Re: Subject: Re: ext3 to include capabilities?

Rogier Wolff (R.E.Wolff@BitWizard.nl)
Sat, 3 Apr 1999 12:20:31 +0200 (MEST)

Albert D. Cahalan wrote:
> Richard Gooch writes:
> > Albert D. Cahalan writes:
>
> >> Well, which do people prefer? (sticky bit or setuid bit)
> >
> > Ths suid but, of course, since setting it is privileged. Thus it is
> > obvious that it is a privileged binary.
>
> Oh my, do we have a bug? The sticky bit is normally for root only.
> Here is Digital UNIX:

That is because the sticky bit is "old fashioned". It used to be used
on often-used binaries that it might be better to cache the
code-segment of this binary than to discard it on exit. As this consumes
precious core (*) memory, that operation is considered privileged.

On modern operating systems (like Linux), the system already does its
best to cache code segments of exiting programs. The sticky bit no
longer has a function.

On directories, a second meaning was assigned for this bit. This is
not privileged.

Roger.

(*) Note the oldfashioned term: This dates back into the time when
Unix ran on machines with 256k core.

-- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
------ Microsoft SELLS you Windows, Linux GIVES you the whole house ------




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