Subject: Re: Autonice bugging my but!
To: None <current-users@NetBSD.ORG>
From: Robert Black <r.black@ic.ac.uk>
List: current-users
Date: 01/23/1996 13:29:40
On Jan 22, 12:47pm, Phil Knaack wrote:
> Subject: Re: Autonice bugging my but!
> >   >Someone mentioned setting the X server (or whatever) to a negative nice
> >   >value.  Using xdm, you can do just that -- I renice mine to -15.
>
> >   This is totally unnecessary.  The autonicer doesn't renice any
> >   processes running as root.  Most people install their X servers setuid
> >   root, by default, so this is not a problem (i. e. they'll never get
> >   autoniced).
>
> matthew green <mrg@eterna.com.au> writes:
>
> >who is 'most' ?  i've never run X as setuid root.
>
> 	I must have missed the original architecture type somewhere ..
> is this on an i386 or no?
>
> 	If so ...
>
>  #define I386_SPECIFIC_ALERT
>
> 	'Most' is most of the people who install X from the XF86 install
> tarballs (the tarballs install 'most' of the servers at mode 4755).
>
> 	I didn't think the XServers would *work* when not suid root; in fact,
> a quick chmod on my machine reveals that XF86_S3 can't open a virtual console
> w/o being suid.
>
>  #undef I386_SPECIFIC_ALERT
>
> 	I assume this isn't i386 specific, because I'd hate to think that
> some of these X functions could be performed by just any userid.

It is quite possible to have things set up so that the necessary operations can
be performed by the current owner of the relevant tty. The main thing which
might run into trouble with this is launching the XServer on a different
virtual terminal from the one it was invoked from. This might make a suid
XServer desirable if you have virtual terminals but remember that many ports do
not.

Cheers

Rob Black
(writing the XServer for netbsd-arm32)

--