[alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Peter Ujfalusi]

Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
other purposes.

Currently it is left empty with the dmaengine-pcm, in this case copy the
pcm->id string as pcm->name.

For example IGT is using this to find the HDMI PCM for testing audio on it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reported-by: Arthur She <arthur.she@linaro.org>
---
Hi,

this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
in v4.18), since then we only use the generic dmaengine PCM but the same issue
applies today.

Regards,
Peter

 sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index 748f5f641002..d93db2c2b527 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
 
 		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
+
+		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
+			strncpy(rtd->pcm->streams[i].pcm->name,
+				rtd->pcm->streams[i].pcm->id,
+				sizeof(rtd->pcm->streams[i].pcm->name));
+		}
 	}
 
 	return 0;
-- 
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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[alsa-devel] Applied "ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set" to the asoc tree

[Mark Brown]

The patch

   ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.3

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

From 2ec42f3147e1610716f184b02e65d7f493eed925 Mon Sep 17 00:00:00 2001
From: Peter Ujfalusi <peter.ujfalusi@ti.com>
Date: Fri, 6 Sep 2019 08:55:24 +0300
Subject: [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the
 name is not set

Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
other purposes.

Currently it is left empty with the dmaengine-pcm, in this case copy the
pcm->id string as pcm->name.

For example IGT is using this to find the HDMI PCM for testing audio on it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reported-by: Arthur She <arthur.she@linaro.org>
Link: https://lore.kernel.org/r/20190906055524.7393-1-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index 748f5f641002..d93db2c2b527 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
 
 		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
 			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
+
+		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
+			strncpy(rtd->pcm->streams[i].pcm->name,
+				rtd->pcm->streams[i].pcm->id,
+				sizeof(rtd->pcm->streams[i].pcm->name));
+		}
 	}
 
 	return 0;
-- 
2.20.1

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Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Takashi Iwai]

On Fri, 06 Sep 2019 07:55:24 +0200,
Peter Ujfalusi wrote:
> 
> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
> other purposes.
> 
> Currently it is left empty with the dmaengine-pcm, in this case copy the
> pcm->id string as pcm->name.
> 
> For example IGT is using this to find the HDMI PCM for testing audio on it.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Reported-by: Arthur She <arthur.she@linaro.org>
> ---
> Hi,
> 
> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
> in v4.18), since then we only use the generic dmaengine PCM but the same issue
> applies today.
> 
> Regards,
> Peter
> 
>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
> index 748f5f641002..d93db2c2b527 100644
> --- a/sound/soc/soc-generic-dmaengine-pcm.c
> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
>  
>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
> +
> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
> +			strncpy(rtd->pcm->streams[i].pcm->name,
> +				rtd->pcm->streams[i].pcm->id,
> +				sizeof(rtd->pcm->streams[i].pcm->name));
> +		}

Any reason to use strncpy() instead of strscpy()?
After merging Mark's branch, I got a compile warning like:
  sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
  accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
  offset [9223372036854775807, -9223372036854775808] [-Wrestrict]


Takashi

>  
>  	return 0;
> -- 
> Peter
> 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
> 
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> 
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Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Peter Ujfalusi]

On 10/09/2019 15.07, Takashi Iwai wrote:
> On Fri, 06 Sep 2019 07:55:24 +0200,
> Peter Ujfalusi wrote:
>>
>> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
>> other purposes.
>>
>> Currently it is left empty with the dmaengine-pcm, in this case copy the
>> pcm->id string as pcm->name.
>>
>> For example IGT is using this to find the HDMI PCM for testing audio on it.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> Reported-by: Arthur She <arthur.she@linaro.org>
>> ---
>> Hi,
>>
>> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
>> in v4.18), since then we only use the generic dmaengine PCM but the same issue
>> applies today.
>>
>> Regards,
>> Peter
>>
>>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
>> index 748f5f641002..d93db2c2b527 100644
>> --- a/sound/soc/soc-generic-dmaengine-pcm.c
>> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
>> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
>>  
>>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
>>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
>> +
>> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
>> +			strncpy(rtd->pcm->streams[i].pcm->name,
>> +				rtd->pcm->streams[i].pcm->id,
>> +				sizeof(rtd->pcm->streams[i].pcm->name));
>> +		}
> 
> Any reason to use strncpy() instead of strscpy()?
> After merging Mark's branch, I got a compile warning like:
>   sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
>   accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
>   offset [9223372036854775807, -9223372036854775808] [-Wrestrict]

