Intel PIII: Is Big Brother Inside? (1999)

Post by anthk » Sun, Mar 14, 2021, 11:54 AM UTC

snailmailman wrote: post #60

JohannMac wrote: post #29

Common to have unique SN in a processor. Let the SW vendors do copy protection too. E.g. at Sonos we used them to associate with the software signed certificate such that you couldn't run a given Players software on another Player without the same SN. When making products via contract manufactures, especially in China, it was a wise procedure.

When I built my pc the cpu came with some free game or game coupon or something. It wasn’t in the box, I instead had to download and run some AMD software that verified that I was in fact using the CPU. I’m under the impression that it detected my specific CPU not just make/model but some sort of unique ID. Presumably this stops people from claiming the code and reselling the cpu,(or at least without reselling it as…

Post by garaetjjte » Sun, Mar 14, 2021, 1:57 PM UTC

marcan_42 wrote: post #75

I'd forgotten tech reporting was just as bad in 1999 as it is today. Here's the important part missing from the article: that serial number is available from userspace, and cannot be intercepted by the kernel in any way. They provided a way to disable it, but not to report, control, or intercept how it is accessed. It is returned by the unprivileged, untrappable* CPUID instruction. Every single UEFI computer sold tod…

Post by lights0123 » Sun, Mar 14, 2021, 7:36 PM UTC

garaetjjte wrote: post #83

marcan_42 wrote: post #75

I'd forgotten tech reporting was just as bad in 1999 as it is today. Here's the important part missing from the article: that serial number is available from userspace, and cannot be intercepted by the kernel in any way. They provided a way to disable it, but not to report, control, or intercept how it is accessed. It is returned by the unprivileged, untrappable* CPUID instruction. Every single UEFI computer sold tod…

>* VMs can trap CPUID On Intel trapping CPUID is also possible without VMs since Ivy Bridge. (Linux exposes it by arch_prctl(ARCH_SET_CPUID))

Post by dataangel » Tue, Mar 16, 2021, 5:59 PM UTC

garaetjjte wrote: post #86

lights0123 wrote: post #85

Earlier quoted context omitted.

And is why https://rr-project.org/ works very well on Intel but barely on AMD.

rr optionally uses CPUID faulting to mask off RDRAND, but this is completely non-critical issue. If this is not available then libraries just need to have envvar switch to disable RDRAND usage. It also uses CPUID faulting for makes traces portable between systems. (if you really need that you can run rr inside VM, and it will work fine) But core rr functionality works just fine on Zen CPUs, after MSR to disable some…