I noticed that we keep querying the preset database for transient units,
which makes little sense, since transient units are well, transient, and
hence not suject to enablement/disablement. Hence, let's shortcut things
and simply not check the preset database for them.
While we are at it, shortcut unit file state checks for transient units,
too. We know they are transient already, we can return that directly,
no need to go to disk.
Finally, treat perpetual units like transient units for the the preset
case: also bypass the preset database. (But keep checking for the unit
file state for them, since it *is* relevant to know whether they were
generated or not.)
Let's avoid dropping opts willy-nilly, especially that we already
carry the logic of determining availability prior to mount (but
make sure we respect the result though, and don't assume things
are available if the check fails).
Except for one place, they are only used by test-watch-pid. Let's also
use manager_get_unit_by_pidref() and friends in the test, and drop the
_pid() variants.
This introduce `LOG_ITEM()` macro that checks format strings in
log_struct() and friends.
Hopefully, this silences false-positive warnings by Coverity.
As reported in https://github.com/systemd/systemd/issues/35405, if the watchdog
ping failed, we effectively started a busy loop here. The previous commits
should fix this, but in general, the protection here is intended as a safety
net in case the logic is broken somewhere else. We shouldn't exclude the
watchdog stuff from this.
Closes https://github.com/systemd/systemd/issues/35405. Apparently some
watchdog devices can be opened, but then the pings start failing after some
time. Since the timestamp of the last successful ping is not updated, we try to
ping again immediately, causing a busy loop and excessive logging.
After trying a few different approaches to fit this into the existing framework
without changing the logic too much, I settled on an approach with a second
timestamp. In particular, the timestamp of the last successful ping is public,
exposed as WatchdogLastPingTimestamp over dbus. It'd be wrong to redefine this
to mean the last ping *attempt*. So we need a second timestamp in some form.
Also, if we give up on pinging, we probably should attempt to disarm the
watchdog. It's possible that the pinging fails, but the watchdog would still
fire. I don't think we want that, since it seems that our internal loop is
working, it's just the watchdog that is broken.
Structured message with SD_MESSAGE_WATCHDOG_PING_FAILED is logged if we fail
to ping.
I tested this by attaching gdb to pid 1 and calling close(watchdog_fd).
We get a bunch of warning messages and then an attempt to close the watchdog:
Mar 21 15:46:17 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:20 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:23 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:26 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:29 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:32 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:35 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:37 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:40 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:43 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:46 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:49 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:52 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:55 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0: Bad file descriptor
Mar 21 15:46:58 fedora systemd[1]: Failed to ping hardware watchdog /dev/watchdog0, closing watchdog after 15 attempts: Bad file descriptor
Mar 21 15:46:58 fedora systemd[1]: Failed to disable hardware watchdog, ignoring: Bad file descriptor
Mar 21 15:46:58 fedora systemd[1]: Failed to disarm watchdog timer, ignoring: Bad file descriptor
I think we need to log at some point if the user configured a watchdog device,
but no devices were found. We can't log ENOENT immediately, because the device
may likely appear during boot. So wait until the end of the initial transaction
and log then.
Those functions call watchdog_setup() and watchdog_setup_pretimeout(), which
internally do a similar check against the static variables watchdog_timeout and
watchdog_pretimeout. The second check is not useful.
Currently DelegateNamespaces= only works for services spawned by the
system manager. User managers will always unshare the user namespace
first even if they're running with CAP_SYS_ADMIN.
Let's add support for DelegateNamespaces= for user managers if they're
running with CAP_SYS_ADMIN. By default, we'll still delegate all
namespaces
for user managers, but this can now be overridden by explicitly passing
DelegateNamespaces=.
If a user manager is running without CAP_SYS_ADMIN, the user manager is
still always unshared first just like before.
A unit might be pending in the empty queue still when we add a PID to
the cgroup. At that point, let's explicitly remove the unit from that
queue.
Fixes: #36781
Currently DelegateNamespaces= only works for services spawned by the
system manager. User managers will always unshare the user namespace
first even if they're running with CAP_SYS_ADMIN.
Let's add support for DelegateNamespaces= for user managers if they're
running with CAP_SYS_ADMIN. By default, we'll still delegate all namespaces
for user managers, but this can now be overridden by explicitly passing
DelegateNamespaces=.
If a user manager is running without CAP_SYS_ADMIN, the user manager is
still always unshared first just like before.
If the pid namespace is delegated, it doesn't matter if we have CAP_SYS_ADMIN,
we'll still fail to mount /proc if part of it is masked on the host so also
check if we can mount /proc if the pid namespace is delegated.
This introduce LOG_ITEM() macro that checks arbitrary formats in
log_struct().
Then, drop _printf_ attribute from log_struct_internal(), as it does not
help so much, and compiler checked only the first format string.
Hopefully, this silences false-positive warnings by Coverity.
Let's return the size in a return parameter instead of the return value.
And if NULL is specified this tells us the caller doesn't care about the
size and expects a NUL terminated string. In that case look for an
embedded NUL byte, and refuse in that case.
This should lock things down a bit, as we'll systematically refuse
embedded NUL strings now when we expect strings.
