GCC version 7 and above generate calls to __divmoddi for 64bit integer
division on 32-bit. Unfortunately, libgcc liberaries of older compilers
lack this symbol and are still in use by Debian/Ubuntu LTS at least.
This enforces the use of unsigned 64-bit values for time in the duration type,
the timeout framework, the timer session, the userland timer-drivers, and the
alarm framework on all platforms. The commit also adapts the code that uses
these tools accross all basic repositories (base, base-*, os. gems, libports,
ports, dde_*) to use unsigned 64-bit values for time as well as far as this
does not imply profound modifications.
Fixes#3208
This commit removes APIs that were previously marked as deprecated. This
change has the following implications:
- The use of the global 'env()' accessor is not possible anymore.
- Boolean accessor methods are no longer prefixed with 'is_'. E.g.,
instead of 'is_valid()', use 'valid()'.
- The last traces of 'Ram_session' are gone now. The 'Env::ram()'
accessor returns the 'Ram_allocator' interface, which is a subset of
the 'Pd_session' interface.
- All connection constructors need the 'Env' as argument.
- The 'Reporter' constructor needs an 'Env' argument now because the
reporter creates a report connection.
- The old overload 'Child_policy::resolve_session_request' that returned
a 'Service' does not exist anymore.
- The base/printf.h header has been removed, use base/log.h instead.
- The old notion of 'Signal_dispatcher' is gone. Use 'Signal_handler'.
- Transitional headers like os/server.h, cap_session/,
volatile_object.h, os/attached*_dataspace.h, signal_rpc_dispatcher.h
have been removed.
- The distinction between 'Thread_state' and 'Thread_state_base' does
not exist anymore.
- The header cpu_thread/capability.h along with the type definition of
'Cpu_thread_capability' has been removed. Use the type
'Thread_capability' define in cpu_session/cpu_session.h instead.
- Several XML utilities (i.e., at os/include/decorator) could be removed
because their functionality is nowadays covered by util/xml_node.h.
- The 'os/ram_session_guard.h' has been removed.
Use 'Constrained_ram_allocator' provided by base/ram_allocator.h instead.
Issue #1987
This patch adjusts the implementation of the base library and core such
that the code no longer relies on deprecated APIs except for very few
cases, mainly to keep those deprecated APIs in tact for now.
The most prominent changes are:
- Removing the use of base/printf.h
- Removing of the log backend for printf. The 'Console' with the
format-string parser is still there along with 'snprintf.h' because
the latter is still used at a few places, most prominently the
'Connection' classes.
- Removing the notion of a RAM session, which does not exist in
Genode anymore. Still the types were preserved (by typedefs to
PD session) to keep up compatibility. But this transition should
come to an end now.
- Slight rennovation of core's tracing service, e.g., the use of an
Attached_dataspace as the Argument_buffer.
- Reducing the reliance on global accessors like deprecated_env() or
core_env(). Still there is a longish way to go to eliminate all such
calls. A useful pattern (or at least a stop-gap solution) is to
pass the 'Env' to the individual compilation units via init functions.
- Avoiding the use of the old 'Child_policy::resolve_session_request'
interface that returned a 'Service' instead of a 'Route'.
Issue #1987
This patch replaces the former prominent use of pointers by references
wherever feasible. This has the following benefits:
* The contract between caller and callee becomes more obvious. When
passing a reference, the contract says that the argument cannot be
a null pointer. The caller is responsible to ensure that. Therefore,
the use of reference eliminates the need to add defensive null-pointer
checks at the callee site, which sometimes merely exist to be on the
safe side. The bottom line is that the code becomes easier to follow.
* Reference members must be initialized via an object initializer,
which promotes a programming style that avoids intermediate object-
construction states. Within core, there are still a few pointers
as member variables left though. E.g., caused by the late association
of 'Platform_thread' objects with their 'Platform_pd' objects.
* If no pointers are present as member variables, we don't need to
manually provide declarations of a private copy constructor and
an assignment operator to avoid -Weffc++ errors "class ... has
pointer data members [-Werror=effc++]".
This patch also changes a few system bindings on NOVA and Fiasco.OC,
e.g., the return value of the global 'cap_map' accessor has become a
reference. Hence, the patch touches a few places outside of core.
Fixes#3135
Since the timer and timeout handling is part of the base library (the
dynamic linker), it belongs to the base repository.
Besides moving the timer and its related infrastructure (alarm, timeout
libs, tests) to the base repository, this patch also moves the timer
from the 'drivers' subdirectory directly to 'src' and disamibuates the
timer's build locations for the various kernels. Otherwise the different
timer implementations could interfere with each other when using one
build directory with multiple kernels.
Note that this patch changes the include paths for the former os/timer,
os/alarm.h, os/duration.h, and os/timed_semaphore.h to base/.
Issue #3101
This patch fixes the following build problem that occurs on recent
GNU/Linux systems:
/usr/include/x86_64-linux-gnu/sys/cdefs.h:307:0: error: "__always_inline" redefined
...
/usr/include/linux/stddef.h:5:0: note: this is the location of the previous definition
The code in 'cdefs.h' does not check if the '__always_inline' is already
defined. The patch works around the problem by including the 'sys/cdefs.h'
first.
This patch removes the detection of statically linked executables from
the base framework. It thereby fixes the corner cases encountered with
Sculpt when obtaining the binaries of the runtime from the depot_rom
service that is hosted within the runtime.
Statically linked binaries and hybrid Linux/Genode (lx_hybrid) binaries
can still be started by relabeling the ROM-session route of "ld.lib.so"
to the binary name, pretending that the binary is the dynamic linker.
