Richard Palethorpe’s Index

Articles

• Bitbanging 1D Nearest-neighbor Reversible Cellular Automata
• Blockchain and why I am selling my Crypto
• Creating a static site with Pandoc and Bulma
• A review of tools for rolling your own C static analysis
• Fuzzy Sync: Winning a rare data race
• Generating type specific deserialisers for BSON.jl
• libactors: Actor model and message passing with Userland RCU
• Linux socket example
• Recording your screen on Linux
• Reproducers make the best (Linux Kernel) tests
• Supporting both Linux CGroup APIs
• Radix sort, Hash map and building C
• Three ways to help your poject fail
• My life in books
• 100 Pull-ups and 100 dips per day challenge
• Some data structures and algorithms in C, built and tested with Zig and Meson
• Zig Vs C - Minimal HTTP server
• Getting NodeJS 18.x to run on the nanos unikernel

Videos

• Automating code review with Sparse
• Fuzzy Sync: Winning a rare data race
• How to write eBPF byte code by hand
• OpenQA with the JDP data analysis framework: Bug tag propagation on 2M+ test results using Julia
• JDP Introduction: A distributed, data analysis framework in Julia

Code

Some of the projects I have been working on. You can see more on GitHub and GitLab.

• Fuzzy Sync: Independent edition of the LTP Fuzzy Sync library. Can be used to create data race reproducers. Alt repo.
• Linux Kernel: The most popular Operating System kernel. In addition to helping find kernel bugs, I have also fixed a few.
  • b9258a2cece4 slcan: Don't transmit uninitialized stack data in padding
  • 0ace17d56824 can, slip: Protect tty->disc_data in write_wakeup and close with RCU
  • redundant nvdimm: Avoid race between probe and reading device attributes
  • redundant mm: memcg/slab: Stop reparented obj_cgroups from charging root (was refused in favor of this)
• Linux Test Project: I have worked on the LTP for the last few years, writing tests and adding library features. For example…
  • Fuzzy Sync
  • C Static Analysis
  • CGroup API.
  • bpf_prog05 Reproducer for CVE-2021-3444 and various 32-bit DIV/MOD by zero issues in eBPF
  • cfs_bandwidth01 Reproducer for various CGroup scheduling bugs
  • cve-2016-7117 Reproduces a use-after-free in a race between recvmmsg() and close()
• GFXPrim/automata: GFXPrim in an ultra lightweight embedded graphics library created by long suffering LTP maintainer Cyril Chrubis. I used it to create a reversible cellular automata viewer.
• Actors.jl: The actor model for Julia. I also started a web framework based on this called Luvvy and a viral agent-based simulation.
• libactors: C Actor model and message passing library using userland read-copy-update (liburcu).
• JDP: Written in Julia; A sprawling data analysis ‘framework’ I made to automatically process kernel test results and bug data. I presented this at FOSDEM and here.
• BSONqs.jl: A fork of BSON.jl which uses Julia’s meta programming features to produce type specific deserialisers dynamically. This allows it to deserialise BSON encoded data into native Julia structs quickly.
• rselisp: An insane attempt at cloning Emacs in Rust. It includes an elisp interpreter and a barely working text editor.
• OpenQA & os-autoinst: A monstrosity of an operating system test framework. Amongst other things, I rewrote the QEMU backend to improve snapshotting and performance. It is mostly written in Perl (sigh).