Unprivileged namespaces are only allowed if the "setgroups" file is set
to "deny" for processes. And we need to write it before writing the
gidmap. Hence add a parameter for that.
Then, also patch all current users to actually enable this. The usecase
generally don't need it (because they don't care about unprivileged
userns), but it doesn't hurt to enable the concept anyway in all current
users (none of them actually runs complex userspace in them, but they
mostly use userns_acquire() for idmapped mounts and similar).
Let's anyway make this option explicit in the function call, to indicate
that the concept exists and is applied.
I think we should work towards always picking up the triplet of $TERM +
$COLORTERM + $NO_COLOR where we so far picked up $TERM only. I think
it's safe to say that at this time, $TERM is not enough anymore to
clearly communicate terminal feature support. Hence, teach PID 1 to pick
$COLORTERM + $NO_COLOR wherever we pick up $TERM.
When we configure a serial or VM terminal and have no $TERM
configuration, then we default to vt220 as a fallback. This is a pretty
safe bet, since the termcap/terminfo definitions for vt220 are
relatively widely available (much like vt100), and (in contrast to
vt100) it supports pageup/pagedown keys. vt220 is a terminal without
color support however, but we do want color support, because in 2025
there's really no terminal emulator without color in this world.
The $COLORTERM env var is used my many emulators and tools to
communicate that ANSI color support is available, despite what $TERM
says. Hence, let's tweak systemd's logic to also set $COLORTERM in case
we set the vt220 $TERM fallback.
This means we define an ahistoric frankenterminal: a vt220 (that
historically definitely didn't have color) that is explicitly configured
to have color.
One effect of this is that coreutils' dircolors command will start to
output color sequences in systemd's serial or VM terminals. (Since it
actually honours $COLORTERM).
Also note that systemd itself checks $COLORTERM since a long time, hence
it makes sense for us to also set it.
Note that this unfortunately doesn't have the desired effect of
propagating $COLORTERM into any getty shell sessions yet. That's because
util-linux' login package currently fiters $COLORTERM (but lets $TERM
though). I filed a bug about that here:
https://github.com/util-linux/util-linux/issues/3463
Admittedly, some of our glyphs _are_ special, e.g. "O=" for SPECIAL_GLYPH_TOUCH ;)
But we don't need this in the name. The very long names make some invocations
very wordy, e.g. special_glyph(SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY).
Also, I want to add GLYPH_SPACE, which is not special at all.
This adds a new EMERGENCY_ACTION_SLEEP_5S flag, which when set will
delay the emergency action for 5s. This is supposed to be used together
with EMERGENCY_ACTION_WARN so that users can actually read the message
we output.
We enable this with all emergency action requests that already set
EMERGENCY_ACTION_WARN, except for the 7x ctrl-alt-del burst reboot,
where the user knows what they do and there's no real reason to wait,
they don't need to be informed.
This also enables both EMERGENCY_ACTION_WARN + EMERGENCY_ACTION_SLEEP_5S
for FailureAction= processing of regular units, where these were so far
off. (it leaves this off for SuccessAction= however!). This is a good
thing to make things more debuggable: if something fails and we reboot
this really deserves notification of the user.
(For SuccessAction= this logic does not apply, since the shutdown action
induced here is apparently intended part of the codeflow, for example in
systemd-reboot.service or a similar unit, where the shutdown is goal and
not exception and derserves no additional noisy reporting).
Inspired by: https://github.com/systemd/systemd/pull/36705#issuecomment-2717014120
So far /run/systemd/ was created as side-effect of initializing the
D-Bus client/server. But in one of the next commits we'll suppress
connecting to D-Bus in test runs, hence let's move the logic our of the
D-Bus code and into manager_startup().
Then, also drop creating it again and again in PID 1 at various places,
and just rely on it to exist.
We have RestartMaxDelaySec= + RestartSteps= to exponentially increase
auto restart durations, but it currently cannot be reset by the service
itself, which makes it sometimes awkward to use. A typical pattern
in real life is that a service was once down (e.g. due to temporary
network interruption) and multiple restarts were attempted. Then,
future restarts would always wait for increated amount of time based on
RestartMaxDelaySec=, even after the original problem got resolved.
Such "persistence" could result in longer unavailablity than there
should be for failures that come later.
(C.f. https://utcc.utoronto.ca/~cks/space/blog/linux/SystemdResettingUnitBackoff)
Let's introduce a new sd_notify() notification for resetting the restart
counter. There were discussions about making this timer-based, but I think
it's more flexible to leave the decision-making to the service. This enables
them to do a combination of N successful requests + uptime check for instance.
Now our baseline of meson is 0.62, hence install_symlink() can be used.
Note, install_symlink() implies install_emptydir() for specified
install_dir. Hence, this also drops several unnecessary
install_emptydir() calls.
Note, the function currently does not support 'relative' and 'force' flags,
so several 'ln -frsT' inline calls cannot be replaced.
For these objectives we ought to execve() at the end, i.e. if we
ever hit the return path something went wrong in do_reexecute().
Let's properly report that via retval.
Lennart Poettering
Yu Watanabe
Mike Yuan
msizanoen
Zbigniew Jędrzejewski-Szmek
Luca Boccassi
Daan De Meyer
Matteo Croce