[pulseaudio-discuss] Is it OK for PulseAudio to crash when BlueZ is buggy?

[Luiz Augusto von Dentz]

Hi Tanu,

On Wed, May 9, 2012 at 8:26 PM, Tanu Kaskinen <tanuk at iki.fi> wrote:
> On Wed, 2012-05-09 at 17:12 +0200, Dalleau, Frederic wrote:
>> > What triggered this was a question about what to do if BlueZ claims that
>> > there are two devices with the same address (that should never happen).
>> > I'd like to store the devices in a hashmap with the address as the key,
>> > so there are complications if there are multiple devices with the same
>> > address. Those complications can be avoided, if I do just:
>> >
>> > pa_assert_se(pa_hashmap_put(bluetooth_core->devices_by_address, device->address) >= 0);
>> >
>> > Why should I implement any more complex error handling?
>>
>> The error handling don't have to be necessarily complex (goto fail?).
>> And the use of an assertion creates the perception that PulseAudio has
>> crashed, whereas in this case (if it ever happened) the bug would not be
>> in pulse.
>>
>> Let's put the question another way : What is the benefit at not being
>> paranoid?
>
> The benefit is simpler code.
>
> It's clearly not a very popular idea to add assertions about D-Bus
> service behavior. I'll forget about it then. It shouldn't be a big
> burden to add the necessary message validation checks. If there is
> clearly invalid stuff in the messages, I'll just ignore the message and
> log an error: "The same address is assigned to multiple devices. This
> may be a bug in BlueZ. In any case, the Bluetooth functionality probably
> won't work very well."
>
> Also, I think I now finally understood David's point about libraries'
> ability to corrupt the process memory: incorrectly behaving libraries
> undermine the trust in all of the process memory in a way that buggy
> D-Bus services can't do. Therefore there's less reason with D-Bus
> services for just giving up and aborting if something unexpected
> happens.
>
> --
> Tanu

Btw, are you sure this is a problem? We can have the same address in
different devices if they are paired with different adapters,
otherwise it is a bug and we should be able to fix it.


-- 
Luiz Augusto von Dentz