Subject: Re: Pointer on callback from kern to userspace?
To: Heiko W.Rupp <>
From: Ignatios Souvatzis <>
List: tech-kern
Date: 01/25/1999 20:37:26
On Mon, Jan 25, 1999 at 12:44:12PM +0100, Heiko W.Rupp wrote:

> I need some examples on how I can implement upcalls from the kernel
> to user processes e.g. once per mbuf passing at some routine.
> This could be implemented like the tun driver with some read and
> write functions like the tun pseudo-interfaces do, but what I
> would rather like is to call foo(pointer to mem area,other params ..)
> from kernel, where foo() in user space and being told the kernel
> earlier (via ioctl e.g.)
> Do we already have something like this?

Uhm... as long as you dont want the _kernel_ to execute the userland code
(I hope you dont), this would more or less be equivalent to /dev/bpf or
/dev/tun (or some similar tap device) combined with SIGIO.