Linux IO_MEM session

[Norman Feske]

Hi Johannes,

> I have tracked down the issue to the Io_mem_dataspace_capability being
> invalid.
> The segfault is caused by _dataspace_size() being called on an invalid
> capability in region_map_mmap.cc.

just a shot in the dark: Have you called 'Rpc_entrypoint::manage(ds)'
for your dataspace object? Or to put the question differently: Is the
dataspace capability that you return in
'Io_mem_session_component::dataspace()' valid inside core? If not, you
have most likely missed to associate your 'Dataspace_component' object
with core's entrypoint.

> I looked into other implementations of base-linux that use the
> Dataspace_capability. They all just instanciate and return it. This is
> also the case for the Io_mem_dataspace_capability yet it seems to be
> invalid by default.
> I tried to return a Dataspace_capability but it can't be casted.
> As far as I understand it I have to either validate the
> Io_mem_dataspace_capability or cast to it.

Could you point me to a branch where I can have look at the code and
reproduce the problem?

Cheers
Norman

-- 
Dr.-Ing. Norman Feske
Genode Labs

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