alsamixer crashes with SIGFPE

alsamixer crashes with SIGFPE

[Florian Faber]

Hi,

there are several spots in alsamixer's mixer_display.c that cause SIGFPE
through division by zero if (max-min) is zero:

bar_height = ((volumes[c] - min) * volume_height + max - min - 1) / (max
- min);

value = ((volumes[0] - min) * 100 + (max - min) / 2) / (max - min);

etc.


Flo
-- 
Machines can do the work, so people have time to think.
public key DA43FEF4          x-hkp://wwwkeys.eu.pgp.net

Re: alsamixer crashes with SIGFPE

[Clemens Ladisch]

Florian Faber wrote:
> there are several spots in alsamixer's mixer_display.c that cause SIGFPE
> through division by zero if (max-min) is zero:
> 
> bar_height = ((volumes[c] - min) * volume_height + max - min - 1) / (max - min);
> value = ((volumes[0] - min) * 100 + (max - min) / 2) / (max - min);

Thanks.  With which hardware do you see this error?


Regards,
Clemens

Re: alsamixer crashes with SIGFPE

[Florian Faber]

Clemens,

>> bar_height = ((volumes[c] - min) * volume_height + max - min - 1) / (max - min);
>> value = ((volumes[0] - min) * 100 + (max - min) / 2) / (max - min);
> 
> Thanks.  With which hardware do you see this error?

I tried it with the hdspm driver after seeing all the complaints about
hdsp no longer working with 2.6.32.

Unfortunately cannot look into that as I no longer have hdsp cards around.


Flo
-- 
Machines can do the work, so people have time to think.
public key DA43FEF4          x-hkp://wwwkeys.eu.pgp.net

Re: alsamixer crashes with SIGFPE

[Clemens Ladisch]

Florian Faber wrote:
>>> bar_height = ((volumes[c] - min) * volume_height + max - min - 1) / (max - min);
>>> value = ((volumes[0] - min) * 100 + (max - min) / 2) / (max - min);
>> 
>> Thanks.  With which hardware do you see this error?
> 
> I tried it with the hdspm driver after seeing all the complaints about
> hdsp no longer working with 2.6.32.

That driver does not appear to have any controls where min==max.
Anyway, I've fixed alsamixer.

The hdsp problems are probably caused by the firmware loader change.


Regards,
Clemens