This can be achieved via init's label rewriting mechanism:
<route>
<service name="ROM" unscoped_label="ld.lib.so">
<parent label="test-platform"/> </service>
</route>
However, as this is quite cryptic and would need to be applied for all
lx_hybrid components, the patch adds a shortcut to init's configuration.
One can simply add the 'ld="no"' attribute to the <start> node of the
corresponding component:
<start name="test-platform" ld="no"/>
Fixes#2866
The native CPU client holds a capability reference and the reference
counter of the capability can reach its limit when many threads are
successively created and destroyed (destroyed by the Linux kernel).
Fixes#2886
The patch adjust the code of the base, base-<kernel>, and os repository.
To adapt existing components to fix violations of the best practices
suggested by "Effective C++" as reported by the -Weffc++ compiler
argument. The changes follow the patterns outlined below:
* A class with virtual functions can no longer publicly inherit base
classed without a vtable. The inherited object may either be moved
to a member variable, or inherited privately. The latter would be
used for classes that inherit 'List::Element' or 'Avl_node'. In order
to enable the 'List' and 'Avl_tree' to access the meta data, the
'List' must become a friend.
* Instead of adding a virtual destructor to abstract base classes,
we inherit the new 'Interface' class, which contains a virtual
destructor. This way, single-line abstract base classes can stay
as compact as they are now. The 'Interface' utility resides in
base/include/util/interface.h.
* With the new warnings enabled, all member variables must be explicitly
initialized. Basic types may be initialized with '='. All other types
are initialized with braces '{ ... }' or as class initializers. If
basic types and non-basic types appear in a row, it is nice to only
use the brace syntax (also for basic types) and align the braces.
* If a class contains pointers as members, it must now also provide a
copy constructor and assignment operator. In the most cases, one
would make them private, effectively disallowing the objects to be
copied. Unfortunately, this warning cannot be fixed be inheriting
our existing 'Noncopyable' class (the compiler fails to detect that
the inheriting class cannot be copied and still gives the error).
For now, we have to manually add declarations for both the copy
constructor and assignment operator as private class members. Those
declarations should be prepended with a comment like this:
/*
* Noncopyable
*/
Thread(Thread const &);
Thread &operator = (Thread const &);
In the future, we should revisit these places and try to replace
the pointers with references. In the presence of at least one
reference member, the compiler would no longer implicitly generate
a copy constructor. So we could remove the manual declaration.
Issue #465
In newer glibc versions, the '__sigword' and '__sigmask' macros are only
available in sigsetops.h which is not installed. These macros are not
system-specific, hence we implement them explicitly ourselves.
Fixes#2616
We moved the stack-area segment 128 MiB behind text and data to comply
with assumptions in the kernel ELF loader.
This commit also reenables static binaries on linux and removes the
unused stack_area.stdlib.ld script.
Fixes#2521
The filename buffer of a dataspace in base-linux is limited to
40 bytes. When using file names longer than this, the remainder
gets dropped silently. Add an error message to aid debugging this
case.
The recently implemented capability resource trading scheme unfortunately
broke the automated capability memory upgrade mechanism needed by base-hw
kernel/core. This commit splits the capability memory upgrade mechanism
from the PD session ram_quota upgrade, and moves that functionality
into a separate Pd_session::Native_pd interface.
Ref #2398
On ARM, we do not have a component-local hardware time-source. The ARM
performance counter has no reliable frequency as the ARM idle command
halts the counter. Thus, we do not do local time interpolation on ARM.
Except we're on the HW kernel. In this case we can read out the kernel
time instead.
Ref #2435
The 'Stack_area_ram_session' is now a 'Stack_area_ram_allocator', which
simplifies the code and remove a dependency from the 'Ram_session'
interface, which we want to remove after all.
Issue #2407
By separating the session-interface concerns from the mechanics of the
dataspace creation, the code becomes simpler to follow, and the RAM
session can be more easily merged with the PD session in a subsequent
step.
Issue #2407
This patch allows core's 'Signal_transmitter' implementation to sidestep
the 'Env::Pd' interface and thereby adhere to a stricter layering within
core. The 'Signal_transmitter' now uses - on kernels that depend on it -
a dedicated (and fairly freestanding) RPC proxy mechanism for signal
deliver, instead of channeling signals through the 'Pd_session::submit'
RPC function.
Previously, the Genode::Timer::curr_time always used the
Timer_session::elapsed_ms RPC as back end. Now, Genode::Timer reads
this remote time only in a periodic fashion independently from the calls
to Genode::Timer::curr_time. If now one calls Genode::Timer::curr_time,
the function takes the last read remote time value and adapts it using
the timestamp difference since the remote-time read. The conversion
factor from timestamps to time is estimated on every remote-time read
using the last read remote-time value and the timestamp difference since
the last remote time read.
This commit also re-works the timeout test. The test now has two stages.
In the first stage, it tests fast polling of the
Genode::Timer::curr_time. This stage checks the error between locally
interpolated and timer-driver time as well as wether the locally
interpolated time is monotone and sufficiently homogeneous. In the
second stage several periodic and one-shot timeouts are scheduled at
once. This stage checks if the timeouts trigger sufficiently precise.
This commit adds the new Kernel::time syscall to base-hw. The syscall is
solely used by the Genode::Timer on base-hw as substitute for the
timestamp. This is because on ARM, the timestamp function uses the ARM
performance counter that stops counting when the WFI (wait for
interrupt) instruction is active. This instruction, however is used by
the base-hw idle contexts that get active when no user thread needs to
be scheduled. Thus, the ARM performance counter is not a good choice for
time interpolation and we use the kernel internal time instead.
