![]() 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> |
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.. | ||
dmasound | ||
.gitignore | ||
ad1848.c | ||
ad1848.h | ||
ad1848_mixer.h | ||
aedsp16.c | ||
audio.c | ||
bin2hex.c | ||
CHANGELOG | ||
coproc.h | ||
dev_table.c | ||
dev_table.h | ||
dmabuf.c | ||
hex2hex.c | ||
kahlua.c | ||
Kconfig | ||
Makefile | ||
midi_ctrl.h | ||
midi_synth.c | ||
midi_synth.h | ||
midibuf.c | ||
mpu401.c | ||
mpu401.h | ||
msnd.c | ||
msnd.h | ||
msnd_classic.c | ||
msnd_classic.h | ||
msnd_pinnacle.c | ||
msnd_pinnacle.h | ||
opl3.c | ||
opl3_hw.h | ||
os.h | ||
pas2.h | ||
pas2_card.c | ||
pas2_midi.c | ||
pas2_mixer.c | ||
pas2_pcm.c | ||
pss.c | ||
README.FIRST | ||
sb.h | ||
sb_audio.c | ||
sb_card.c | ||
sb_card.h | ||
sb_common.c | ||
sb_ess.c | ||
sb_ess.h | ||
sb_midi.c | ||
sb_mixer.c | ||
sb_mixer.h | ||
sequencer.c | ||
sleep.h | ||
sound_calls.h | ||
sound_config.h | ||
sound_firmware.h | ||
sound_timer.c | ||
soundcard.c | ||
soundvers.h | ||
swarm_cs4297a.c | ||
sys_timer.c | ||
trix.c | ||
tuning.h | ||
uart401.c | ||
uart6850.c | ||
ulaw.h | ||
v_midi.c | ||
v_midi.h | ||
vidc.c | ||
vidc.h | ||
vidc_fill.S | ||
waveartist.c | ||
waveartist.h |
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