Author Archives: daveti

About daveti

Interested in kernel hacking, compilers, machine learning and guitars.

“make deb-pkg” broken

Posted on March 15, 2018

Last time when I hacked the Linux kernel on Ubuntu, it was 4.4 on LTS 14.04. Time flies. Now I need to hack the kernel 4.13 again on LTS 16.04, and find the kernel build broken. It is fine that … Continue reading →

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Running Multics on Linux (Fedora 27)

Posted on January 17, 2018

This post follows the “Multics Simulator Instructions”[1] (with some tweaks) to setup Multics simulator dps8m and run Multics on my Fedora 27. Other Linux distro (Ubuntu/Debian/Raspbian) may need some changes but basically work the same way. Experience the cutting-edge secure … Continue reading →

Posted in OS, Security | Tagged , , , | 1 Comment

Some notes on the Monotonic Counter in Intel SGX and ME

Posted on November 10, 2017

SGX sealing is vulnerable to rollback attacks as the enclave is not able to tell if the sealed data is the latest or a old copy. To mitigate this attack, monotonic counter (MC) has been introduced in Intel SGX SDK … Continue reading →

Posted in Security | Tagged , , , | 12 Comments

Why list and charlist are confusing in Elixir

Posted on October 6, 2017

This post talks about list and charlist in Elixir, and discusses one specific issue in Elixir. Let’s look at the confusing thing in Elixir: iex(2)> a = [7] ‘\a’ iex(3)> b = ‘\a’ ‘\a’ iex(4)> a == b true iex(5)> … Continue reading →

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A PoC of DoS attack in Elixir Actor Model

Posted on September 29, 2017

The naive way of using the Actor model in Elixir is using “receive” in a loop, which is then “spawn”d as a Erlang process. Unfortunately, a potential DoS attack could happen if the pattern matching is not coded carefully with … Continue reading →

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A pitfall of GenServer programming in Elixir

Posted on September 29, 2017

OTP as a programming platform/framework, empowers not only Erlang, but also Elixir. This post looks into a pitfall when programming GenServer in Elixir, and provides a potential solution. All callbacks in the GenServer behavior have a limited and pre-defined possible … Continue reading →

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Pitfalls in negative indexing in C

Posted on August 3, 2017

Negative indexing in C, such as a[-1], is legit, although rarely used. There are reasons (pitfalls) why negative indexing is not recommended. This post discusses these pitfalls when using negative indexing (for fun). 1. Negative indexing within the bound In … Continue reading →

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