With this commit, the timeout library becomes a basic library. That means
that it is linked against the LDSO which then provides it to the program it
serves. Furthermore, you can't use the timeout library anymore without the
LDSO because through the kernel-dependent LDSO make-files we can achieve a
kernel-dependent timeout implementation.
This commit introduces a structured Duration type that shall successively
replace the use of Microseconds, Milliseconds, and integer types for duration
values.
Open issues:
* The timeout test fails on Raspberry PI because of precision errors in the
first stage. However, this does not render the framework unusable in general
on the RPI but merely is an issue when speaking of microseconds precision.
* If we run on ARM with another Kernel than HW the timestamp speed may
continuously vary from almost 0 up to CPU speed. The Timer, however,
only uses interpolation if the timestamp speed remained stable (12.5%
tolerance) for at least 3 observation periods. Currently, one period is
100ms, so its 300ms. As long as this is not the case,
Timer_session::elapsed_ms is called instead.
Anyway, it might happen that the CPU load was stable for some time so
interpolation becomes active and now the timestamp speed drops. In the
worst case, we would now have 100ms of slowed down time. The bad thing
about it would be, that this also affects the timeout of the period.
Thus, it might "freeze" the local time for more than 100ms.
On the other hand, if the timestamp speed suddenly raises after some
stable time, interpolated time can get too fast. This would shorten the
period but nonetheless may result in drifting away into the far future.
Now we would have the problem that we can't deliver the real time
anymore until it has caught up because the output of Timer::curr_time
shall be monotone. So, effectively local time might "freeze" again for
more than 100ms.
It would be a solution to not use the Trace::timestamp on ARM w/o HW but
a function whose return value causes the Timer to never use
interpolation because of its stability policy.
Fixes#2400
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.
Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.
This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
This patch mirrors the accounting and trading scheme that Genode employs
for physical memory to the accounting of capability allocations.
Capability quotas must now be explicitly assigned to subsystems by
specifying a 'caps=<amount>' attribute to init's start nodes.
Analogously to RAM quotas, cap quotas can be traded between clients and
servers as part of the session protocol. The capability budget of each
component is maintained by the component's corresponding PD session at
core.
At the current stage, the accounting is applied to RPC capabilities,
signal-context capabilities, and dataspace capabilities. Capabilities
that are dynamically allocated via core's CPU and TRACE service are not
yet covered. Also, the capabilities allocated by resource multiplexers
outside of core (like nitpicker) must be accounted by the respective
servers, which is not covered yet.
If a component runs out of capabilities, core's PD service prints a
warning to the log. To observe the consumption of capabilities per
component in detail, the PD service is equipped with a diagnostic
mode, which can be enabled via the 'diag' attribute in the target
node of init's routing rules. E.g., the following route enables the
diagnostic mode for the PD session of the "timer" component:
<default-route>
<service name="PD" unscoped_label="timer">
<parent diag="yes"/>
</service>
...
</default-route>
For subsystems based on a sub-init instance, init can be configured
to report the capability-quota information of its subsystems by
adding the attribute 'child_caps="yes"' to init's '<report>'
config node. Init's own capability quota can be reported by adding
the attribute 'init_caps="yes"'.
Fixes#2398
This patch reworks the implementation of core's RAM service to make use
of the 'Session_object' and to remove the distinction between the
"metadata" quota and the managed RAM quota. With the new implementation,
the session implicitly allocates its metadata from its own account. So
there is not need to handle 'Out_of_metadata' and 'Quota_exceeded' via
different exceptions. Instead, the new version solely uses the
'Out_of_ram' exception.
Furthermore, the 'Allocator::Out_of_memory' exception has become an alias
for 'Out_of_ram', which simplifies the error handling.
Issue #2398
This patch replaces the former use of size_t with the use of the
'Ram_quota' type to improve type safety (in particular to avoid
accidentally mixing up RAM quotas with cap quotas).
Issue #2398
The 'Ram_allocator' interface contains the subset of the RAM session
interface that is needed to satisfy the needs of the 'Heap' and
'Sliced_heap'. Its small size makes it ideal for intercepting memory
allocations as done by the new 'Constrained_ram_allocator' wrapper
class, which is meant to replace the existing 'base/allocator_guard.h'
and 'os/ram_session_guard.h'.
Issue #2398
This commit enables compile-time warnings displayed whenever a deprecated
API header is included, and adjusts the existing #include directives
accordingly.
Issue #1987
The init component used to create the CPU/RAM/PD/ROM sessions (the child
environment) for its children by issuing session requests to its parent,
which is typically core. This policy was hard-wired. This patch enables
the routing of the environment sessions of the children of init
according to the configured routing policy.
Because there is no hard-wired policy regarding the environment sessions
anymore, routes to respective services must be explicitly declared in
the init configuration. For this reason, the patch adjusts several run
scripts in this respect.
This patch removes the outdated '<if-args>' special handling of session
labels. The '<if-args>' feature will eventually be removed completely
(ref #2250)
Issue #2197
Issue #2215
Issue #2233
Issue #2250
This patch enables warnings if one of the deprecate functions that rely
in the implicit use of the global Genode::env() accessor are called.
For the time being, some places within the base framework continue
to rely on the global function while omitting the warning by calling
'env_deprecated' instead of 'env'.
Issue #1987
This patch make the ABI mechanism available to shared libraries other
than Genode's dynamic linker. It thereby allows us to introduce
intermediate ABIs at the granularity of shared libraries. This is useful
for slow-moving ABIs such as the libc's interface but it will also
become handy for the package management.
To implement the feature, the build system had to be streamlined a bit.
In particular, archive dependencies and shared-lib dependencies are now
handled separately, and the global list of 'SHARED_LIBS' is no more.
Now, the variable with the same name holds the per-target list of shared
libraries used by the target.
