Search: “printf”

Testing race conditions with memory access tracing and stack-based delay injection

Google Project Zero released MAccConc, Linux kernel tooling that traces memory accesses to explore and test race condition interleavings.

A Google Project Zero researcher published MAccConc (Memory Access Concurrency), tooling for exploring possible interleavings of multithreaded test cases in the Linux kernel, available on GitHub. The tools use KCOV with ASAN outline-mode instrumentation to record per-access memory traces, enabling automatic testing of all A-B-A interleavings plus terminal and GUI explorers for manual analysis. The work targets confirming race condition candidates, building reliable regression tests, and enabling concurrency fuzzing, drawing on ideas from SKI and Ned Williamson's sockfuzzer.

Google Project Zero·Sep 8, 07:00 UTC · 8d agoResearch1

Hillingar - MirageOS Unikernels on NixOS

A technical write-up details Hillingar, enabling reproducible Nix-based builds and NixOS deployment of MirageOS OCaml unikernels such as authoritative DNS servers.

This blog post (published December 2022, updated February 2025) describes Hillingar, work from the author's master's thesis enabling reproducible builds and deployments of MirageOS OCaml unikernels using Nix and a custom NixOS module, demonstrated with an authoritative DNS server. MirageOS unikernels embed application and low-level OS code in a single kernel, allowing dead-code elimination that reduces attack surface and improves efficiency. The post covers challenges such as solving opam dependency version constraints when linking a single dependency set.

Lobsters · security·Sep 4, 09:17 UTC · 11d agoTools1

XHToken/Spark-X2.5-4B-GGUF — new model trending #30 on Hugging Face

XHToken released GGUF weights of Spark-X2.5-4B, a compact model with 1M-token context and 200+ language support, under Apache 2.0.

The Hugging Face repository provides BF16 GGUF conversions of Spark-X2.5-4B, a compact general-purpose language model for conversation, writing, translation, reasoning, coding, tool use, and agentic workflows. The model uses a hybrid attention architecture, supports a native context length up to 1M tokens, and covers more than 200 languages. Local inference is supported through Ollama and LM Studio via an XHToken llama.cpp fork, with a --think=false flag to disable thinking mode for faster responses. Released under Apache License 2.0; it was trending #30 on Hugging Face at publication.

Hugging Face trending models·Aug 28, 11:26 UTC · 18d agoModel release

Brush shell 0.4.0 tightens script safety, widens platform support

Help Net Security·May 4, 00:00 UTC · May 4, 2026AI tools & infra