Linux Weekly News

Email has become somewhat unfashionable as a collaboration tool for open-source projects, but there are still a number of projects—such as PostgreSQL and the Linux kernel—that expect contributors to send and review patches via email. The aerc mail client is aimed at developers looking for a text-based, efficient, and extensible client that is meant to be used for working with Git and email. It uses Vim-style keybindings by default, and has an interface inspired by tmux that lets users manage multiple accounts, mails, and embedded terminals at once.

Rust, like C, has its own memory model describing how concurrent access to the same data by multiple threads can behave. The Linux kernel, however, has its own ideas. The Linux kernel memory model (LKMM) is subtly different from both the standard C memory model and Rust's model. At Kangrejos, Boqun Feng gave a presentation about the need to reconcile the memory models used by Rust and the kernel, including a few potential avenues for doing so. While no consensus was reached, it is an area of active discussion.

Version 4.0.0 of the LibreSSL TLS/cryptography stack has been released. Changes include a cleanup of the MD4 and MD5 implementations, removal of unused DSA methods, changes in libtls protocol parsing to ignore unsupported TLSv1.1 and TLSv1.0 protocols, and many more internal changes and bug fixes.

Paul McKenney gave a presentation at Kangrejos this year that wasn't (directly) related to Rust. Instead, he spoke about the work he has been doing in concert with many other contributors on improving the handling of subtle concurrency problems in C++. Although he cautioned that his talk was only an overview, and not a substitute for reading the relevant papers, he hoped that the things the C++ community is working on would be of interest to the Rust developers present as well, and potentially inform future work on the language. McKenney's talk was, as is his style, full of subtle examples of weird multithreaded behavior. Interested readers may wish to refer to his slides in an attempt to follow along.

Version 1.4 of the Inkscape open-source vector-graphics editor has been released. Highlights of this release include a filter gallery, import for Affinity Designer files, internal links in exported PDFs, and more. See the release notes for all of the new features. LWN previewed the 1.4 release in early October.

It is too early to say what the outcome will be in the ongoing fight between Automattic and WP Engine, but the WordPress community at large is already the loser. Automattic founder and CEO Matt Mullenweg has been using his control of the project, and the WordPress.org infrastructure, to punish WP Engine and remove some dissenting contributors from discussion channels. Most recently, Mullenweg has instituted a hostile fork of a WP Engine plugin and the forked plugin is replacing the original via WordPress updates.

So the diffstat looks a bit odd, because one of the fixes here caused the UTF tables to be regenerated, and an effective one-liner change turned into 6703 lines of diff.

But if you ignore that effect, everything looks normal.

At Kangrejos, Gary Guo wanted to discuss three problems with the way Rust and C code in the kernel interact: mismatched types, too many type casts, and the overhead of helper functions. To fix the first two problems, Guo proposed changing the way the kernel maps C types into Rust types. The last problem was a bit trickier, but he has a clever workaround for that, based on tricking the compiler into inlining the helper functions across language boundaries.