From owner-freebsd-arm@FreeBSD.ORG  Fri Dec 19 16:48:47 2008
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To: gjb@semihalf.com
From: "M. Warner Losh" <imp@bsdimp.com>
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Cc: arm@FreeBSD.org, embedded@FreeBSD.org
Subject: Re: Multiple virtual mappings considered harmful on ARM
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In message: <494BAA90.7000801@semihalf.com>
            Grzegorz Bernacki <gjb@semihalf.com> writes:
: 2. Root cause.
...
: So we end up with at least two virtual addresses for each page.
...
: 4. More general solution.
: This is the second time we indentified a problem of the same nature related to
: multiple virtual mapping on ARM, and are wondering about some more general
: solution that would prevent us from such problems (very subtle and hard to
: nail down) in the future. We were thinking at least about an extension to
: DIAGNOSTIC that would detect such attempts or so. Any other suggestions or
: comments welcome.

I think this is an excellent idea.  MIPS will need this too, since it
too suffers from the virtual aliasing problem.

Warner