Reliable process tracking

[Edward Tomasz Napierała]

Wiadomość napisana przez Jilles Tjoelker <jilles at stack.nl> w dniu 7 sie 2013, o godz. 22:19:
> On Mon, Aug 05, 2013 at 01:13:10PM +0200, Edward Tomasz Napierała wrote:
>> Wiadomość napisana przez Jilles Tjoelker <jilles at stack.nl> w dniu 4 sie 2013, o godz. 15:46:
>>> When shutting down a service or requesting status, rc.subr currently
>>> uses a combination of pidfiles and process names. This is fairly but not
>>> completely reliable once it is set up correctly (which can take a lot of
>>> work and possibly patching the daemon to use pidfile(3) from our
>>> libutil). It is also incapable of killing multiprocess daemons such as
>>> CGI web servers without cooperation of the daemon.
> 
>>> I think what is needed here is a facility that marks a process and all
>>> of its descendants. Removing the mark should be a privileged or at least
>>> an unusual operation; no unprivileged function specified by POSIX such
>>> as setsid() should do this.
> 
>> I've actually thought about that when I added setloginclass(2).  It's
>> trivial to modify rc.subr to use su(8) to set login class for each
>> service.  It should be trivial to modify pkill(1) and killall(1) to
>> add "-c" option to kill all processes in a given login class.
> 
> There are some problems with su -c:
> 
> * It refuses to set a login class name that is not in /etc/login.conf.
>  Given that multiple instances of a service should each have their own
>  kernel login class, it may make sense to allow specifying the
>  login.conf entry separate from the kernel login class.

Indeed.  I'll try to figure out something.

FWIW, I've just committed a patch that adds "-c" flag to pkill.

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