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authorTakashi Iwai <tiwai@suse.de>2023-07-06 17:53:57 +0200
committerTakashi Iwai <tiwai@suse.de>2023-07-06 18:01:59 +0200
commit89dbb335cb6a627a4067bc42caa09c8bc3326d40 (patch)
tree8bf187a9bc1cb9ca2287b3ebafe93c234e57ba6e /sound
parent5284876d82da4453df0e21f1d243b026281a6558 (diff)
ALSA: jack: Fix mutex call in snd_jack_report()
snd_jack_report() is supposed to be callable from an IRQ context, too, and it's indeed used in that way from virtsnd driver. The fix for input_dev race in commit 1b6a6fc5280e ("ALSA: jack: Access input_dev under mutex"), however, introduced a mutex lock in snd_jack_report(), and this resulted in a potential sleep-in-atomic. For addressing that problem, this patch changes the relevant code to use the object get/put and removes the mutex usage. That is, snd_jack_report(), it takes input_get_device() and leaves with input_put_device() for assuring the input_dev being assigned. Although the whole mutex could be reduced, we keep it because it can be still a protection for potential races between creation and deletion. Fixes: 1b6a6fc5280e ("ALSA: jack: Access input_dev under mutex") Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/cf95f7fe-a748-4990-8378-000491b40329@moroto.mountain Tested-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20230706155357.3470-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/core/jack.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/sound/core/jack.c b/sound/core/jack.c
index 88493cc31914..03d155ed362b 100644
--- a/sound/core/jack.c
+++ b/sound/core/jack.c
@@ -654,6 +654,7 @@ void snd_jack_report(struct snd_jack *jack, int status)
struct snd_jack_kctl *jack_kctl;
unsigned int mask_bits = 0;
#ifdef CONFIG_SND_JACK_INPUT_DEV
+ struct input_dev *idev;
int i;
#endif
@@ -670,17 +671,15 @@ void snd_jack_report(struct snd_jack *jack, int status)
status & jack_kctl->mask_bits);
#ifdef CONFIG_SND_JACK_INPUT_DEV
- mutex_lock(&jack->input_dev_lock);
- if (!jack->input_dev) {
- mutex_unlock(&jack->input_dev_lock);
+ idev = input_get_device(jack->input_dev);
+ if (!idev)
return;
- }
for (i = 0; i < ARRAY_SIZE(jack->key); i++) {
int testbit = ((SND_JACK_BTN_0 >> i) & ~mask_bits);
if (jack->type & testbit)
- input_report_key(jack->input_dev, jack->key[i],
+ input_report_key(idev, jack->key[i],
status & testbit);
}
@@ -688,13 +687,13 @@ void snd_jack_report(struct snd_jack *jack, int status)
int testbit = ((1 << i) & ~mask_bits);
if (jack->type & testbit)
- input_report_switch(jack->input_dev,
+ input_report_switch(idev,
jack_switch_types[i],
status & testbit);
}
- input_sync(jack->input_dev);
- mutex_unlock(&jack->input_dev_lock);
+ input_sync(idev);
+ input_put_device(idev);
#endif /* CONFIG_SND_JACK_INPUT_DEV */
}
EXPORT_SYMBOL(snd_jack_report);