syscall calling question

Attilio Rao asmrookie at
Sat May 6 16:35:49 UTC 2006

The only functions can be called at userspace are syscalls through
software interrupt.


2006/5/6, Gergely CZUCZY <phoemix at>:
> hello,
> There's an issue on jails i've decided to look into
> (jails keep on stucking into the system). Yet, i examining
> the 6-STABLE tree, and there is a point i don't understands
> in there is jail_attach (i've picked a call) defined,
> while i was unable to find any jail-related functions defined in
> lib/libc. The only place they are defined is under kern/kern_jail.c,
> which has a different prototype than the one in the libc (according
> to the manual page and the source of jexec(8)).
> my question is, from a userland libcall, how does a kernel-functions
> be invoked? i couldn't figure it out by looking at the source, and
> also the developers handbook hadn't told this to me.
> Bye,
> Gergely Czuczy
> mailto: gergely.czuczy at
> PGP:
> Weenies test. Geniuses solve problems that arise.
> Version: GnuPG v1.4.1 (GNU/Linux)
> 3rNhcT0HMGG7WFP2x727d9w=
> =hBAi

Peace can only be achieved by understanding - A. Einstein

More information about the freebsd-hackers mailing list