As noted above the former enum for the local-attachment address we
discovered address clashes on current Linux installations, esp. 32-bit
runtime on 64-bit Linux. The local_attach_addr is now configurable in
the run script and the memory maps heuristics were removed.
* Instead of always re-load page-tables when a thread context is switched
only do this when another user PD's thread is the next target,
core-threads are always executed within the last PD's page-table set
* remove the concept of the mode transition
* instead map the exception vector once in bootstrap code into kernel's
memory segment
* when a new page directory is constructed for a user PD, copy over the
top-level kernel segment entries on RISCV and X86, on ARM we use a designated
page directory register for the kernel segment
* transfer the current CPU id from bootstrap to core/kernel in a register
to ease first stack address calculation
* align cpu context member of threads and vms, because of x86 constraints
regarding the stack-pointer loading
* introduce Align_at template for members with alignment constraints
* let the x86 hardware do part of the context saving in ISS, by passing
the thread context into the TSS before leaving to user-land
* use one exception vector for all ARM platforms including Arm_v6
Fix#2091
* introduce new syscall (core-only) to create privileged threads
* take the privilege level of the thread into account
when doing a context switch
* map kernel segment as accessable for privileged code only
Ref #2091
* introduces central memory map for core/kernel
* on 32-bit platforms the kernel/core starts at 0x80000000
* on 64-bit platforms the kernel/core starts at 0xffffffc000000000
* mark kernel/core mappings as global ones (tagged TLB)
* move the exception vector to begin of core's binary,
thereby bootstrap knows from where to map it appropriately
* do not map boot modules into core anymore
* constrain core's virtual heap memory area
* differentiate in between user's and core's main thread's UTCB,
which now resides inside the kernel segment
Ref #2091
In the past, a signal context, that was chosen for handling by
'Signal_receiver::pending_signal and always triggered again before
the next call of 'pending_signal', caused all other contexts behind
in the list to starve. This was the case because 'pending_signal'
always took the first pending context in its context list.
We avoid this problem now by handling pending signals in a round-robin
fashion instead.
Ref #2532
Ensure that the timer does not handle timeouts again within 1000
microseconds after the last handling of timeouts. This makes denial of
service attacks harder. This commit does not limit the rate of timeout
signals handled inside the timer but it causes the timer to do it less
often. If a client continuously installs a very small timeout at the
timer it still causes a signal to be submitted to the timer each time
and some extra CPU time to be spent in the internal handling method. But
only every 1000 microseconds this internal handling causes user timeouts
to trigger.
If we would want to limit also the call of the internal handling method
to ensure that CPU time is spent beside the RPCs only every 1000
microseconds, things would get more complex. For instance, on NOVA
Time_source::schedule_timeout(0) must be called each time a new timeout
gets installed and becomes head of the scheduling queue. We cannot
simply overwrite the already running timeout with the new one.
Ref #2490
This patch merges two similar rules, which create content at 'include'
into a single rule. This prevents a possible race condition when
creating archives in parallel.
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
In nested scenarios like driver_manager.run, the initial session quota
for IO_PORT, IO_PORT, and IRQ sessions is expectedly insufficient.
However, the condition is properly handled by re-attemping the request
with a slightly increased quota. Still, core prints a warning each time
the request is denied for quota reasons, which spams the log. This patch
removes the non-critical message.
This should actually never happen. However if it happens, be a bit robuster
and don't provide the memory for re-use (which causes tons of other trouble
afterwards).
Issue #2505
There are hardware timers whose frequency can't be expressed as
ticks-per-microsecond integer-value because only a ticks-per-millisecond
integer-value is precise enough. We don't want to use expensive
floating-point values here but nonetheless want to translate from ticks
to time with microseconds precision. Thus, we split the input in two and
translate both parts separately. This way, we can raise precision by
shifting the values to their optimal bit position. Afterwards, the results
are shifted back and merged together again.
As this algorithm is not so trivial anymore and used by at least three
timer drivers (base-hw/x86_64, base-hw/cortex_a9, timer/pit), move it to a
generic header to avoid redundancy.
Ref #2400
When building Genode on a Linux system running in a Xen Dom0, the 'xen'
run target can run a Genode scenario in a Xen DomU.
Usage: in build/x86_*/etc/build.conf, define:
RUN_OPT = --include boot_dir/$(KERNEL) --include image/iso --include power_on/xen --include log/xen --include power_off/xen
The Xen DomU runs in HVM mode and loads Genode from an ISO image. Serial
log output is printed to the console and graphical output is shown in an
SDL window.
The Xen DomU ist managed using the 'xl' command line tool and it is
possible to add configuration options in the 'xen_args' variable in a run
script. Common options are:
- disabling the graphical output:
append xen_args { sdl="0" }
- configuring a network device:
append xen_args { vif=\["model=e1000,mac=02:00:00:00:01:01,bridge=xenbr0"\] }
- configuring USB input devices:
append xen_args { usbdevice=\["mouse","keyboard"\] }
Note: the 'xl' tool requires super-user permissions and interactive
password input can be troublesome in combination with 'expect' and is not
practical for automatic tests. For this reason, the current implementation
assumes that no password input is needed when running 'sudo xl', which can
be achieved by creating a file '/etc/sudoers.d/xl' with the content
'user ALL=(root) NOPASSWD: /usr/sbin/xl'
(where 'user' is the Linux user name).
Fixes#2504
When running core as the kernel inside every component, a separate
stack area for core is needed that is different from the user-land
component's one.
Ref #2091
