[PATCH 3.19 110/177] ALSA: fireworks/bebob/dice/oxfw: allow stream destructor after releasing runtime

Greg Kroah-Hartman
2015-03-16T14:16:00Z

From: Takashi Sakamoto <o-takashi@sakamocchi.jp>

commit d23c2cc4485d10f0cedfef99dd2961d9652b1b3f upstream.

Currently stream destructor in each driver has a problem to be called in
a context in which sound card object is released, because the destructors
call amdtp_stream_pcm_abort() and touch PCM runtime data.

The PCM runtime data is destroyed in application's context with
snd_pcm_close(), on the other hand PCM substream data is destroyed after
sound card object is released, in most case after all of ALSA character
devices are released. When PCM runtime is destroyed and PCM substream is
remained, amdtp_stream_pcm_abort() touches PCM runtime data and causes
Null-pointer-dereference.

This commit changes stream destructors and allows each driver to call
it after releasing runtime.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/firewire/bebob/bebob_stream.c | 12 ++++--------
sound/firewire/dice/dice-stream.c | 18 ++++++++++++------
sound/firewire/fireworks/fireworks_stream.c | 15 ++++++++++-----
sound/firewire/oxfw/oxfw-stream.c | 6 ++++--
4 files changed, 30 insertions(+), 21 deletions(-)

--- a/sound/firewire/bebob/bebob_stream.c
+++ b/sound/firewire/bebob/bebob_stream.c
@@ -410,8 +410,6 @@ break_both_connections(struct snd_bebob
static void
destroy_both_connections(struct snd_bebob *bebob)
{
- break_both_connections(bebob);
-
cmp_connection_destroy(&bebob->in_conn);
cmp_connection_destroy(&bebob->out_conn);
}
@@ -712,16 +710,14 @@ void snd_bebob_stream_update_duplex(stru
mutex_unlock(&bebob->mutex);
}

+/*
+ * This function should be called before starting streams or after stopping
+ * streams.
+ */
void snd_bebob_stream_destroy_duplex(struct snd_bebob *bebob)
{
mutex_lock(&bebob->mutex);

- amdtp_stream_pcm_abort(&bebob->rx_stream);
- amdtp_stream_pcm_abort(&bebob->tx_stream);
-
- amdtp_stream_stop(&bebob->rx_stream);
- amdtp_stream_stop(&bebob->tx_stream);
-
amdtp_stream_destroy(&bebob->rx_stream);
amdtp_stream_destroy(&bebob->tx_stream);

--- a/sound/firewire/dice/dice-stream.c
+++ b/sound/firewire/dice/dice-stream.c
@@ -311,14 +311,21 @@ end:
return err;
}

+/*
+ * This function should be called before starting streams or after stopping
+ * streams.
+ */
static void destroy_stream(struct snd_dice *dice, struct amdtp_stream *stream)
{
- amdtp_stream_destroy(stream);
+ struct fw_iso_resources *resources;

if (stream == &dice->tx_stream)
- fw_iso_resources_destroy(&dice->tx_resources);
+ resources = &dice->tx_resources;
else
- fw_iso_resources_destroy(&dice->rx_resources);
+ resources = &dice->rx_resources;
+
+ amdtp_stream_destroy(stream);
+ fw_iso_resources_destroy(resources);
}

int snd_dice_stream_init_duplex(struct snd_dice *dice)
@@ -332,6 +339,8 @@ int snd_dice_stream_init_duplex(struct s
goto end;

err = init_stream(dice, &dice->rx_stream);
+ if (err < 0)
+ destroy_stream(dice, &dice->tx_stream);
end:
return err;
}
@@ -340,10 +349,7 @@ void snd_dice_stream_destroy_duplex(stru
{
snd_dice_transaction_clear_enable(dice);

- stop_stream(dice, &dice->tx_stream);
destroy_stream(dice, &dice->tx_stream);
-
- stop_stream(dice, &dice->rx_stream);
destroy_stream(dice, &dice->rx_stream);

dice->substreams_counter = 0;
--- a/sound/firewire/fireworks/fireworks_stream.c
+++ b/sound/firewire/fireworks/fireworks_stream.c
@@ -100,17 +100,22 @@ end:
return err;
}

+/*
+ * This function should be called before starting the stream or after stopping
+ * the streams.
+ */
static void
destroy_stream(struct snd_efw *efw, struct amdtp_stream *stream)
{
- stop_stream(efw, stream);
-
- amdtp_stream_destroy(stream);
+ struct cmp_connection *conn;

if (stream == &efw->tx_stream)
- cmp_connection_destroy(&efw->out_conn);
+ conn = &efw->out_conn;
else
- cmp_connection_destroy(&efw->in_conn);
+ conn = &efw->in_conn;
+
+ amdtp_stream_destroy(stream);
+ cmp_connection_destroy(&efw->out_conn);
}

static int
--- a/sound/firewire/oxfw/oxfw-stream.c
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -337,6 +337,10 @@ void snd_oxfw_stream_stop_simplex(struct
stop_stream(oxfw, stream);
}

+/*
+ * This function should be called before starting the stream or after stopping
+ * the streams.
+ */
void snd_oxfw_stream_destroy_simplex(struct snd_oxfw *oxfw,
struct amdtp_stream *stream)
{
@@ -347,8 +351,6 @@ void snd_oxfw_stream_destroy_simplex(str
else
conn = &oxfw->in_conn;

- stop_stream(oxfw, stream);
-
amdtp_stream_destroy(stream);
cmp_connection_destroy(conn);
}