[PATCH] ASoC: SOF: Intel: Fix stream cleanup on pcm close
Field "substream" gets assigned during stream setup in hda_dsp_pcm_hw_params() but it is never cleared afterwards during hda_dsp_pcm_close(). Now, any non-pcm operation e.g.: compress can mistakenly make use of that pointer as it's bypassing all "if (s->substream)" checks.
Nulling the pointer during close operation ensures no wild pointers are left behind.
Fixes: cdae3b9a47aa ("ASoC: SOF: Intel: Add Intel specific HDA PCM operations") Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com --- sound/soc/sof/intel/hda-pcm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/soc/sof/intel/hda-pcm.c b/sound/soc/sof/intel/hda-pcm.c index a46a6baa1c3f..4b3a89cf20e7 100644 --- a/sound/soc/sof/intel/hda-pcm.c +++ b/sound/soc/sof/intel/hda-pcm.c @@ -246,5 +246,6 @@ int hda_dsp_pcm_close(struct snd_sof_dev *sdev,
/* unbinding pcm substream to hda stream */ substream->runtime->private_data = NULL; + hstream->substream = NULL; return 0; }
On 2/18/20 8:10 AM, Cezary Rojewski wrote:
Field "substream" gets assigned during stream setup in hda_dsp_pcm_hw_params() but it is never cleared afterwards during hda_dsp_pcm_close(). Now, any non-pcm operation e.g.: compress can mistakenly make use of that pointer as it's bypassing all "if (s->substream)" checks.
Nulling the pointer during close operation ensures no wild pointers are left behind.
Fixes: cdae3b9a47aa ("ASoC: SOF: Intel: Add Intel specific HDA PCM operations") Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com
sound/soc/sof/intel/hda-pcm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/soc/sof/intel/hda-pcm.c b/sound/soc/sof/intel/hda-pcm.c index a46a6baa1c3f..4b3a89cf20e7 100644 --- a/sound/soc/sof/intel/hda-pcm.c +++ b/sound/soc/sof/intel/hda-pcm.c @@ -246,5 +246,6 @@ int hda_dsp_pcm_close(struct snd_sof_dev *sdev,
/* unbinding pcm substream to hda stream */ substream->runtime->private_data = NULL;
- hstream->substream = NULL; return 0; }
Humm, yes we should clean this, but wondering if the close() operation is the right place. Doing this is hda_dsp_stream_hw_free() sounds more logical to me?
On 2020-02-18 17:45, Pierre-Louis Bossart wrote:
On 2/18/20 8:10 AM, Cezary Rojewski wrote:
Field "substream" gets assigned during stream setup in hda_dsp_pcm_hw_params() but it is never cleared afterwards during hda_dsp_pcm_close(). Now, any non-pcm operation e.g.: compress can mistakenly make use of that pointer as it's bypassing all "if (s->substream)" checks.
Nulling the pointer during close operation ensures no wild pointers are left behind.
Fixes: cdae3b9a47aa ("ASoC: SOF: Intel: Add Intel specific HDA PCM operations") Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com
sound/soc/sof/intel/hda-pcm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/soc/sof/intel/hda-pcm.c b/sound/soc/sof/intel/hda-pcm.c index a46a6baa1c3f..4b3a89cf20e7 100644 --- a/sound/soc/sof/intel/hda-pcm.c +++ b/sound/soc/sof/intel/hda-pcm.c @@ -246,5 +246,6 @@ int hda_dsp_pcm_close(struct snd_sof_dev *sdev, /* unbinding pcm substream to hda stream */ substream->runtime->private_data = NULL; + hstream->substream = NULL; return 0; }
Humm, yes we should clean this, but wondering if the close() operation is the right place. Doing this is hda_dsp_stream_hw_free() sounds more logical to me?
Ain't hda-pcm.c the best place for it as "hstream->substream = substream" happens there too? If the cleanup is to be done in _hw_free(), then I'd expect the same to happen to the original assignments. Doubt we want to do the later so.. _close() for the win?
In general the existing hstream->substream initialization looks kinda disconnected from the actual stream assignment code - _stream_get() - as if the duties of the state machine were shared.
Czarek
Hi Cezary,
diff --git a/sound/soc/sof/intel/hda-pcm.c b/sound/soc/sof/intel/hda-pcm.c index a46a6baa1c3f..4b3a89cf20e7 100644 --- a/sound/soc/sof/intel/hda-pcm.c +++ b/sound/soc/sof/intel/hda-pcm.c @@ -246,5 +246,6 @@ int hda_dsp_pcm_close(struct snd_sof_dev *sdev, /* unbinding pcm substream to hda stream */ substream->runtime->private_data = NULL; + hstream->substream = NULL; return 0; }
Humm, yes we should clean this, but wondering if the close() operation is the right place. Doing this is hda_dsp_stream_hw_free() sounds more logical to me?
Ain't hda-pcm.c the best place for it as "hstream->substream = substream" happens there too? If the cleanup is to be done in _hw_free(), then I'd expect the same to happen to the original assignments. Doubt we want to do the later so.. _close() for the win?
In general the existing hstream->substream initialization looks kinda disconnected from the actual stream assignment code - _stream_get() - as if the duties of the state machine were shared.
I am having difficulties interpreting your answer, i.e. I don't know what the last sentence refers to.
Currently open() and close() are perfectly symmetrical, I don't really see why you'd want to change and add an imbalanced set of operations, unless you moved
hstream->substream = substream;
to the open() instead of hw_params().
Or alternatively add a hw_free() in hda-pcm.c to mirror what's done in hw_params.
On 2020-02-18 20:05, Pierre-Louis Bossart wrote:
Ain't hda-pcm.c the best place for it as "hstream->substream = substream" happens there too? If the cleanup is to be done in _hw_free(), then I'd expect the same to happen to the original assignments. Doubt we want to do the later so.. _close() for the win?
In general the existing hstream->substream initialization looks kinda disconnected from the actual stream assignment code - _stream_get() - as if the duties of the state machine were shared.
I am having difficulties interpreting your answer, i.e. I don't know what the last sentence refers to.
It's just safer to tie substream assignment directly with _stream_get() so problems such as this don't stay hidden and arise later during the development process. _stream_assign() in /hda/ext/hdac_ext_stream/ & _stream_release in /hda/hdac_stream do exactly that.
Currently open() and close() are perfectly symmetrical, I don't really see why you'd want to change and add an imbalanced set of operations, unless you moved
hstream->substream = substream;
to the open() instead of hw_params().
Or alternatively add a hw_free() in hda-pcm.c to mirror what's done in hw_params.
Relocated to _hw_free(). Thanks.
participants (2)
-
Cezary Rojewski -
Pierre-Louis Bossart