By separating the plain MMIO access implementation from the generic bit
and offset logic of registers, we can now use the latter also with other
types of register access like I2C. The register and MMIO front-ends have
not changed due to the separation.
Ref #2196
With the commit "init: session-label rewriting", the stack usage
increased due to the handling of session-label strings as local
variables. The stack overrun occurred in the vmm scenario on
base-hw.
There was a race when the component entrypoint wanted to do
'wait_and_dispatch_one_signal'. In this function it raises a flag for
the signal proxy thread to notice that the entrypoint also wants to
block for signals. When the flag is set and the signal proxy wakes up
with a new signal, it tried to cancel the blocking of the entrypoint.
However, if the entrypoint had not reached the signal blocking at this
point, the cancel blocking failed without a solution. Now, the new
Kernel::cancel_next_signal_blocking call solves the problem by storing a
request to cancel the next signal blocking of a thread immediately
without blocking itself.
Ref #2284
It can happen that when Cpu_free_component is constructed the insertion
of the object through 'manage' succeeds for the EP put not for the pager
EP, which in turn raises an Out_of_meta_data exception. Because we are
within the constructor, the descstructor is not called, leading to a
dangling object pool entry for the EP.
issue #2289
If not dissolved in ~Entrypoint, the signal proxy is found within NOVA's
and FOC's object pool upon Rpc_entrypoint destruction. This leads to a
deadlock because the signal proxy is destructed before the RPC EP.
issue #2284
This patch ensures that the POLICY::release is called whenever the
session creation aborted with an exception. In the original version, an
exception like 'Quota_exceeded' caused a single-session root interface
to deny subsequent session requests.
This patch enhances the 'Child' and 'Child_policy' with the ability to
separate the different steps of bootstrapping children. If the
'Child_policy::initiate_env_sessions()' returns false, the child's
environment sessions remain unrouted at construction time. This way,
child objects for many children can be initialized to a state that
allows the children to represent services for other children. Therefore,
session routing can be applied before any child executes.
At this stage, the environment RAM sessions of all children can be
created. Note that this step still has the limitation that RAM sessions
are generally expected to be provided by either the parent or a local
service.
Once all children are equipped with RAM, they can in principle receive
session-quota donations. Hence, all other environment sessions can now
be arbitrarily routed and initiated.
Once the environment of a child is complete, the child's process and
initial thread is created.
This patch improves the accounting for the backing store of
session-state meta data. Originally, the session state used to be
allocated by a child-local heap partition fed from the child's RAM
session. However, whereas this approach was somehow practical from a
runtime's (parent's) point of view, the child component could not count
on the quota in its own RAM session. I.e., if the Child::heap grew at
the parent side, the child's RAM session would magically diminish. This
caused two problems. First, it violates assumptions of components like
init that carefully manage their RAM resources (and giving most of them
away their children). Second, if a child transfers most of its RAM
session quota to another RAM session (like init does), the child's RAM
session may actually not allow the parent's heap to grow, which is a
very difficult error condition to deal with.
In the new version, there is no Child::heap anymore. Instead, session
states are allocated from the runtime's RAM session. In order to let
children pay for these costs, the parent withdraws the local session
costs from the session quota donated from the child when the child
initiates a new session. Hence, in principle, all components on the
route of the session request take a small bite from the session quota to
pay for their local book keeping
Consequently, the session quota that ends up at the server may become
depleted more or less, depending on the route. In the case where the
remaining quota is insufficient for the server, the server responds with
'QUOTA_EXCEEDED'. Since this behavior must generally be expected, this
patch equips the client-side 'Env::session' implementation with the
ability to re-issue session requests with successively growing quota
donations.
For several of core's services (ROM, IO_MEM, IRQ), the default session
quota has now increased by 2 KiB, which should suffice for session
requests to up to 3 hops as is the common case for most run scripts. For
longer routes, the retry mechanism as described above comes into effect.