Ubuntu provides position independent shared objects for libraries, e.g.,
libsdl1.2-dev. To appropriatly link it to Genode, the linker flag
'-no-pie' has to be added to the make file.
This patch removes the component_entry_point library, which used to
proved a hook for the libc to intercept the call of the
'Component::construct' function. The mechansim has several shortcomings
(see the discussion in the associated issue) and was complex. So we
eventually discarded the approach in favor of the explicit handling of
the startup.
A regular Genode component provides a 'Component::construct' function,
which is determined by the dynamic linker via a symbol lookup.
For the time being, the dynamic linker falls back to looking up a 'main'
function if no 'Component::construct' function could be found.
The libc provides an implementation of 'Component::construct', which
sets up the libc's task handling and finally call the function
'Libc::Component::construct' from the context of the appllication task.
This function is expected to be provided by the libc-using application.
Consequently, Genode components that use the libc have to implement the
'Libc::Component::construct' function.
The new 'posix' library provides an implementation of
'Libc::Component::construct' that calls a main function. Hence, POSIX
programs that merely use the POSIX API merely have to add 'posix' to the
'LIBS' declaration in their 'target.mk' file. Their execution starts at
'main'.
Issue #2199
This patch makes the benefit of the recently introduced unified Genode
ABI available to developers by enabling the use of multiple kernels from
within a single build directory. The create_builddir tool has gained a
new set of kernel-agnostic platform arguments such as x86_32, or panda.
Most build targets within directories are in principle compatible with
all kernels that support the selected hardware platform. To execute a
scenario via the run tool, one has to select the kernel to use by
setting the 'KERNEL' argument in the build configuration
(etc/build.conf). Alternatively, the 'KERNEL' can be specified as
command-line argument of the Genode build system, e.g.:
make run/log KERNEL=nova
This allows us to easily switch from one kernel to another without
rebuilding any Genode component except for the very few kernel-specific
ones.
The new version of the 'create_builddir' tool is still compatible with
the old version. The old kernel-specific build directories can still be
created. However, those variants will eventually be removed.
Note that the commit removes the 'ports-foc' repository from the
generated 'build.conf' files. As this is only meaningful for 'foc',
I did not want to include it in the list of regular repositories (as
visible in a 'x86_32' build directory). Hence, the repository must
now be manually added in order to use L4Linux.
Issue #2190
This patch changes the child-construction procedure to allow the routing
of environment sessions to arbitrary servers, not only to the parent.
In particular, it restores the ability to route the LOG session of the
child to a LOG service provided by a child of init. In principle, it
becomes possible to also route the immediate child's PD, CPU, and RAM
environment sessions in arbitrary ways, which simplifies scenarios that
intercept those sessions, e.g., the CPU sampler.
Note that the latter ability should be used with great caution because
init needs to interact with these sessions to create/destruct the child.
Normally, the sessions are provided by the parent. So init is safe at
all times. If they are routed to a child however, init will naturally
become dependent on this particular child. For the LOG session, this is
actually not a problem because even though the parent creates the LOG
session as part of the child's environment, it never interacts with the
session directly.
Fixes#2197
This patch removes possible ambiguities with respect to the naming of
kernel-dependent binaries and libraries. It also removes the use of
kernel-specific global side effects from the build system. The reach of
kernel-specific peculiarities has thereby become limited to the actual
users of the respective 'syscall-<kernel>' libraries.
Kernel-specific build artifacts are no longer generated at magic places
within the build directory (like okl4's includes, or the L4 build
directories of L4/Fiasco and Fiasco.OC, or the build directories of
various kernels). Instead, such artifacts have been largely moved to the
libcache. E.g., the former '<build-dir>/l4/' build directory for the L4
build system resides at '<build-dir>/var/libcache/syscall-foc/build/'.
This way, the location is unique to the kernel. Note that various tools
are still generated somewhat arbitrarily under '<build-dir>/tool/' as
there is no proper formalism for building host tools yet.
As the result of this work, it has become possible to use a joint Genode
build directory that is usable with all kernels of a given hardware
platform. E.g., on x86_32, one can now seamlessly switch between linux,
nova, sel4, okl4, fiasco, foc, and pistachio without rebuilding any
components except for core, the kernel, the dynamic linker, and the timer
driver. At the current stage, such a build directory must still be
created manually. A change of the 'create_builddir' tool will follow to
make this feature easily available.
This patch also simplifies various 'run/boot_dir' plugins by removing
the option for an externally hosted kernel. This option remained unused
for many years now.
Issue #2190
This patch decouples the kernel-specific implementation of the dynamic
linker from its kernel-agnostic binary interface. The name of the
kernel-specific dynamic linker binary now corresponds to the kernel,
e.g., 'ld-linux.lib.so' or 'ld-nova.lib.so'. Applications are no longer
linked directly against a concrete instance of the dynamic linker but
against a shallow stub called 'ld.lib.so'. This stub contains nothing
but the symbols provided by the dynamic linker. It thereby represents
the Genode ABI.
At system-integration time, the kernel-specific run/boot_dir back ends
integrate the matching the kernel-specific variant of the dynamic linker
as 'ld.lib.so' into the boot image.
The ABI symbol file for the dynamic linker is located at
'base/lib/symbols/ld'. It contains the joint ABI of all supported
architectures. The new utility 'tool/abi_symbols' eases the creation of
such an ABI symbol file for a given shared library. Its result should be
manually inspected and edited as needed.
The patch removes the 'syscall' library from 'base_libs.mk' to avoid
polluting the kernel-agnostic ABI with kernel-specific interfaces.
Issue #2190
Issue #2195
This patch unconditionally applies the labeling of sessions and thereby
removes the most common use case of 'Child_policy::filter_session_args'.
