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Theodore Ts'o
Works at Google
Attended MIT
Lives in Medford, MA
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Work
Occupation
Linux Kernel Hacker
Employment
  • Google
    Staff Engineer, 2010 - present
  • IBM
    Senior Technical Staff Member, 2001 - 2010
  • VA Linux Systems
    Principal Engineer, 1999 - 2001
  • MIT
    Senior Systems Programmer, 1990 - 1999
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Currently
Medford, MA
Previously
Chicago, IL - Long Island, NY
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Introduction
I am the first North American Linux Kernel Developer, having started working with Linux in September, 1991.  I have also served as the tech lead for the MIT Kerberos V5 development team, and was the architect at IBM in charge of bringing bring real-time Linux in support of real-time Java to the US Navy.   I previously served as CTO for the Linux Foundation, and am currently employed at Google.
Education
  • MIT
    Computer Science, 1986 - 1990
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Theodore Ts'o

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+AT&T: The same company that cooperated with the NSA is now playing man-in-the-middle and manipulating your http connections to inject advertisements.
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Michael Olsen's profile photoJohn Randolph's profile photoErnesto Crespo's profile photoThomas Brandtstaetter's profile photo
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"I think that's an overly paranoid perspective" -- I doubt they would have been obvious about how they did it, but we know from the Snowden releases that they deliberately sabotaged IETF work in the past. You do acknowledge that, yes?
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Theodore Ts'o

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Dear lazy G+ --- has anyone managed to compile coreutils for aarch64-android (i..e, arm64 for Android's bionic libc)?    I'm aware of Sonelli's docker repo[1], but it only supports 32-bit arm, and it's not at all obvious how the patches in that repo work around the truly awe-inspiring abstraction violations committed by coreutils into the C library's stdio implementation (among other non-portable hacks perpetrated by the coreutils sources).

If you have, patches and instructions for how to set up the cross compilation environment (preferably using the Android NDK, but I'm not picky) would be gratefully appreciated.

[1] https://github.com/Sonelli/android-coreutils

EDIT: Wasn't as bad as I feared.   Using coreutils 8.24 fixed most of the problems, and the rest weren't that nasty to work around, mercifully.
android-coreutils - A docker image that builds the GNU coreutils binaries for Android
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Wasn't as bad as I feared.   Using coreutils 8.24 fixed most of the problems, and the rest weren't that nasty to work around, mercifully.
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Theodore Ts'o

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Very interesting... some vegatables (including organic veggies, so paying $$$ extra may not help; in fact, it might make it worse) may be using fertilizer which has a lot of heavy metals.    
A molecular biologist is finding what could be dangerous levels of heavy metals in plants like kale. And they've shown up the most in organic varieties.
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The main problem within this article is it should have been splitted/divided to 2 or 3 articles.

Measuring heavy metals ( +Colin McMillen​ ) does not need double blind studies. But the duplicate containers need to be used and the other one filled with destilled water etc. so that possible contamination is eliminated.

Chelation threapies are something which might work or then not, or are just placebo. BUT spending $$$s and feeling good is therapy too if it helps, or spending $$$s to alcohol if it helps. But even mentioning this should have been in a separate article.

Eating too much cruciferous is not healthy eating because those are poisonous. So constantly eating salads (plant) or making kale smoothies is not healthy. This has been known issue for decades.
These plants are fighting against insects etc. and do generate all kinds of poisonous substaces which can easily be detected in original wild plants.

Once a week cruciferous plants. There are also other edible vegetables ... nuts .. mushrooms ...

(a lacto-vegetarian since 1974)
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Theodore Ts'o

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So it looks like Chrome beta finally has High DPI support for Linux.   Excellent!

(I'm currently running 43.0.2357.18 but I see 43.0.2357.37 has been downloaded and I should get that as soon as I restart my browser.)
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Greg S
 
So it seems you have to manually specify the dimensions for the things like the tabs and the height of the navigation bar and menus. So I did:

$ xrandr --dpi 144
$ google-chrome-beta  --force-device-scale-factor=1.5 &

And I get a consistent rendering that's a reasonable size. I'm not sure why the Chrome UX people want to have comically large tabs and menus but scaling things down (the correct dpi for the Pixel is 192 and "scale factor" 2) makes them quite reasonable.
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Theodore Ts'o

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Very, very, scary.   This once again proves that if you can run local code, you can probably break root one way or another.