For the time being, we give a warning whenever the server-side quota
check triggers the retry mechanism. The warning may eventually be
removed at a later stage.
This method is a hook to enable a runtime to respond to state changes.
In particular, in init this hook is used to trigger the generation of a
new state report, if configured.
Furthermore, the patch introduces the 'generate_client_side_info' and
'generate_server_side_info' methods to the 'Session_state', which
generates an XML representation of the session states to appear in
reports produced by init.
Issue #2246
Normally, the platform driver helpers adapt the global run variables directly
via append. But the introduction of a more elegant run script style, that
incorporates dependent strings inline may be a good idea. Thus, we need the
backends of the helpers available as functions that return their string rather
than appending it.
The old interface still exists and uses the new interface as backend.
Ref #2193
The new return value of 'resolve_session_request' allows the child
policy to define the label used as the policy selector at the server.
Because this patch introduces the distinction of the child-provided
label from the label as presented to the server along with the session
request, the latter is now handled as a dedicated 'Session_state'
argument.
Issue #2248
There existed a race when 'wait_and_dispatch_one_signal' is called form
a RPC context, because the 'signal_proxy' or 'main' will block and the
signal semaphore, when the EP then calls 'wait_and_dispatch_one_signal',
the signal proxy is woken up ands sends an RPC to the EP, leading to a
dead lock if no further signal arrive, because the EP will then remain
blocked in the signal semaphore.
Therefore, for this case, the signal proxy will now perform a semaphore
up operation and does not perform an RPC if the EP is within
'wait_and_dispatch_one_signal'.
A Signal_handler may schedule a hook function that is executed after the
signal handler returned. This can be used if the hook function may
trigger a (nested) signal handler by means of
wait_and_dispatch_one_signal(). Otherwise, an occurrence of the same
signal that triggered the original signal handler results in a dead lock
just before calling the nested handler (due to the Signal_context
destruction lock).
Put the initialization of the cpu cores, setup of page-tables, enabling of
MMU and caches into a separate component that is only used to bootstrap
the kernel resp. core.
Ref #2092
This hook allows the export of the allocator's state by a derrived
class. I.e., the final state of the allocator used for bootstrapping
core.
Ref #2092
First, calls to manage and dissolve signal contexts now check if the
signal receiver was constructed. There is a small window during suspend
where it is destructed before reconstructed again.
Last, we ensure that processing of incoming signal was deblocked by the
suspend signal before entering the suspend operation. This way we ensure
already queued signal are handled.
This commit enables compile-time warnings displayed whenever a deprecated
API header is included, and adjusts the existing #include directives
accordingly.
Issue #1987
This function returns the information whether the used platform relies
on USB HID for interactive scenarios by default as is the case for most
ARM platforms. In contrast, for x86 the USB driver can be omitted because
we can use the PS/2 driver (that is readily available in repos/os/).
If the detach address is not the beginning of the region, one gets:
"virtual void Genode::Allocator_avl_base::free(void*): given
address (0x180e0) is not the block start address (0x18000)"
Instead, print an explicit warning in front of the detach call.
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 commit addresses the situation where an environment session
outlives the session-providing service. In this case, the env session
got already invaidated at the destruction time of the server. However,
the underlying session-state structure continues to exist until the
client is destructed. During the eventual destruction of such a dangling
environment session, we have to be careful not to interact with the
no-longer existing service.
Ref #2197
This patch addresses the corner case of destructing a child that
provides an enviroment session to another child. Before this patch,
this situation could result in an infinite loop.
The problem was introduced as a side effect of issue #2197 "base: apply
routing policy to environment sessions".
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 commit mostly removes the globally visible NR_OF_CPUS define
from the global makefile specifiers defined in the base-hw repository.
Whereever necessary it adds platform specific makefiles to the base
repository when they were missing.
Ref #2190
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.
