If a calling process execve()s a setuid program, it can appear to be
uid 0. Since we're receiving requests over DBus, avoid this by simply
passing system-bus-name as a subject.
69ab8088 unified parsing of status files and removed the logic of
skipping extra '0's when getting the effective capabilities. Restore
that logic, so that the same capabilities are always mapped to the
same strings in the journal.
A session-device is a device that is bound to a seat and used by a
session-controller to run the session. This currently includes DRM, fbdev
and evdev devices. A session-device can be created via RequestDevice() on
the dbus API of the session. You can drop it via ReleaseDevice() again.
Once the session is destroyed or you drop control of the session, all
session-devices are automatically destroyed.
Session devices follow the session "active" state. A device can be
active/running or inactive/paused. Whenever a session is not the active
session, no session-device of it can be active. That is, if a session is
not in foreground, all session-devices are paused.
Whenever a session becomes active, all devices are resumed/activated by
logind. If it fails, a device may stay paused.
With every session-device you request, you also get a file-descriptor
back. logind keeps a copy of this fd and uses kernel specific calls to
pause/resume the file-descriptors. For example, a DRM fd is muted
by logind as long as a given session is not active. Hence, the fd of the
application is also muted. Once the session gets active, logind unmutes
the fd and the application will get DRM access again.
This, however, requires kernel support. DRM devices provide DRM-Master for
synchronization, evdev devices have EVIOCREVOKE (pending on
linux-input-ML). fbdev devices do not provide such synchronization methods
(and never will).
Note that for evdev devices, we call EVIOCREVOKE once a session gets
inactive. However, this cannot be undone (the fd is still valid but mostly
unusable). So we reopen a new fd once the session is activated and send it
together with the ResumeDevice() signal.
With this infrastructure in place, compositors can now run without
CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to
acquire a session and listen for devices via udev_monitor. For every
device they want to open, they call RequestDevice() on logind. This
returns a fd which they can use now. They no longer have to open the
devices themselves or call any privileged ioctls. This is all done by
logind.
Session-switches are still bound to VTs. Hence, compositors will get
notified via the usual VT mechanisms and can cleanup their state. Once the
VT switch is acknowledged as usual, logind will get notified via sysfs and
pause the old-session's devices and resume the devices of the new session.
To allow using this infrastructure with systems without VTs, we provide
notification signals. logind sends PauseDevice("force") dbus signals to
the current session controller for every device that it pauses. And it
sends ResumeDevice signals for every device that it resumes. For
seats with VTs this is sent _after_ the VT switch is acknowledged. Because
the compositor already acknowledged that it cleaned-up all devices.
However, for seats without VTs, this is used to notify the active
compositor that the session is about to be deactivated. That is, logind
sends PauseDevice("force") for each active device and then performs the
session-switch. The session-switch changes the "Active" property of the
session which can be monitored by the compositor. The new session is
activated and the ResumeDevice events are sent.
For seats without VTs, this is a forced session-switch. As this is not
backwards-compatible (xserver actually crashes, weston drops the related
devices, ..) we also provide an acknowledged session-switch. Note that
this is never used for sessions with VTs. You use the acknowledged
VT-switch on these seats.
An acknowledged session switch sends PauseDevice("pause") instead of
PauseDevice("force") to the active session. It schedules a short timeout
and waits for the session to acknowledge each of them with
PauseDeviceComplete(). Once all are acknowledged, or the session ran out
of time, a PauseDevice("force") is sent for all remaining active devices
and the session switch is performed.
Note that this is only partially implemented, yet, as we don't allow
multi-session without VTs, yet. A follow up commit will hook it up and
implemented the acknowledgements+timeout.
The implementation is quite simple. We use major/minor exclusively to
identify devices on the bus. On RequestDevice() we retrieve the
udev_device from the major/minor and search for an existing "Device"
object. If no exists, we create it. This guarantees us that we are
notified whenever the device changes seats or is removed.
We create a new SessionDevice object and link it to the related Session
and Device. Session->devices is a hashtable to lookup SessionDevice
objects via major/minor. Device->session_devices is a linked list so we
can release all linked session-devices once a device vanishes.
Now we only have to hook this up in seat_set_active() so we correctly
change device states during session-switches. As mentioned earlier, these
are forced state-changes as VTs are currently used exclusively for
multi-session implementations.
Everything else are hooks to release all session-devices once the
controller changes or a session is closed or removed.
There's now some more obvious overlap amongst the two utf8 validation
functions, but no more than there already was previously.
This also adds some menial tests for anyone who wants to do more
merging of these two in the future.
Previously the specifier calls could only indicate OOM by returning
NULL. With this change they will return negative errno-style error codes
like everything else.
