3 ms·

Bizarre the M1 is immune to both; I'm more secure by not upgrading. (Sure, there's still a few, but they are mostly minor by comparison, or newer chips are also

Bizarre the M1 is immune to both; I'm more secure by not upgrading. (Sure, there's still a few, but they are mostly minor by comparison, or newer chips are also affected.)

sodality2 2y ago
Newer CPUs use more and more "hacks" - out of order execution, caching, speculative execution, branch prediction, etc - to gain performance improvements. The further back you go, the less vulnerable CPUs generally are to these (but possibly more vulnerable to other kinds of attacks).
- badgersnake 2y ago
  Indeed, my Apple Watch (series 3) has always been immune to all spectre type attacks, the CPU is too simple. It doesn’t do speculative execution at all.
- hinkley 2y ago
  I can’t imagine taking a cpu design class in this more cynical era. So much of the speed these days seems to come down to distilling smoke and mirrors into physical form.
  - sodality2 2y ago
    On the other hand, research into finding these vulnerabilities seems to be booming. Though presumably, so is the grey-hat market.
- School-Cotton 2y ago
  But M1 is squarely a modern CPU. It uses all the techniques you mention (as does every high-performance CPU since the Pentium Pro era).
  - sodality2 2y ago
    For sure. But the further you go along, the _more_ of these tricks it uses and relies upon to improve performance. New vulnerabilities that are discovered are likely to take advantage of some feature on the spectrum of these “hacks”, from new to old. Because older “hacks” are well-known and studied, newly discovered vulnerabilities are more likely to target features in the newer end of that spectrum (AKA newer CPUs).
  - IshKebab 2y ago
    Does it have a Load Value Predictor?
    - School-Cotton 2y ago
      I don't know.
    - saagarjha 2y ago
      No.
tptacek 2y ago
The M1 doesn't have load address or value predictors. It's less sophisticated, and so has a smaller microarchitectural attack surface.
- ForOldHack 2y ago
  It has a power button, which effectively reduces the microarchitectural attack surface to zero.
lxgr 2y ago
That's vulnerable to DMP-based side channel attacks though (like GoFetch [1]), which you can only protect against in software [2] on the M3 and beyond. [1] https://gofetch.fail/ https://gofetch.fail/ [2] https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Enable-DIT-for-constant-time-cryptographic-operations https://developer.apple.com/documentation/xcode/writing-arm6...

Bizarre the M1 is immune to both; I'm more secure by not upgrading. (Sure, there's still a few, but they are mostly minor by comparison, or newer chips are also affected.)

sodality2 2y ago

Newer CPUs use more and more "hacks" - out of order execution, caching, speculative execution, branch prediction, etc - to gain performance improvements. The further back you go, the less vulnerable CPUs generally are to these (but possibly more vulnerable to other kinds of attacks).

badgersnake 2y ago
Indeed, my Apple Watch (series 3) has always been immune to all spectre type attacks, the CPU is too simple. It doesn’t do speculative execution at all.
hinkley 2y ago
I can’t imagine taking a cpu design class in this more cynical era. So much of the speed these days seems to come down to distilling smoke and mirrors into physical form.
- sodality2 2y ago
  On the other hand, research into finding these vulnerabilities seems to be booming. Though presumably, so is the grey-hat market.
School-Cotton 2y ago
But M1 is squarely a modern CPU. It uses all the techniques you mention (as does every high-performance CPU since the Pentium Pro era).
- sodality2 2y ago
  For sure. But the further you go along, the _more_ of these tricks it uses and relies upon to improve performance. New vulnerabilities that are discovered are likely to take advantage of some feature on the spectrum of these “hacks”, from new to old. Because older “hacks” are well-known and studied, newly discovered vulnerabilities are more likely to target features in the newer end of that spectrum (AKA newer CPUs).
- IshKebab 2y ago
  Does it have a Load Value Predictor?
  - School-Cotton 2y ago
    I don't know.
  - saagarjha 2y ago
    No.

tptacek 2y ago

The M1 doesn't have load address or value predictors. It's less sophisticated, and so has a smaller microarchitectural attack surface.

ForOldHack 2y ago
It has a power button, which effectively reduces the microarchitectural attack surface to zero.

lxgr 2y ago

That's vulnerable to DMP-based side channel attacks though (like GoFetch [1]), which you can only protect against in software [2] on the M3 and beyond. [1] https://gofetch.fail/ https://gofetch.fail/ [2] https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms#Enable-DIT-for-constant-time-cryptographic-operations https://developer.apple.com/documentation/xcode/writing-arm6...