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
These functions are marked as always inline through the 'SELF_RELOC' macro. This
became necessary because on riscv functions calls are performed through the
global offset table, which is not initialized at this point.
Fixes#2203
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 removes the manually maintained symbol map from the dynamic
linker. This way, the symbol map stays in sync with the ABI and - more
importantly - no longer uses wildcards. So the symbols exported by the
dynamic linker are strictly limited by the ABI.
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
The header is foc-specific. It used to shadow the generic one provided
by the base repository, which contradicts with the kernel-agnostic
Genode API. Hence, it had to be moved to a foc-specific location.
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
The main thread does no longer execute application code. It is solely
responsible for the initialization of the component's entrypoint and for
retrieving asynchronous notifications. Since the stack usage is no
longer dependent on application-specific code, we can significantly
shrink it to reduce the memory footprint of components. In the worst
case - should the stack overrun - we would observe a page fault because
the stack is placed in the stack area, surrounded by guard pages.
This patch replaces the former machine-word-dependent default stack size
by the fixed value of 64 KiB which should suffice for components on both
32 and 64 bit. Previously, the default stack size on 64 bit was 128 KiB,
which is wasteful. If a component needs more stack than 64 KiB, it can
specify a custon stack size by implementing 'Component::stack_size'.
The initial stack is solely used to initialize the Genode environment
along with the application stack located in the stack area. It never
executes application code. Hence, we can make it small. To check that it
is not dimensioned too small, the patch introduces a sanity check right
before switching to the application stack.
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
The heap typically first tries to allocate larger chunks than necessary, and
if it fails the actual minimal one. The first attempt already triggers warnings
which are not critical at all. If the second (critical) allocation fails,
then there are additionally checks and warnings already in place.
Issue #1039
The code in Core's Cpu_session_component::create_thread might throw a
capability refernce-count overflow if one creates many threads, which would
kill core if not handled.
Ref #2120
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 data structure is meant as a safe alternative for a list wherever
the list is solely used to remember objects and iterate through them in
an unspecified order. One use case is the 'Service_registry'.
This data structure allows the association of objects with IDs. IDs are
kept in an AVL tree. So in contrast to a bit allocator, the ID space can be
sparsely populated and does not need to be dimensioned. The lifetime of
an ID is bound to an 'Element' object, which relieves the programmer
from manually allocating/deallocating IDs for objects.
Issue #2120
We preserve lower RAM for device drivers with physical memory
constraints. If no physical RAM constraint exists, the allocations above
3G (32-bit) or 4G (64-bit) are preferred.
This fixes a regression on Ubuntu 16.04 (resp. Linux systems with recent
kernel versions) and address-space randomization originating from an
uninitialized relocation base of 0.
This patch is a preparation of the forthcoming async parent interface.
Note that this patch increases the size of connection objects.
Furthermore it adds a diagnostic message whenever a connection fails.
Issue #2166
Unfortunately, the volatile object does not inherit the noncopyable
attribute of the enclosed object. By making all volatile objects
noncopyable, we prevent the accidental copying of a noncopyable object
wrapped in a volatile object.
Replace 'dump()' debug utilities within Allocator_avl with Output::print
equivalents, and use the new Avl_tree::for_each utility to simplify
the implementation.
Ref #2159
This overload covers the common case for initializing a string from a
literal without employing the 'Output' mechanism. This way, such
strings can by constructed without calling virtual functions, which in
turn makes the 'String' usable for the 'init_rtld' phase of the dynamic
linker.
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
This patch adds the missing exception handling for depleted RM session
quotas. If core runs out of session quota while creating a new region
map, it now reflects this condition as a Region_map::Out_of_metadata
exception to the RM client. Thanks to Denis Huber for reporting the
issue!
This patch revives our ds_ownership test from 2012, which just revealed
a regression in core where the dataspace-free operation of the RAM
service would unconditionally destroy dataspace objects from foreign
sessions. The patch fixes the bug and adds an updated version of the
test to the autopilot.
