@@ -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);
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> Signed-off-by: Takashi Iwai <tiwai@suse.de> --- sound/core/jack.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)