void now. The actual return value was ignored before (see device_remove() in drivers/base/dd.c), so there is no problem introduced by converting `return -EINVAL` to `return`. Signed-off-by: Uwe Kleine-König Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/affb5a7107e9d678ce85dc7f0b87445928cd6b94.1765283601.git.u.kleine-koenig@baylibre.com

ALSA: seq: oss: Clean up core code with guard()

2025-08-29T09:52:36+00:00

Replace the manual mutex lock/unlock pairs with guard() for code simplification. Only code refactoring, and no behavior change. Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20250827080520.7544-9-tiwai@suse.de

ALSA: seq: Fix assignment in if condition

2021-06-09T15:30:26+00:00

There are lots of places doing assignments in if condition in ALSA sequencer core, which is a bad coding style that may confuse readers and occasionally lead to bugs. This patch is merely for coding-style fixes, no functional changes. Link: https://lore.kernel.org/r/20210608140540.17885-57-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: seq: oss: Avoid mutex lock for a long-time ioctl

2020-09-23T12:45:14+00:00

Recently we applied a fix to cover the whole OSS sequencer ioctls with the mutex for dealing with the possible races. This works fine in general, but in theory, this may lead to unexpectedly long stall if an ioctl like SNDCTL_SEQ_SYNC is issued and an event with the far future timestamp was queued. For fixing such a potential stall, this patch changes the mutex lock applied conditionally excluding such an ioctl command. Also, change the mutex_lock() with the interruptible version for user to allow escaping from the big-hammer mutex. Fixes: 80982c7e834e ("ALSA: seq: oss: Serialize ioctls") Suggested-by: Pavel Machek Link: https://lore.kernel.org/r/20200922083856.28572-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: seq: oss: Serialize ioctls

2020-08-05T06:27:39+00:00

Some ioctls via OSS sequencer API may race and lead to UAF when the port create and delete are performed concurrently, as spotted by a couple of syzkaller cases. This patch is an attempt to address it by serializing the ioctls with the existing register_mutex. Basically OSS sequencer API is an obsoleted interface and was designed without much consideration of the concurrency. There are very few applications with it, and the concurrent performance isn't asked, hence this "big hammer" approach should be good enough. Reported-by: syzbot+1a54a94bd32716796edd@syzkaller.appspotmail.com Reported-by: syzbot+9d2abfef257f3e2d4713@syzkaller.appspotmail.com Suggested-by: Hillf Danton Cc: Link: https://lore.kernel.org/r/20200804185815.2453-1-tiwai@suse.de Signed-off-by: Takashi Iwai

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

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 Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

ALSA: seq: Fix poll() error return

2018-07-26T06:23:26+00:00

The sanity checks in ALSA sequencer and OSS sequencer emulation codes return falsely -ENXIO from poll callback. They should be EPOLLERR instead. This was caught thanks to the recent change to the return value. Cc: Signed-off-by: Takashi Iwai

sound: annotate ->poll() instances

2017-11-27T21:20:02+00:00

Signed-off-by: Al Viro

ALSA: seq: oss: Don't drain at closing a client

2016-03-01T19:26:40+00:00

The OSS sequencer client tries to drain the pending events at releasing. Unfortunately, as spotted by syzkaller fuzzer, this may lead to an unkillable process state when the event has been queued at the far future. Since the process being released can't be signaled any longer, it remains and waits for the echo-back event in that far future. Back to history, the draining feature was implemented at the time we misinterpreted POSIX definition for blocking file operation. Actually, such a behavior is superfluous at release, and we should just release the device as is instead of keeping it up forever. This patch just removes the draining call that may block the release for too long time unexpectedly. BugLink: http://lkml.kernel.org/r/CACT4Y+Y4kD-aBGj37rf-xBw9bH3GMU6P+MYg4W1e-s-paVD2pg@mail.gmail.com Reported-by: Dmitry Vyukov Cc: Signed-off-by: Takashi Iwai

ALSA: Fix compat_ioctl handling for OSS emulations

2015-12-03T16:40:21+00:00

The ALSA PCM, mixer and sequencer OSS emulations provide the 32bit compatible ioctl, but they just call the 64bit native ioctl as is. Although this works in most cases, passing the argument value as-is isn't guaranteed to work on all architectures. We need to convert it via compat_ptr() instead. This patch addresses the missing conversions. Since all relevant ioctls in these functions take the argument as a pointer, we do the pointer conversion in each compat_ioctl and pass it as a 64bit value to the native ioctl. Signed-off-by: Takashi Iwai