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From: Terry Lambert <terry@lambert.org>
Message-Id: <199611151758.KAA26424@phaeton.artisoft.com>
Subject: Re: Sockets question...
To: bde@zeta.org.au (Bruce Evans)
Date: Fri, 15 Nov 1996 10:58:51 -0700 (MST)
Cc: bde@zeta.org.au, jgreco@brasil.moneng.mei.com, terry@lambert.org,
        hackers@FreeBSD.ORG, jdp@polstra.com, scrappy@ki.net
In-Reply-To: <199611151754.EAA20990@godzilla.zeta.org.au> from "Bruce Evans" at Nov 16, 96 04:54:32 am
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> Oops, pass the pointy hat.  This is a non-example since i forgot to
> increase the read size and forget to tell you to invoke it with
> /kernel as stdin.  Increasing the read size to 0x20000 gives
> more interesting behaviour:
> 
> 	on system 1 with 32MB RAM: the kernel panics with a double fault

This is, I think, expected behaviour for a page which is not present but
for which a kmem mapping exists.  This happens because the /kernel file
is mapped to /dev/kmem.

If you try this with a different file (one without an established mapping),
what happens?


> 	on system 2 with 8MB RAM: read returns -1.
> 
> I have seen a similar panic for writing from a bad address like
> 0xfffffc00 but I couldn't duplicate the problem and I thought it had
> something to do with a fixed vm bug.

Or an unfixed one. 8-(.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.