Basically when a session ends, logind notices and restores VT_AUTO so the
kernel takes back VT-switching over.
logind achieves that by watching the process that took control of the session
(via the "TakeControl" D-Bus method), aka "the watched process", which can
be different from the one that initially opened the VT aka "the terminal
controlling process".
In this case the terminal controlling process can exit after the watched one
did and while logind is restoring the VT.
Even if logind took care to re-open the VT in case the VT was already in HUP
state, it wasn't enough because the terminal controlling process could have
exited right after, leaving the VT in HUP state and in VT_PROCESS mode making
further VT-switching impossible.
This patch fixes this situation by forcing logind to become the terminal
controlling process.
Fixes: #9754.
systemd already sets the umask (see e3b8d0637d). When
running under systemd, we don't need to set it. And when *not* running under
systemd, for example during development, there is no reason to override the user
config. Let's just drop those calls.
$ git grep -e 'umask\(' -l 'src/*generator*' |xargs perl -i -0pe 's|^[^\n]*umask\([^\n]+\n\n||gms'
We keep a mark whether a single-shot timer was triggered in the caller's
variable initial. When such a timer elapses while we are
serializing/deserializing the inner state, we consider the timer
incorrectly as elapsed and don't trigger it later.
This patch exploits last_trigger timestamp that we already serialize,
hence we can eliminate the argument initial completely.
A reproducer for OnBootSec= timers:
cat >repro.c <<EOD
/*
* Compile: gcc repro.c -o repro
* Run: ./repro
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
int main(int argc, char *argv[]) {
char command[1024];
int pause;
struct timespec now;
while (1) {
usleep(rand() % 200000); // prevent periodic repeats
clock_gettime(CLOCK_MONOTONIC, &now);
printf("%i\n", now.tv_sec);
system("rm -f $PWD/mark");
snprintf(command, 1024, "systemd-run --user --on-boot=%i --timer-property=AccuracySec=100ms "
"touch $PWD/mark", now.tv_sec + 1);
system(command);
system("systemctl --user list-timers");
pause = (1000000000 - now.tv_nsec)/1000 - 70000; // fiddle to hit the middle of reloading
usleep(pause > 0 ? pause : 0);
system("systemctl --user daemon-reload");
sync();
sleep(2);
if (open("./mark", 0) < 0)
if (errno == ENOENT) {
printf("mark file does not exist\n");
break;
}
}
return 0;
}
EOD
This removes the call to log_close(), and refactors how fork() is done. Now
the parent also goes through normal cleanup. This isn't necessary to use the
macro, but it feels cleaner this way.
This removes a call to log_close(). I don't think this should matter.
The call to mac_selinux_init() is moved after parse_argv(). We probably
don't need selinux when printing help().
For PID 1 we adjust the umask to 0, but generators should not run that
way, given that they might be implemented as shell scripts and such.
Let's hence explicitly adjust the umask for them.
We already do this for unit generators. Let's do this for env
generators, too.
Let's not bother contributors with spurious failures nobody can't
seem to reproduce. There is an issue about that where we're trying
to figure out what's going on: https://github.com/systemd/systemd/issues/10696.
The agent is closed after the static destuctors but before the pager.
No users of DEFINE_MAIN_FUNCTION* were using a polkit agent, so this makes no
functional difference.