Re: the new VMt

yodaiken
2000-09-25T21:12:50Z

On Mon, Sep 25, 2000 at 04:47:21PM -0400, Benjamin C.R. LaHaise wrote:
> On Mon, 25 Sep 2000 yodaiken@fsmlabs.com wrote:
>
> > On Mon, Sep 25, 2000 at 09:23:48PM +0100, Alan Cox wrote:
> > > > my prediction is that if you show me an example of
> > > > DoS vulnerability, I can show you fix that does not require bean counting.
> > > > Am I wrong?
> > >
> > > I think so. Page tables are a good example
> >
> > I'm not too sure of what you have in mind, but if it is
> > "process creates vast virtual space to generate many page table
> > entries -- using mmap"
> > the answer is, virtual address space quotas and mmap should kill
> > the process on low mem for page tables.
>
> No. Page tables are not freed after munmap (and for good reason). The
> counting of page table "beans" is critical.

I've seen the assertion before, reasons would be interesting.

--
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Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com