Fixes#2065
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
and show some message about. On sel4 sometimes exceptions are thrown and no
message is shown, it just seems to hang. With this patch at least you get
an idea that something bad happened.
Issue #2044
- remove special handling from base-nova
- add to rpc_server where it actually should be applied to
- required to work for sel4 cancel_blocking
Issue #2044
The linker scripts are known to reside in BASE_DIR. By using them
directly from this location instead of searching them in the
REPOSITORIES, we don't need to specify the repos/base as a repository in
order to link.
This patch handles x86_32 and x86_64 separately since this is the SPEC
value directly supplied to the package build tool. This way, we achieve
that a CROSS_DEV_PREFIX is defined for each supported argument.
Those headers implement a platform-specific mechanism. They are never
used by components directly.
This patch also cleans up a few other remaining platform-specific
artifact such as the Fiasco.OC-specific assert.h.
Issue #1993
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
Session_label constructor now takes a bare string rather than a
serialized argument buffer.
Replace all instances of previous constructor with 'label_from_args'
function.
Issue #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 static 'Thread::mystack()' function returns the stack boundaries of
the calling thread. It is useful when a thread uses a diffent stack than
the primary one.
Fixes#2037
- platform_drv announces a separate "Acpi" session
- platform_drv waits for ROM "system" to change state to "acpi_ready"
- acpica waits for "Acpi" announcement
- acpica uses the platform driver via "Acpi" to reconfigure PCI devices
- acpica changes "system" state to "acpi_ready" after it ready with initialization
- platform_drv reacts on "system" state change to "acpi_ready" by announcing "Platform" session
- drivers start to operate as usual
Issue #2009
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
The whole XML comment has to be parsed as one XML tag to support strange
but valid combinations like
<!---->
<!--invisible-tag></invisible-tag-->
Fixes#1424
Quota_exceeded message are of no use during session construction, since
the arguments of the ram_quota are used and no upgrade can take place (the
session construction failed and is so not available for upgrade)
Fixes#1983
This patch removes the outdates doc/architecture.txt since the
topics are covered by the book. We keep repos/os/doc/init.txt
because it contains a few details not present in the book (yet).
The patch streamlines the terminology a bit. Furthermore, it
slightly adjusts a few source-code comments to improve the book's
functional specification chapter.
* Adds public timeout syscalls to kernel API
* Kernel::timeout installs a timeout and binds a signal context to it that
shall trigger once the timeout expired
* With Kernel::timeout_max_us, one can get the maximum installable timeout
* Kernel::timeout_age_us returns the time that has passed since the
calling threads last timeout installation
* Removes all device specific back-ends for the base-hw timer driver and
implements a generic back-end taht uses the kernel timeout API
* Adds assertions about the kernel timer frequency that originate from the
requirements of the the kernel timeout API and adjusts all timers
accordingly by using the their internal dividers
* Introduces the Kernel::Clock class. As member of each Kernel::Cpu object
it combines the management of the timer of the CPU with a timeout scheduler.
Not only the timeout API uses the timeout scheduler but also the CPUs job
scheduler for installing scheduling timeouts.
* Introduces the Kernel::time_t type for timer tic values and values inherited
from timer tics (like microseconds).
Fixes#1972
Evaluate fadt xml node in report from acpi_drv. If the io ports in the range
of 0xcf8+4 are necessary for the reset than the platform driver will
react on the 'system' state 'reset' and reboot.
Issue #1962
- add a new function 'binary_ready_hook_for_gdb()' in ldso. GDB can set a
breakpoint at this function to know when ldso has loaded the binary
into memory.
- get the thread state from the NOVA kernel immediately on 'pause()'
Fixes#1968
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
This patch supplements each existing connection type with an new
constructor that is meant to replace the original one. The new
one takes a reference to the component's environment as argument and
thereby does not rely on the presence of the globally accessible
'env()' interface.
