The CPU session interfaces comes with the ability to install an
exception handler per thread. This patch enhances the feature with the
provision of a default signal handler that is used if no thread-specific
handler is installed. The default signal handler can be set by
specifying an invalid thread capability and a valid signal context
capability.
Furthermore, this patch relaxes the requirement of the order of the
calls of 'exception_handler' and 'set_pager'. Originally, the exception
handler could be installed not before setting a pager. Now, we remember
the installed exception handler in the 'Cpu_thread' and propagate to to
the platform thread at a later time.
It happens that ram_session and rm_session itself are invoking alloc
respectively free on the very same sliced heap inside core.
Lock only the sliced_heap list implementation and let the session locking to
the session implementation of rm_session and ram_session.
The ram_session and rm_session must take care to proper lock since inside
both implementations already the session handling thread and the service thread
are running parallel.
With commit 1389b63050 in thread.cc for base-foc
a bug was fixed, where the memory of the context got freed up before running
the de-constructor.
Apply the fix also to base and base-mb.
For base-nova thread creation related exception can be thrown, since the
Pager_objects are threads. Catch the exception and re-throw the
expected/documented exception in rm_session.
This commit avoids that core dies with an unhandled exception if a thread
couldn't be created (e.g. because the limit has been reached).
Sanity check that the context area has been attached. Otherwise the code
later tries to access the context area and core dies with a unhandled page
fault.
The Linux version of core used a part of the BSS to simulate access to
physical memory. All dataspaces would refer to a portion of 'some_mem'.
So every time when core would access the dataspace content, it would
access its local BSS. For all processes outside of core, dataspaces were
represented as files. This patch removes the distinction between core
and non-core processes. Now, core uses the same 'Rm_session_mmap'
implementation as regular processes. This way, the 'some_mem' could be
abandoned. We still use BSS variable for allocating core-local meta
data through.
This patch reflects eventual allocation errors in a more specific way to
the caller of 'alloc_aligned', in particular out-of-metadata and
out-of-memory are considered as different conditions.
Related to issue #526.
This patch introduces clean synchronization between the entrypoint
thread and the caller of the 'Rpc_entrypoint' destructor. The most
important change is the handling of the 'Ipc_server' destruction. This
object is in the local scope of the server's entry function. However,
since the server loop used to be an infinite loop, there was hardly any
chance to destruct the object in a clean way. Hence, the
'Rpc_entrypoint' destructor used to explicitly call '~Ipc_server'.
Unfortunately, this approach led to problems because there are indeed
rare cases where the server thread leaves the scope of the entry
function, namely uncaught exceptions. In such a case, the destructor
would have been called twice.
With the new protocol, we make sure to leave the scope of the entry
function and thereby destroy the 'Ipc_server' object as expected. This
is achieved by propagating the exit condition through a local RPC call
to the entrypoint. This way, the blocking state of the entrypoint
becomes unblocked. Furthermore, '~Rpc_entrypoint' makes use of the new
'join' function to wait for the completion of the server thread.
On Linux, we want to attach additional attributes to processes, i.e.,
the chroot location, the designated UID, and GID. Instead of polluting
the generic code with such Linux-specific platform details, I introduced
the new 'Native_pd_args' type, which can be customized for each
platform. The platform-dependent policy of init is factored out in the
new 'pd_args' library.
The new 'base-linux/run/lx_pd_args.run' script can be used to validate
the propagation of those attributes into core.
Note that this patch does not add the interpretation of the new UID and
PID attributes by core. This will be subject of a follow-up patch.
Related to #510.
Using the new 'join()' function, the caller can explicitly block for the
completion of the thread's 'entry()' function. The test case for this
feature can be found at 'os/src/test/thread_join'. For hybrid
Linux/Genode programs, the 'Thread_base::join()' does not map directly
to 'pthread_join'. The latter function gets already called by the
destructor of 'Thread_base'. According to the documentation, subsequent
calls of 'pthread_join' for one thread may result in undefined behaviour.
So we use a 'Genode::Lock' on this platform, which is in line with the
other platforms.
Related to #194, #501
The IPC-server object exists solely on the stack of the entrypoint
thread and, therefore, would never be destructed as the thread is just
killed. Now, the object is explicitly destructed in the entrypoint
destructor. An alternative solution could instruct the entrypoint thread
the terminate, which would automatically cleanup its stack.
