Author Archives: daveti

About daveti

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

Kernel Code Execution Time Measurement (kcetm)

This post mainly talks about the correct usage of tsc counters provided by Intel x86/x86-64 architectures to measure the Linux kernel code execution time. Most of the content here is borrowed/inspired from [1]. Note that this is NOT a post … Continue reading

Posted in Dave's Tools, OS, Programming | Tagged , , , , , , , , | 1 Comment

Rowhammer Pine64

Rowhammer attacks have been well known, and gotten a lot of publications already. However, we notice that most rowhammers happened on x86 architecture due to the easy access to clflush from the user space. ARM architecture (both ARMv7 and ARMv8) … Continue reading

Posted in Linux Distro, OS, Security | Tagged , , , , , | Leave a comment

“make deb-pkg” broken

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

Posted in Linux Distro | Tagged , , | Leave a comment

Running Multics on Linux (Fedora 27)

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

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

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

Posted in Programming | Tagged , , , , | Leave a comment

A PoC of DoS attack in Elixir Actor Model

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

Posted in Programming, Security, Static Code Analysis | Tagged , , , , | Leave a comment