See #26688: getenv() is not thread-safe, and could a possible source of
problems when a multi-threaded program calls setenv()/putenv()/unsetenv() in
parallel. It is not possible to avoid getenv() calls in general, since $PATH,
$LANG, $SHELL, $USER, $HOME, $TZ may need to be accessed at any time.
Add a warning to our docs so that people are aware of the issue.
Closes#26688. (Real fixes will need to be in glibc and gnome-shell or other
programs.)
The text is added to threads-aware.xml to be included in various places. By
including it in libsystemd-pkgconfig.xml, it is automatically added to all sd-*
pages. The text is also included explicitly in pages for a few other functions
which are call getenv().
For any user on a semi-recent kernel, effectively this setting is pointless.
We should deprecate it once not needed anymore for the v1 hierarchy. For
now, adjust the description.
When cpu controller is disabled, thing would often still behave as if
it was. And since the cpu controller can be enabled "magically" e.g. by
starting user@1000, add a note for users to be careful. Autogrouping
is described well in the man page, incl. how to enable or disable it,
so it should be enough to refer to that.
For CPUWeight=: there is an important distinction between our default of
[not set], and the kernel default of "100". Let's not say that our default
is "100" because then 'systemctl show' output is hard to explain.
For task accounting, it's the kernel that does the accounting, not systemd.
For a user, information which cgroup controllers are enabled based on
the unit configuration is rather important. Not only because it determines
what resource control is peformed by the kernel, but also because controllers
have a non-negligible cost, especially for deep nesting, and users may want
to *not* have controllers enabled.
Our documentation did its best to avoid the topic so far. This was partially
caused by the support for cgroup v1, which meant that any discussion of
controllers had to be conditional and messy. But v1 is deprecated on its way
out, so it should be fine to just describe what happens with v2.
The text is extended with a discussion of how controllers are enabled and
disabled, and an example, and for various settings that enable controllers
the relevant controller is now mentioned.
The details discussion of how search and route-only domains work is in
systemd-resolved.service(8). But users are more likely to look at
resolved.conf(5), because that's where Domains= is described. So let's add a
reference to the other man page there, and also strengthen the text a bit. In
particular, in systemd-resolved.service(8) we say "route-only", which makes
the distinction with search domains clearer. Let's use the same in the other
man page too.
This is based on feedback from Lukáš Nykrýn that the man page is not clear
enough.
Detect image type using "bootctl kernel-identify $kernel",
store result in KERNEL_INSTALL_IMAGE_TYPE.
Extend layout autodetection to check the kernel image type
and pick layout=uki for UKIs.
Resolves: #25822
The update-man-rules and update-dbus-docs targets are both declared in the
main meson.build and man/meson.build, so we cannot build the target with
'meson compile' command:
====
$ meson compile update-man-rules
INFO: autodetecting backend as ninja
ERROR: Can't invoke target `update-man-rules`: ambiguous name.Add target type and/or path:
- ./man/update-man-rules:custom
- ./update-man-rules:run
====
Let's rename the targets declared in man/meson.build.
And also: by default, for the systemd-user service and for local
sessions (i.e. those assigned to a seat): let's imply CAP_WAKE_SYSTEM
for them by default. Yes, let's pass one specific capability by default to local
unprivileged users.
The capability services exactly once purpose: to allow system wake-up
from suspend via alarm clocks, hence is relatively limited in focus. By
adding this tools such as GNOME's Alarm Clock app can simply allocate a
CLOCK_REALTIME_ALARM (or ask systemd --user to do this) timer and it
will wake up the system as necessary.
Note that systemd --user will not pass the ambient caps on by default,
so even with this change, individual services need to use
AmbientCapabilities= to pass this on to the individual programs.
Fixes: #17564#21382
Let's read more kernel command line arguments from SMBIOS OEM string
io.systemd.stub.kernel-cmdline-extra. This allows adding debug kernel
command line arguments when booting in qemy without having to modify
the UKI.
Even when a mount namespace is created, previously host's sysfs is used,
especially with RootDirectory= or RootImage=, thus service processes can
still access the properties of the network interfaces in the main network
namespace through sysfs.
This makes, sysfs is remounted with the new network namespace tag, except
when PrivateMounts= is explicitly disabled. Hence, the properties of the
network interfaces in the main network namespace cannot be accessed by
service processes through sysfs.
Fixes#26422.
In some cases, we want to exclude a directory's contents but not
the directory itself. In other cases, we want to exclude a directory
and its contents. Let's extend the denylist logic in copy.h to support
both by changing the denylist from a set to hashmap so we can store the
deny type as the value.
We also modify the repart ExcludeFiles= option to make use of this. If
a directory to exclude ends with a "/", we'll only exclude its contents.
Otherwise, we'll exclude the full directory.