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A common problem in kernel development is controlling when a specific task should be done. Kernel code often executes in contexts where some actions (sleeping, for example, or calling into filesystems) are not possible. Other actions, while possible, may prevent the kernel from taking care of a more important task in a timely manner. The kernel community has developed a number of deferred-execution mechanisms designed to ensure that every task is handled at the right time. One of those mechanisms, tasklets, has been eyed for removal for years; that removal might just happen in the near future.

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The Zig language 2024 roadmap was presented in a talk last week on Zig Showtime (a show covering Zig news). Andrew Kelley, the benevolent dictator for life of the Zig project, presented his goals for the language, largely focusing on compiler performance and continuing progress toward stabilization for the language. He discussed details of his plan for incremental compilation, and addressed the sustainability of the project in terms of both code contributions and financial support.

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Filesystem development is not an easy task; the performance demands are typically high, and the consequences for mistakes usually involve lost data and irate users. The implementation of a virtual (or "pseudo") filesystem — a filesystem implemented within the kernel and lacking a normal backing store — can also be challenging, but for different reasons. A series of conversations around the eventfs virtual filesystem has turned a spotlight on the difficulty of creating a virtual filesystem for Linux.

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Return-oriented programming (ROP) attacks are hard to defend against. Partial mitigations such as address-space layout randomization, stack canaries, and other techniques are commonly deployed to try and frustrate ROP attacks. Now, OpenBSD is experimenting with a new mitigation that makes it harder for attackers to make system calls, although some security researchers have expressed doubt that it will prove effective at stopping real-world attacks. In his announcement message, Theo de Raadt said that this work "makes some specific low-level attack methods unfeasable on OpenBSD, which will force the use of other methods."

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EmacsConf 2023 was, like its recent predecessors, an online conference with lots of talks about various aspects of the Emacs editor—though, of course, it is way more than just an editor. Last year's edition was held in early December. One of the talks that looked interesting was on Emacs development, which was given live by John Wiegley. In it, he briefly described some of the biggest features coming in Emacs 30, which is the next major version coming for the tool.

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In December, the Rust project released a call for proposals for inclusion in the 2024 edition. Rust handles backward incompatible changes by using Editions, which permit projects to specify a single stable edition for their code and allow libraries written in different editions to be linked together. Proposals for Rust 2024 are now in, and have until the end of February to be debated and decided on. Once the proposals are accepted, they have until May to be implemented in time for the 2024 edition to be released in the second half of the year.

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While the mathematical realm of numbers is infinite, computers are only able to represent a finite subset of them. That can lead to problems when arithmetic operations would create numbers that the computer is unable to store as the intended type. This condition, called "overflow" or "wraparound" depending on the context, can be the source of bugs, including unpleasant security vulnerabilities, so it is worth avoiding. This patch series from Kees Cook is intended to improve the kernel's handling of these situations, but it is running into a bit of resistance.

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The free-software community has managed to build a body of software that is worth, by most estimates, many billions of dollars; all of this code is freely available to anybody who wants to use or modify it. It is an unparalleled example of independent actors working cooperatively on a common resource. Free software is certainly a success story, but all is not perfect. One of the community's greatest strengths — convincing companies to contribute to this common resource — is also part of one of its biggest weaknesses.

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