Rm_session_cap invalid

[Steffen Liebergeld]

Hi Norman,

Am 26.05.2010 16:19, schrieb Norman Feske:
> Hi Steffen,
> 
>> during startup of the init task, the init thread tries to get an
>> "Env::rm_session" from core. Core responds by giving it a capability
>> with local_name() == 0, which is invalid in my context. The cap is
>> returned from _process.rm_session_cap(), which is implemented in process.h:
>> Rm_session_capability rm_session_cap() const {return _rm.cap(); }
>> _rm is defined as Rm_connection in class Process. I am unsure however,
>> which Constructor belongs to to Rm_connection, and why it sets the
>> capability to zero. Can you help me by pointing me to the right spots?
> 
> The 'Env::rm_session' is the RM session managing the address space of
> the process. It is created by the parent (in your case, core) at
> construction time of the 'Child' object. The RM session is created via
> core's 'env()->parent()->session()', which is directed to the core-local
> 'Core_parent::session()' function (in 'core/main.cc'). For checking if
> the constuction of init's RM session succeeded, I recommend you to
> instrument the '_create_session' function in 'core/include/rm_root.h'
> and the 'Core_parent::session()' function. Check for the capabilities
> returned by 'ls->root()->session(args)'.

Thank you. I created the following trace:

int main(): --- start init ---
int main(): Ok we have 231 MB transfered to init
virtual Genode::Session_capability Genode::Core_parent::session(const
char*, const char*): service_name="RM" cap.cap()=9000 cap.local_name=16
virtual Genode::Session_capability Genode::Core_parent::session(const
char*, const char*): service_name="PD" cap.cap()=9000 cap.local_name=18

Both capabilities are valid in this context.

Genode::Process::Process(Genode::Dataspace_capability, \
	Genode::Ram_session_capability, Genode::Cpu_session_capability,\
	Genode::Parent_capability, const char*, char* const*):\
	name="init" rm_session_cap().cap()=9000\
	rm_session_cap().local_name()=16

So after the Process::Process ran, _process->rm_session_cap() should
return the correct capabilities... Lets see:

virtual Genode::Session_capability
	Genode::Child::session(const char*, const char*):
		_ram_session_cap.cap()=9000 local_name=7

virtual int
	Genode::Parent_server::dispatch(int, Genode::Ipc_istream&,
	Genode::Ipc_ostream&):
		server name="Env::ram_session" args="" cap()=9000
		local_name=7

Ok, worked for the ram_session.

virtual Genode::Session_capability
	Genode::Child::session(const char*, const char*):
		_cpu_session_cap.cap()=9000 local_name=10

virtual int
	Genode::Parent_server::dispatch(int, Genode::Ipc_istream&,
	Genode::Ipc_ostream&):
		server name="Env::cpu_session" args="" cap()=9000
		local_name=10

Ok, worked for the cpu_session as well.

virtual Genode::Session_capability
	Genode::Child::session(const char*, const char*):
		_process.rm_session_cap().cap()=0 local_name=0

virtual int
	Genode::Parent_server::dispatch(int, Genode::Ipc_istream&,
	Genode::Ipc_ostream&):
		server name="Env::rm_session" args="" cap()=0
		local_name=0

Did not work for the rm_session. Do you have any ideas?

Many thanks,
Steffen

-- 
Dipl.-Inf. Steffen Liebergeld <steffen at ...37...>
Security in Telecommunications
TU Berlin/ Deutsche Telekom Laboratories
Ernst-Reuter-Platz 7, 10587 Berlin
Phone: +30 8353 58 263
Web: http://www.t-labs.tu-berlin.de/sect