Hi,all
I'm using latest kernel 4.1-rc3 on ubuntu 14.04.2 LTS X86_64,
and I found that, after resuming from suspend-to-memory,
the systemd-shim deamon will execute a 'poweroff', which 
shuts the system down. 

here's my step to reproduce the bug:

1.echo mem > /sys/power/state //ok
2.wait for 30 seconds        //ok
3.push power button          //ok
4.system resumes automatically //ok
5.after a few seconds, system shutdown //oh no...

I replace /sbin/shutdown with a script that prints the current process backtrace by pstree, then the system will not halt after resumming from suspend-to-memory. Here's my script:

# cat /sbin/shutdown
#!/bin/sh
pstree -a > /home/chenyu/shutdown_trace.log

and here's the backtrace when system is executing my 'shutdown', after resumming, we can see that, systemd-shim invokes 'sh -c /sbin/poweroff':


init
  |-ModemManager
  |   `-2*[{ModemManager}]
  |-NetworkManager
  |   `-3*[{NetworkManager}]
  |-acpid -c /etc/acpi/events -s /var/run/acpid.socket
  |   `-sh -c /etc/acpi/powerbtn.sh
  |-anacron -s
  |-avahi-daemon
  |   `-avahi-daemon
  |-bluetoothd
  |-cron
  |-cups-browsed
  |-cupsd -f
  |   `-dbus dbus:// 
  |-dbus-daemon --system --fork
  |-getty -8 38400 tty4
  |-getty -8 38400 tty5
  |-getty -8 38400 tty2
  |-getty -8 38400 tty3
  |-getty -8 38400 tty6
  |-irqbalance
  |-kerneloops
  |-login --       
  |   `-bash
  |       `-sudo -s
  |           `-bash
  |-ondemand /etc/init.d/ondemand background
  |   `-sleep 60
  |-polkitd --no-debug
  |   `-2*[{polkitd}]
  |-rsyslogd
  |   `-3*[{rsyslogd}]
  |-sshd -D
  |-systemd-logind
  |-systemd-shim
  |   |-sh -c /sbin/poweroff
  |   |   `-shutdown /sbin/shutdown -h -P now
  |   |       `-pstree -a
  |   `-2*[{systemd-shim}]
  |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   |-systemd-udevd --daemon
  |   `-systemd-udevd --daemon
  |-upstart-file-br --daemon
  |-upstart-socket- --daemon
  |-upstart-udev-br --daemon
  `-whoopsie
      `-2*[{whoopsie}]

Since I'm not sure why systemd-shim act like this, I would be 
happy to debug with your suggestion, and give feedback to you.


Thanks a lot!

Best Regards,
Yu