Furthermore, the patch removes an ambiguity of the session labels of
sessions created by the parent of behalf of its child, e.g., the PD
session created as part of 'Child' now has the label "<child-name>"
whereas an unlabeled PD-session request originating from the child
has the label "<child-name> -> ". This way, the routing-policy of
'Child_policy::resolve_session_request' can differentiate both cases.
As a consequence, the stricter labeling must now be considered wherever
a precise label was specified as a key for a session route or a server-
side policy selection. The simplest way to adapt those cases is to use a
'label_prefix' instead of the 'label' attribute. Alternatively, the
'label' attribute may used by appending " -> " (note the whitespace).
Fixes#2171
This is a redesign of the root and parent interfaces to eliminate
blocking RPC calls.
- New session representation at the parent (base/session_state.h)
- base-internal root proxy mechanism as migration path
- Redesign of base/service.h
- Removes ancient 'Connection::KEEP_OPEN' feature
- Interface change of 'Child', 'Child_policy', 'Slave', 'Slave_policy'
- New 'Slave::Connection'
- Changed child-construction procedure to be compatible with the
non-blocking parent interface and to be easier to use
- The child's initial LOG session, its binary ROM session, and the
linker ROM session have become part of the child's envirenment.
- Session upgrading must now be performed via 'env.upgrade' instead
of performing a sole RPC call the parent. To make RAM upgrades
easier, the 'Connection' provides a new 'upgrade_ram' method.
Issue #2120
This patch fixes a race condition triggered by the thread test running
on Linux inside VirtualBox. The 'test_stack_alloc' sporadically produced
one of two errors: A segfault in the 'Thread::deinit_platform_thread' on
the attempt to access the 'native_thread' of the to-be-destructed thread
(this data structure is located on the thread's stack). Or, an error
message about a region conflict within the stack area.
The problem was that two instances of 'Region_map_mmap' issued a
sequence of munmap and mmap each. Even though each instance locked the
attach/detach operations, the lock was held per instance. In a situation
where two instances performed attach/detach operations in parallel, the
syscall sequences could interfere with each other.
In the test scenario, the two region-map instances are the test's
address space and the stack area. When creating a thread, the thread's
trace-control dataspace is attached at an arbitrary place (picked by
the Linux kernel) within the address space whereas the stack is attached
at the stack area. The problem is the following sequence:
Thread A wants to destruct a thread:
1. Remove stack from stack area
(issue unmap syscall)
2. Preserve virtual address range that was occupied from the stack
so that Linux won't use it
(issue mmap syscall)
Thread B wants to construct a thread:
1. Request trace-control dataspace from CPU session
2. Attach trace-control dataspace to address space at a location
picked by the Linux kernel
(issue mmap syscall)
The problem occurs when thread B's second step is executed in between
the steps 1 and 2 of thread A and the Linux kernel picks the
just-unmapped address as the location for the new trace-control mapping.
Now, the trace control dataspace is mapped at the virtual address that
was designated for the stack of the to-be-created thread, and the
attempt to map the real stack fails.
The patch fixes the problem by replacing the former region-map-local
locks by a component-global lock.
Furthermore, it cleans up core's implementation of the support function
for the region-map-mmap implementation, eliminating the temporary
unlocking of the region-map lock during RPC.
Instead of solving the problem to deliver ROM modules to core while booting
differently for the several kernels (multi-boot, elfweaver, core re-linking),
this commit unifies the approaches. It always builds core as a library, and
after all binaries are built from a run-script, the run-tool will link an
ELF image out of the core-library and all boot modules. Thereby, core can
access its ROM modules directly.
This approach now works for all kernels except Linux.
With this solution, there is no [build_dir]/bin/core binary available anymore.
For debugging purposes you will find a core binary without boot modules, but
with debug symbols under [run_dir].core.
Fix#2095
base generic code:
* Remove unused verbosity code from mmio framework
* Remove escape sequence end heuristic from LOG
* replace Core_console with Core_log (no format specifiers)
* move test/printf to test/log
* remove `printf()` tests from the log test
* check for exact match of the log test output
base-fiasco:
* remove unused Fiasco::print_l4_threadid function
base-nova:
* remove unused hexdump utility from core
base-hw:
* remove unused Kernel::Thread::_print_* debug utilities
* always print resource summary of core during startup
* remove Kernel::Ipc_node::pd_label (not used anymore)
base*:
* Turn `printf`,`PWRN`, etc. calls into their log equivalents
Ref #1987Fix#2119
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.
While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).
To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.
Issue #1987
Thread stacks with less than 4K usable space are insufficient for our
implementation of Linux exception signal handling. If such a unusually
small stack overflows the SIGSEGV handler will not be able to print the
diagnostic message leaving no hint of the cause of the stuck process.
Conveying the ROM filename as the final label element simplifies
routing policy and session construction.
Annotations by nfeske:
This commit also changes the ROM session to use base/log.h instead of
base/printf.h, which produced build error of VirtualBox because the
vbox headers have a '#define Log', which collides with the content of
base/log.h. Hence, this commit has to take precautions to resolve this
conflict.
The commit alse refines the previous session-label change by adding a
new 'Session_label::prefix' method and removing the use of 'char const *'
from this part of the API.
Fixes#1787
This patch establishes the sole use of generic headers across all
kernels. The common 'native_capability.h' is based on the version of
base-sel4. All traditional L4 kernels and Linux use the same
implementation of the capability-lifetime management. On base-hw, NOVA,
Fiasco.OC, and seL4, custom implementations (based on their original
mechanisms) are used, with the potential to unify them further in the
future.
This change achieves binary compatibility of dynamically linked programs
across all kernels.
