kernel.git/sound/core/seq/oss, branch linux-4.15.y

ALSA: seq: Fix OSS sysex delivery in OSS emulation

2017-11-07T15:05:24Z

The SYSEX event delivery in OSS sequencer emulation assumed that the event is encoded in the variable-length data with the straight buffering. This was the normal behavior in the past, but during the development, the chained buffers were introduced for carrying more data, while the OSS code was left intact. As a result, when a SYSEX event with the chained buffer data is passed to OSS sequencer port, it may end up with the wrong memory access, as if it were having a too large buffer. This patch addresses the bug, by applying the buffer data expansion by the generic snd_seq_dump_var_event() helper function. Reported-by: syzbot Reported-by: Mark Salyzyn Cc: Signed-off-by: Takashi Iwai

ALSA: seq: Allow the tristate build of OSS emulation

2017-06-09T20:09:45Z

Currently OSS sequencer emulation is tied with ALSA sequencer core, both are built in the same level; i.e. when CONFIG_SND_SEQUENCER=y, the OSS sequencer emulation is also always built-in, even though the functionality can be built as an individual module. This patch changes the rule and allows users to build snd-seq-oss module while others are built-in. Essentially, it's just a few simple changes in Kconfig and Makefile. Some driver codes like opl3 need to convert from the simple ifdef to IS_ENABLED(). But that's all. You might wonder how about the dependency: right, it can be messy, but it still works. Since we rewrote the sequencer binding with the standard bus, the driver can be bound at any time on demand. So, the synthesizer driver module can be loaded individually from the OSS emulation core before/after it. Signed-off-by: Takashi Iwai

sched/headers: Prepare to move signal wakeup & sigpending methods from into

2017-03-02T07:42:32Z

Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

ALSA: seq_oss: Change structure initialisation to C99 style

2016-06-15T08:13:54Z

Replace the in order struct initialisation style with explicit field style. The Coccinelle semantic patch used to make this change is as follows: @decl@ identifier i1,fld; type T; field list[n] fs; @@ struct i1 { fs T fld; ...}; @@ identifier decl.i1,i2,decl.fld; expression e; position bad.p, bad.fix; @@ struct i1 i2@p = { ..., + .fld = e - e@fix ,...}; Also, removed some unnecessary comments. Signed-off-by: Amitoj Kaur Chawla Signed-off-by: Takashi Iwai

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

2016-03-01T19:26:40Z

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: seq: Degrade the error message for too many opens

2016-01-25T10:52:23Z

ALSA OSS sequencer spews a kernel error message ("ALSA: seq_oss: too many applications") when user-space tries to open more than the limit. This means that it can easily fill the log buffer. Since it's merely a normal error, it's safe to suppress it via pr_debug() instead. Cc: Signed-off-by: Takashi Iwai

ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup()

2016-01-25T10:49:10Z

ALSA sequencer OSS emulation code has a sanity check for currently opened devices, but there is a thinko there, eventually it spews warnings and skips the operation wrongly like: WARNING: CPU: 1 PID: 7573 at sound/core/seq/oss/seq_oss_synth.c:311 Fix this off-by-one error. Reported-by: Dmitry Vyukov Cc: Signed-off-by: Takashi Iwai

ALSA: Fix compat_ioctl handling for OSS emulations

2015-12-03T16:40:21Z

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

ALSA: seq_oss: fix waitqueue_active without memory barrier in snd-seq-oss

2015-10-09T07:45:52Z

snd_seq_oss_readq_put_event() seems to be missing a memory barrier which might cause the waker to not notice the waiter and miss sending a wake_up as in the following figure. snd_seq_oss_readq_put_event snd_seq_oss_readq_wait ------------------------------------------------------------------------ /* wait_event_interruptible_timeout */ /* __wait_event_interruptible_timeout */ /* ___wait_event */ for (;;) { prepare_to_wait_event(&wq, &__wait, state); spin_lock_irqsave(&q->lock, flags); if (waitqueue_active(&q->midi_sleep)) /* The CPU might reorder the test for the waitqueue up here, before prior writes complete */ if ((q->qlen>0 || q->head==q->tail) ... __ret = schedule_timeout(__ret) if (q->qlen >= q->maxlen - 1) { memcpy(&q->q[q->tail], ev, sizeof(*ev)); q->tail = (q->tail + 1) % q->maxlen; q->qlen++; ------------------------------------------------------------------------ There are two other place in sound/core/seq/oss/ which have similar code. The attached patch removes the call to waitqueue_active() leaving just wake_up() behind. This fixes the problem because the call to spin_lock_irqsave() in wake_up() will be an ACQUIRE operation. I found this issue when I was looking through the linux source code for places calling waitqueue_active() before wake_up*(), but without preceding memory barriers, after sending a patch to fix a similar issue in drivers/tty/n_tty.c (Details about the original issue can be found here: https://lkml.org/lkml/2015/9/28/849). Signed-off-by: Kosuke Tatsukawa Signed-off-by: Takashi Iwai

ALSA: replace CONFIG_PROC_FS with CONFIG_SND_PROC_FS

2015-05-27T19:25:19Z

We may disable proc fs only for sound part, to reduce ALSA memory footprint. So add CONFIG_SND_PROC_FS and replace the old CONFIG_PROC_FSs in alsa code. With sound proc fs disabled, we can save about 9KB memory size on X86_64 platform. Signed-off-by: Jie Yang Reviewed-by: Mark Brown Signed-off-by: Takashi Iwai