The original constructors are marked as deprecated. Once we have
completely abolished the use of the global 'env()', we will remove them.
Fixes#1960
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.
Now rlibs are actually linked to programs. Target files have been
modified to not generate code that requires compiler-rt. Added a target
for libstd-rust, but it's very broken right now. Moved alloc_system to
the libports folder because either a memory allocator needs to be
written in rust or posix_memalign needs to be implemented. Changed
liblibc to use freebsd as the OS instead of netbsd. Added a library with
unwind dummy functions.
Rust relies on atomic builtins, which are not implemented in libgcc for
ARM. One was implemented in rust, which was sufficient to get the
current rust test to run. Rust libs were added into the group of libs
for the linker so order no longer matters. The raspberry pi now uses an
armv6 target.
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
Most slab allocators in core use a sliced heap as backing store. Since
sliced-heap allocations are performed at page-granularity, it is
sensible to dimension the slab blocks to fill whole pages.
This patch cleans up the implementation of the sliced heap, adds a
constructor that takes references instead of pointers, and adds the
function 'meta_data_size' to determine the meta-data overhead per block.
The latter can be used to dimension slab allocators such that slab
blocks use whole pages.
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
Since the dynamic linker depends on the XML utils and we plan to replace
the ancient 'Arg_string' with XML, it is time to move the 'Xml_node' and
'Xml_generator' to base/include.
We will eventually remove the delivery of the number of occurred signals
to the recipient. There haven't been any convincing use cases for this
feature. In the contrary, it actually led to wrong design choices in the
past where the rate of signals carried information (such as the progress
of time) that should better be obtained via an explicit RPC call.
The old 'Signal_rpc_member' template retains the old interface for now.
But the new 'Signal_handler' omits the 'unsigned' argument from the
handler function.
GNU ar only uses a flat module (object) name space but supports multiple
instances of objects with the same name. As we use subdirectories with
source file names that may clash (e.g., signal/common.cc and
server/common.cc in the base library) some of our static library
archives have multiple object instances. This is not an issue on archive
creation but works not as expected when updating archives. To avoid
updates of library archives we delete the files before calling GNU ar.
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
We don't want Genode environment objects that register their destructor
for program exit as it is mostly unnecessary and easily produces
dangling pointers. Thus, use unmanaged_singleton instead of the static
keyword.
Fixes#1941
When using the Allocator interface, one can't tell which alignment
resulting allocations fulfill. However, at least on ARM, given the
architectural alignment requirements of ARM memory accesses, one wants
memory allocations (what allocators are for in most cases) to be word
aligned automatically. Previously, at least the AVL allocator simply
called alloc_aligned without defining align in its alloc implementation.
This led to unaligned access faults (the default was 0) when using the
AVL allocator as Allocator (as done in the metadata management of a SLAB
of an AVL that uses the AVL as backing store). To avoid such pitfalls
in the future, we force users of alloc_aligned to always specify align
(why use alloc_aligned without align anyway).
Ref #1941
This is a generalisation approach of the hw_zynq target. As the boards
typically use UART1 instead of UART0 (used by qemu), we have to
distinguish between those. Moreover, in general hw_zynq does not imply
zynq_qemu anymore, so that the support of particular boards can be
placed in third-party or community repositories (e.g. Genode world).
Fixes#1926
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
This patch changes the organization of the slab blocks within the slab
allocator. Originally, blocks were kept in a list sorted by the number
of free entries. However, it turned out that the maintenance of this
invariant involves a lot of overhead in the presence of a large number
of blocks. The new implementation manages blocks within a ring in no
particular order and maintains a pointer to the block where the next
allocation is attempted. This alleviates the need for sorting blocks
when allocating and deallocating.
Fixes#1908
This patch ensures that the 'Allocator_avl' releases all memory obtained
from the meta-data allocator at destruction time. If allocations are
still dangling, it produces a warning, hinting at possible memory leaks.
