diff mbox series

ASoC: soc-compress: Reposition and add pcm_mutex

Message ID 016401d90ac4$7b6848c0$7238da40$@samsung.com (mailing list archive)
State New, archived
Headers show
Series ASoC: soc-compress: Reposition and add pcm_mutex | expand

Commit Message

강신형 Dec. 8, 2022, 5:18 a.m. UTC
If panic_on_warn is set and compress stream(DPCM) is started,
then kernel panic occurred because card->pcm_mutex isn't held appropriately.
In the following functions, warning were issued at this line
"snd_soc_dpcm_mutex_assert_held".

static int dpcm_be_connect(struct snd_soc_pcm_runtime *fe,
		struct snd_soc_pcm_runtime *be, int stream)
{
	...
	snd_soc_dpcm_mutex_assert_held(fe);
	...
}

void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream)
{
	...
	snd_soc_dpcm_mutex_assert_held(fe);
	...
}

void snd_soc_runtime_action(struct snd_soc_pcm_runtime *rtd,
			    int stream, int action)
{
	...
	snd_soc_dpcm_mutex_assert_held(rtd);
	...
}

int dpcm_dapm_stream_event(struct snd_soc_pcm_runtime *fe, int dir,
	int event)
{
	...
	snd_soc_dpcm_mutex_assert_held(fe);
	...
}

These functions are called by soc_compr_set_params_fe, soc_compr_open_fe
and soc_compr_free_fe
without pcm_mutex locking. And this is call stack.

[  414.527841][ T2179] pc : dpcm_process_paths+0x5a4/0x750
[  414.527848][ T2179] lr : dpcm_process_paths+0x37c/0x750
[  414.527945][ T2179] Call trace:
[  414.527949][ T2179]  dpcm_process_paths+0x5a4/0x750
[  414.527955][ T2179]  soc_compr_open_fe+0xb0/0x2cc
[  414.527972][ T2179]  snd_compr_open+0x180/0x248
[  414.527981][ T2179]  snd_open+0x15c/0x194
[  414.528003][ T2179]  chrdev_open+0x1b0/0x220
[  414.528023][ T2179]  do_dentry_open+0x30c/0x594
[  414.528045][ T2179]  vfs_open+0x34/0x44
[  414.528053][ T2179]  path_openat+0x914/0xb08
[  414.528062][ T2179]  do_filp_open+0xc0/0x170
[  414.528068][ T2179]  do_sys_openat2+0x94/0x18c
[  414.528076][ T2179]  __arm64_sys_openat+0x78/0xa4
[  414.528084][ T2179]  invoke_syscall+0x48/0x10c
[  414.528094][ T2179]  el0_svc_common+0xbc/0x104
[  414.528099][ T2179]  do_el0_svc+0x34/0xd8
[  414.528103][ T2179]  el0_svc+0x34/0xc4
[  414.528125][ T2179]  el0t_64_sync_handler+0x8c/0xfc
[  414.528133][ T2179]  el0t_64_sync+0x1a0/0x1a4
[  414.528142][ T2179] Kernel panic - not syncing: panic_on_warn set ...

So, I reposition and add pcm_mutex to resolve lockdep error.

Signed-off-by: Shinhyung Kang <s47.kang@samsung.com>
---
 sound/soc/soc-compress.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

 	fe->dpcm[stream].runtime = fe_substream->runtime;
@@ -184,7 +186,6 @@ static int soc_compr_open_fe(struct snd_compr_stream
*cstream)
 	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_OPEN;
 	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_NO;
 
-	mutex_lock_nested(&fe->card->pcm_mutex, fe->card->pcm_subclass);
 	snd_soc_runtime_activate(fe, stream);
 	mutex_unlock(&fe->card->pcm_mutex);
 
@@ -215,7 +216,6 @@ static int soc_compr_free_fe(struct snd_compr_stream
*cstream)
 
 	mutex_lock_nested(&fe->card->pcm_mutex, fe->card->pcm_subclass);
 	snd_soc_runtime_deactivate(fe, stream);
-	mutex_unlock(&fe->card->pcm_mutex);
 
 	fe->dpcm[stream].runtime_update = SND_SOC_DPCM_UPDATE_FE;
 
@@ -234,6 +234,8 @@ static int soc_compr_free_fe(struct snd_compr_stream
*cstream)
 
 	dpcm_be_disconnect(fe, stream);
 
+	mutex_unlock(&fe->card->pcm_mutex);
+
 	fe->dpcm[stream].runtime = NULL;
 
 	snd_soc_link_compr_shutdown(cstream, 0);
@@ -409,8 +411,9 @@ static int soc_compr_set_params_fe(struct
snd_compr_stream *cstream,
 	ret = snd_soc_link_compr_set_params(cstream);
 	if (ret < 0)
 		goto out;
-
+	mutex_lock_nested(&fe->card->pcm_mutex, fe->card->pcm_subclass);
 	dpcm_dapm_stream_event(fe, stream, SND_SOC_DAPM_STREAM_START);
+	mutex_unlock(&fe->card->pcm_mutex);
 	fe->dpcm[stream].state = SND_SOC_DPCM_STATE_PREPARE;
 
 out:

Comments

Mark Brown Jan. 28, 2023, 10:48 a.m. UTC | #1
On Thu, 08 Dec 2022 14:18:18 +0900, 강신형 wrote:
> If panic_on_warn is set and compress stream(DPCM) is started,
> then kernel panic occurred because card->pcm_mutex isn't held appropriately.
> In the following functions, warning were issued at this line
> "snd_soc_dpcm_mutex_assert_held".
> 
> static int dpcm_be_connect(struct snd_soc_pcm_runtime *fe,
> 		struct snd_soc_pcm_runtime *be, int stream)
> {
> 	...
> 	snd_soc_dpcm_mutex_assert_held(fe);
> 	...
> }
> 
> [...]

Applied to

   broonie/sound.git for-next

Thanks!

[1/1] ASoC: soc-compress: Reposition and add pcm_mutex
      commit: aa9ff6a4955fdba02b54fbc4386db876603703b7

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark
diff mbox series

Patch

diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index 870f13e1d389..7bce5088b455 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -149,6 +149,8 @@  static int soc_compr_open_fe(struct snd_compr_stream
*cstream)
 	if (ret < 0)
 		goto be_err;
 
+	mutex_lock_nested(&fe->card->pcm_mutex, fe->card->pcm_subclass);
+
 	/* calculate valid and active FE <-> BE dpcms */
 	dpcm_process_paths(fe, stream, &list, 1);