Furthermore, the patch introduces a Native_capability::print method,
which allows the easy output of the kernel-specific capability
representation using the base/log.h API.
Issue #1993
This patch alleviates the need for a Native_capability::Dst at the API
level. The former use case of this type as argument to
Deprecated_env::reinit uses the opaque Native_capability::Raw type
instead. The 'Raw' type contains the portion of the capability that is
transferred as-is when delegating the capability (i.e., when installing
the parent capability into a new component, or when installing a new
parent capability into a new forked Noux process). This information can
be retrieved via the new Native_capability::raw method.
Furthermore, this patch moves the functions for retriving the parent
capability to base/internal/parent_cap.h, which is meant to be
implemented in platform-specific ways. It replaces the former set of
startup/internal/_main_parent_cap.h headers.
Issue #1993
The alternate stack must use the stack area as, e.g., Thread::myself()
depends on this property. Hybrid components do not depend on this
property and, therefore, use a static stack buffer.
Fixes#1935
This patch introduces the Genode::raw function that prints output
directly via a low-level kernel mechanism, if available.
On base-linux, it replaces the former 'raw_write_str' function.
On base-hw, it replaces the former kernel/log.h interface.
Fixes#2012
This patch moves the thread operations from the 'Cpu_session'
to the 'Cpu_thread' interface.
A noteworthy semantic change is the meaning of the former
'exception_handler' function, which used to define both, the default
exception handler or a thread-specific signal handler. Now, the
'Cpu_session::exception_sigh' function defines the CPU-session-wide
default handler whereas the 'Cpu_thread::exception_sigh' function
defines the thread-specific one.
To retain the ability to create 'Child' objects without invoking a
capability, the child's initial thread must be created outside the
'Child::Process'. It is now represented by the 'Child::Initial_thread',
which is passed as argument to the 'Child' constructor.
Fixes#1939
The recent move of the initial three region maps into the PD session
breaks the noux.run test on Linux because the address spaces are locally
managed on this platform but the generic code of Noux still tries to
execute the regular procedure of creating the virtualized PD session for
a new Noux process. This patch handles a corner case that occurs on
Linux but no other platform. It enables the successful creation of the
virtualized PD session so that the test runs to completion. Still noux
on Linux remains to be limited to non-forking programs.
Issue #1938
It turns out that the name function does not have much use in practice
except for naming the thread of the component's initial entrypoint. For
dynamically linked components, this thread is created by the dynamic
linker. It is named "ep" in these cases. Considering that we will
eventually turn all regular components into dynamically linked
executables, the additional information provided by the
Component::name() function remains unused. So it is better to not bother
the component developers with adding boilerplate code.
This patch cleans up the thread API and comes with the following
noteworthy changes:
- Introduced Cpu_session::Weight type that replaces a formerly used
plain integer value to prevent the accidental mix-up of
arguments.
- The enum definition of Cpu_session::DEFAULT_WEIGHT moved to
Cpu_session::Weight::DEFAULT_WEIGHT
- New Thread constructor that takes a 'Env &' as first argument.
The original constructors are now marked as deprecated. For the
common use case where the default 'Weight' and 'Affinity' are
used, a shortcut is provided. In the long term, those two
constructors should be the only ones to remain.
- The former 'Thread<>' class template has been renamed to
'Thread_deprecated'.
- The former 'Thread_base' class is now called 'Thread'.
- The new 'name()' accessor returns the thread's name as 'Name'
object as centrally defined via 'Cpu_session::Name'. It is meant to
replace the old-fashioned 'name' method that takes a buffer and size
as arguments.
- Adaptation of the thread test to the new API
Issue #1954
This patch moves the base library from src/base to src/lib/base,
flattens the library-internal directory structure, and moves the common
parts of the library-description files to base/lib/mk/base.inc and
base/lib/mk/base-common.inc.
Furthermore, the patch fixes a few cosmetic issues (whitespace and
comments only) that I encountered while browsing the result.
Fixes#1952
The original 'Env' interface as returned by 'Genode::env()' has been
renamed to 'Env_deprecated' and moved to deprecated/env.h. The new version
of base/env.h contains the interface passed to modern components that
use the component API via base/component.h.
Issue #1832
This patch makes the former 'Process' class private to the 'Child'
class and changes the constructor of the 'Child' in a way that
principally enables the implementation of single-threaded runtime
environments that virtualize the CPU, PD, and RAM services. The
new interfaces has become free from side effects. I.e., instead
of implicitly using Genode::env()->rm_session(), it takes the reference
to the local region map as argument. Also, the handling of the dynamic
linker via global variables is gone. Now, the linker binary must be
provided as constructor argument.
Fixes#1949
This patch replaces the former 'Pd_session::bind_thread' function by a
PD-capability argument of the 'Cpu_session::create_thread' function, and
removes the ancient thread-start protocol via 'Rm_session::add_client' and
'Cpu_session::set_pager'. Threads are now bound to PDs at their creation
time and implicitly paged according to the address space of the PD.
Note the API change:
This patch changes the signature of the 'Child' and 'Process' constructors.
There is a new 'address_space' argument, which represents the region map
representing the child's address space. It is supplied separately to the
PD session capability (which principally can be invoked to obtain the
PD's address space) to allow the population of the address space
without relying on an 'Pd_session::address_space' RPC call.
Furthermore, a new (optional) env_pd argument allows the explicit
overriding of the PD capability handed out to the child as part of its
environment. It can be used to intercept the interaction of the child
with its PD session at core. This is used by Noux.
Issue #1938
This patch integrates three region maps into each PD session to
reduce the session overhead and to simplify the PD creation procedure.
Please refer to the issue cited below for an elaborative discussion.
