agetty from util-linux is meanwhile following the configuration file
specification for /etc/issue. The usage of "--issue-file" breaks this
on distributions with current util-linux.
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.
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.
Although extremely unlikely, there is a race present in solely checking the
$LISTEN_PID environment variable, due to PID recycling. Fix that by introducing
$LISTEN_PIDFDID, which contains the 64-bit ID of a pidfd for the child process
that is not subject to recycling.
By default agetty will not display /run/issue.d/ if /etc/issue exists.
This is quite unfortunate and has actually been fixed upstream in:
https://github.com/util-linux/util-linux/commit/508fb0e7ac103b68531a59db2a4473897853ab52
However, no release has been tagged with this yet, and it doesn't look
like this will happen any time soon. Hence, for now, let's add a
work-around and manually override the issue files to include.
This should be reverted once a new util-linux/agetty release has been
tagged, and found its way into the relevant distributions. Given this is
mostly about cosmetics we do not have to precisely sync the package
updates on this, but only roughly.
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Thorsten Kukuk
Mike Yuan
Yu Watanabe
Daan De Meyer
Vitaly Kuznetsov
Zbigniew Jędrzejewski-Szmek
Dimitri John Ledkov
Daniel Foster