OpenCloudOS-Kernel/sound/oss
Alexey Khoroshilov bc26d4d06e sound/oss: fix deadlock in sequencer_ioctl(SNDCTL_SEQ_OUTOFBAND)
A deadlock can be initiated by userspace via ioctl(SNDCTL_SEQ_OUTOFBAND)
on /dev/sequencer with TMR_ECHO midi event.

In this case the control flow is:
sound_ioctl()
-> case SND_DEV_SEQ:
   case SND_DEV_SEQ2:
     sequencer_ioctl()
     -> case SNDCTL_SEQ_OUTOFBAND:
          spin_lock_irqsave(&lock,flags);
          play_event();
          -> case EV_TIMING:
               seq_timing_event()
               -> case TMR_ECHO:
                    seq_copy_to_input()
                    -> spin_lock_irqsave(&lock,flags);

It seems that spin_lock_irqsave() around play_event() is not necessary,
because the only other call location in seq_startplay() makes the call
without acquiring spinlock.

So, the patch just removes spinlocks around play_event().
By the way, it removes unreachable code in seq_timing_event(),
since (seq_mode == SEQ_2) case is handled in the beginning.

Compile tested only.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-18 09:05:55 +02:00
..
dmasound sound: dmasound_atari: Remove obsolete IRQ_TYPE_SLOW 2015-01-15 13:44:51 +01:00
.gitignore oss: remove maui_boot.h from .gitignore and dontdiff 2012-09-01 08:36:09 -07:00
CHANGELOG
Kconfig x86, platforms: Remove SGI Visual Workstation 2014-02-27 08:07:39 -08:00
Makefile x86, platforms: Remove SGI Visual Workstation 2014-02-27 08:07:39 -08:00
README.FIRST
ad1848.c sound/oss: Remove uncompilable DBG macro use 2014-04-04 18:20:10 +02:00
ad1848.h [PATCH] The scheduled removal of some OSS drivers 2006-10-04 07:55:32 -07:00
ad1848_mixer.h fix file specification in comments 2006-10-03 23:01:26 +02:00
aedsp16.c sound: aedsp16: Buffer overflow 2009-07-29 14:37:12 +02:00
audio.c sound: Remove unnecessary semicolon 2012-10-06 16:47:53 +02:00
bin2hex.c
coproc.h sound/oss/coproc.h: Checkpatch cleanup 2010-03-02 11:22:19 +01:00
dev_table.c sound: Deparenthesize negative error returns 2015-03-24 11:41:37 +01:00
dev_table.h sound/oss: remove offset from load_patch callbacks 2011-03-23 22:47:46 +01:00
dmabuf.c sound: oss: remove last sleep_on users 2014-01-14 16:12:07 +01:00
hex2hex.c oss: Mark loadhex static in hex2hex.c 2009-11-15 15:01:42 -08:00
kahlua.c PCI: Remove DEFINE_PCI_DEVICE_TABLE macro use 2014-08-12 12:15:14 -06:00
midi_ctrl.h
midi_synth.c sound/oss: remove offset from load_patch callbacks 2011-03-23 22:47:46 +01:00
midi_synth.h sound/oss: remove offset from load_patch callbacks 2011-03-23 22:47:46 +01:00
midibuf.c sound: oss: midibuf: fix sleep_on races 2014-01-14 16:11:44 +01:00
mpu401.c sound: oss: mpu401.c: Cleaning up variable is set more than once 2014-06-25 14:32:03 +02:00
mpu401.h IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
msnd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
msnd.h [PATCH] introduce fmode_t, do annotations 2008-10-21 07:47:06 -04:00
msnd_classic.c
msnd_classic.h sound: sound/oss/: remove CVS keywords 2008-05-27 15:56:20 +02:00
msnd_pinnacle.c sound/oss: use current->state helpers 2015-01-15 08:32:27 +01:00
msnd_pinnacle.h sound: sound/oss/: remove CVS keywords 2008-05-27 15:56:20 +02:00
