Irenes (many)2d ago

when Intel introduced a cpuid instruction, around 1998 or so

there was a debate on the Linux kernel mailing list as to whether Linux should provide a way to call that instruction

you know, because of its potential uses for surveillance and how that was sharply at odds with the idea of computers being owned by their users

Show threadIrenes (many)2d ago
the resolution, at least for a while, was that Linux would implement an interface for programs to invoke the instruction, but would also add an interface that allows the user to instruct the kernel to lie and return a user-specified identifier instead
Show threadgaytabase2d ago
@ireneista that's kind of funny. i'm glad we can use cpuid though, a lot of my performance gaming relies on it.
Show threadIrenes (many)2d ago
@dysfun sure, but you understand it relies on it in the sense that DRM and anticheat look at it, right? it's not a feature that helps with graphics or anything like that
Show threadJosh Simmons
@ireneista @dysfun that's not what cpuid is used for, cpuid is used for feature detection, e.g. "if the CPU supports avx2 enable avx2" or "on this specific microcode version work around this bug". It's not literally giving you a serial number for the CPU.
Mar 19 at 10:02pmPhanpy
Show threadgaytabase2d ago
@dotstdy @ireneista it can do that too. although they don't put in serial numbers any more i don't think.
Show threadPhilippa Cowderoy2d ago
@dysfun @dotstdy @ireneista data protection legislation seems likely to interfere there, yeah
Show threadIrenes (many)2d ago
@dotstdy @dysfun please see the other replies, we've had this explained to us at length. we agree that the cpuid instruction did a lot of things and apparently the serial-number feature in the Pentium 3 was very short-lived, and was an addition to the cpuid instruction not the entirety of what it did.
Show threadIrenes (many)2d ago
@dotstdy @dysfun our intent is only to report on a specific controversy from the 90s (we're told that specifically, this played out in 1999), we think we were pretty open about the fact we haven't followed everything that's happened around cpuid since then
Show threadJosh Simmons2d ago

@ireneista @dysfun Yeah i'm just saying that

> but you understand it relies on it in the sense that DRM and anticheat look at it, right? it's not a feature that helps with graphics or anything like that

Is very misleading, it's not what games use it for legitimately (which is actually something that "helps with graphics"), and it's also not the full story of how anti-cheats and malware detect tampering / fingerprint either. That's largely a whole other can of worms.

Show threadIrenes (many)2d ago

@dotstdy @dysfun apologies, we had started to respond to this and then our computer overheated....

anyway, our apologies for making a stronger statement than warranted. we do see your point and you're right to raise it.