linux_dsm_epyc7002/sound
Mark Hills 027c70021b ALSA: echoaudio: Race conditions around "opencount"
Use of atomics does not make these statements robust:

       atomic_inc(&chip->opencount);
       if (atomic_read(&chip->opencount) > 1 && chip->rate_set)
               chip->can_set_rate=0;

and

       if (atomic_read(&chip->opencount)) {
               if (chip->opencount) {
                       changed = -EAGAIN;
               } else {
                       changed = set_digital_mode(chip, dmode);

It would be necessary to atomically increment or decrement the value
and use the returned result. And yet we still need to prevent other
threads making use of "can_set_rate" while we set it.

However in all but one case the atomic is misleading as they are already
running with "mode_mutex" held.

Decisions are made on mode setting are often intrinsically connected
to "opencount" because some operations are not permitted unless
there is sole ownership.

So instead simplify this, and use "mode_mutex" as a lock for all reference
counting and mode setting.

Signed-off-by: Mark Hills <mark@xwax.org>
Link: https://lore.kernel.org/r/20200708101848.3457-2-mark@xwax.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-07-09 12:58:35 +02:00
..
ac97 ALSA: ac97: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:11 +01:00
aoa treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
arm ASoC: arm: use asoc_rtd_to_cpu() / asoc_rtd_to_codec() macro for DAI pointer 2020-03-27 14:44:56 +00:00
atmel ALSA: atmel: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:12 +01:00
core ALSA: pcm: Fix build error on m68k and others 2020-07-07 13:13:12 +02:00
drivers ALSA: vx_core: remove warning for empty loop body 2020-07-07 12:13:16 +02:00
firewire ALSA: firewire: fix kernel-doc 2020-07-07 12:09:32 +02:00
hda ASoC: Updates for v5.8 2020-06-01 20:26:07 +02:00
i2c ALSA: i2c: Constify snd_kcontrol_new items 2020-01-03 09:24:24 +01:00
isa ALSA: isa/gus: remove 'set but not used' warning 2020-07-07 12:02:24 +02:00
mips ALSA: sgio2audio: Remove usage of dropped hw_params/hw_free functions 2020-03-06 12:06:41 +01:00
oss .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
parisc sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
pci ALSA: echoaudio: Race conditions around "opencount" 2020-07-09 12:58:35 +02:00
pcmcia ALSA: pcmcia/pdaudiocf: fix kernel-doc 2020-07-07 12:12:55 +02:00
ppc powerpc updates for 5.8 2020-06-05 12:39:30 -07:00
sh ALSA: sh: Fix compile warning wrt const 2020-01-05 16:15:14 +01:00
soc Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
sparc ALSA: sparc: More constifications 2020-01-05 16:14:56 +01:00
spi ALSA: spi: More constification 2020-01-05 16:15:13 +01:00
synth ALSA: emux: More constifications 2020-01-05 16:14:46 +01:00
usb ALSA: usb/line6: remove 'defined but not used' warning 2020-07-08 09:13:40 +02:00
x86 treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
xen ALSA: xen: remove 'set but not used' warning 2020-07-07 12:11:39 +02:00
ac97_bus.c ALSA: ac97: Treat snd_ac97_bus_ops as const 2020-01-03 09:24:08 +01:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
last.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
Makefile
sound_core.c sound: fix a memory leak bug 2019-08-08 08:18:32 +02:00