- if no affinity was set for a new thread before calling
Cpu_session::start(), the CPU session's affinity gets set for this
thread
- documentation fix: <affinity_space> -> <affinity-space>
Fixes#873.
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.
- use the generic 'crt0.s' for Linux
- move the read-only '__dso_handle' definition into the '.text' section
- move the '__initial_sp' definition into the '.bss' section
- remove the '_main_utcb' definition
Part of #766.
This patch introduces a new platform 'linux_arm' for building and running
Genode/Linux on an ARM device.
Known limitations:
- libc 'setjmp()'/'longjmp()' doesn't currently save/restore floating
point registers
Fixes#746.
Try to free the metadata of a thread only if created by Genode. The code
did not cause any actual problems. I just stumbled over the inconsistency
while reviewing the code.
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 happened when I killed one of the genode clients which was
tracked via an expception_handler. In this case the wait4 syscall
returned 0 and the for(;;) was looped eternally. This caused an
100% CPU utilization for the core binary.
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.
core does not use POSIX threads when built for the 'lx_hybrid_x86'
platform, so we need to reserve the thread-context area via a segment in
the program to prevent clashes with vdso and shared libraries.
Fixes#639.
If page faults are handled concurrently (as for base-nova) the traverse lookup
call in rm_session_component must be thread safe, which it isn't.
If the faulting area is backed by nested dataspaces which are managed by
various rm_sessions then a race happens under following circumstances
(triggered occasionally by the bomb test).
The traverse lookup may return a pointer to a rm_session of a nested dataspace.
If the rm_session is in parallel subject to destruction it happened that faults
got enqueued to the faulters list of the deleted rm_session and internally to
a list of the current rm_session of the Rm_client.
During destruction of the faulting Rm_client the associated rm_session will
be dissolved from the Rm_client, which leads to dereferencing the
dangling pointer of the already destructed rm_session.
On base-nova the memory of the rm_session object get unmapped eventually, so
that the de-referencing of the dangling pointer caused page faults in core.
The memory on other kernels inside core never get unmapped so that the
bug doesn't trigger visible faults.
The patch replace the keeping of a rm_session pointer by keeping a
capability instead. The rm_session object must be looked up now explicitly in
the Object_pool implementation, which implements proper reference counting on
the rm_session object.
Issue #549
This patch removes the 'soname' link option for building the host
library for the 'lx_hybrid_ctors' test. Without this option, the
library's absolute path at build time gets hardcoded into the
application, which should be okay for this simple test case.
Fixes#638.
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.
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.
With this patch, core responds to SIGCHLD signals of terminating Genode
processes by reflecting these events as exceptions to the CPU session
interface. This way, Genode processes become able to respond to
terminating Genode child processes.
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 improves the life-time management of socket descriptors and
addresses several corner cases exposed by the 'bomb' test.
The lookup and association of file descriptors with global IDs have been
turned into an atomic operation. Otherwise, multiple threads interacting
with the singleton 'ep_sd_registry' may override each other's
associations.
Closing the socket pair used for the reply channel has been implemented
via the RAII pattern to capture all corner cases, in particular
exceptions.
If blocking operations are interrupted by signals, we throw a
'Blocking_canceled' exception.
We preserve core's socket descriptor at 'PARENT_SOCKET_HANDLE' to avoid
a corner case where the parent capability is going to dup2'ed to the
same handle.
Support for 'Thread_base::join' within core to enable leaving Genode via
Control-C.
With this patch, custom UIDs and GIDs can be assigned to individual
Genode processes or whole Genode subsystems.
The new 'base-linux/run/lx_uid.run' script contains an example of how to
use the feature.
Fixes#510
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.
This ensures that the cwd of the process is within the chroot
environment, improving security for root processes.
The cwd after the chroot is the same as before, this is needed to
start binaries given as relative path name.
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
When an IPC server is finalized two important things should happen:
First, the association of the server socket with a capability must be
invalidated. And finally, the server socket pair (server side and client
side) must be closed.
Related to #38.
This patch fixes the 'lx_hybrid_pthread_ipc.run' test. In order to use
the 'Genode::Lock' we need to set the SIGUSR1 handler to an empty handler.
Normally, this happens when creating a thread via the Genode API. But as
this test creates a thread via the pthread library and thereby bypasses
the Genode API, the signal handler remained unset.
The thread ID reported to core was not always initialized prior the RPC
call. The 'startup_lock' ensures that the thread is completely
initialized before this information gets propagated.
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.
When building in hybrid Linux/Genode mode, there exist two definitions
of 'size_t', one in the 'Genode' namespace and one imported from the
glibc headers.
Christian Prochaska
Josef Söntgen
Norman Feske
Torsten Hilbrich
Alexander Boettcher
Christian Helmuth
Martin Stein