I have not seen such a warning.
'may overlap up to 0 bytes' ?
snd_pcm_info {
...
        unsigned char id[64];           /* ID (user selectable) */
        unsigned char name[80];         /* name of this device */
        unsigned char subname[32];      /* subdevice name */
...
};

and strncpy() supposed to be something like this:
char * strncpy(char *dest, const char *src, size_t n)
{
	size_t i;

	for (i = 0; i < n && src[i] != '\0'; i++)
		dest[i] = src[i];
	for ( ; i < n; i++)
		dest[i] = '\0';

	return dest;
}

I can see if I can get my compilers to show the warning and try
strscpy() if it helps on it.

> 
> 
> Takashi
> 
>>  
>>  	return 0;
>> -- 
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>
>> _______________________________________________
>> Alsa-devel mailing list
>> Alsa-devel@alsa-project.org
>> https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Takashi Iwai]

On Tue, 10 Sep 2019 16:23:59 +0200,
Peter Ujfalusi wrote:
> 
> 
> 
> On 10/09/2019 15.07, Takashi Iwai wrote:
> > On Fri, 06 Sep 2019 07:55:24 +0200,
> > Peter Ujfalusi wrote:
> >>
> >> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
> >> other purposes.
> >>
> >> Currently it is left empty with the dmaengine-pcm, in this case copy the
> >> pcm->id string as pcm->name.
> >>
> >> For example IGT is using this to find the HDMI PCM for testing audio on it.
> >>
> >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> >> Reported-by: Arthur She <arthur.she@linaro.org>
> >> ---
> >> Hi,
> >>
> >> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
> >> in v4.18), since then we only use the generic dmaengine PCM but the same issue
> >> applies today.
> >>
> >> Regards,
> >> Peter
> >>
> >>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
> >>  1 file changed, 6 insertions(+)
> >>
> >> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
> >> index 748f5f641002..d93db2c2b527 100644
> >> --- a/sound/soc/soc-generic-dmaengine-pcm.c
> >> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
> >> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
> >>  
> >>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
> >>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
> >> +
> >> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
> >> +			strncpy(rtd->pcm->streams[i].pcm->name,
> >> +				rtd->pcm->streams[i].pcm->id,
> >> +				sizeof(rtd->pcm->streams[i].pcm->name));
> >> +		}
> > 
> > Any reason to use strncpy() instead of strscpy()?
> > After merging Mark's branch, I got a compile warning like:
> >   sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
> >   accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
> >   offset [9223372036854775807, -9223372036854775808] [-Wrestrict]
> 
> I have not seen such a warning.
> 'may overlap up to 0 bytes' ?
> snd_pcm_info {
> ...
>         unsigned char id[64];           /* ID (user selectable) */
>         unsigned char name[80];         /* name of this device */
>         unsigned char subname[32];      /* subdevice name */
> ...
> };
> 
> and strncpy() supposed to be something like this:
> char * strncpy(char *dest, const char *src, size_t n)
> {
> 	size_t i;
> 
> 	for (i = 0; i < n && src[i] != '\0'; i++)
> 		dest[i] = src[i];
> 	for ( ; i < n; i++)
> 		dest[i] = '\0';
> 
> 	return dest;
> }
> 
> I can see if I can get my compilers to show the warning and try
> strscpy() if it helps on it.

strncpy() doesn't guarantee the string termination if you pass the
exact buffer size.  Better to use strscpy() in such a case.


thanks,

Takashi
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Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Takashi Iwai]

