4 ms·

Mostly, it seems to be a difference in design philosphy - AMD processors prevent speculative reads of data that shouldn't be accessible almost everywhere, where

by makomk 7y ago

Mostly, it seems to be a difference in design philosphy - AMD processors prevent speculative reads of data that shouldn't be accessible almost everywhere, whereas Intel ones allow them pretty much everywhere. This particular attack requires TSX which AMD processors don't have, but I don't think it'd work on AMD processors anyway because they're not missing the security check that Intel ones are. If I remember rightly, there were other now-mitigated exploits for this line fill buffer leak that didn't require TSX. (The one exception is also interesting. AMD processors allow speculative reads past the end of x86 segments and past BOUND instructions, which of course no-one uses these days. This suggests there may have been a deliberate decision to block them in the more important cases.)

temac 7y ago
It is known since... forever?, that one should not speculate across security boundaries. This was not enough to avoid Spectre, but this was largely enough to avoid TONS of security vulns Intel is also susceptible to. Somebody messed-up big time. Or from a business point of view did they? Intel current problems are manufacturing and the continuously lower power of their "legacy" processor (except due to manufacturing problems, this "legacy" is still mostly the current one) makes it so that people are buying more. Of course there is AMD back in the game, but the market demand is large enough; plus AMD would have been there anyway, and, in the fiction that Intel did take good parts of the perf hit upfront instead of the secu vulns, as competitive as in the current situation. The people most annoyed are the users. Intel got away by pretending this was not really defects in their product but only new SW tricks that they will help defend against, and their clients just let them say that without much complaint (well, I guess big ones got some rebate...) but security researchers and/or processor designers know very well this is bullshit (see the vulns papers and FAQ) and that they simply fucked-up big time on Meltdown, MDS, etc. I don't care that a few other vendors did some of the same mistakes: they are still mistakes and design flaws, and not even something new. Pretty much the only new shinny thing in this stream of vulns was Spectre and the few variants that appeared quite early on (but NOT Meltdown&co). The rest are design flaws that comes from the "oh not a big deal to leak that potentially privileged data, we will drop anything and trap before any derivative can go out anyway" mentality. Yeah, no, I'm sorry but the funding paper about speculation already told to not do that :/ Either they did not do their homework, or they voluntarily chose to violate the rule.
- simias 7y ago
  >It is known since... forever?, that one should not speculate across security boundaries. ... if you value security over raw performance. Clearly Intel has decided at some point that it was worth playing with fire in order to get ahead in benchmarks. In their defence it seems to have worked reasonably well for them for quite a while. >The people most annoyed are the users. I wish, but I wonder how much of that is true. Are most users even aware of these problems? They get patched automatically by OS vendors and then most of the time they won't hear about them anymore. I think the "nobody gets fired for choosing Intel" will probably still prevail for quite some time.
  - ptx 7y ago
    "In their defence"? The fact that things worked well for the perpetrator (until they were caught) at the expense of the victim isn't an argument usually brought up by the defence.
    - jrochkind1 7y ago
      It is when the only "court" is how much money you can make.
      - gdy 7y ago
        And you are accused of being stupid.
  - qeternity 7y ago
    For most of Intel’s existence people ran fairly trusted workloads side-by-side. It wasn’t until “the cloud” that things really changed.
  - rcthompson 7y ago
    I wonder how much of Intel's long-term perceived lead over AMD in performance is explained by compromising on these security issues that are only in the past few years being (known to be) exploited.
hinkley 7y ago
"Faster than possible" seems really appropriate here. They built a bunch of tech debt into their processors to boost their numbers, and now they hens are coming home to roost. What I'm wondering is how many changes this will make to their product roadmap, and to what degree it will make next generation chips look lackluster compared to what people (think they) have now.

by makomk 7y ago

temac 7y ago

It is known since... forever?, that one should not speculate across security boundaries. This was not enough to avoid Spectre, but this was largely enough to avoid TONS of security vulns Intel is also susceptible to. Somebody messed-up big time. Or from a business point of view did they? Intel current problems are manufacturing and the continuously lower power of their "legacy" processor (except due to manufacturing problems, this "legacy" is still mostly the current one) makes it so that people are buying more. Of course there is AMD back in the game, but the market demand is large enough; plus AMD would have been there anyway, and, in the fiction that Intel did take good parts of the perf hit upfront instead of the secu vulns, as competitive as in the current situation. The people most annoyed are the users. Intel got away by pretending this was not really defects in their product but only new SW tricks that they will help defend against, and their clients just let them say that without much complaint (well, I guess big ones got some rebate...) but security researchers and/or processor designers know very well this is bullshit (see the vulns papers and FAQ) and that they simply fucked-up big time on Meltdown, MDS, etc. I don't care that a few other vendors did some of the same mistakes: they are still mistakes and design flaws, and not even something new. Pretty much the only new shinny thing in this stream of vulns was Spectre and the few variants that appeared quite early on (but NOT Meltdown&co). The rest are design flaws that comes from the "oh not a big deal to leak that potentially privileged data, we will drop anything and trap before any derivative can go out anyway" mentality. Yeah, no, I'm sorry but the funding paper about speculation already told to not do that :/ Either they did not do their homework, or they voluntarily chose to violate the rule.

simias 7y ago
>It is known since... forever?, that one should not speculate across security boundaries. ... if you value security over raw performance. Clearly Intel has decided at some point that it was worth playing with fire in order to get ahead in benchmarks. In their defence it seems to have worked reasonably well for them for quite a while. >The people most annoyed are the users. I wish, but I wonder how much of that is true. Are most users even aware of these problems? They get patched automatically by OS vendors and then most of the time they won't hear about them anymore. I think the "nobody gets fired for choosing Intel" will probably still prevail for quite some time.
- ptx 7y ago
  "In their defence"? The fact that things worked well for the perpetrator (until they were caught) at the expense of the victim isn't an argument usually brought up by the defence.
  - jrochkind1 7y ago
    It is when the only "court" is how much money you can make.
    - gdy 7y ago
      And you are accused of being stupid.
- qeternity 7y ago
  For most of Intel’s existence people ran fairly trusted workloads side-by-side. It wasn’t until “the cloud” that things really changed.
- rcthompson 7y ago
  I wonder how much of Intel's long-term perceived lead over AMD in performance is explained by compromising on these security issues that are only in the past few years being (known to be) exploited.

hinkley 7y ago

"Faster than possible" seems really appropriate here. They built a bunch of tech debt into their processors to boost their numbers, and now they hens are coming home to roost. What I'm wondering is how many changes this will make to their product roadmap, and to what degree it will make next generation chips look lackluster compared to what people (think they) have now.