Since the recent move of the process creation into core, the original chroot trampoline
mechanism implemented in 'os/src/app/chroot' does not work anymore. A
process could simply escape the chroot environment by spawning a new
process via core's PD service. Therefore, this patch moves the chroot
support into core. So the chroot policy becomes mandatory part of the
process creation. For each process created by core, core checks for
'root' argument of the PD session. If a path is present, core takes the
precautions needed to execute the new process in the specified chroot
environment.
This conceptual change implies minor changes with respect to the Genode
API and the configuration of the init process. The API changes are the
enhancement of the 'Genode::Child' and 'Genode::Process' constructors to
take the root path as argument. Init supports the specification of a
chroot per process by specifying the new 'root' attribute to the
'<start>' node of the process. In line with these changes, the
'Loader::Session::start' function has been enhanced with the additional
(optional) root argument.
g++ 4.4.5 outputs the following warnings in our code using the loader
session:
.../base/include/base/capability.h: In member function 'typename Genode::Trait::Call_return<typename IF::Ret_type>::Type Genode::Capability<RPC_INTERFACE>::call() const [with IF = Loader::Session::Rpc_view_geometry, RPC_INTERFACE = Loader::Session]':
.../base/include/base/capability.h:207: warning: 'ret.Genode::Capability<Loader::Session>::Return<Loader::Session::Rpc_view_geometry>::_value.Loader::Session::View_geometry::width' may be used uninitialized in this function
.../base/include/base/capability.h:207: warning: 'ret.Genode::Capability<Loader::Session>::Return<Loader::Session::Rpc_view_geometry>::_value.Loader::Session::View_geometry::height' may be used uninitialized in this function
.../base/include/base/capability.h:207: warning: 'ret.Genode::Capability<Loader::Session>::Return<Loader::Session::Rpc_view_geometry>::_value.Loader::Session::View_geometry::buf_x' may be used uninitialized in this function
.../base/include/base/capability.h:207: warning: 'ret.Genode::Capability<Loader::Session>::Return<Loader::Session::Rpc_view_geometry>::_value.Loader::Session::View_geometry::buf_y' may be used uninitialized in this function
This is easily fixed with providing a default constructor.
Because of the C++ rules regarding initialer lists code that used
them for View_geometry had to be modified to use a normal construction
call. In my tests only Nitpicker had to be changed.
By adding a "mac=XX:XX:XX:XX:XX:XX" attribute/value pair to the nic_bridge's
configuration one can define the first MAC address from which the nic_brigde
will allocate MACs for it's clients. Note: that the least relevant byte will
be ignored, and ranges from 0-255. Fixes#424.
This patch implements a service which provides the contents of a tar
archive via the 'File_system::Session' interface.
Configuration:
<config>
<archive name="tar_archive.tar" />
<policy label="label_of_client" root="/rootdir/for/client" />
</config>
Fixes#333.
Increase size of block session backing store so it can handle maximum supported
packet size. Synchronize client threads during packet allocation.
Fixes#276
This patch extends the RAM session interface with the ability to
allocate DMA buffers. The client specifies the type of RAM dataspace to
allocate via the new 'cached' argument of the 'Ram_session::alloc()'
function. By default, 'cached' is true, which correponds to the common
case and the original behavior. When setting 'cached' to 'false', core
takes the precautions needed to register the memory as uncached in the
page table of each process that has the dataspace attached.
Currently, the support for allocating DMA buffers is implemented for
Fiasco.OC only. On x86 platforms, it is generally not needed. But on
platforms with more relaxed cache coherence (such as ARM), user-level
device drivers should always use uncacheable memory for DMA transactions.
This commit adds a terminal_log component, and a run-script which demonstrates
its usage. The terminal_log component provides the LOG service, and prints
every log-output prefixed by the session-label via a terminal-session.
This patch introduces the file-system-session interface, provides an
implementation of this interface in the form of an in-memory file
system, and enables the libc to use the new file-system facility.
The new interface resides in 'os/include/file_system_session/'. It
uses synchronous RPC calls for functions referring to directory
and meta-data handling. For transferring payload from/to files, the
packet-stream interface is used. I envision that the asynchronous design
of the packet-stream interface fits well will the block-session
interface. Compared to Unix-like file-system APIs, Genode's file-system
session interface is much simpler. In particular, it does not support
per-file permissions. On Genode, we facilitate binding policy (such as
write-permission) is sessions rather than individual file objects.
As a reference implementation of the new interface, there is the
new 'ram_fs' service at 'os/src/server/ram_fs'. It stores sparse
files in memory. At the startup, 'ram_fs' is able to populate the
file-system content with directories and ROM modules as specified
in its configuration.
