[systemd-devel] Child of daemon sending SIGCHLD to systemd

[Vito Caputo]

On Mon, Jun 29, 2020 at 12:19:54PM -0500, Ian Pilcher wrote:
> <snip>
> 
> Is there a circumstance in which the grandchild (freecusd_smart_helper)
> would send SIGCHLD to systemd while its parent is still running?
> 

I don't know about freecusd, but if it uses a fire-and-forget approach
to launching helpers, as in it double-forks, so it doesn't need to
bother with asynchronously reaping zombies, then the second fork
becomes a child of init.  That results in the second forked child
becoming a child of init, sending SIGCHLD to init on exit.

This is a normal thing, that's part of the init processes job, to be a
process orphanage of sorts and reap orphaned processes.

Regards,
Vito Caputo