Roundtable

roundtable@muug.ca

4 participants
2592 discussions

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.

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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.

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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

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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.

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

04 Jan '18

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

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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-…

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MUUG Meeting, Jan 9, 7:30pm -- Fusion Compositing Software, xargs
by Gilbert E. Detillieux 02 Jan '18

02 Jan '18

*** Please note the updated meeting location below *** The Manitoba UNIX User Group (MUUG) will be holding its next monthly meeting on Tuesday, January 9. The meeting topic for this month is as follows: Fusion Compositing Software Tyhr Trubiak will give a basic introduction to the node-based digital compositing software: Blackmagic Fusion, which now has versions available for free on linux. Blackmagic Fusion is one of the many different software packages movie studios use to do visual effects in post-production on movies such as Thor, The Martian and Avengers: Age of Ultron. It is a GUI used to manipulate motion graphics. Take a detour from bash command manipulation and give your mouse a chance to have some fun. RTFM: xargs (redux) Adam Thompson will present an RTFM on xargs, a command line utility to forward output from one command to the command line of another. The group usually holds its meetings at 7:30pm on the second Tuesday of every month from September to June. (There are no meetings in July and August.) Meetings are open to the general public; you don't have to be a MUUG member to attend. ******************************************************************* Please note our *NEW* meeting location for this month: *Room 1C16A* Centennial Hall, University of Winnipeg, entrance on Ellice Ave. between Spence St. and Balmoral St. Parking is available on the surrounding streets and in the lots on nearby streets. Look for signage once you're at the building, or ask a security guard. ******************************************************************* For more information about MUUG, and its monthly meetings, check out their web server: https://muug.ca/ Help us promote this month's meeting, by putting this poster up on your workplace bulletin board or other suitable public message board: https://muug.ca/meetings/MUUGmeeting.pdf -- Manitoba UNIX User Group E-mail: <gedetil(a)muug.ca> c/o Gilbert E. Detillieux Web: http://muug.ca/ University of Manitoba Phone: (204)474-8161 Winnipeg MB CANADA R3T 2N2 Fax: (204)474-7609

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Garbonzo's 20% off gift card (for after the meetings)
by Bradford C. Vokey 24 Dec '17

24 Dec '17

Hello MUUG'ers! For those that go to Garbonzo's after the meetings, Garbonzo's gift card bonus offer is ending TODAY! Buy a $100 gift card, get a $20 bonus! Expires December 24th at midnight! You can order online here: https://canadinns.com/giftcards I am buying 2 for myself. === Bradford C. Vokey Treasurer Manitoba UNIX User Group ===

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Email client selection blog post
by Adam Thompson 24 Dec '17

24 Dec '17

Someone was looking for a new email client recently here... Don't know if this will help, but here's hoping: https://snork.ca/posts/2017-03-04-the-quest-for-a-desktop-email-client/ -- Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Desktop PIM/mail programs
by Glen Ditchfield 23 Dec '17

23 Dec '17

Aside from plain orneryness, I picked Linux long ago because of KDE, and KDE because of Kontact. And because it was long ago, I still pull my mail off the ISP's server and dump it into a local Maildir folder, my contacts are still in a vCard file, my calendar is still in a vCalendar file. The "Cascade of Attention-Deficit Teenagers" development process (Google it) made this harder with each KDE release. For a long time I was willing to edit RC files to trick it into using boring text files in my home directory instead of shiny new formats in hidden directories, but the CADT Team finally produced a release where the shiny desktop search daemon rendered the maildir folders unusable if a mail filter tried to move mail out of the inbox. After three rebuilds I gave up and switched to Evolution. Evolution is mostly adequate, but I just spent 5 hours composing a carefully argued response to a proposal, and Evolution threw it away when I tried to apply the TT style to a word in a bulleted list. So, it you wanted PIM functions on an Ubuntu 17.10 laptop, and you wanted to keep your files locally, and you wanted to know where all the relevant files were so you could back them up, what would you use?

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