To enable libc-using programs to access the new file-system interface,
there is the new libc plugin at 'libports/src/lib/libc-fs'. Using this
plugin, files stored on a native Genode file system can be accessed
using the traditional POSIX file API.
To see how the three parts described above fit together, the test
case at 'libports/run/libc_fs' can be taken as reference. It reuses
the original 'libc_ffat' test to exercise several file operations
on a RAM file-system using the libc API.
:Known limitations:
The current state should be regarded as work in progress. In particular
the error handling is not complete yet. Not all of the session functions
return the proper exceptions in the event of an error. I plan to
successively refine the interface while advancing the file-system
implementations. Also the support for truncating files and symlink
handling are not yet implemented.
Furthermore, there is much room for optimization, in particular for the
handling of directory entries. Currently, we communicate only one dir
entry at a time, which is bad when traversing large trees. However, I
decided to focus on functionality first and defer optimizations (such as
batching dir entries) to a later stage.
The current implementation does not handle file modification times at
all, which may be a severe limitation for tools that depend on this
information such as GNU make. Support for time will be added after we
have revisited Genode's timer-session interface (issue #1).
Fixes#54Fixes#171
The original loader service was primarily motivated by the
browser-plugin scenario presented on our live CD. The new version
implements a more general session interface, which widens the
application scope of the service and, at the same time, reduces its
implementation complexity.
The complexity reduction is achieved by removing the original limitation
of supplying the new sub system as a single binary blob only. The server
used to implement heuristics and functionality for dealing with
different kinds of blobs such as ELF images or TAR archives. This has
been replaced by a session-local ROM service, which can be equipped with
an arbitrary number of ROM modules supplied by the loader client prior
starting the new sub system. Even though the TAR support has been
removed, a separate instance of the 'tar_rom' service can be used within
the subsystem to provide the formerly built-in functionality.
This patch introduces support for ROM sessions that update their
provided data during the lifetime of the session. The 'Rom_session'
interface had been extended with the new 'release()' and 'sigh()'
functions, which are needed to support the new protocol. All ROM
services have been updated to the new interface.
Furthermore, the patch changes the child policy of init
with regard to the handling of configuration files. The 'Init::Child'
used to always provide the ROM dataspace with the child's config file
via a locally implemented ROM service. However, for dynamic ROM
sessions, we need to establish a session to the real supplier of the ROM
data. This is achieved by using a new 'Child_policy_redirect_rom_file'
policy to handle the 'configfile' rather than handling the 'configfile'
case entirely within 'Child_config'.
To see the new facility in action, the new 'os/run/dynamic_config.run'
script provides a simple scenario. The config file of the test program
is provided by a service, which generates and updates the config data
at regular intervals.
In addition, new support has been added to let slaves use dynamic
reconfiguration. By using the new 'Child_policy_dynamic_rom_file', the
configuration of a slave can be changed dynamically at runtime via the
new 'configure()' function.
The config is provided as plain null-terminated string (instead of a
dataspace capability) because we need to buffer the config data anyway.
So there is no benefit of using a dataspace. For buffering configuration
data, a 'Ram_session' must be supplied. If no 'Ram_session' is specified
at construction time of a 'Slave_policy', no config is supplied to the
slave (which is still a common case).
An example for dynamically reconfiguring a slave is provided by
'os/run/dynamic_config_slave.run'.
The ROM prefetcher service can be used to prefetch complete ROM files,
which is handy when using the iso9660 server (which normally reads file
content block-wise on demand). The server used to perform the
prefetching upon request of the respective ROM session. This patch adds
a facility for prefetching a predefined list of files. It is primarily
intended for eagerly fetching live-CD content in the background after
having passed the first boot stage.
This patch makes use of the recently added support for const RPC
functions by turning 'Framebuffer::Session::mode()' and
'Input::Session::is_pending()' into const functions.
The 'mode_sigh' function allows the client to receive notifications
about server-side display-mode changes. To respond to such a signal, the
client can use the new 'release' function, which acknowledges the mode
change at the server and frees the original framebuffer dataspace. Via a
subsequent call of 'dataspace', a framebuffer dataspace corresponding to
the new mode can be obtained. Related to issue #11.
As a preliminary step for working on issue #11, this patch revisits the
'Framebuffer::info' RPC call. Instead of using C-style out paramters,
the new 'mode()' RPC call returns the mode information as an object of
type 'Mode'. Consequently, mode-specific functions such as
'bytes_per_pixel' have been moved to the new 'Framebuffer::Mode' class.
