Description of problem: rapidly stop / starting a service segfaults systemd. Result was rather limited system functionality $ sudo reboot Failed to start reboot.target: Activation of org.freedesktop.systemd1 timed out Failed to open /dev/initctl: No such device or address Failed to talk to init daemon. Version-Release number of selected component (if applicable): Name : systemd Arch : x86_64 Epoch : 0 Version : 219 Release : 24.fc22 mariadb-server rpm (built from 10.1 branch - https://github.com/MariaDB/server/tree/10.1) - cmake . -DBUILD_CONFIG=mysql_release -DRPM=fedora22 && make -j 8 package Steps to Reproduce: ############################ sudo systemctl stop mariadb;sudo systemctl start mariadb # needs to be fast, do not sleep more than 1 sec # delay does not matter sudo systemctl disable mariadb # delay does not matter sudo systemctl enable mariadb # delay does not matter sudo systemctl status mariadb ############################ Here the service starts showing the infamous ############################ ● mariadb.service - MariaDB database server Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled) Drop-In: /etc/systemd/system/mariadb.service.d └─migrated-from-my.cnf-settings.conf Active: inactive (dead) since Wed 2015-10-14 15:04:58 UTC; 58s ago Main PID: 880 (mysqld) Status: "Taking your SQL requests now..." CGroup: /system.slice/mariadb.service └─880 /usr/sbin/mysqld ############################ If I then shut down the MariaDB server, e.g. via the shutdown command (or just SIGTERM the process), Actual results: 17:40 root@spaceman ~ # systemctl stop mariadb.service ; systemctl start mariadb.service 17:40 root@spaceman ~ # systemctl status -l mariadb.service ● mariadb.service - MariaDB database server Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled) Drop-In: /etc/systemd/system/mariadb.service.d └─migrated-from-my.cnf-settings.conf Active: active (running) since Wed 2015-10-14 17:40:30 CEST; 3s ago Process: 8715 ExecStartPre=/usr/bin/sync (code=exited, status=0/SUCCESS) Main PID: 8748 (mysqld) Status: "Taking your SQL requests now..." CGroup: /system.slice/mariadb.service └─8748 /usr/sbin/mysqld Oct 14 17:40:28 spaceman systemd[1]: Starting MariaDB database server... Oct 14 17:40:29 spaceman mysqld[8748]: 2015-10-14 17:40:29 139704082127040 [Note] /usr/sbin/mysqld (mysqld 10.1.8-MariaDB-log) starting as process 8748 ... Oct 14 17:40:30 spaceman systemd[1]: Started MariaDB database server. 17:40 root@spaceman ~ # systemctl stop mariadb.service ; systemctl start mariadb.service 17:41 root@spaceman ~ # systemctl disable mariadb.service ; systemctl enable mariadb.service Removed symlink /etc/systemd/system/mysqld.service. Removed symlink /etc/systemd/system/multi-user.target.wants/mariadb.service. Removed symlink /etc/systemd/system/mysql.service. Created symlink from /etc/systemd/system/mysql.service to /usr/lib/systemd/system/mariadb.service. Created symlink from /etc/systemd/system/mysqld.service to /usr/lib/systemd/system/mariadb.service. Created symlink from /etc/systemd/system/multi-user.target.wants/mariadb.service to /usr/lib/systemd/system/mariadb.service. 17:41 root@spaceman ~ # systemctl status -l mariadb.service ● mariadb.service - MariaDB database server Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled) Drop-In: /etc/systemd/system/mariadb.service.d └─migrated-from-my.cnf-settings.conf Active: inactive (dead) since Wed 2015-10-14 17:41:11 CEST; 26s ago Main PID: 8949 (mysqld) Status: "Taking your SQL requests now..." CGroup: /system.slice/mariadb.service └─8949 /usr/sbin/mysqld Oct 14 17:41:11 spaceman systemd[1]: Starting MariaDB database server... Oct 14 17:41:13 spaceman mysqld[8949]: 2015-10-14 17:41:13 140174393092288 [Note] /usr/sbin/mysqld (mysqld 10.1.8-MariaDB-log) starting as process 8949 ... Oct 14 17:41:16 spaceman systemd[1]: Started MariaDB database server. 17:41 root@spaceman ~ # mysql -u root -e 'shutdown' Broadcast message from systemd-journald@spaceman (Wed 2015-10-14 17:42:15 CEST): systemd[1]: Caught , dumped core as pid 9204. Broadcast message from systemd-journald@spaceman (Wed 2015-10-14 17:42:15 CEST): systemd[1]: Freezing execution. Expected results: Additional info: gdb --batch --eval-command="thread apply all bt" /usr/lib/systemd/systemd core.9204 | tee systemd-backtrace.txt [New LWP 9204] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Core was generated by `/usr/lib/systemd/systemd --switched-root --system --deserialize 22'. Program terminated with signal SIGABRT, Aborted. #0 0x00007fcb43f3ad07 in kill () at ../sysdeps/unix/syscall-template.S:81 81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS) Thread 1 (LWP 9204): #0 0x00007fcb43f3ad07 in kill () at ../sysdeps/unix/syscall-template.S:81 #1 0x0000558c8168a4dd in crash.lto_priv.227 (sig=6) at ../src/core/main.c:168 #2 #3 0x00007fcb43f3a9c8 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55 #4 0x00007fcb43f3c65a in __GI_abort () at abort.c:89 #5 0x0000558c81720ff2 in log_assert_failed_unreachable (text=, file=, line=, func=) at ../src/shared/log.c:758 #6 0x0000558c8172cafd in service_sigchld_event.lto_priv.358 (u=0x558c83188fb0, pid=, code=, status=0) at ../src/core/service.c:2460 #7 0x0000558c8174b4ff in manager_dispatch_sigchld (m=m@entry=0x558c83071db0) at ../src/core/manager.c:1678 #8 0x0000558c8174d4e5 in manager_dispatch_signal_fd.lto_priv.949 (source=, fd=, revents=, userdata=0x558c83071db0) at ../src/core/manager.c:1937 #9 0x0000558c817435a0 in source_dispatch.lto_priv.632 (s=0x558c83072980) at ../src/libsystemd/sd-event/sd-event.c:2115 #10 0x0000558c816b4180 in sd_event_dispatch (e=0x558c83072580) at ../src/libsystemd/sd-event/sd-event.c:2472 #11 0x0000558c8174c8c0 in sd_event_run (timeout=18446744073709551615, e=0x558c83072580) at ../src/libsystemd/sd-event/sd-event.c:2501 #12 manager_loop (m=0x558c83071db0) at ../src/core/manager.c:2056 #13 0x0000558c816856d1 in main (argc=, argv=) at ../src/core/main.c:1763