Takashi Iwai ddce57a6f0 ALSA: dummy: Implement timer backend switching more safely ... Currently the selected timer backend is referred at any moment from the running PCM callbacks. When the backend is switched, it's possible to lead to inconsistency from the running backend. This was pointed by syzkaller fuzzer, and the commit [7ee96216c3: ALSA: dummy: Disable switching timer backend via sysfs] disabled the dynamic switching for avoiding the crash. This patch improves the handling of timer backend switching. It keeps the reference to the selected backend during the whole operation of an opened stream so that it won't be changed by other streams. Together with this change, the hrtimer parameter is reenabled as writable now. NOTE: this patch also turned out to fix the still remaining race. Namely, ops was still replaced dynamically at dummy_pcm_open: static int dummy_pcm_open(struct snd_pcm_substream *substream) { .... dummy->timer_ops = &dummy_systimer_ops; if (hrtimer) dummy->timer_ops = &dummy_hrtimer_ops; Since dummy->timer_ops is common among all streams, and when the replacement happens during accesses of other streams, it may lead to a crash. This was actually triggered by syzkaller fuzzer and KASAN. This patch rewrites the code not to use the ops shared by all streams any longer, too. BugLink: http://lkml.kernel.org/r/CACT4Y+aZ+xisrpuM6cOXbL21DuM0yVxPYXf4cD4Md9uw0C3dBQ@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>		2016-02-08 08:15:35 +01:00
..
mpu401
opl3	Merge branch 'for-linus' into for-next	2015-03-09 08:42:00 +01:00
opl4	ALSA: opl4: Fix / cleanup ifdef CONFIG_PROC_FS	2015-05-29 07:49:55 +02:00
pcsp	ALSA: drivers: pcsp: Fix printout of resolution	2015-05-12 09:14:51 +02:00
vx
aloop.c	ALSA: aloop: Drop unnecessary ifdef CONFIG_PROC_FS	2015-05-29 07:46:05 +02:00
dummy.c	ALSA: dummy: Implement timer backend switching more safely	2016-02-08 08:15:35 +01:00
Kconfig
Makefile
ml403-ac97cr.c
mtpav.c
mts64.c
pcm-indirect2.c	treewide: Fix typos in printk	2015-12-08 14:59:19 +01:00
pcm-indirect2.h
portman2x4.c
serial-u16550.c
virmidi.c