Finally, it properly reverts all 'add_range' operations.
This patch fixes a use-after-free problem raised by the recent ability of
the slab allocator to dynamically release empty slab blocks. The
Rm_session_component::detach function used to rely on the assumption
that the region metadata co-located with the allocator metadata of the
'_map' would stay intact even after a 'free' if the region.
This patch makes sure that the dataspace pool is flushed before
destructing the heap-local allocator-avl instance. With the original
destruction order, the allocator would still contain dangling
allocations on the account of the dataspace pool when destructed. In
practice, this caused no problem because the underlying backing store is
eventually freed on the destruction of the pool. But it triggers a
runtime warning of the allocator since it has become more strict with
regard to dangling allocations.
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
Rust relies on atomic builtins, which are not implemented in libgcc for
ARM. One is implemented in rust, which is sufficient to get the
current rust test to run.
Issue #1899
Check if the binary pointer is valid before attempting to lookup the
symbol. Shared objects with unresolved symbols and missing depencies,
e.g a library that references 'errno' but is not linked against libc,
will now produce an error message when they are loaded by the dynamic
linker.
Fixes#1904.
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
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
Previously, ports that were needed for a scenario and that were not
prepared or outdated, triggered one assertion each during the second
build stage. The commit slots a mechanism in ahead that gathers all
these ports during the first build stage and reports them in form of a
list before the second build stage is entered. This list can be used
directly as argument for tool/ports/prepare_port to prepare respectively
update the ports. If, however, this mechanism is not available, for
example because a target is build without the first build stage, the old
assertion still prevents the target from running into troubles with a
missing port.
Fixes#1872
Enable the ACPI functionality in the platform_drv on hw_x86_64_muen and
provide a simple generated XML report as ROM session in order to make
the PCI configuration space available.
This is a requirement to implement support for MSI on hw_x86_64_muen.
The wrapper functions (e.g., 'Unwind_*' and friends) now have the same signature
as the original function in 'libgcc', reside in a separate C file which is
archived to cxx.lib.a. In supc++.o we prefix the wrapped functions with '_cxx_'.
This also enables support for riscv.
related to #1880
This prevents a sporadic null-pointer dereference in the nic_loopback
test, which occurred once in 100 runs. I'm not sure if there's still a
race window (we may investigate) with context dissolve.
This commit enables multi-processing for all Cortex A9 SoCs we currently
support. Moreover, it thereby enables the L2 cache for i.MX6 that was not
enabled until now. However, the QEMU variants hw_pbxa9 and hw_zynq still
only use 1 core, because the busy cpu synchronization used when initializing
multiple Cortex A9 cores leads to horrible boot times on QEMU.
During this work the CPU initialization in general was reworked. From now
on lots of hardware specifics were put into the 'spec' specific files, some
generic hook functions and abstractions thereby were eliminated. This
results to more lean implementations for instance on non-SMP platforms,
or in the x86 case where cache maintainance is a non-issue.
Due to the fact that memory/cache coherency and SMP are closely coupled
on ARM Cortex A9 this commit combines so different aspects.
Fix#1312Fix#1807
When unblocking a thread in Semaphore::up() while holding the fifo meta-data
lock, it might happen that the lock holder gets destroyed by the one it was
unblocking. This happened for instance in the pthread test in the past, where
thread destruction was synchronized via a semaphore. There is no need to hold
the lock during the unblock operation, so we should do it outside the critical
section.
Fix#1333
Previously we used a pretty slow external clock source for the timer. This
resulted in such a low TICS_PER_MS value that the granularity wasn't
sufficient to find a setup with a precision better than 1 second error per
minute. Now we use the so-called High Frequency Reference Clock as input
with TICS_PER_MS=33333 and the timer precision is significantly < 1 second per
minute.
