Re: Misc Fixes

Steffen Grunewald (
Fri, 12 Jul 1996 09:18:17 +0200 (MET DST)

"Alan Cox writes"
|> > Not to jump in or anything, but...
|> > How about a small kernel function to return the current securelevel value?
|> > int get_securelevel();
|> > Then export THAT to modules.
|> It doesnt help. The malicious module does
|> unsigned long **ptr=(unsigned long **)&get_securelevel;
|> unsigned long *securelevelptr=ptr[SOME_CONSTANT];
|> *securelevelptr=0;

So we have to implement some `immutable memory' mechanism. once the
securelevel is set, it has to be (and the whole page) turned to readonly.
What a waste of valuable memory ! (I hear people complain about kernel
bloat once again :-)