+Jej B This is an example of a vulnerability for which if you use a hypervisor, you would be much safer than if you were merely using containers for your security isolation.
Posted by Mark Seaborn, sandbox builder and breaker, with contributions by Thomas Dullien, reverse engineer [This guest post continues Project Zero’s practice of promoting excellence in security research on the Project Zero b...
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+Jej B, no, all I'm saying is that the only exploit that has yet been demonstrated is one that will have lower success rates in a VM with hugepage mappings than in a container directly on a physical host. You appear to be searching for hostility where there is none.
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Theodore Ts'o

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With apologies to John von Neumann, anyone who makes function prototypes change depending on a #define, like those who considers arithmetical methods of producing random digits, is in a state of sin.
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Yeah, that would make me cranky, too!
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Theodore Ts'o

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I just wanted to give a shout out to +SendGrid.  Even though I'm very clearly outside their primary target market as far as paying customers are concerned, they quickly provisioned me with a free tier account which I was able to use with gce-xfstests so that someone can get e-mail notifications from a GCE VM running the file system regression tests.

Setting it up was relatively painless: https://git.kernel.org/cgit/fs/ext2/xfstests-bld.git/commit/?id=052e1564a5c2b17f23a2eae27be7c27be737e7c7

If you're using gce-xfstests, you will need to get your own sendgrid account (just ask to have a free tier account provisioned), and then configure GCE_SG_USER and GCE_SG_PASS in ~/.config/kvm-xfstests.

Thanks, +SendGrid!
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Theodore Ts'o

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I have xfstests running under Google Compute Engine!   It uses kexec to launch the kernel to be tested, and using a n1-highcpu-4 machine with 100GB of SSD provisioned Persistent Disk, and given that I have 10 test configs with each test config taking 40 minutes to run the auto test group for a total of test runtime of around 7 hours, I estimate that it costs roughly $1.25 to do a complete regression test run for ext4.  (BTW, this used to take 24 hours to run on my laptop or desktop)
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+Marc-Antoine Ruel  If you can point me at the relevant code that I might be able to borrow, that would be great!
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Theodore Ts'o

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To people making commits to the Linux kernel.  It would save me a bunch of work (and for others are trying to gather statistics for things like "who writes the Linux kernel") if you use an editor macro to add the "Signed-off-by" and "Acked-by" lines.   This avoids noise like this:

1 Eric Dumaze <edumazet@google.com>
441 Eric Dumazet <edumazet@google.com>
1 Eric Dumazet  <edumazet@google.com>
1 Eric DUmazet <edumazet@google.com>
1 Eric Dumazet <edumzet@google.com>
1 Eric Dumazet <eric.dumazet@gmail.com>

I also see variation in the git Author and Committer fields, although admittedly less since this tends to be automated; however there are times when it's obvious that some developers don't have a .gitconfig file on all of their systems.

kthxbye
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The problem is old and goes all the way to the top of the organization:

commit 8c6b065b792061c2e471d530127f2348fd9d243d
Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date:   Fri Jul 20 15:36:31 2007 +0100

    pata_cs5520: Fix probe bug regression introduced in 2.6.22

    Signed-off-by: Alan Cox <alan@redhat.com>
    Signed-off-by: Linux Torvalds <torvalds@linux-foundation.org>
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Theodore Ts'o

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Trying to port features to the Qualcom msm kernel makes me very grumpy.   It would be awfully nice if Qualcomm engineers would (a) not break building the kernel under x86, and (b) use randconfig to make sure the kernel builds with something other than a very specific .config file.    Sigh....
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https://lwn.net/Articles/647524/ "Obstacles to contribution in embedded Linux"
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Theodore Ts'o

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If you are a voter in the US, please consider signing this.

If you aren't, don't be too smug. Pretty much all other countries have less controls on their spooks compared to the US; some countries might be less competent at implementing a panopticon, but GHCQ (for example) has admitted that they can put any British subject under surveillance if they feel like it, without needing to suspect that the person has committed a crime, and without asking a judge first. 
Read our letter to U.S. House and Senate leadership on how our surveillance laws should be changed. Then add your name to show your support. #United4NSAReform
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Given the metadata retention laws the Australian govt just pushed through, "smug" is not where I'm at. Was amusing have a Greens senator using his speech during the debate telling people to go and find a VPN provider though :)
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Theodore Ts'o

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I like this live version better than the version on the "Dot the Dragon's Eyes" album!
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Always enjoyed her shows at Passim when I lived in Boston.
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Yummy corn fritters and pecan rolls are included free at the beginning of the meal! I liked the riverside view.
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