Note the API change:
With this patch, the semantics of core's RM service have changed. Now,
the service is merely a tool for creating and destroying managed
dataspaces, which are rarely needed. Regular components no longer need a
RM session. For this reason, the corresponding argument for the
'Process' and 'Child' constructors has been removed.
The former interface of the 'Rm_session' is not named 'Region_map'. As a
minor refinement, the 'Fault_type' enum values are now part of the
'Region_map::State' struct.
Issue #1938
The return code of assign_parent remained unused. So this patch
removes it.
The bind_thread function fails only due to platform-specific limitations
such as the exhaustion of ID name spaces, which cannot be sensibly
handled by the PD-session client. If occurred, such conditions used to
be reflected by integer return codes that were used for diagnostic
messages only. The patch removes the return codes and leaves the
diagnostic output to core.
Fixes#1842
Besides unifying the Msgbuf_base classes across all platforms, this
patch merges the Ipc_marshaller functionality into Msgbuf_base, which
leads to several further simplifications. For example, this patch
eventually moves the Native_connection_state and removes all state
from the former Ipc_server to the actual server loop, which not only
makes the flow of control and information much more obvious, but is
also more flexible. I.e., on NOVA, we don't even have the notion of
reply-and-wait. Now, we are no longer forced to pretend otherwise.
Issue #1832
This patch unifies the CPU session interface across all platforms. The
former differences are moved to respective "native-CPU" interfaces.
NOVA is not covered by the patch and still relies on a custom version of
the core-internal 'cpu_session_component.h'. However, this will soon be
removed once the ongoing rework of pause/single-step on NOVA is
completed.
Fixes#1922
First, we use an alternate stack for signal handling now. The stack is
shared among all threads of the component, which is okay as we only
handle exceptions with log output and pass on to the default handler
(that terminates the execution). The primary motivation for the
alternate stack is the detection of SIGSEGV due to stack overflows.
Also, hybrid components now handle exception signals by logging and the
support for multi-threaded applications was improved.
Fixes#1935
This commit introduces the new `Component` interface in the form of the
headers base/component.h and base/entrypoint.h. The os/server.h API
has become merely a compatibilty wrapper and will eventually be removed.
The same holds true for os/signal_rpc_dispatcher.h. The mechanism has
moved to base/signal.h and is now called 'Signal_handler'.
Since the patch shuffles headers around, please do a 'make clean' in the
build directory.
Issue #1832
This commit replaces the stateful 'Ipc_client' type with the plain
function 'ipc_call' that takes all the needed state as arguments.
The stateful 'Ipc_server' class is retained but it moved from the public
API to the internal ipc_server.h header. The kernel-specific
implementations were cleaned up and simplified. E.g., the 'wait'
function does no longer exist. The badge and exception code are no
longer carried in the message buffers but are handled in kernel-specific
ways.
Issue #610
Issue #1832
This patch moves details about the stack allocation and organization
the base-internal headers. Thereby, I replaced the notion of "thread
contexts" by "stacks" as this term is much more intuitive. The fact that
we place thread-specific information at the bottom of the stack is not
worth introducing new terminology.
Issue #1832
The interfaces linux_cpu_session, local_capability, linux_dataspace,
linux_native_pd are mere implementation necessities. They are meant for the
internal use by the framework only. So it is appropriate to move them to
base/internal/.
Issue #1832
By moving the stub implementation to rm_session_client.cc, we can use
the generic base/include/rm_session/client.h for base-linux and
base-nova and merely use platform-specific implementations.
Issue #1832
This patch establishes a common organization of header files
internal to the base framework. The internal headers are located at
'<repository>/src/include/base/internal/'. This structure has been
choosen to make the nature of those headers immediately clear when
included:
#include <base/internal/lock_helper.h>
Issue #1832
This patch integrates the functionality of the former CAP session into
the PD session and unifies the approch of supplementing the generic PD
session with kernel-specific functionality. The latter is achieved by
the new 'Native_pd' interface. The kernel-specific interface can be
obtained via the Pd_session::native_pd accessor function. The
kernel-specific interfaces are named Nova_native_pd, Foc_native_pd, and
Linux_native_pd.
The latter change allowed for to deduplication of the
pd_session_component code among the various base platforms.
To retain API compatibility, we keep the 'Cap_session' and
'Cap_connection' around. But those classes have become mere wrappers
around the PD session interface.
Issue #1841
This patch removes the SIGNAL service from core and moves its
functionality to the PD session. Furthermore, it unifies the PD service
implementation and terminology across the various base platforms.
Issue #1841
On Linux the linker can now be loaded at arbitrary addresses, this became
necessary for newer kernel versions. The 'linux_arm' target is not supported.
Issue #1728
Under some circumstances, the diagnostic message in the exception signal
handler was not printed. This could happen due to a dead lock in the
console library if the console code itself produces the exception while
possessing the mutex, e.g., by exhausting a undersized stack. Now, we
directly write to the log session via the stdout_write() hook or use
raw_write_str() in core.
Dataspace components inherit from RPC objects which are non-copyable from now
on. Therefore, the Rom_session_component's constructor had to be modified
to not construct a dataspace component on the stack and assign it in the
following.
Ref #1704
Destroying an object within the scope of a lambda/functor executed
in the object pool's apply function leads potentially to memory corruption.
Within the scope the corresponding object is locked and unlocked when
leaving the scope. Therefore, it is illegal to free the object's memory meanwhile.
This commit eliminates several places in core that destroyed wrongly in
the object pool's scope.