On Tue, 10 Sep 2019 16:46:04 +0200,
Takashi Iwai wrote:
> 
> On Tue, 10 Sep 2019 16:23:59 +0200,
> Peter Ujfalusi wrote:
> > 
> > 
> > 
> > On 10/09/2019 15.07, Takashi Iwai wrote:
> > > On Fri, 06 Sep 2019 07:55:24 +0200,
> > > Peter Ujfalusi wrote:
> > >>
> > >> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
> > >> other purposes.
> > >>
> > >> Currently it is left empty with the dmaengine-pcm, in this case copy the
> > >> pcm->id string as pcm->name.
> > >>
> > >> For example IGT is using this to find the HDMI PCM for testing audio on it.
> > >>
> > >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> > >> Reported-by: Arthur She <arthur.she@linaro.org>
> > >> ---
> > >> Hi,
> > >>
> > >> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
> > >> in v4.18), since then we only use the generic dmaengine PCM but the same issue
> > >> applies today.
> > >>
> > >> Regards,
> > >> Peter
> > >>
> > >>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
> > >>  1 file changed, 6 insertions(+)
> > >>
> > >> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
> > >> index 748f5f641002..d93db2c2b527 100644
> > >> --- a/sound/soc/soc-generic-dmaengine-pcm.c
> > >> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
> > >> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
> > >>  
> > >>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
> > >>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
> > >> +
> > >> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
> > >> +			strncpy(rtd->pcm->streams[i].pcm->name,
> > >> +				rtd->pcm->streams[i].pcm->id,
> > >> +				sizeof(rtd->pcm->streams[i].pcm->name));
> > >> +		}
> > > 
> > > Any reason to use strncpy() instead of strscpy()?
> > > After merging Mark's branch, I got a compile warning like:
> > >   sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
> > >   accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
> > >   offset [9223372036854775807, -9223372036854775808] [-Wrestrict]
> > 
> > I have not seen such a warning.
> > 'may overlap up to 0 bytes' ?
> > snd_pcm_info {
> > ...
> >         unsigned char id[64];           /* ID (user selectable) */
> >         unsigned char name[80];         /* name of this device */
> >         unsigned char subname[32];      /* subdevice name */
> > ...
> > };
> > 
> > and strncpy() supposed to be something like this:
> > char * strncpy(char *dest, const char *src, size_t n)
> > {
> > 	size_t i;
> > 
> > 	for (i = 0; i < n && src[i] != '\0'; i++)
> > 		dest[i] = src[i];
> > 	for ( ; i < n; i++)
> > 		dest[i] = '\0';
> > 
> > 	return dest;
> > }
> > 
> > I can see if I can get my compilers to show the warning and try
> > strscpy() if it helps on it.
> 
> strncpy() doesn't guarantee the string termination if you pass the
> exact buffer size.  Better to use strscpy() in such a case.

On the second thought, if pcm->id isn't NULL-terminated, it would
result in OOB access.  So, if strncpy() usage is just to guarantee for
the zero-fill, that's OK, to ignore as a possibly spurious old gcc
warning...


Takashi
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Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Peter Ujfalusi]

On 10/09/2019 15.07, Takashi Iwai wrote:
> On Fri, 06 Sep 2019 07:55:24 +0200,
> Peter Ujfalusi wrote:
>>
>> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
>> other purposes.
>>
>> Currently it is left empty with the dmaengine-pcm, in this case copy the
>> pcm->id string as pcm->name.
>>
>> For example IGT is using this to find the HDMI PCM for testing audio on it.
>>
>> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
>> Reported-by: Arthur She <arthur.she@linaro.org>
>> ---
>> Hi,
>>
>> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
>> in v4.18), since then we only use the generic dmaengine PCM but the same issue
>> applies today.
>>
>> Regards,
>> Peter
>>
>>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
>> index 748f5f641002..d93db2c2b527 100644
>> --- a/sound/soc/soc-generic-dmaengine-pcm.c
>> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
>> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
>>  
>>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
>>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
>> +
>> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
>> +			strncpy(rtd->pcm->streams[i].pcm->name,
>> +				rtd->pcm->streams[i].pcm->id,
>> +				sizeof(rtd->pcm->streams[i].pcm->name));
>> +		}
> 
> Any reason to use strncpy() instead of strscpy()?
> After merging Mark's branch, I got a compile warning like:
>   sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
>   accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
>   offset [9223372036854775807, -9223372036854775808] [-Wrestrict]

