Skip to content
By using Twitter’s services you agree to our Cookies Use. We and our partners operate globally and use cookies, including for analytics, personalisation, and ads.

This is the legacy version of twitter.com. We will be shutting it down on June 1, 2020. Please switch to a supported browser, or disable the extension which masks your browser. You can see a list of supported browsers in our Help Center.

  • Home Home Home, current page.
  • About

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @
  • Language: English
    • Bahasa Indonesia
    • Bahasa Melayu
    • Català
    • Čeština
    • Dansk
    • Deutsch
    • English UK
    • Español
    • Filipino
    • Français
    • Hrvatski
    • Italiano
    • Magyar
    • Nederlands
    • Norsk
    • Polski
    • Português
    • Română
    • Slovenčina
    • Suomi
    • Svenska
    • Tiếng Việt
    • Türkçe
    • Ελληνικά
    • Български език
    • Русский
    • Српски
    • Українська мова
    • עִבְרִית
    • العربية
    • فارسی
    • मराठी
    • हिन्दी
    • বাংলা
    • ગુજરાતી
    • தமிழ்
    • ಕನ್ನಡ
    • ภาษาไทย
    • 한국어
    • 日本語
    • 简体中文
    • 繁體中文
  • Have an account? Log in
    Have an account?
    · Forgot password?

    New to Twitter?
    Sign up
tehjh's profile
Jann Horn
Jann Horn
Jann Horn
@tehjh

Tweets

Jann Horn

@tehjh

works at Google Project Zero. personal account.

Joined August 2011

Tweets

  • © 2020 Twitter
  • About
  • Help Center
  • Terms
  • Privacy policy
  • Imprint
  • Cookies
  • Ads info
Dismiss
Previous
Next

Go to a person's profile

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @

Promote this Tweet

Block

  • Tweet with a location

    You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more

    Your lists

    Create a new list


    Under 100 characters, optional

    Privacy

    Copy link to Tweet

    Embed this Tweet

    Embed this Video

    Add this Tweet to your website by copying the code below. Learn more

    Add this video to your website by copying the code below. Learn more

    Hmm, there was a problem reaching the server.

    By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.

    Preview

    Why you're seeing this ad

    Log in to Twitter

    · Forgot password?
    Don't have an account? Sign up »

    Sign up for Twitter

    Not on Twitter? Sign up, tune into the things you care about, and get updates as they happen.

    Sign up
    Have an account? Log in »

    Two-way (sending and receiving) short codes:

    Country Code For customers of
    United States 40404 (any)
    Canada 21212 (any)
    United Kingdom 86444 Vodafone, Orange, 3, O2
    Brazil 40404 Nextel, TIM
    Haiti 40404 Digicel, Voila
    Ireland 51210 Vodafone, O2
    India 53000 Bharti Airtel, Videocon, Reliance
    Indonesia 89887 AXIS, 3, Telkomsel, Indosat, XL Axiata
    Italy 4880804 Wind
    3424486444 Vodafone
    » See SMS short codes for other countries

    Confirmation

     

    Welcome home!

    This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.

    Tweets not working for you?

    Hover over the profile pic and click the Following button to unfollow any account.

    Say a lot with a little

    When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.

    Spread the word

    The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.

    Join the conversation

    Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.

    Learn the latest

    Get instant insight into what people are talking about now.

    Get more of what you love

    Follow more accounts to get instant updates about topics you care about.

    Find what's happening

    See the latest conversations about any topic instantly.

    Never miss a Moment

    Catch up instantly on the best stories happening as they unfold.

    1. Eleanor Saitta‏ @Dymaxion 18 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @jonathanstray

      Yeah. I can absolutely see the problem with ms granularity timers, but they're refusing to allow any bucketed information at all. You get three-hour bucketed battery use data and that's it. Not great for "why is this device laggy right now".

      1 reply 0 retweets 6 likes
    2. Rich Felker‏ @RichFelker 18 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @Dymaxion @jonathanstray

      This is why I root and run top...

      1 reply 0 retweets 1 like
    3. Eleanor Saitta‏ @Dymaxion 18 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @RichFelker @jonathanstray

      Rooting massively reduces the effective security of the device. Even turning on dev tools isn't a great idea, which your now have to do to even get memory usage.

      1 reply 0 retweets 5 likes
    4. Rich Felker‏ @RichFelker 18 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @Dymaxion @jonathanstray

      Depending on your threat model, possibly. But Google doesn't give good alternatives to know or trust what your own device is doing & they're hardly trustworthy.

      1 reply 0 retweets 0 likes
    5. Dan Kaminsky‏Verified account @dakami 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @RichFelker @Dymaxion @jonathanstray

      It is relatively plausible that they’re putting out a panic patch because mobile is dreadfully affected.

      2 replies 0 retweets 3 likes
    6. Eleanor Saitta‏ @Dymaxion 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @dakami @RichFelker @jonathanstray

      No, this was with Oreo as a whole, and it doesn't feel like an emergency mitigation. And second+ granularity buckets aren't conceivably a side channel.

      1 reply 0 retweets 0 likes
    7. Dan Kaminsky‏Verified account @dakami 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @Dymaxion @RichFelker @jonathanstray

      I've been arguing for coarse grain time buckets against side channels for years, so I don't disagree. But Android's almost certainly rife with thousands of variations of attacks here. Coarse grain reactions also include turning it off until you understand it better.

      1 reply 0 retweets 1 like
    8. Eleanor Saitta‏ @Dymaxion 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @dakami @RichFelker @jonathanstray

      Yeah. I don't get the feeling that's what they're doing, though.

      2 replies 0 retweets 0 likes
    9. Jann Horn‏ @tehjh 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @Dymaxion @dakami and

      to clarify: are you talking about procfs hardening with hidepid? and are you saying that you'd want them to add a replacement API with artificially coarse CPU usage information?

      1 reply 0 retweets 0 likes
    10. Eleanor Saitta‏ @Dymaxion 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @tehjh @dakami and

      Yes. To let users understand what the system is doing. Not necessarily even accessible from non-SYSTEM apps.

      1 reply 0 retweets 1 like
      Jann Horn‏ @tehjh 19 Jan 2018
      • Report Tweet
      • Report NetzDG Violation
      Replying to @Dymaxion @dakami and

      FWIW, even on release builds, you can enable USB debugging in the settings, "adb shell" into the phone over USB and run "top". the adb shell account has access to the "readproc" group, which bypasses hidepid. (yes, that might be less nice to use than an app on the phone.)

      9:17 PM - 19 Jan 2018
      • 1 Like
      • Rich Felker
      1 reply 0 retweets 1 like
        1. Eleanor Saitta‏ @Dymaxion 19 Jan 2018
          • Report Tweet
          • Report NetzDG Violation
          Replying to @tehjh @dakami and

          Yeah. I'd honestly rather leave dev mode off on phones I use for real work, but it's also not an even semi-normal user solution.

          0 replies 0 retweets 0 likes
          Thanks. Twitter will use this to make your timeline better. Undo
          Undo

      Loading seems to be taking a while.

      Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.

        Promoted Tweet

        false

        • © 2020 Twitter
        • About
        • Help Center
        • Terms
        • Privacy policy
        • Imprint
        • Cookies
        • Ads info