The object pool is assumed to be empty on destruction of the entrypoint.
If not, we warn and at least dissolve all RPC objects.
Since the recent move of the process creation into core, the original chroot trampoline
mechanism implemented in 'os/src/app/chroot' does not work anymore. A
process could simply escape the chroot environment by spawning a new
process via core's PD service. Therefore, this patch moves the chroot
support into core. So the chroot policy becomes mandatory part of the
process creation. For each process created by core, core checks for
'root' argument of the PD session. If a path is present, core takes the
precautions needed to execute the new process in the specified chroot
environment.
This conceptual change implies minor changes with respect to the Genode
API and the configuration of the init process. The API changes are the
enhancement of the 'Genode::Child' and 'Genode::Process' constructors to
take the root path as argument. Init supports the specification of a
chroot per process by specifying the new 'root' attribute to the
'<start>' node of the process. In line with these changes, the
'Loader::Session::start' function has been enhanced with the additional
(optional) root argument.
On Linux, we use the session label for naming the corresponding Linux
process. When looking up the processes via 'ps', the Genode process
hierarchy becomes immediately visible.
This patch alleviates the need for any non-core process to create Unix
domain sockets locally. All sockets used for RPC communication are
created by core and subsequently passed to the other processes via RPC
or the parent interface. The immediate benefit is that no process other
than core needs to access the 'rpath' directory in order to communicate.
However, access to 'rpath' is still needed for accessing dataspaces.
Core creates one socket pair per thread on demand on the first call of
the 'Linux_cpu_session::server_sd()' or 'Linux_cpu_session::client_sd()'
functions. 'Linux_cpu_session' is a Linux-specific extension to the CPU
session interface. In addition to the socket accessors, the extension
provides a mechanism to register the PID/TID of a thread. Those
information were formerly propagated into core along with the thread
name as argument to 'create_thread()'.
Because core creates socket pairs for entrypoints, it needs to know all
threads that are potential entrypoints. For lx_hybrid programs, we
hadn't had propagated any thread information into core, yet. Hence, this
patch also contains the code for registering threads of hybrid
applications at core.
With this patch an error message gets printed in
'Allocator_avl_base::free()' if the given address is not the start address
of the allocated block.
Fixes#459.
By now all services in core where created, and registered in the generic
main routine. Although there exists already a x86-specific service (I/O ports)
there was no possibility to announce core-services for certain platforms only.
This commit introduces a hook function in the 'Platform' class, that enables
registration of platform-specific services. Moreover, the io-port service
is offered on x86 platforms only now.
The 'delete (void *)' operator gets referenced by compiler generated code,
so it must be publicly defined in the 'cxx' library. These compiler
generated calls seem to get executed only subsequently to explicit
'delete (void *)' calls in application code, which are not supported by
the 'cxx' library, so the 'delete (void *)' implementation in the 'cxx'
library does not have to do anything. Applications should use the
'delete (void *)' implementation of the 'stdcxx' library instead. To make
this possible, the 'delete (void *)' implementation in the 'cxx' library
must be 'weak'.
Fixes#419.
Added generic 'Irq_proxy' class to core includes (ported from base-okl4). It can
be used to implement shared IRQ support for various base platforms. It will
generate one thread per IRQ and unblocks waiting clients (IRQ sessions) upon
interrupt receipt.
Issue #390
This patch introduces the functions 'affinity' and 'num_cpus' to the CPU
session interface. The interface extension will allow the assignment of
individual threads to CPUs. At this point, it is just a stub with no
actual platform support.
Let the Fiasco.OC base platform succeed the cap_integrity run-script meaning
that it is not feasible anymore to fake a capability by using a valid one
together with a guessed local_name.
Rm_client is derived from Pager_object. If the Pager_object is also
derived from Thread_base (which is the case for NOVA) then the
Rm_client object must be destructed without holding the rm_session_object
lock. The native platform specific Thread_base implementation has to take
care that all in-flight page handling requests are finished before
destruction. On NOVA it is done by doing an IPC to the pager thread.
(performed in Pager_object::dissolve() in base-nova). The
called thread than executes its operation until end which also requires
in some cases to take the rm_session_object lock.
Since _client_slab insertion/deletion also must be performed
synchronized but can't be protected by the rm_session_object lock
because of the described dead_lock situation, we have
to use a synchronized allocator object to perform insertion and
deletion of Rm_clients.
