Roundtable January 2018

roundtable@muug.ca

15 participants
11 discussions

Net neutrality: the meat of the matter
by Bill Newman 01 Feb '18

01 Feb '18

We know all the technical details but this is the real story. Burger King nails it <https://actionnetwork.org/petitions/burger-king-explains-net-neutrality?lin…>.

2 1

Power bar/surge suppressor
by Kevin McGregor 29 Jan '18

29 Jan '18

Hey, what's the prevailing opinion on power bars with built-in surge suppressors? How long do they last? Should they be replaced every, say, 5 years?

4 5

Sourcing a small rack
by Kevin McGregor 29 Jan '18

29 Jan '18

I have some equipment (switches, etc.) that I'd like to mount on a rack at home. Does anyone know where I can get a decent rack (used is fine) for a low price? Or a good DIY substitute?

4 5

sigh
by Dan Keizer 24 Jan '18

24 Jan '18

http://www.linuxjournal.com/content/linux-journal-ceases-publication

3 2

Horrific CPU flaws (Meltdown / Spectre)
by Trevor Cordes 22 Jan '18

22 Jan '18

As most of you probably know, new CPU bugs have just been found (1 affecting mostly Intel, 1 affecting Intel + AMD; both potentially affecting phones). I wouldn't mind a MUUG discussion about this. News on the net seems to be pretty low-caliber. Some are better than others. https://spectreattack.com/ seems to be good... but I wouldn't hit that site without a JS blocker. Apparently (could be a myth) these bugs can be triggered by JS in a web page!!! CVE/NVD doesn't seem to have ratings for this yet (still "reserved"). The good news: >From what I read, it's a read-only attack, apparently they can dump your entire RAM without root access. Not great, but better than a RW attack! KPTI/Kaiser/Meltdown appears to all reference the same thing. Intel only (so far... maybe add ARM), definitely not AMD (so far). Fix can't be done in microcode or firmware. So it'll be patched in kernels (all OS's). OK, great, who cares. But... the patch causes 5-30% performance hit across the board; the more syscalls the program makes, the worse your hit. Fun. The fix is basically move kernel page tables out of RAM when executing user code. Then swap it back in. Joy. Hmmm, by coincidence, Intel's very latest CPUs (unsure on definition of "latest") are rumoured to have an instruction to make this less painful... hmmmmmmm. Spectre seems to be more of a mystery. Apparently it allows progs to read other prog's memory, but not kernel RAM. And no OS fix planned yet? Affects all CPUs with out-of-order exec, which is basically everything in the last, what, 15 years? This one worries me more. However, they say it's harder to implement the hack, so maybe it'll turn out to be a red herring in reality. If it's as scary as some make it sound, we could be seriouly fskc'd because there isn't a syscall boundary to easily insert a nice page table swap into. Going back to my university days and my hardware architecture classes, I find the technical side of this to be fascinating. It looks like they are preying upon weaknesses in CPU handling of speculative loads, indirect addressing, and long pipelines. The fact that the CPUs weren't properly designed to not allow such insane access is quite shocking to me. Pipelines are supposed to be thrown away after an incorrect guess. Nothing should be leaking. Saying "we did it for performance reasons" is quite lame. If anyone finds some good mid- / mid-high-level technical explanations of the on-chip flaws, please post links. It'll be interesting to see what the next gen(s) of CPUs do to specifically address this. Given design/fab lifecycles it could be years before new CPUs have this fixed. Surely pipelines / OOE aren't going away. Heck, even RISC wouldn't have saved us, as they are monga pipeline dependent. My hunch is PPC is Spectre vulnerable, but it'll be interesting to find out more. The above is all just my take on things after binge-reading about 8 different articles on it. If I'm wrong on something, please correct me. Supposedly Linus has ranted on it already, but I can't find it anywhere, so if you have a link to a Linus rant, please share. In the meantime, get ready for all your newer/supported devices to get 5%+ slower, and all your older devices to get p0wned. Me, I'm going to jump on that new ECC workstation I've been eyeing... I won't be able to handle any slowdown on my current, ancient box. Final thought... why didn't anyone figure this flaw out earlier in the last 10 years it existed? Wonder who was exploiting it this whole time... wonder how long Intel knew (not the "official" version). Anyone laying bets on class-actions and/or CPU recalls? Not sure Intel could make enough CPUs (or afford it) to replace every CPU it sold in the last 10 years.

5 10

UnifrakturMaguntia, a Unicode Fraktur Font
by Adam Thompson 21 Jan '18

21 Jan '18

Because I know there are a few other typography geeks here... http://unifraktur.sourceforge.net/maguntia.html This is, IMHO, the typography equivalent to running Win2k inside a JavaScript x86 VM... Neat, but *why*? (But still neat.) -Adam -- Sent from my Android device with K-9 Mail. Please excuse my brevity.

2 1

Looking for dev Access 2003 -> Web based solution
by Gerald Brandt 16 Jan '18

16 Jan '18

Hi, I think I asked this about 6 months ago, but here it is again... I'm looking for a developer that can take an Access 2003 based system and convert it to a web based one. I prefer PHP, but I'm flexible. Any pointers? Thanks, Gerald

1 0

UNIX hardware selection - one guy's conclusions
by Adam Thompson 07 Jan '18

07 Jan '18

https://begriffs.com/posts/2017-05-17-openbsd-workstation-guide.html I can't figure out how to put this cleanly into our newsletter, or I'd let the next editor chew up an entire page with it :-). -Adam -- Sent from my Android device with K-9 Mail. Please excuse my brevity.

1 0

Linus Rant on Speculative Execution
by Daryl F 04 Jan '18

04 Jan '18

https://lkml.org/lkml/2018/1/3/797 -Daryl

1 0

Linux Journal back (that was quick)
by Trevor Cordes 04 Jan '18

04 Jan '18

Oh ya, forget what the latest MUUGLines just told you, it looks like Linux Journal is back in business! Thanks LJ for the horrible timing. Good for their publicity, though! https://linux.slashdot.org/story/18/01/02/199239/linuxjournal-which-ceased-…

1 0

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Roundtable January 2018