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Date:      Wed, 5 May 1999 07:43:39 -0400 (EDT)
From:      Brian Feldman <green@unixhelp.org>
To:        Doug Rabson <dfr@nlsystems.com>
Cc:        CyberPsychotic <fygrave@tigerteam.net>, freebsd-hackers@FreeBSD.ORG, tech@openbsd.org
Subject:   Re: io ports reading/writing
Message-ID:  <Pine.BSF.4.10.9905050742530.43394-100000@janus.syracuse.net>
In-Reply-To: <Pine.BSF.4.05.9905051016150.411-100000@herring.nlsystems.com>

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On Wed, 5 May 1999, Doug Rabson wrote:

> On Wed, 5 May 1999, CyberPsychotic wrote:
> 
> > ~ 
> > ~ The access control for io ports is controlled by the file-system
> > ~ permissions on /dev/io. In a standard setup, only root can access this
> > ~ device.
> > ~ 
> > 
> >  yes. But I was refering to linux scheme, where you can set the port-range,
> > so the code wouldn't make any unintentional damage. (like if you're working
> > with cmos you could only permit 0x70/0x71 ports, so even if code goes nuts,
> > your disks will be safe). This is basically programmer's problem of course,
> > but the feature is very handy.
> 
> I don't quite understand the i386 architecture at this level but I seem to
> remember that this support would require significant changes in the way we
> handle processes and there might have been some performance implications.
> I don't think its a big problem in practice.

What about i386_[gs]et_ioperm()?

> 
> --
> Doug Rabson				Mail:  dfr@nlsystems.com
> Nonlinear Systems Ltd.			Phone: +44 181 442 9037
> 
> 
> 
> 
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