Re: [PATCH] per-user signal pending and message queue limits

From: Andrew Morton
Date: Tue Apr 20 2004 - 17:53:41 EST

Marcelo Tosatti <marcelo.tosatti@xxxxxxxxxxxx> wrote:
> I wonder if it is a good idea to base mqueue limitation on the number of
> > message queues and not take into account how big they are.
> > 64 message queues with 1 byte msgsize and 1 maxmsg is certainly quite
> > harmless and the system could have even more queues for such a user,
> > while 64 message queues with 16K msgsize (current default) and 40 maxmsg
> > (also default) eats ~ 40M of kernel memory.
> Indeed, it seems more correct to account for something else than "nr of message queues".
> Memory occupied sounds better, yeap?
> I'm sending the patch anyway, we can use the same RLIMIT_MSGQUEUE and user->msg_queues later
> on with another meaning.
> Here it goes the update version, Andrew:

But we still have the global mq and signal limits? These permit local
denials of service attacks. See

The major advantage of your work is that we can now remove those limits.
You'll be needing a 2.4 backport ;)

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