Fixes#1805
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
* enable i915 driver from Linux 3.14.5
* tested for generation 5 till 8 GPUs
The driver can be configured at run-time via the config ROM. Every
connector of the graphic card can be configured separately using the
following syntax
<config>
<connector name="LVDS-11" width="1280" height="800" enabled="true"/>
</config>
Also, when enabled within the intel framebuffer driver configuration like
the following
<config buffered="yes"/>
a simple ram dataspace is propagated to the client and the driver
itselfs copies from that buffer to the framebuffer triggered via refresh
calls. This option is useful to alleviate tearing effects.
The driver distributes all available connectors of the graphic card and
their supported resolutions via a report. It looks like follows
<connectors>
<connector name="LVDS-11" connected="1">
<mode width="1280" height="800" hz="60"/>
...
</connector>
...
</connectors>
The driver distributes the report only if this is stated within its
configuration, like the following
<config>
<report connectors="yes"/>
</config>
Fix#1764
'block_for_signal' and 'pending_signal' now set pending flag in signal context
in order to determine pending signal. The context list is also used by the
'Signal_receiver' during destruction.
Fixes#1738
Currently, when a signal arrives in the main thread, the signal dispatcher is
retrieved and called from the main thread, the dispatcher uses a proxy object
that in turn sends an RPC to the entry point. This becomes a problem when the
entry point destroys the dispatcher object, before the dispatch function has
been called by the main thread. Therefore, the main thread should simply send an
RPC to the entry point upon signal arrival and the dispatching should be handled
solely by the entry point.
Issue #1738
Holding the object pool's lock while trying to obtain an object's lock
can leave to dead-lock situations, when more than one thread tries to
access multiple objects at once (e.g.: when transfer_quota gets called
simultanously by the init and entrypoint thread in core). To circumvent
holding the object pool lock too long, but access object pointers safely
on the other hand, this commit updates the object pool implementation
to use weak pointers during the object retrieval.
Fix#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
The commit consumes the argument of a unsupported printf command.
Without the commit - a subsequent command uses the argument of the preceding
command, which may cause memory corruption or page faults for sequences using
string commands, e.g.
Genode::printf("%#x %s\n", 0x20, "Test");
'#' is not supported by Genode::printf. In this scenario a pagefault at
address 0x20 is caused.
Fixes#1701
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
With the introducation of the Audio_in session interface it makes
sense to rename the current available audio drivers. At the moment
only the dde_bsd audio_drv supports Audio_out as well as Audio_in.
The Linux audio_drv only supports Audio_out (there is no demand for
Audio_in support currently) but is renamed nonetheless to make it
easiert to write generic run scripts.
Issue #1644.
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.
Increase internal chunk size of heap only if an allocation succeeded
beforehand. Otherwise the chunk size increases with every unsuccessful
invocation and a upgrade of the used ram session will be insufficient and of
no use at all.
Fixes#1632
Moves the Bios Data Area header from base-hw to base. Modifies the
base-nova core console that it uses the header as replacement for
the previous BDA bit logic.
Ref #1625
Introduces a class Unmanaged_singleton_constructor that can be declared as
friend to be able to call unmanaged_singleton on classes with a private
constructor. Enables the appliance of the singleton pattern.
Ref #1625
This commit eliminates the mutual interlaced taking of destruction lock,
list lock and weak pointer locks that could lead to a dead-lock situation
when a lock pointer was tried to construct while a weak object is in
destruction progress.
Now, all weak pointers are invalidated and dequeued at the very
beginning of the weak object's destruction. Moreover, before a weak pointer
gets invalidated during destruction of a weak object, it gets dequeued, and
the list lock is freed again to avoid the former dead-lock.
Fix#1607
Up to now it was not possible to trace threads that use a different
Cpu_session rather than env()->cpu_session() (as done by VirtualBox).
This problem is now solved by setting the Cpu_session explicitly when
creating the event logger and attaching the trace control area when
creating the thread.
Fixes#1618.