Travis tests are failing, probably because /proc/meminfo is not available
in the test environment. The same might be true in some virtualized systems,
so just treat missing /proc/meminfo as a sign that hibernation is not
possible.
Condition that is checked is taken from upower:
active(anon) < free swap * 0.98
This is really stupid, because the kernel knows the situation better,
e.g. there could be two swap files, and then hibernation would be
impossible despite passing this check, or the kernel could start
supporting compressed swap and/or compressed hibernation images, and
then this this check would be too stringent. Nevertheless, until
we have something better, this should at least return a true negative
if there's no swap.
Logging of capabilities in the journal is changed to not strip leading
zeros. I consider this more readable anyway.
http://cgit.freedesktop.org/upower/tree/src/up-daemon.c#n613https://bugzilla.redhat.com/show_bug.cgi?id=1007059
It is best to catch such errors early. If invalid UTF-8 ends up being
given to dbus methods, the program will crash:
process 20801: arguments to dbus_message_iter_append_basic() were incorrect, assertion "_dbus_check_is_valid_utf8 (*string_p)" failed in file dbus-message.c line 2598.
This makes verbose behave like short mode, i.e. try to show
the source timestamp, and fall back to journald timestamp
only if unavailable or unparsable. I think verbose should
be like short, only showing more fields, and showing different
timestamps would be confusing.
So far, we would show up to 128 bytes from a message, simply
cutting of the rest. With multiline messages, it is quite common
for a message to be longer than that, and this model doesn't really
work anymore.
A new limit is added: up to 3 lines will be shown, unless --full is
used (c.f. first line below). The limit for bytes is extended to 300
bytes. An ellipsis will always be used, if some form of truncation
occurs. If the tail of the message is cut off, either because of
length or line limit, dots will be shown at the end of the last
line. If this last line is short, the dots will be simply appended. If
the last line is too long for that, it will be ellipsized with dots at
the very end.
Note that the limits are in bytes, not characters, and we suck at
outputting unicode strings (c.f. last three lines below).
Aug 11 10:46:21 fedora python[67]: test message
line
line...
Aug 11 10:50:47 fedora python[76]: test message word word word word word word word word word word word wor...
Aug 11 10:55:11 fedora python[83]: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
Aug 11 11:03:21 fedora python[90]: ąąąąąąąąąąąąąąąąąąąąąąąąąąąąąą...
Aug 11 11:03:53 fedora python[97]: aąąąąąąąąąąąąąąąąąąąąąąąąąąąąąą...
Aug 11 11:25:45 fedora python[121]: aąąąąąąąąąąąąąąąąąąąąąąąąąąąąąąąąąą�...
Stop importing non-sensical kernel-exported variables. All
parameters in the kernel command line are exported to the
initial environment of PID1, but suppressed if they are
recognized by kernel built-in code. The EFI booted kernel
will add further kernel-internal things which do not belong
into userspace.
The passed original environ data of the process is not touched
and preserved across re-execution, to allow external reading of
/proc/self/environ for process properties like container*=.
In case of scripts, _EXE is set to the interpreter name, and
_COMM is set based on the file name. Add a match for _COMM,
and _EXE if the interpreter is not a link (e.g. for yum,
the interpreter is /usr/bin/python, but it is a link to
/usr/bin/python2, which in turn is a link to /usr/bin/python2.7,
at least on Fedora, so we end up with _EXE=/usr/bin/python2.7).
I don't think that such link chasing makes sense, because
the final _EXE name is more likely to change.
Previously, the logging sockets were asynchronous and if clogged we'd
lose messages. We did this to be extra careful given that PID 1 might
need to spawn the logging daemon as response to PID 1's own log messages
and we really should avoid a deadlock in that case.
As it turns out this causes loss of too many messages, hence make the
socket blocking again, however put a time limit on it to avoid unbounded
deadlocks in the unlikely case they happen.
https://bugs.freedesktop.org/show_bug.cgi?id=66664
If you have a ASCII only terminal, there is no way to set the charmap to
ANSI_X3.4-1968, other than using LC_CTYPE=C.
We don't want to assume a UTF-8 capable terminal in this case and only
do so, if LANG, LC_ALL and LC_CTYPE are unset.
Jan: test-tables fails on my system. The one it's failing on is:
syscall: 222 → (null) → -1
... and indeed, our own tables should not have holes, but syscall
tables certainly might.
In a User-Mode Linux session:
$ systemd-detect-virt
none
Although it is possible to reliably detect virtualization:
$ cat /proc/cpuinfo
processor : 0
vendor_id : User Mode Linux
model name : UML
mode : skas
host : Linux kytes 3.11.0-rc1-00009-ge5fd680 (...)
bogomips : 7007.43
So, grep for the string "\nvendor_id\t: User Mode Linux\n" in
/proc/cpuinfo, and say "uml" when asked.
