[alsa-devel] [PATCH] ALSA: hda - hdmi get jack from hda_jack_tbl when not dyn_pcm_assign

[Takashi Iwai]

On Thu, 18 Feb 2016 09:02:24 +0100,
Yang, Libin wrote:
> 
> Hi Takashi,
> 
> > -----Original Message-----
> > From: Takashi Iwai [mailto:tiwai at suse.de]
> > Sent: Thursday, February 18, 2016 3:54 PM
> > To: libin.yang at linux.intel.com
> > Cc: alsa-devel at alsa-project.org; Lin, Mengdong; Yang, Libin
> > Subject: Re: [PATCH] ALSA: hda - hdmi get jack from hda_jack_tbl when
> > not dyn_pcm_assign
> > 
> > On Thu, 18 Feb 2016 06:25:02 +0100,
> > libin.yang at linux.intel.com wrote:
> > >
> > > From: Libin Yang <libin.yang at linux.intel.com>
> > >
> > > On Intel platform, if !dyn_pcm_assign, spec->pcm_rec[].jack is not
> > > NULL even after snd_hda_jack_tbl_clear() is called to free snd_jack.
> > > This may cause access invalid memory when calling snd_jack_report.
> > >
> > > Please see more detail from:
> > > https://bugs.freedesktop.org/show_bug.cgi?id=94079
> > >
> > > Signed-off-by: Libin Yang <libin.yang at linux.intel.com>
> > > ---
> > >  sound/pci/hda/patch_hdmi.c | 16 ++++++++++++++--
> > >  1 file changed, 14 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/sound/pci/hda/patch_hdmi.c
> > b/sound/pci/hda/patch_hdmi.c
> > > index f4443b5..3b47101 100644
> > > --- a/sound/pci/hda/patch_hdmi.c
> > > +++ b/sound/pci/hda/patch_hdmi.c
> > > @@ -1962,6 +1962,7 @@ static void sync_eld_via_acomp(struct
> > hda_codec *codec,
> > >  {
> > >  	struct hdmi_spec *spec = codec->spec;
> > >  	struct hdmi_eld *eld = &spec->temp_eld;
> > > +	struct hda_jack_tbl *jack_tbl;
> > >  	struct snd_jack *jack = NULL;
> > >  	int size;
> > >
> > > @@ -1989,10 +1990,21 @@ static void sync_eld_via_acomp(struct
> > hda_codec *codec,
> > >  	/* pcm_idx >=0 before update_eld() means it is in monitor
> > >  	 * disconnected event. Jack must be fetched before update_eld()
> > >  	 */
> > > -	if (per_pin->pcm_idx >= 0)
> > > +	/* if !dyn_pcm_assign, get jack from hda_jack_tbl
> > > +	 * in !dyn_pcm_assign case, spec->pcm_rec[].jack is not
> > > +	 * NULL even after snd_hda_jack_tbl_clear() is called to
> > > +	 * free snd_jack. This may cause access invalid memory
> > > +	 * when calling snd_jack_report
> > > +	 */
> > > +	if (per_pin->pcm_idx >= 0 && spec->dyn_pcm_assign)
> > >  		jack = spec->pcm_rec[per_pin->pcm_idx].jack;
> > > +	else {
> > > +		jack_tbl = snd_hda_jack_tbl_get(codec, per_pin-
> > >pin_nid);
> > > +		if (jack_tbl)
> > > +			jack = jack_tbl->jack;
> > > +	}
> > >  	update_eld(codec, per_pin, eld);
> > > -	if (jack == NULL && per_pin->pcm_idx >= 0)
> > > +	if (jack == NULL && per_pin->pcm_idx >= 0 && spec-
> > >dyn_pcm_assign)
> > >  		jack = spec->pcm_rec[per_pin->pcm_idx].jack;
> > >  	if (jack == NULL)
> > >  		goto unlock;
> > 
> > I'd create a separate small helper function, e.g. pin_to_jack()
> > doing like:
> > 
> > pin_idx_to_jack(codec, per_pin)
> > {
> > 	if (spec->dyn_pcm_assign) {
> > 		if (per_pin->pcm_idx < 0)
> > 			return NULL;
> > 		return spec->pcm_rec[per_pin->pcm_idx].jack;
> > 	} else {
> > 		jack_tbl = snd_hda_jack_tbl_get(codec, per_pin-
> > >pin_nid);
> > 		if (!jack_tbl)
> > 			return NULL;
> > 		return jack_tbl->jack;
> > 	}
> > }
> > 
> > Then the code update_eld() will be cleaner,
> > 
> > 	jack = pin_to_jack(codec, per_pin);
> > 	update_eld(codec, per_pin, eld);
> > 	if (!jack)
> > 		jack = pin_to_jack(codec, per_pin);
> > 	if (!jack)
> > 		goto unlock;
> > 
> > Alternatively, assign pcm_rec[].jack beforehand for non-dyn PCM.
> > It's fixed, so you can assign it in initialization.
> 
> Get it. So your patch will be merged to for-next soon? Thanks.

I *would* do, but I won't write it but wait for your renewed patch ;)


Takashi