4 ms·

Is it really cheating? What they are doing is well known and published, with one side effect that didn’t get rolled back (which seems more like a bug). At lea

by DougN7 9y ago

Is it really cheating? What they are doing is well known and published, with one side effect that didn’t get rolled back (which seems more like a bug). At least that’s what I’ve understood from what I’ve read.

lmm 9y ago
Implementing a cool optimization that happens to break your processor's security features is cheating, yes, even if you did it unintentionally, like accidentally taking a performance-enhancing drug.
- mannykannot 9y ago
  Intent matters, at least to me. This does not seem to be a case like VW's diesel-emissions shenanigans.
  - _ph_ 9y ago
    The problem still is: one of the units responsible for increasing the processor performance was not working correctly. So the increased performance of the processor was obtained by not working correctly. That qualifies as cheating - if not by intent but then by nature of the design. It remains to be investigated how much of the security implications of their design choices was or could have been known to Intel. The fundamental attack concept was known for many years.
    - bonzini 9y ago
      It is working correctly. A side channel is unfortunate, but in no way comparable to a missed page fault.
    - matthewmacleod 9y ago
      No, it just doesn’t. You’re diluting the meaning of that term to irrelevance. There are plenty of other words that adequately describe what happened - sloppy, careless, short-sighted. Cheating isn’t one of them.
      - LamaOfRuin 9y ago
        You can easily cheat, without bad faith, by being sloppy or careless. You can also cheat in bad faith and call it being sloppy or careless. Breaking rules often has nothing to do with intent.
- emn13 9y ago
  They didn't unintentionally break security features; they knowingly did so - the potential for information disclosure was widely documented. In their defense - the solution isn't trivial in general, and large parts of at least spectre apply in ways a CPU would be hard pressed to prevent (how is a CPU to know that even though memory isn't marked as protected from currently running code in actual fact that's because the JIT and the JIT-tted code are running in the same memory space?). But the intel CPUs are leaking a lot more data than reasonable.
  - pritambaral 9y ago
    Your parent was talking about Meltdown; that's the one that breaks security features, specifically: memory safety of a higher privilege level from a lower one.
- seanmcdirmid 9y ago
  In that case, probably no processors are “clean” as 100% elimination of all bugs is highly unlikely. Just like a bit of growth hormones slipped into your food supply without your knowledge.

by DougN7 9y ago

lmm 9y ago

Implementing a cool optimization that happens to break your processor's security features is cheating, yes, even if you did it unintentionally, like accidentally taking a performance-enhancing drug.

mannykannot 9y ago
Intent matters, at least to me. This does not seem to be a case like VW's diesel-emissions shenanigans.
- _ph_ 9y ago
  The problem still is: one of the units responsible for increasing the processor performance was not working correctly. So the increased performance of the processor was obtained by not working correctly. That qualifies as cheating - if not by intent but then by nature of the design. It remains to be investigated how much of the security implications of their design choices was or could have been known to Intel. The fundamental attack concept was known for many years.
  - bonzini 9y ago
    It is working correctly. A side channel is unfortunate, but in no way comparable to a missed page fault.
  - matthewmacleod 9y ago
    No, it just doesn’t. You’re diluting the meaning of that term to irrelevance. There are plenty of other words that adequately describe what happened - sloppy, careless, short-sighted. Cheating isn’t one of them.
    - LamaOfRuin 9y ago
      You can easily cheat, without bad faith, by being sloppy or careless. You can also cheat in bad faith and call it being sloppy or careless. Breaking rules often has nothing to do with intent.
emn13 9y ago
They didn't unintentionally break security features; they knowingly did so - the potential for information disclosure was widely documented. In their defense - the solution isn't trivial in general, and large parts of at least spectre apply in ways a CPU would be hard pressed to prevent (how is a CPU to know that even though memory isn't marked as protected from currently running code in actual fact that's because the JIT and the JIT-tted code are running in the same memory space?). But the intel CPUs are leaking a lot more data than reasonable.
- pritambaral 9y ago
  Your parent was talking about Meltdown; that's the one that breaks security features, specifically: memory safety of a higher privilege level from a lower one.
seanmcdirmid 9y ago
In that case, probably no processors are “clean” as 100% elimination of all bugs is highly unlikely. Just like a bit of growth hormones slipped into your food supply without your knowledge.