Re: Preventing Pentium Deaths

H. Peter Anvin (hpa@transmeta.com)
11 Nov 1997 05:07:01 GMT


Followup to: <199711110432.XAA30273@jupiter.cs.uml.edu>
By author: "Albert D. Cahalan" <acahalan@cs.uml.edu>
In newsgroup: linux.dev.kernel
>
> Write+exec permission can be disabled. It is only used for
> buffer overrun exploits, trampolines, crashme, and other junk.
> Normal programs can run just fine. If that limit is too painful,
> the kernel can automatically switch between rw- and r-x perms
> whenever it gets an exception (checking the memory of course).
>

Bull. This this one of the suckier parts of the x86 architecture.

>
> For future systems: binfmt_elf could refuse to execute user code.
> Normal users must use Java or some approved script language.
> This protects against all future CPU bugs.
>

Sure, whatever. This is Linux, not JavaOS. We actually care about
speed.

-hpa

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