[alsa-devel] snd_seq_parse_address accesses uninitialised data

[Henning Thielemann]

On Mon, 24 Sep 2012, Takashi Iwai wrote:

> At Mon, 24 Sep 2012 16:20:50 +0200 (CEST),
> Henning Thielemann wrote:
>>
>> For me valgrind is pretty useless if I have to manually distinguish real
>> problems from false alarms in a long list of valgrind messages. Are you
>> sure that it is generally ok to pass pointers to uninitialized data to
>> ioctl also if in this particular case the pointer is not touched by ioctl?
>
> Only client field is read, and this is the field properly initialized
> in alsa-lib code.  Others are fields to be filled by the kernel, so it
> doesn't matter at all what's left there.
>
>> If yes, then I think valgrind must be somehow teached to ignore this
>> particular case.
>
> I have no idea how to teach valgrind, sorry.

I also asked in the valgrind mailing list and got this answer:
    http://sourceforge.net/mailarchive/forum.php?thread_name=506089CA.5030309%40bitwagon.com&forum_name=valgrind-users

Of course, I can suppress the message for me, but I expect that more 
people will stumble on it. Thus I'd prefer a resolution of the problem in 
ALSA.