opl3.c sound/oss/opl3: remove some stray whitespace 2015-02-25 20:08:15 +01:00
opl3_hw.h
os.h Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
pas2.h sound: Move prototype declaration to header file oss/pas2.h from oss/pas2_card.c 2014-02-07 18:24:42 +01:00
pas2_card.c sound: Move prototype declaration to header file oss/pas2.h from oss/pas2_card.c 2014-02-07 18:24:42 +01:00
pas2_midi.c fix file specification in comments 2006-10-03 23:01:26 +02:00
pas2_mixer.c sound/oss: Remove uncompilable DBG macro use 2014-04-04 18:20:10 +02:00
pas2_pcm.c sound/oss: Remove uncompilable DBG macro use 2014-04-04 18:20:10 +02:00
pss.c sound: oss: Deletion of unnecessary checks before the function call "vfree" 2015-01-04 15:11:56 +01:00
sb.h
sb_audio.c sound: oss/sb_audio: cap value in sb201_audio_set_speed() 2012-11-18 10:24:49 +01:00
sb_card.c Fix common misspellings 2011-03-31 11:26:23 -03:00
sb_card.h
sb_common.c sound/oss: Remove uncompilable DBG macro use 2014-04-04 18:20:10 +02:00
sb_ess.c sound/sb_ess: white space cleanups 2015-02-25 20:08:21 +01:00
sb_ess.h
sb_midi.c sound/sb_midi: a couple indenting fixes 2015-02-25 20:08:27 +01:00
sb_mixer.c sound: Remove unnecessary semicolon 2012-10-06 16:47:53 +02:00
sb_mixer.h fix file specification in comments 2006-10-03 23:01:26 +02:00
sequencer.c sound/oss: fix deadlock in sequencer_ioctl(SNDCTL_SEQ_OUTOFBAND) 2015-04-18 09:05:55 +02:00
sleep.h sound: oss: remove last sleep_on users 2014-01-14 16:12:07 +01:00
sound_calls.h [PATCH] kill sound/oss/*_syms.c 2006-10-04 07:55:32 -07:00
sound_config.h sound/oss: Remove uncompilable DBG macro use 2014-04-04 18:20:10 +02:00
sound_firmware.h
sound_timer.c sound: oss: use strlcpy() in sound_timer_init() 2011-09-29 08:12:33 +02:00
soundcard.c sound/oss: Remove uncompilable DBG macro use 2014-04-04 18:20:10 +02:00
soundvers.h
swarm_cs4297a.c sound/oss: use current->state helpers 2015-01-15 08:32:27 +01:00
sys_timer.c sound: sys_timer: indent poll_def_tmr() correctly 2015-02-25 20:08:07 +01:00
trix.c sound: oss: Deletion of unnecessary checks before the function call "vfree" 2015-01-04 15:11:56 +01:00
tuning.h [PATCH] The scheduled removal of some OSS drivers 2006-10-04 07:55:32 -07:00
uart401.c sound: oss: uart401: remove unneeded NULL check 2014-11-22 21:48:33 +01:00
uart6850.c sound: Remove unnecessary semicolon 2012-10-06 16:47:53 +02:00
ulaw.h
v_midi.c sound: Deparenthesize negative error returns 2015-03-24 11:41:37 +01:00
v_midi.h sound/oss/v_midi.h: Checkpatch cleanup 2010-03-02 11:22:08 +01:00
vidc.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
vidc.h IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
vidc_fill.S [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach 2008-08-07 09:55:48 +01:00
waveartist.c sound: oss: Remove typedefs wanc_info and wavnc_port_info 2014-08-06 16:42:40 +02:00
waveartist.h fix file specification in comments 2006-10-03 23:01:26 +02:00

README.FIRST

The modular sound driver patches were funded by Red Hat Software 
(www.redhat.com). The sound driver here is thus a modified version of 
Hannu's code. Please bear that in mind when considering the appropriate
forums for bug reporting. 

Alan Cox