fwiw I run it again with sparse and it only reports these:
 CHECK   sound/soc/soc-generic-dmaengine-pcm.c
sound/soc/soc-generic-dmaengine-pcm.c:177:42: warning: restricted snd_pcm_format_t degrades to integer
sound/soc/soc-generic-dmaengine-pcm.c:177:47: warning: restricted snd_pcm_format_t degrades to integer
sound/soc/soc-generic-dmaengine-pcm.c:177:71: warning: restricted snd_pcm_format_t degrades to integer
  CC      sound/soc/soc-generic-dmaengine-pcm.o

gcc 6.4.0...9.2.0
sparse 0.6.0

> 
> 
> Takashi
> 
>>  
>>  	return 0;
>> -- 
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>
>> _______________________________________________
>> Alsa-devel mailing list
>> Alsa-devel@alsa-project.org
>> https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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Re: [alsa-devel] [PATCH] ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set

[Takashi Iwai]

On Wed, 11 Sep 2019 09:22:53 +0200,
Peter Ujfalusi wrote:
> 
> 
> 
> On 10/09/2019 15.07, Takashi Iwai wrote:
> > On Fri, 06 Sep 2019 07:55:24 +0200,
> > Peter Ujfalusi wrote:
> >>
> >> Some tools use the snd_pcm_info_get_name() to try to identify PCMs or for
> >> other purposes.
> >>
> >> Currently it is left empty with the dmaengine-pcm, in this case copy the
> >> pcm->id string as pcm->name.
> >>
> >> For example IGT is using this to find the HDMI PCM for testing audio on it.
> >>
> >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> >> Reported-by: Arthur She <arthur.she@linaro.org>
> >> ---
> >> Hi,
> >>
> >> this was actually reported for 4.14 kernel with omap-pcm (replaced by sdma-pcm
> >> in v4.18), since then we only use the generic dmaengine PCM but the same issue
> >> applies today.
> >>
> >> Regards,
> >> Peter
> >>
> >>  sound/soc/soc-generic-dmaengine-pcm.c | 6 ++++++
> >>  1 file changed, 6 insertions(+)
> >>
> >> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
> >> index 748f5f641002..d93db2c2b527 100644
> >> --- a/sound/soc/soc-generic-dmaengine-pcm.c
> >> +++ b/sound/soc/soc-generic-dmaengine-pcm.c
> >> @@ -306,6 +306,12 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
> >>  
> >>  		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
> >>  			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
> >> +
> >> +		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
> >> +			strncpy(rtd->pcm->streams[i].pcm->name,
> >> +				rtd->pcm->streams[i].pcm->id,
> >> +				sizeof(rtd->pcm->streams[i].pcm->name));
> >> +		}
> > 
> > Any reason to use strncpy() instead of strscpy()?
> > After merging Mark's branch, I got a compile warning like:
> >   sound/soc/soc-generic-dmaengine-pcm.c:311:4: warning: 'strncpy'
> >   accessing 80 bytes at offsets 88 and 24 may overlap up to 0 bytes at
> >   offset [9223372036854775807, -9223372036854775808] [-Wrestrict]
> 
> fwiw I run it again with sparse and it only reports these:
>  CHECK   sound/soc/soc-generic-dmaengine-pcm.c
> sound/soc/soc-generic-dmaengine-pcm.c:177:42: warning: restricted snd_pcm_format_t degrades to integer
> sound/soc/soc-generic-dmaengine-pcm.c:177:47: warning: restricted snd_pcm_format_t degrades to integer
> sound/soc/soc-generic-dmaengine-pcm.c:177:71: warning: restricted snd_pcm_format_t degrades to integer
>   CC      sound/soc/soc-generic-dmaengine-pcm.o
> 
> gcc 6.4.0...9.2.0
> sparse 0.6.0

That happens only with some cross-build on my build tests, so it must
be a pretty minor issue.

But in general, almost all strncpy() use case can be replaced
gracefully with a safer function, either strscpy() or strscpy_pad().
IOW, if you see strncpy(), the patch looks doubtful :)


thanks,

Takashi


> 
> > 
> > 
> > Takashi
> > 
> >>  
> >>  	return 0;
> >> -- 
> >> Peter
> >>
> >> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> >> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
> >>
> >> _______________________________________________
> >> Alsa-devel mailing list
> >> Alsa-devel@alsa-project.org
> >> https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> >>
> 
> - Péter
> 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
> 
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