Re: CPU that will not execute data?

From: Volker Birk (bumens_at_dingens.org)
Date: 09/21/05

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    Date: 21 Sep 2005 14:35:41 +0200

    peter <nospam@nospam.com> wrote:
    > I remember once reading about new processor design to prevent the CPU from
    > executing data, thereby eliminating arbitrary code execution in
    > buffer-overrun attacks.
    > I haven't heard this idea mentioned for a while. What happens to it? Can
    > this idea be retrofitted to existing CPUs?

    Only CPUs in von Neumann architecture have those problems, i.e. computers
    with Hardvard architecture don't have such problems at all.

    I think, what you're meaning is the idea to prevent the execution of
    code in stack segments on CPUs, which have a von Neuman architecture,
    like the x86, SPARC, Itanium and so on. I.e. AMD is calling this "NX",
    "no execution".

    Many CPUs already are supporting this, and some operating systems
    support it as well, like some releases of Solaris, OpenBSD, Linux and
    Windows.

    http://en.wikipedia.org/wiki/NX_bit

    Yours,
    VB. 

    -- 
"Es kann nicht sein, dass die Frustrierten in Rom bestimmen, was in
deutschen Schlafzimmern passiert".
                                    Harald Schmidt zum "Weltjugendtag"
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