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Secretly Monopolizing the CPU Without Being Root
An anonymous reader writes "This year's
Usenix security symposium
includes a
paper
that implements a "cheat" utility, which allows any non-privileged user to
run his/her program, e.g., like so 'cheat 99% program'
thereby insuring that the programs would get 99% of the CPU
cycles, regardless of the presence of any other applications in the
system, and in some cases (like Linux), in a way that keeps the program
invisible from CPU monitoring tools (like 'top'). The utility exclusively
uses standard interfaces and can be trivially implemented by any
beginner non-privileged programmer. Recent efforts to improve the
support for multimedia applications make systems more susceptible to
the attack.
All prevalent operating systems but Mac OS X are vulnerable, though by
this kerneltrap story,
it appears that the new CFS Linux scheduler attempts to address the
problem that were raised by the paper."
Back in my day we called it renice.
Yes, I'm kidding. Please don't post a long reply explaining how renice differs from this cheat thing. It isn't necessary.
Why not leave the post but allow a "retracted" tickbox? Thus at least the owner of the comment can effectively say "I was wrong, boneheaded, whatever" without having to post another comment and wait two minutes to do it? and all that shows up it a one-liner under the comment:
This comment has been retracted by its poster
-nB
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
Some instances of IBM's VM.. (VM/HPO, VM/ESA and z/VM.. VM/370 and VM/SP had a more simplified version with only 2 queues).
--Ivan
Absolutely. In fact I think it should go half a step further. In the interest of civility, using this feature should hide the message from casual viewing. But a single click will still bring up the original so that you can't use slashdot to be a complete ass and then censor yourself after the damage is done :)