Race in reboot/poweroff path at init?

[Laurent Bercot]

>    There's the sigqueue() mechanism out there. From the man page, it 
>seems it's essentially dedicated to send data together with the signal, 
>but it also has a queueing mechanism implemented in the kernel. Wether 
>this allows the message to be kept in the queue until the destination 
>process unmasks it, this isn't written explicitely in the man, but 
>maybe somebody knows it. Anyway your case is a perfect test bench.

  From what I understand from the POSIX page for sigqueue(), it only 
makes
a difference if the receiver has already installed a signal handler with
SA_SIGINFO. If the receiver hasn't installed a signal handler yet, the
signal just gets delivered as is.
  So it's not a mechanism that can be used to defer signals until the
receiver has installed a signal handler.

--
  Laurent