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Date:      Sun, 31 Aug 2003 20:50:02 +0100 (BST)
From:      "=?iso-8859-1?q?Pedro=20F.=20Giffuni?=" <giffunip@yahoo.com>
To:        Peter Jeremy <PeterJeremy@optushome.com.au>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: Non-executable mappings now in NetBSD too
Message-ID:  <20030831195002.95875.qmail@web13403.mail.yahoo.com>
In-Reply-To: <20030831091544.GA86421@cirb503493.alcatel.com.au>

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 --- Peter Jeremy <PeterJeremy@optushome.com.au> wrote: 
...
> 
> Based on some recent BUGTRAQ postings, OpenBSD has a trick to support
> full protection on the i386.  The text segment and executable part of
> shared libraries are placed at low virtual addresses and CS is
> restricted to only cover the low address space.  I don't know whether
> it's worthwhile to implement something along these lines in FreeBSD.
> 

I think we'll have to do it sooner or later simply because they do it ;). The
issue is, of course, Linux emulation and backward compatibility. 

I think we could do the same but ignore the CS restriction if the user is
trusted and running inside a jail.

cheers,

    Pedro.

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