Arm MTE and Speculative Oracles
A note about speculative oracles and the Arm Memory Tagging Extension (MTE).
reflexive.space
Latest posts
Enabling DCI.DbC on a Jasper Lake NUC
A story about hacking on UEFI firmware for Intel platforms.
μarchonomicon: Return Instructions
Some notes and impressions about the properties of return instructions.
Some Notes on Zenbleed
This article explores the conditions for triggering "Zenbleed" (CVE-2023-20593).
Speculating on the Apple M2: Local Prediction
This article explores the local branch prediction on Apple's "Avalanche" microarchitecture.
Bare-metal Programming on the Apple M2
This is short review about creating a bare-metal microbenchmarking environment for the Apple M2 (specifically, for my new 13" MacBook Pro with the T8112).
Speculating on Zen 2 (Part 2)
This is the second part of my exploration into branch prediction and speculation in the Zen 2 microarchitecture, where we look at the behavior of unconditional direct branches and continue digging into details about the branch predictor.
Speculating on Zen 2 (Part 1)
This is the first part of my exploration into branch prediction and speculation in the Zen 2 microarchitecture, where I introduce a lot of context and present some tests with conditional branches.
Playing with PMCs on Zen 2 Machines
Anecdote about having fun with x86 performance-monitoring counters.
Playing with AMD IBS
Anecdote about having fun with AMD's "instruction-based sampling" features.
"Communication"
A veiled complaint about Elon Musk tweeting on how Neuralink creates the possibility of "conceptual telepathy."
Decoding ARMv5 Instructions in Rust
tl;dr I wrote a somewhat-simple crate for decoding 32-bit ARMv5 and Thumb instructions called armbf .
The Trefoil Knot
A story about being afraid to write poetry.
Tiny 'hello, world' Binaries
A friend of mine brought up a great question some months ago: "Why does GCC spit out a huuuge ELF when I compile the simplest possible 'hello, world' program? Shouldn't it be a lot smaller than ~8Kb? That seems pretty big ..."
Classic Stack-Smashing
This is an example of a classic stack-smashing attack, and some discussion about associated mitigations in Linux.
Exploring Kernel Tracing with eBPF
Some thoughts after watching Brendan Gregg's LCA2017 talk about developments in eBPF tracing. Figured I'd play around with it a bit. It's really cool!
To Take the World for a Machine
Social systems are complicated, and people are not machines.