Allow CPUSchedulingPolicy to be set to "ext". SCHED_EXT is a new
scheduling policy in Linux v6.12 that allows processes to be scheduled
using custom BPF schedulers instead of the default in-kernel ones.
Selectively setting the SCHED_EXT policy is useful for systems running
in "partial mode" where not all processes are run using a custom
scheduler.
Fallback to SCHED_OTHER and print an error message for systems where
SCHED_EXT isn't available.
Note that we still have to block SIGCHLD so that
we can be certain the process is not reaped before
we get the pidfd to it. safe_fork() and friends are
used in libsystemd where we don't control how the
SIGCHLD signal is configured. Specifically, kernel
autoreaping could be enabled which is why we have
to block SIGCHLD until we get the pidfd so that the
kernel cannot autoreap the process before we get
the pidfd.
First, don't require blocking SIGCHLD for WEXITED. We watch for WEXITED
via pidfd instead of signalfd, so no need to insist on blocking SIGCHLD
anymore if we're only watching for WEXITED.
Second, do a proper check to see if the kernel autoreaping logic is
enabled. That has nothing to do with SIGCHLD being blocked for the current
thread or not. Instead, the kernel autoreaping logic is enabled either if
the disposition is set to SIG_IGN or if the SA_NOCLDWAIT flag is enabled.
* Specifying all 3 of FORK_DEATHSIG_SIG{KILL,TERM,INT} for
the middle man makes zero sense. Use SIGKILL only.
* Make sure operations on except_fds work sensibly - close/pack/
de-ocloexecify fds only in the second level, so that the namespace
fds remain usable across first safe_fork().
* Fire FORK_NEW_*NS after attaching to the desired namespaces,
not already in the outer process.
* Insist on PDEATHSIG being enabled to ensure propagation of killing.
* Suppress more redundant flags.
This allows us to query the window size without moving the cursor. We have
various reports about the cursor being in an unexpected position and/or state.
Closes https://github.com/systemd/systemd/issues/37526.
While blocking dlopen() in child generally makes sense, it does
also lead to misery - in the very case of extension/cred refreshing
it then enforces loading of libcryptsetup/libacl in pid1, which
are otherwise never used. Let's add a flag to opt out hence, but
still prohibit it in namespace_fork/enter().
manager_varlink_init_resolve_hook and manager_varlink_init_userdb are very
similar, but one didn't set a description and the other one had an error
message which didn't print the offending path.
Define constants for the paths, and also change other similar constants
to have slightly shorter names. (It's an "address" and "path", but we don't
need to have both parts in the name, esp. that it makes the name very long.)
Latest glibc uses _Generic to have strstr() and other functions return
const char* or char* based on whether the input is a const char* or a
char*. This causes build failures as we previously always expected a
char*.
Let's fix the compilation failures and add our own macros similar to
glibc's to have string functions that return a mutable or const pointer
depending on the input.
Latest glibc uses _Generic to have strstr() and other functions return
const char* or char* based on whether the input is a const char* or a
char*. This causes build failures as we previously always expected a char*.
Let's fix the compilation failures and add our own macros similar to glibc's
to have string functions that return a mutable or const pointer depending on
the input.
When in --empower mode, all created files will be owned by the current
user, which could be problematic when creating files outside of the
current user's home directory, as other processes running as the same
user would be able to edit those files.
While this is a bit of an edge case since users already have to go through
the effort of writing --empower to indicate they want a privileged session
as the current user, it's not unphatomable to think they could start an
empowered session which they later return to and continue using. Currently,
it's not easy to differentiate a regular run0 session and an empowered session
at a glance, so users might think they're using a regular run0 session when
they're actually using an empowered session.
To address this problem, let's give empowered session their own identify, by
making the background orange, using the pumpkin emoji as the shell prompt
prefix and giving them an orange circle as the PTY title.
Some of the functions were ignoring failure in cleanup, others weren't. If we
got a reply, it's better to use it, so ignore failures in cleanup everywhere.
This moves the open call earlier, so that we do any state-changing operations
if we actually managed to open the nonblocking fd. The code is easier to follow
this way and might be more robust.
Suprisingly, this fixes https://github.com/systemd/systemd/issues/39055: it
seems that run0 chowns /dev/stdin (in my case /dev/pts/0) to root:root, and the
second run0 can read and write stdin/stdout throught the already-open fds,
but fd_reopen fails.
Fixes https://github.com/systemd/systemd/issues/39055.
Now that we dlopen() so many deps, it might happen by accident that we
end up dlopen()ening stuff when we entered a container, which we should
really avoid, to not mix host and container libraries.
Let's add a global variable we can set when we want to block dlopen() to
ever succeed. This is then checked primarily in
dlopen_many_sym_or_warn(), where we'll generate EPERM plus a log
message.
There are a couple of other places we invoke dlopen(), without going
through dlopen_many_sym_or_warn(). This adds the same check there.
In my tests, the sequence works on Ptyxis 49.0, gnome-terminal-3.56.3,
xterm-401, rxvt-unicode-9.31, under tmux-3.5a, over ssh and serial console
connected to ptyxis. It did not work on a text console in a VM (TERM=linux) or
under kmscon-9.1.0 (TERM=vt102).
This moves the open call earlier, so that we do any state-changing operations
if we actually managed to open the nonblocking fd. This makes the code more
robust because if the fdreopen call fails, we won't make modifications to the
state of the terminal.
The function socket_address_listen() is declared at shared/socket-label.c,
however its prototype was in basic/socket-util.h. This moves the
prototype to shared/socket-label.h.
Also, enum SocketAddressBindIPv6Only is not used anymore in basic/*.[ch].
Let's move the definition and its string table to shared/socket-label.[ch].
Follow-up for b25a930f0e.
This checks whether a file descriptor is valid and opened in a mode that
allows writing (O_WRONLY or O_RDWR). This is useful when we want to
verify that inherited FDs can actually be used for output operations
before dup'ing them.
The helper explicitly handles O_PATH file descriptors, which cannot be
used for I/O operations and thus are never writable.
$ sudo build/systemd-run --uid=asdf whoami
$ journalctl -e
(whoami)[1007784]: run-p1007782-i5200512.service: Failed to determine user credentials: No such process
(whoami)[1007784]: run-p1007782-i5200512.service: Failed at step USER spawning /usr/sbin/whoami: No such process
systemd[1]: run-p1007782-i5200512.service: Main process exited, code=exited, status=217/USER
systemd[1]: run-p1007782-i5200512.service: Failed with result 'exit-code'.
Now:
(whoami)[1013204]: run-p1013202-i5205932.service: Failed to determine credentials for user 'asdf': Unknown user
(whoami)[1013204]: run-p1013202-i5205932.service: Failed at step USER spawning /usr/sbin/whoami: Invalid argument
systemd[1]: run-p1013202-i5205932.service: Main process exited, code=exited, status=217/USER
systemd[1]: run-p1013202-i5205932.service: Failed with result 'exit-code'.
Matt Fleming
Daan De Meyer
Mike Yuan
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Luca Boccassi
Yu Watanabe
Alexis-Emmanuel Haeringer
David Tardon
Chris Down