PTI Support To Address Meltdown Nearing The Finish Line For x86 32-bit Linux

[phoronix]

Phoronix: PTI Support To Address Meltdown Nearing The Finish Line For x86 32-bit Linux

While Page Table Isolation (PTI/KPTI) has been available since the Meltdown CPU vulnerability was disclosed at the start of the year, that's been for x86_64 Linux while the x86 32-bit support has remained a work-in-progress and only relatively recently has come together...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-x86-32-Bit-PTI-Close

[starshipeleven]

Hah! Take that all you people that say 32bit is not dead! Where is your dog now?

/sarcasm

[Weasel]

Re: the Westmere comparison nitpick: you know it's not only people with old (32-bit only) CPUs that use 32-bit OSes. I know I know... some people have a different opinion or choice in the matter (or lack of choice in some cases). They might not even be "real" OSes but virtualized.

[stormcrow]

Hah! Take that all you people that say 32bit is not dead! Where is your dog now?

/sarcasm

How mature of you.

There are still plenty of Intel x86 back end systems running in closets around the world still doing their job 15-20 years since they were made. I have an old PowerEdge server myself that's still fully functional I keep around when I need legacy hardware interface support modern systems don't have any longer. x86 is not dead, it just doesn't have the mind share base and urgency required to back port a complex system of fixes when there are no microcode fixes available - and never will be fixed.

That doesn't necessarily make these old systems useless either. Most of them are running custom code with little to no outside exposure so the vulnerability surface to the kind of attacks required for Meltdown/Specter exploits is minimal to practically non-existent. The primary threat model with Meltdown/Specter are cloud providers where multiple VMs may be running on the same physical hardware where some of those VMs could be hostile. No cloud service providers use x86 legacy hardware that I'm aware. That still leaves a lot of ARM hardware out there and a great deal of those are 32 bit architecture as well.

So yeah, that dog may be old - my PowerEdge server - but it's still there, still as hale as it was when it came off the assembly line but it ain't dead and neither are thousands of other similar systems. I personally don't care about KPTI and other mitigations on that particular computer.

Quite frankly, Meltdown might be LESS scary than Specter 1.1 and 1.2 that was just announced which reportedly makes all current Specter mitigation techniques moot. These guys won a huge bounty (100,000 USD) from Intel. Very well deserved for damned good work.

https://www.bleepingcomputer.com/news/security/new-spectre-11-and-spectre-12-cpu-flaws-disclosed/

[starshipeleven]

How mature of you.

Did you miss the "/sarcasm"? I was joking, although there is some truth in my statement.

x86 is not dead, it just doesn't have the mind share base and urgency required to back port a complex system of fixes when there are no microcode fixes available - and never will be fixed.

That's exactly what I meant for "dead". I meant that it's very low priority as now it's mostly running legacy hardware and legacy applications, very far from the frontlines, and as such it is not seeing fixes soon, if at all.

I'm not against 32bit x86 hardware per-se, I use/deploy Geode boards (with as much as 128mb of ram, ZOMG) for basic networking, firewall or VOIP or home-ish automation control and they are fine, my employer bought a couple crates of them for dirt cheap (something like less than 5$ per board) just because they are ancient.

[QUOTE]Most of them are running custom code with little to no outside exposure so the vulnerability surface to the kind of attacks required for Meltdown/Specter exploits is minimal to practically non-existent. The primary threat model with Meltdown/Specter are cloud providers where multiple VMs may be running on the same physical hardware where some of those VMs could be hostile. No cloud service providers use x86 legacy hardware that I'm aware. That still leaves a lot of ARM hardware out there and a great deal of those are 32 bit architecture as well.[QUOTE]Also on desktop PCs. Of course there is little chance of anyone really trying to hack a Linux desktop, at least for the forseeable future.

[angrypie]

Did you miss the "/sarcasm"? I was joking, although there is some truth in my statement.

Does anyone older than 12 use the "sarcasm" pseudo-tag?

[starshipeleven]

Does anyone older than 12 use the "sarcasm" pseudo-tag?

Yup. Kids use smileys/emoticons/emoji.