Kernel developers are encouraged to send their changes in small batches as a way of making life easier for reviewers. So when a longtime developer and maintainer hits the list with a 437-patch series touching 859 files, eyebrows are certain to head skyward. Specifically, this series from Jens Axboe is cleaning up one of the core abstractions that has been part of the Linux kernel almost since the beginning; authors of device drivers (among others) will have to take note.

In Unix-like systems, an open file descriptor carries the right to access the opened object in specific ways. As a general rule, that file descriptor does not enable access to any other objects. The recently merged BPF token feature runs counter to this practice by creating file descriptors that carry specific BPF-related access rights. A similar but different approach to capability-carrying file descriptors, in the form of directory file descriptors that include their own credentials, is currently under consideration in the kernel community.

Version 1.78.0 of the Rust language has been released. Changes include a new mechanism for diagnostic attributes, changes to how assertions around unsafe blocks are handled, and more.

Rust now supports a #[diagnostic] attribute namespace to influence compiler error messages. These are treated as hints which the compiler is not required to use, and it is also not an error to provide a diagnostic that the compiler doesn't recognize. This flexibility allows source code to provide diagnostics even when they're not supported by all compilers, whether those are different versions or entirely different implementations.

Version 5.0 of the Yocto Project distribution builder has been released. The list of new features is long; see the release notes for the details.

This Mastodon stream from Lennart Poettering describes a sudo replacement — called run0 — that will be part of the upcoming systemd 256 release. It takes a rather different approach to the execution of privileged commands, avoiding the use of setuid (which he calls "SUID") permissions entirely.

So, in my ideal world, we'd have an OS entirely without SUID. Let's throw out the concept of SUID on the dump of UNIX' bad ideas. An execution context for privileged code that is half under the control of unprivileged code and that needs careful manual clean-up is just not how security engineering should be done in 2024 anymore.

Version 2.45.0 of the Git source-code management system has been released. Changes include a new list command for git reflog, a couple of new configuration variables for git diff, the ability to drop redundant commits while cherry-picking, a number of performance improvements, and more.

Security updates have been issued by Debian (org-mode), Oracle (shim and tigervnc), Red Hat (ansible-core, avahi, buildah, container-tools:4.0, containernetworking-plugins, edk2, exfatprogs, fence-agents, file, freeglut, freerdp, frr, grub2, gstreamer1-plugins-bad-free, gstreamer1-plugins-base, gstreamer1-plugins-good, harfbuzz, httpd, ipa, kernel, libjpeg-turbo, libnbd, LibRaw, libsndfile, libssh, libtiff, libvirt, libX11, libXpm, mingw components, mingw-glib2, mingw-pixman, mod_http2, mod_jk and mod_proxy_cluster, motif, mutt, openssl and openssl-fips-provider, osbuild and osbuild-composer, pam, pcp, pcs, perl, pmix, podman, python-jinja2, python3.11, python3.11-cryptography, python3.11-urllib3, qemu-kvm, qt5-qtbase, runc, skopeo, squashfs-tools, systemd, tcpdump, tigervnc, toolbox, traceroute, webkit2gtk3, wpa_supplicant, xorg-x11-server, xorg-x11-server-Xwayland, and zziplib), SUSE (docker, ffmpeg, ffmpeg-4, frr, and kernel), and Ubuntu (anope, freerdp3, and php7.0, php7.2, php7.4, php8.1).

Robert McQueen has posted a message from the GNOME Foundation board describing the current financial situation, plans to improve it, and an increase in the size of the board.

The Foundation has a reserves policy which specifies a minimum amount of money we have to keep in our accounts. This is so that if there is a significant interruption to our usual income, we can preserve our core operations while we work on new funding sources. We've now "hit the buffers" of this reserves policy, meaning the Board can't approve any more deficit budgets – to keep spending at the same level we must increase our income.

The 6.9-rc6 kernel prepatch is out for testing.

