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Comment by chmaynard | Hacker News Reader

Does anyone know if the IBM AS/400 architecture is affected?

Edit: I'm referring to the System/38 architecture that used capability-based addressing.

The AS/400 nowadays is called "IBM i". The note says IBM i is affected: "AIX and i operating system patches will start to become available February 12".

Since the mid-1990s it has run on POWER so if POWER is affected it obviously would be too.

Another question is whether it is actually exploitable from OS/i userspace.

Well, if you consider PASE lets you run AIX binaries, if it is exploitable on AIX the same exploit would probably work on IBM i. (PASE only supports a subset of AIX system calls though.)

Also, if it is exploitable from Java, nowadays the IBM i JVM is J9, almost the same as AIX. (This used to be different – the "Classic JVM" was integrated into the TIMI infrastructure, so quite different from JVMs on other platforms.)

I'm more interested in the non-PASE (more accurately, non-Teraspace) situation. The single level store maps every program into the same address space. Will POWER speculatively access another user's data before it discovers that the pointer is invalid or the array index is out of range?

Yes, it is an interesting case, I hope we get more detail than this paper soon.

Yeah, they replaced their custom CISC with a POWER + a bunch of extra instructions + a special processor mode + RAM with extra bits.

I dont find something mentioning Spectre or Meltdown in the original blog post fom IBM, but POWER 6 (2007) is most probably not affected by Metdown as it is an in-order architecture.

Its called IBM System i nowadays, and hasn't been called AS/400 since 2000 [1].

FTA: "We will provide further communication on supported generations prior to POWER7+, including firmware patches and availability."

POWER7+ is used in since 2012. They all seem to be based on POWER architecture these days (first devices using PowerPC/POWER3 in 1997).

Also of note, the firmware patches will be available on jan 9 but they also require OS patches. The Linux patches will be available on jan 9 and the AIX patches arrive on feb 12. They don't mention IBM i (OS/400) at all.

[1] https://en.wikipedia.org/wiki/IBM_System_i

Not sure if the content changed, but the article currently states: "AIX and i operating system patches will start to become available February 12."

My bad, thanks for the correction. Probably I misread.

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