Re: [RFD] 'nice' attribute for executable files

Horst von Brand
2005-04-01T17:30:48Z

Wiktor <victorjan@poczta.onet.pl> said:
> Horst von Brand wrote:
> > Even better: Write a C wrapper for each affected program that just renices
> > it as needed.

> I suggest to implement scalable solution, so the final user wont't have
> to write separate wrapper for *each* program.

Final user doesn't. It is a job for whoever writes the program, or packages
it for a distro. If even required.

> universal wrapper is
> better solution, but (now i know, that implementing something that can
> be dangerous if used incorrectly is so evil, that only the devil could
> have proposed it) it forces use of database (that normally would be kept
> in filesystem's file metadata) and if some-malicious-person would have
> accessed it in write mode (as result of wrong file permissions), the
> system performerance would be in danger. in my solution, there is
> per-file attribute, accessible only for root, and if hacker has root
> permissions, existence of nice attribute is meaningless.

Anything like this that can be accessed by plain users (not root) is
inherently dangerous. It is for a reason that only root can increase the
priority of a process. If you allow reniceing and place some kind of limit
on it, even Aunt Tillie will run her programs with priority maxed out, and
we are back were we are today.
--
Dr. Horst H. von Brand User #22616 counter.li.org
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