Fix#1713
* Move the Synced_interface from os -> base
* Align the naming of "synchronized" helpers to "Synced_*"
* Move Synced_range_allocator to core's private headers
* Remove the raw() and lock() members from Synced_allocator and
Synced_range_allocator, and re-use the Synced_interface for them
* Make core's Mapped_mem_allocator a friend class of Synced_range_allocator
to enable the needed "unsafe" access of its physical and virtual allocators
Fix#1697
Unfortunately, the 'gcc -dumpmachine' magic does not suffice on all
Linux distros, so we just add the well-known paths for i386-linux-gnu
and x86_64-linux-gnu.
Fixes#1694
Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:
repos/base/include/spec
repos/base/mk/spec
repos/base/lib/mk/spec
repos/base/src/core/spec
...
Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.
Fix#1673
Instead of returning pointers to locked objects via a lookup function,
the new object pool implementation restricts object access to
functors resp. lambda expressions that are applied to the objects
within the pool itself.
Fix#884Fix#1658
For most platforms except of NOVA a distinction between pager entrypoint
and pager activation is not needed, and only exists due to historical
reasons. Moreover, the pager thread's execution path is almost identical
between most platforms excluding NOVA, HW, and Fisco.OC. Therefore,
this commit unifies the pager loop for the other platforms, and removes
the pager activation class.
This patch enable clients of core's TRACE service to obtain the
execution times of trace subjects (i.e., threads). The execution time is
delivered as part of the 'Subject_info' structure.
Right now, the feature is available solely on NOVA. On all other base
platforms, the returned execution times are 0.
Issue #813
Currently, libc_noux includes the 'base/src/base/env/platform_env.h' file
to be able to reinitialize the environment using the 'Platform_env'
interface. For base-linux, a special version of this file exists and the
inclusion of the generic version in libc_noux causes GCC 4.9 to make wrong
assumptions about the memory layout of the 'Env' object returned by
'Genode::env()'.
This commit moves the reinitialization functions to the 'Env' interface to
avoid the need to include the 'platform_env.h' file in libc_noux.
Fixes#1510
The thread library (thread.cc) in base-foc shared 95% of the code with
the generic implementation except myself(). Therefore, its
implementation is now separated from the other generic sources into
myself.cc, which allows base-foc to use a foc-specific primitive to
enable our base libraries in L4Linux.
Issue #1491
Physical CPU quota was previously given to a thread on construction only
by directly specifying a percentage of the quota of the according CPU
session. Now, a new thread is given a weighting that can be any value.
The physical counter-value of such a weighting depends on the weightings
of the other threads at the CPU session. Thus, the physical quota of all
threads of a CPU session must be updated when a weighting is added or
removed. This is each time the session creates or destroys a thread.
This commit also adapts the "cpu_quota" test in base-hw accordingly.
Ref #1464
This patch adds const qualifiers to the functions Allocator::consumed,
Allocator::overhead, Allocator::avail, and Range_allocator::valid_addr.
Fixes#1481
* Instead of using local capabilities within core's context area implementation
for stack allocation/attachment, simply do both operations while stack gets
attached, thereby getting rid of the local capabilities in generic code
* In base-hw the UTCB of core's main thread gets mapped directly instead of
constructing a dataspace component out of it and hand over its local
capability
* Remove local capability implementation from all platforms except Linux
Ref #1443
The global capability ID counter is not used by NOVA and Fiasco.OC
and in the future not needed by base-hw too. Thereby, remove the static
counter variable from the generic code base and add it where appropriated.
Ref #1443
Enable platform specific allocations and ram quota accounting for
protection domains. Needed to allocate object identity references
in the base-hw kernel when delegating capabilities via IPC.
Moreover, it can be used to account translation table entries in the
future.
Ref #1443
The emergency dataspace is used to accommodate the corner case where
a signal context capability is created while issuing the first
resource request. Normally, the attempt to upgrade the signal-session
quota under such a constrained situation would fail. By freeing the
emergency dataspace in this situation, we regain enough quota to
upgrade the signal session.
This is a follow up commit for "base: Raise RAM quota of signal session
to 16K" and fixes the resource_request test on 64-bit platforms.
In the init configuration one can configure the donation of CPU time via
'resource' tags that have the attribute 'name' set to "CPU" and the
attribute 'quantum' set to the percentage of CPU quota that init shall
donate. The pattern is the same as when donating RAM quota.
! <start name="test">
! <resource name="CPU" quantum="75"/>
! </start>
This would cause init to try donating 75% of its CPU quota to the child
"test". Init and core do not preserve CPU quota for their own
requirements by default as it is done with RAM quota.
The CPU quota that a process owns can be applied through the thread
constructor. The constructor has been enhanced by an argument that
indicates the percentage of the programs CPU quota that shall be granted
to the new thread. So 'Thread(33, "test")' would cause the backing CPU
session to try to grant 33% of the programs CPU quota to the thread
"test". By now, the CPU quota of a thread can't be altered after
construction. Constructing a thread with CPU quota 0 doesn't mean the
thread gets never scheduled but that the thread has no guaranty to receive
CPU time. Such threads have to live with excess CPU time.
Threads that already existed in the official repositories of Genode were
adapted in the way that they receive a quota of 0.
This commit also provides a run test 'cpu_quota' in base-hw (the only
kernel that applies the CPU-quota scheme currently). The test basically
runs three threads with different physical CPU quota. The threads simply
count for 30 seconds each and the test then checks wether the counter
values relate to the CPU-quota distribution.
fix#1275
On ARM it's relevant to not only distinguish between ordinary cached memory
and write-combined one, but also having non-cached memory too. To insert the
appropriated page table entries e.g.: in the base-hw kernel, we need to preserve
the information about the kind of memory from allocation until the pager
resolves a page fault. Therefore, this commit introduces a new Cache_attribute
type, and replaces the write_combined boolean with the new type where necessary.
