[PATCH AUTOSEL 6.6 43/47] ALSA: pcmtest: stop timer before buffer is released

Sasha Levin
2023-12-11T13:53:55Z

From: Ivan Orlov <ivan.orlov0322@gmail.com>

[ Upstream commit eb99b1b72a424a79f56c972e0fd7ad01fe93a008 ]

Stop timer in the 'trigger' and 'sync_stop' callbacks since we want
the timer to be stopped before the DMA buffer is released. Otherwise,
it could trigger a kernel panic in some circumstances, for instance
when the DMA buffer is already released but the timer callback is
still running.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20231206223211.12761-1-ivan.orlov0322@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/drivers/pcmtest.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
index b59b78a092240..b8bff5522bce2 100644
--- a/sound/drivers/pcmtest.c
+++ b/sound/drivers/pcmtest.c
@@ -397,7 +397,6 @@ static int snd_pcmtst_pcm_close(struct snd_pcm_substream *substream)
struct pcmtst_buf_iter *v_iter = substream->runtime->private_data;

timer_shutdown_sync(&v_iter->timer_instance);
- v_iter->substream = NULL;
playback_capture_test = !v_iter->is_buf_corrupted;
kfree(v_iter);
return 0;
@@ -435,6 +434,7 @@ static int snd_pcmtst_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
// We can't call timer_shutdown_sync here, as it is forbidden to sleep here
v_iter->suspend = true;
+ timer_delete(&v_iter->timer_instance);
break;
}

@@ -512,12 +512,22 @@ static int snd_pcmtst_ioctl(struct snd_pcm_substream *substream, unsigned int cm
return snd_pcm_lib_ioctl(substream, cmd, arg);
}

+static int snd_pcmtst_sync_stop(struct snd_pcm_substream *substream)
+{
+ struct pcmtst_buf_iter *v_iter = substream->runtime->private_data;
+
+ timer_delete_sync(&v_iter->timer_instance);
+
+ return 0;
+}
+
static const struct snd_pcm_ops snd_pcmtst_playback_ops = {
.open = snd_pcmtst_pcm_open,
.close = snd_pcmtst_pcm_close,
.trigger = snd_pcmtst_pcm_trigger,
.hw_params = snd_pcmtst_pcm_hw_params,
.ioctl = snd_pcmtst_ioctl,
+ .sync_stop = snd_pcmtst_sync_stop,
.hw_free = snd_pcmtst_pcm_hw_free,
.prepare = snd_pcmtst_pcm_prepare,
.pointer = snd_pcmtst_pcm_pointer,
@@ -530,6 +540,7 @@ static const struct snd_pcm_ops snd_pcmtst_capture_ops = {
.hw_params = snd_pcmtst_pcm_hw_params,
.hw_free = snd_pcmtst_pcm_hw_free,
.ioctl = snd_pcmtst_ioctl,
+ .sync_stop = snd_pcmtst_sync_stop,
.prepare = snd_pcmtst_pcm_prepare,
.pointer = snd_pcmtst_pcm_pointer,
};
--
2.42.0