This patch fixes the handling of the corner case where the allocation of
a trace buffer throws 'Out_of_caps' or 'Out_of_ram'. Under this
circumstance, the '_buffer' would still be flagged with the 'size',
which prevented any subsequent allocation attempt. This patch fixes the
problem by initializing the 'size' after the potentially throwing
allocation.
The problem triggered with the test-trace_logger after the accounting of
core's TRACE service (replacing the 'Allocator_guard' by
'Constrained_ram_allocator') became more accurate.
Related to issue #3750
The 'WHITESPACE' case of the _calc_len method wrongly accessed the
character before checking upper bound of the token. The problem is fixed
by switching the order of both conditions.
Fixes#3756
This patch removes old 'Allocator_guard' utility and replaces its use
with the modern 'Constrained_ram_allocator'.
The adjustment of core in this respect has the side effect of a more
accurate capability accounting in core's CPU, TRACE, and RM services.
In particular, the dataspace capabilities needed for core-internal
allocations via the 'Sliced_heap' are accounted to the client now.
The same goes for nitpicker and nic_dump as other former users of the
allocator guard. Hence, the patch also touches code at the client and
server sides related to these services.
The only remaining user of the 'Allocator_guard' is the Intel GPU
driver. As the adaptation of this component would be too invasive
without testing, this patch leaves this component unchanged by keeping a
copy of the 'allocator_guard.h' locally at the component.
Fixes#3750
This patch largely reverts the commit "base: lay groundwork for
base-linux caps change" because the use of 'epoll' instead of 'select'
alleviated the need to allocate large FD sets, which motivated the
introduction of the 'Native_context' hook.
Related to issue #3581
The sandbox library supports the forwarding of session requests from the
outside to one of the hosted children according to a policy. This patch
introduces the distinction between two cases, which previously triggered
the denial of the session request.
- There exists no matching policy for the requested session
- There exists a matching policy but the referred server child
does not exist (yet)
Whereas the proper response to the first case is the denial of the
request, the second case can occur in situation where a dynamic init is
used to implement a staged startup, for example via the deploy
mechanism. In such cases, a policy may exist as a static rule while the
server has not been started yet. This patch changes the behavior such
that such requests are stalled.
The patch is accompanied with test cases for exercising both situations.
Fixes#3733
If trace is enabled for component than an attempt to put message into
trace buffer is performed using log_output policy. If it succeeds than
message is not put to logs using log service.
Fixes#3714
On Linux, Genode used to represent each RPC object by a socket
descriptor of the receiving thread (entrypoint) and a globally-unique
value that identifies the object. Because the latter was transferred as
plain message payload, clients had to be trusted to not forge the
values. For this reason, Linux could not be considered as a productive
Genode base platform but remained merely a development vehicle.
This patch changes the RPC mechanism such that each RPC object is
represented by a dedicated socket pair. Entrypoints wait on a set of
the local ends of the socket pairs of all RPC objects managed by the
respective entrypoint. The epoll kernel interface is used as the
underlying mechanism to wait for a set of socket descriptors at the
server side.
When delegating a capability, the remote end of the socket pair is
transferred to the recipient along with a plaintext copy of the
socket-descriptor value of the local end. The latter value serves as a
hint for re-identifiying a capability whenever it is delegated back to
its origin. Note that the client is not trusted to preserve this
information. The integrity of the hint value is protected by comparing
the inode values of incoming and already present capablities at the
originating site (whenever the capability is invoked or presented to the
owner of the RPC object).
The new mechanism effectively equips base-linux with Genode's capablity
model as described in the Chapter 3 of the Genode Foundations book.
That said, the sandboxing of components cannot be assumed at this point
because each component has still direct access to the Linux system-call
interface.
This patch is based on the extensive exploration work conducted by
Stefan Thoeni who strongly motivated the inclusion of this feature into
Genode.
Issue #3581
