This patch extends the 'Parent::session()' and 'Root::session()'
functions with an additional 'affinity' parameter, which is inteded to
express the preferred affinity of the new session. For CPU sessions
provided by core, the values will be used to select the set of CPUs
assigned to the CPU session. For other services, the session affinity
information can be utilized to optimize the locality of the server
thread with the client. For example, to enable the IRQ session to route
an IRQ to the CPU core on which the corresponding device driver (the IRQ
client) is running.
This patch introduces new types for expressing CPU affinities. Instead
of dealing with physical CPU numbers, affinities are expressed as
rectangles in a grid of virtual CPU nodes. This clears the way to
conveniently assign sets of adjacent CPUs to subsystems, each of them
managing their respective viewport of the coordinate space.
By using 2D Cartesian coordinates, the locality of CPU nodes can be
modeled for different topologies such as SMP (simple Nx1 grid), grids of
NUMA nodes, or ring topologies.
The Rpc_exit call is delivered via RPC which results in a deadlock
if the Rpc_entrypoint has not been started yet. To prevent this
situation we active the Rpc_entrypoint explicitly before we call
Rpc_exit.
Fixes#811.
With this patch, the 'futex' syscall gets used for blocking and unblocking
of threads in the Linux-specific lock implementation.
The 'Native_thread_id' type, which was previously used in the
lock-internal 'Applicant' class to identify a thread to be woken up,
was not suitable anymore for implementing this change. With this patch,
the 'Thread_base*' type gets used instead, which also has the positive
effect of making the public 'cancelable_lock.h' header file
platform-independent.
Fixes#646.
This patch simplifies the way of how Genode's base libraries are
organized. Originally, the base API was implemented in the form of many
small libraries such as 'thread', 'env', 'server', etc. Most of them
used to consist of only a small number of files. Because those libraries
are incorporated in any build, the checking of their inter-dependencies
made the build process more verbose than desired. Also, the number of
libraries and their roles (core only, non-core only, shared by both core
and non-core) were not easy to capture.
Hereby, the base libraries have been reduced to the following few
libraries:
- startup.mk contains the startup code for normal Genode processes.
On some platform, core is able to use the library as well.
- base-common.mk contains the parts of the base library that are
identical by core and non-core processes.
- base.mk contains the complete base API implementation for non-core
processes
Consequently, the 'LIBS' declaration in 'target.mk' files becomes
simpler as well. In the most simple case, only the 'base' library must
be mentioned.
Fixes#18
The distinction between 'ipc.h' and 'ipc_generic.h' is no more. The only
use case for platform-specific extensions of the IPC support was the
marshalling of capabilities. However, this case is accommodated by a
function interface ('_marshal_capability', '_unmarshal_capability'). By
moving the implementation of these functions from the headers into the
respective ipc libraries, we can abandon the platform-specific 'ipc.h'
headers.
reverts 68156918ee
"base: apply thread.cc fix of foc to base"
Depending on the context area a fixed location is calculated where the
memory for the stack is attached to. If the context area is released before the
detach call, the very same context area can be reused and memory for the new
stack is attached for a new thread. The detach of the old thread would then
revoke the mapping for the new thread which will cause a un-handled page fault.
Issue #549
With this patch, the 'Signal_receiver::dissolve()' function does not return
as long as the signal context to be dissolved is still referenced by one
or more 'Signal' objects. This is supposed to delay the destruction of the
signal context while it is still in use.
Fixes#594.
Several users of the signal API used custom convenience classes to
invoke signal-handling functions on the reception of incoming signals.
The 'Signal_dispatcher' pattern turned out to be particularly useful. To
avoid the duplication of this code across the code base, this patch
adds the interface to 'base/signal.h'.
Furthermore, the patch changes the 'Signal::num()' return type from int
to unsigned because negative numbers are meaningless here.
Fixes#511
Add functionality to lookup an object and lock it. Additional the case is
handled that a object may be already in-destruction and the lookup will deny
returning the object.
The object_pool generalize the lookup and lock functionality of the rpc_server
and serve as base for following up patches to fix dangling pointer issues.
When releasing a lock we must take care that all state is written back to
memory and is not cached in registers. The volatile flag of the lock variable
only means to the compiler that this value must be written immediately.
Other values changed before may be kept by the compiler in registers, which we
don't want here.
Additionally the compiler is free to reorder the code in order to optimize.
That means the code we intend to be executed inside the critical section can
get be reordered and can be executed after we reset the lock variable in the
unlock implementation. The volatile statement of the lock variable doesn't
prevent reordering of instructions which are independent.
By adding a explicit memory barrier, we force the compiler to generate code
that writes back all the register content to memory/cache (and avoid a
bunch of hard to find bugs ...)
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.
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.
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.
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.
This commit introduces placement new/delete, and a constructor for
Heap::Dataspace objects. It fixes the usage of uninitialized Dataspace
objects when expanding the heap that lead to problems in conjunction
with Native_capability smart-pointer in base-foc. Please refer to
issue #203.
When a portion of the sliced heap gets freed, the corresponding block
gets removed from the list of blocks, and it's dataspace containing the
block gets detached, but it's destructor never gets called. This leads
to leaking capabilities, when Native_capability is implemented as
smart-pointer, because the destructor of Ram_dataspace_capability that
is part of the Block object gets never called.
If any operand of the '?' operator is of an unsigned type, the result
is unsigned by default. Thanks to Julian Stecklina for finding
this out.
Fixes#189.
With this patch clients of the RM service can state if they want a mapping
to be executable or not. This allows dataspaces to be mapped as
non-executable on Linux by default and as executable only if needed.
Partially fixes#176.
Norman Feske
Alexander Boettcher
Josef Söntgen
Christian Prochaska
Martin Stein
Christian Helmuth
Stefan Kalkowski