GrapheneOS (@GrapheneOS@grapheneos.social)
grapheneos.social
We have a partial port of GrapheneOS to the Pixel 11 series after a week of work on it. We're unable to complete the port due to lack of support for ARM hardware memory tagging in software, firmware and near certainly hardware. It appears Google cut an important security feature to save money.

If GrapheneOS stops supporting future Pixels, and Motorola is only targeting the flagship market for their compatible phones, we’re looking at truly dark days ahead.

  • TrollAccount69@lemmy.ml
    3·
    14 hours ago

    It’s really easy to come to that conclusion.

    Realistically speaking a team is trying to hit a set of requirements under a set of constraints when they design a soc (or any cpu if you wanna dive into the cisc world and see the wild variation in security featureset across even the same generation of chips). That means using existing designs with a die shrink or something is often the right choice when you’re shooting for the low cost portion of the market. The technology referenced here, enhanced memory tagging extensions, is a hardware implementation of tagging that requires a specific revision of the arm design and it’s a relatively new change (mte, the precursor to emte, is flawed and not used).

    So it’s not by dint of wanting to fuck you over that the designers of socs would make one without emte.

    • grue@lemmy.world
      2·
      11 hours ago

      That means using existing designs with a die shrink or something is often the right choice when you’re shooting for the low cost portion of the market. The technology referenced here, enhanced memory tagging extensions, is a hardware implementation of tagging that requires a specific revision of the arm design and it’s a relatively new change (mte, the precursor to emte, is flawed and not used).

      I’m writing this on a Pixel 8 running GrapheneOS, which I’m pretty sure is a “recommended” device that supports all the security features and is also multiple generations old.

      If new lower-end devices use die-shrink versions of previously flagship SoCs, as you say, then I simply do not buy the notion that there’s any good reason not to put a die-shrink version of this SoC in a new lower-end phone.

      • TrollAccount69@lemmy.ml
        2·
        10 hours ago

        I don’t have the datasheet in front of me but I’m almost 100% sure your tensor doesn’t have emte, which is the type of mte the graphene people are requiring for new devices.

        • grue@lemmy.world
          2·
          9 hours ago

          From https://grapheneos.org/faq#recommended-devices :

          8th generation and later Pixels also have support for the incredibly powerful hardware memory tagging security feature as part of moving to new ARMv9 CPU cores. GrapheneOS uses hardware memory tagging by default to protect the base OS and known compatible user installed apps against exploitation, with the option to use it for all apps and opt-out on a case-by-case basis for the few incompatible with it. Pointer authentication, branch target identification and other ARM security features were also introduced at the same time as hardware memory tagging.