This takes inspiration from AT_FDCWD, but always references the root dir
rather than the cwd. This allows various convenience uses, as we can now
reference the root dir without actually allocating an fd for chaseat(),
fd_get_path() and various others.
The value of XAT_FDROOT is chosen so that it is not a valid fd (essential,
because we do not intend to hook this up everywhere, just where we need
it, just like AT_FCWD only works in some syscalls), and we want uses at
the wrong places to fail cleanly. It also uses a valud outside of the
range where we usually return negative errnos, i.e. < -ERRNO_MAX.
GRND_INSECURE was added in kernel 5.6, and our baseline on kernel is
5.10. Let's assume it always works. Even if it does not work, we have
further fallback logics. So, this should be safe.
The previous minimum required version 5.4 will be EOL on 2025-12.
Let's bump the required minimum kernel version to the next LTS release 5.10
(released on 2020-12-13, EOL on 2026-12, CIP support until 2031-01).
The new recommended baseline 5.14 is the version that CentOS 9 uses.
CentOS 9 will EOL on 2027-05.
See also #38608.
As announced by a few releases now, finally drop support for
sysvinit scripts.
Keep rc-local generator for now, as it's really a distinct
feature even though from the same era.
The current tree doesn't even compile with libidn(1) after
2c7bdaf9f1, which included
a non-existent call to check_dlopen_blocked() somehow.
Hence, it feels safe to just nuke legacy support from
our repo.
Previously, if execution failed, we'd log at error level both from the
child and the parent, and we were using a bogus variable for the argument
name:
$ build/systemd-inhibit list
Failed to execute : No such file or directory
list failed with exit status 1.
In general, we can and should assume that the program the user is calling
is well behaved, so it'll log the error on its own if appropriate. So we
shouldn't log on "normal errors", but only if the child is terminated by
a signal.
And since the program name is controlled by the user, use quotes everywhere
to avoid ambiguity.
Now:
$ build/systemd-inhibit false
(nothing)
$ build/systemd-inhibit bash -c 'kill -SEGV $$'
src/basic/process-util.c:895: 'bash' terminated by signal SEGV.
Let's introduce these for the following two reasons:
- Using them makes sure the parameter names match between declaration
and definition (if both use the corresponding macros).
- They make sure developers can't forget the _const_ and _pure_
attributes for the declarations.
This commit also includes some include sorting fixes
There are multiple ways to encode ANSI ST, and we generally prefer ESC \
for it, for reasons explained in terminal-util.h. Hence, let's actually
follow this rule in the terminal reset logic, and use the ANSI_ST macro.
This will change the byte sequence generated (as it means we use ESC \
rather than BEL), but it doesn't change behaviour, as the two sequences
should be equivalent.
This introduces RECURSE_DIR_UNLINK + RECURSE_DIR_UNLINK_GRACEFUL as new
return values for recurse_dir() callbacks. If either is returned the
inode currently processed will be removed and iteration continues with
the next item.
This is useful to have in the recurse_dir() mechanism itself (rather
than implement in the callback itself), due to ordering: we want to pin
the inodes via an fd while calling the callbacks, but we have to close
it before removal of the inodes. By moving this into the recurse_dir()
infra, we can implement this easily.
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.
Lennart Poettering
Yu Watanabe
Luca Boccassi
Mike Yuan
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
Jörg Behrmann
Luiz Amaral
Matt Fleming