3 ms·

It would be an interesting test, wouldn't it? See if Transmeta Crusoe is vulnerable to Spectre? But, even if it is... keep in mind that when running x86 instr

It would be an interesting test, wouldn't it? See if Transmeta Crusoe is vulnerable to Spectre? But, even if it is... keep in mind that when running x86 instructions, you still have the x86 translation software proxy layer... that means that could could grab any given offending / problem-causing x86 instruction -- when you encountered it, and recode the VLIW output from it to output a different set of native VLIW instructions -- that you knew were safe... In other words, with a Transmeta Crusoe -- if the x86 translation layer is open source and you possess it (and can code / understand things) -- then you'll have some options there. Which is unlike a regular x86 CPU -- where the way it decodes and executes instructions -- cannot be changed in any way by the user...

detaro 6y ago
Transmeta Crusoe is unlikely to be vulnerable, but it's Intel contemporaries aren't either. So you'd need to be looking at some hypothetical "today" version. An open system with such a design would indeed be fascinating (the original wasn't open, and Transmeta was big on their patents on this stuff). More flexibility than microcode patches too.
- peter_d_sherman 6y ago
  >An open system with such a design would indeed be fascinating Agreed completely! >More flexibility than microcode patches too Agreed completely!
- ruslan 6y ago
  Elbrus 2000 is a mass-produced VLIW microprocessor with binary translation of x86. There is a set of different models having different number of cores and DSP blocks. https://en.wikipedia.org/wiki/Elbrus_2000 https://en.wikipedia.org/wiki/Elbrus_2000
monocasa 6y ago
The code morphing software itself is almost certainly a new source of new side channel spectre like attacks. Like being able to tell if something is already in the translation cache via timing.
- mhh__ 6y ago
  It would be much easier for a vendor to turn off speculative compilation in that case though, i.e. for HPC you want all the performance, but a cloud vendor could still protect vulnerable interfaces.
  - monocasa 6y ago
    The compilation doesn't need to be speculative. It'd be a lot like the micro op cache attack that was on the front page not too long ago. The point is to leak privileged code flow.
    - peter_d_sherman 6y ago
      Well, again, if the x86 code morphing software is available and open source, and if someone understands this software and can modify it -- then that's infinitely infinitely better (from a security perspective) -- than having to run x86 code directly on a regular AMD/Intel x86 processor... In the latter case -- you have absolutely no control whatsoever over how the processor interprets and dispatches its x86 instructions...
      - monocasa 6y ago
        Oh totally. I'm more sure than not that something like an open source code morphing software could be made more secure against side channel attacks with greater flexibility than is afforded micro code updates. I'm mainly saying that it's a problem space that both has actively shipping implemetnations (Nvidia Denver), has new levels of cache which affect performance based on previous codeflows, and hasn't been fully explored publicly AFAIK. There's probs some dragons in there in at least the pre spectre versions of that software.
- ampdepolymerase 6y ago
  You can just try attacking Apple's M1 since the technologies are quite similar.

detaro 6y ago

Transmeta Crusoe is unlikely to be vulnerable, but it's Intel contemporaries aren't either. So you'd need to be looking at some hypothetical "today" version. An open system with such a design would indeed be fascinating (the original wasn't open, and Transmeta was big on their patents on this stuff). More flexibility than microcode patches too.

peter_d_sherman 6y ago
>An open system with such a design would indeed be fascinating Agreed completely! >More flexibility than microcode patches too Agreed completely!
ruslan 6y ago
Elbrus 2000 is a mass-produced VLIW microprocessor with binary translation of x86. There is a set of different models having different number of cores and DSP blocks. https://en.wikipedia.org/wiki/Elbrus_2000 https://en.wikipedia.org/wiki/Elbrus_2000

monocasa 6y ago

The code morphing software itself is almost certainly a new source of new side channel spectre like attacks. Like being able to tell if something is already in the translation cache via timing.

mhh__ 6y ago
It would be much easier for a vendor to turn off speculative compilation in that case though, i.e. for HPC you want all the performance, but a cloud vendor could still protect vulnerable interfaces.
- monocasa 6y ago
  The compilation doesn't need to be speculative. It'd be a lot like the micro op cache attack that was on the front page not too long ago. The point is to leak privileged code flow.
  - peter_d_sherman 6y ago
    Well, again, if the x86 code morphing software is available and open source, and if someone understands this software and can modify it -- then that's infinitely infinitely better (from a security perspective) -- than having to run x86 code directly on a regular AMD/Intel x86 processor... In the latter case -- you have absolutely no control whatsoever over how the processor interprets and dispatches its x86 instructions...
    - monocasa 6y ago
      Oh totally. I'm more sure than not that something like an open source code morphing software could be made more secure against side channel attacks with greater flexibility than is afforded micro code updates. I'm mainly saying that it's a problem space that both has actively shipping implemetnations (Nvidia Denver), has new levels of cache which affect performance based on previous codeflows, and hasn't been fully explored publicly AFAIK. There's probs some dragons in there in at least the pre spectre versions of that software.
ampdepolymerase 6y ago
You can just try attacking Apple's M1 since the technologies are quite similar.