angel(2) system call, the quest for immortality, aka kill(2) with SIGSTOP/SIGKILL will *not* work

[Eugene Grosbein]

28.08.2018 23:36, Warm White Wolf wrote:

> Seriously : suppose your well crafted, eventually audited program, is more
> important than
> your whole informatic system, perhaps the raison d'etre of your business.
> You want to live,
> more than the 1% errors of your sysadmins.
> 
> Ludic : you have an account in the Unix machines at your university. You
> wrote your small
> HTTPD, and you want that your sysadmins won't kill your power-httpd.
> 
> fork(void) was pretty extremy at it's time...
> 
> As a power Unix-user, a config option for the kernel, at compile-time, can
> be provided...

This does not protect a process from power outage. And this does not (and should not)
protect a process from system shutdown/reboot to install critical updates, for example.

Well crafted programm must be designed to be ready to such events,
be able to recover and continue execution after restart.

And well crafted operating systems do not kill processes with SIGKILL easily,
they use other means to inform processes to terminate execution, so is FreeBSD.