Things continue to look pretty normal, and nothing here really stands out. The biggest single change that stands out in the diffstat is literally a documentation update, everything else looks pretty small and spread out.

The 6.8.8, 6.6.29, 6.1.88, and 5.15.157 stable kernels have been released; each contains another set of important fixes.

Update: 6.1.89 was released two days later to fix a build problem in 6.1.88.

Video playback is undeniably one of the most important features in modern consumer devices. Yet, surprisingly, users are by and large unaware of the intricate engineering involved in the compression and decompression of video data, with codecs being left to find a delicate balance between image quality, bandwidth, and power consumption. In response to constant performance pressure, video codecs have become complex and hardware implementations are now common, but programming these devices is becoming increasingly difficult and fraught with opportunities for exploitation. I hope to convey how Rust can help fix this problem.

At the CPU level, a memory model describes, among other things, the amount of freedom the processor has to reorder memory operations. If low-level code does not take the memory model into account, unpleasant surprises are likely to follow. Naturally, different CPUs offer different memory models, complicating the portability of certain types of concurrent software. To make life easier, some Arm CPUs offer the ability to emulate the x86 memory model, but efforts to make that feature available in the kernel are running into opposition.

Version 24.04 LTS of the Ubuntu distribution is out.

This release continues Ubuntu's proud tradition of integrating the latest and greatest open source technologies into a high-quality, easy-to-use Linux distribution. The team has been hard at work through this cycle, together with the community and our partners, to introduce new features and fix bugs.

The list of changes and enhancements is long; click below for some details. More information can be found in the release notes; see also this page for a summary of security-related changes.

Linux, famously, appears in a wide range of systems. While servers and large data centers get a lot of the attention, and this year will always be the year of the Linux desktop, there is also a great deal of Linux to be found in realtime and embedded applications. Two talks held in the realtime and embedded tracks of the 2024 Open Source Summit North America provided listeners with an update on how Linux is doing in those areas. Work on realtime Linux appears to be nearing completion, while the embedded community is still pushing forward at full speed.

The LWN.net Weekly Edition for April 25, 2024 is available.

Version 9.0 of the QEMU emulator has been released. "This release contains 2700+ commits from 220 authors." The list of improvements is long; see the announcement and the changelog for details.

The Rust programming language, it is hoped, will bring a new level of safety to the Linux kernel. At the moment, though, there are still a number of impediments to getting useful Rust code into the kernel. In the Embedded Open Source Summit track of the Open Source Summit North America, Fabien Parent provided an overview of his work aimed at improving the infrastructure needed to write the device drivers needed by embedded systems in Rust; there is still some work to be done.

Security updates have been issued by Debian (glibc and samba), Fedora (chromium, cjson, mingw-python-idna, and pgadmin4), Mageia (kernel, kmod-xtables-addons, kmod-virtualbox, kernel-linus, and perl-Clipboard), Red Hat (go-toolset:rhel8, golang, java-11-openjdk, kpatch-patch, and shim), Slackware (freerdp), SUSE (apache-commons-configuration, glibc, jasper, polkit, and qemu), and Ubuntu (google-guest-agent, google-osconfig-agent, linux-lowlatency-hwe-6.5, pillow, and squid).

The Open Home Foundation has announced its existence as a home and support resource for free home-automation projects.

We created the Open Home Foundation to fight for the fundamental principles of privacy, choice, and sustainability for smart homes. And every person who lives in one.

Ahead of today, we've transferred over 240 projects, standards, drivers, and libraries—Home Assistant, ESPHome, Zigpy, Piper, Improv Wi-Fi, Wyoming, and so many more—to the Open Home Foundation. This is all about looking into the future. We've done this to create a bulwark against surveillance capitalism, the risk of buyout, and open-source projects becoming abandonware. To an extent, this protection extends even against our future selves—so that smart home users can continue to benefit for years, if not decades. No matter what comes.