The kernel project, for many years, lacked a formal testing setup; it wasoften joked that testing was the project's main reason for keeping usersaround. While many types of kernel testing can only be done in thepresence of specific hardware, there are other parts of the kernelthat could be more widely tested. Over time, though, the kernel has gainedtwo separate testing frameworks and a growing body of automated tests to gowith them. These two frameworks - kselftests and KUnit - take differentapproaches to the testing problem; now thispatch series from Thomas Weischuh aims to bring them together.
Security updates have been issued by Debian (djvulibre and slurm-wlm), Red Hat (apache-commons-vfs, container-tools:rhel8, kernel, kernel-rt, podman, python3, rsync, socat, and sudo), SUSE (apache2, helm-mirror, incus, kernel, openssl-3, python-Django, and systemd), and Ubuntu (dcmtk, File::Find::Rule, ghostscript, jquery, and libssh).
The U-Boot universal bootloader projecthas announced the release of version 2025.07. It has multiple new featuresincluding "uthreads" (inspired by the "bthreads" coroutines in the barebox bootloader), exFAT support,new architecture and SoC support and improvements to existing platforms,cleanups, better testing, and more. Project leader Tom Rini took theopportunity to mention his effortstoward getting some help with the project and more formal governance:
The GNU project's Bourne AgainSHell (Bash) has released version 5.3, with some significant newfeatures, including some from the associated Readline 8.3 release, which providescommand-line editing and other features for Bash and lots of otherprograms. Bash 5.3 has a "new form of command substitution that executes the command inthe current shell execution context", pathname-completion sortingwill be handled based on the GLOBSORT shell variable, generatedcompletions can go to a shell variable instead of to stdout, the sourcecode has been updated to C23, and more. Meanwhile:
Niriis a relatively new Rust-based compositorfor Wayland with a different take on tiling window management: windowsare placed onscreen in an "infinite" row that can expand beyond thebounds of the visible workspace. It is not a full-blown desktopenvironment, but niri may be a suitable option for Linux users whowant tiling features and the minimalism of a window manager forWayland.
Thepedalboardlibrary for Python is aimed at audio processing of various sorts, fromconverting between formats to adding audio effects. The maintainer ofpedalboard, Peter Sobot, gave a talk about audio in Python atPyCon US 2025, which was held in Pittsburgh,Pennsylvania in May. He started from the basics of digital audio and thenmoved into working with pedalboard. There were, as might be guessed, audio examplesin the talk, along with some visual information; interested readers may want to view the YouTube video of thepresentation.
The kernel project makes a strong promise to its users: the kernel ABI willnot be changed in ways that break user-space code. The occasional failurenotwithstanding, kernel developers do try to live up to that promise. Theyare handicapped by one little problem, though: there is no description ofwhat the kernel ABI is, and no comprehensive way to test whether a givenchange breaks it. The kernel APIspecification framework proposed (in its second revision) by SashaLevin addresses some of those concerns, but the solution is incomplete anddoes not come for free.
The NetdevFoundation, which is "a user-led effort under the supervision of theLinux Foundation, focused on financially supporting Linux networkingdevelopment", has announced itsexistence.
Every release of the Linux kernel has lots of new features, many of whichare accessible from user space. Usually, though, the GNU C Library (glibc)and tools that access the Linux user-space API lag behind the kernelreleases. Geoffrey Thomas showed how Python programs can access these newkernel features as soon as the kernel is released in his "What's New in theLinux Kernel... from Python" talk atPyCon US 2025. While he had twoexamples of accessing new kernel features, the real goal of the talk was todemonstrate how to go about connecting Python tothe Linux kernel.
The copyleft-next project is aneffort to develop a next-generation copyleft license; it was covered here back in 2013 (as well as in 2015 and 2021). The project has stalled in recentyears, but now Richard Fontana and Bradley Kuhn have announceda new effort to push copyleft-next forward:
Version 5.0 of theGNU Health Hospital Information System has been released. This project,working to support medical offices, shows just how far the free-softwareeffort can reach. Changes in this release include improved reporting andanalytics, more comprehensive handling of many types of patientinformation, a reworked medical-imaging subsystem, better insurance andbilling functionality, and more.
Transparent huge pages (THPs) are, theoretically, supposed to allow processes tobenefit from larger page sizes without changes to their code. This does work,but the performance impacts from THPs are not always a benefit, so systemadministrators with specific knowledge of their workloads may want the abilityto fine-tune THPs to the application. On May15, Usama Arifshared a patch set that would add aprctl() option for setting THP defaults for a process; that patchset has sparked discussion about whether such a setting is a good fit forprctl(), and what alternative designs may work instead.
The extensible scheduler class("sched_ext") allows the loading of a custom CPU scheduler into the kernelas a set of BPF functions; it was merged for the 6.12 kernel release.Since then, sched_ext has enabled a wide range of experimentation withscheduling algorithms. At the 2025 OpenSource Summit North America, Ching-Chun ("Jim") Huang presented workthat has been done to apply (local) machine learning to the problem ofscheduling processes on complex systems.
A changeproposal to end support for 32-bit x86 (i686) applications on thex86_64 architecture with the Fedora44 release has been withdrawnafter significant pushback. As proposed, the change could havehad a significant impact on gamers, compiler development, and the Bazzite project, which uses Fedora as abase for a gaming-focused distribution. While i686 gets a reprieve fornow, the question still lingers: who is going to keep the necessaryi686 packages in working order when few upstream maintainers orvolunteer packagers care about the architecture?
In 2023, Fujita Tomonoriwrote a Rust version of the existing driver for theAsix AX88796B embedded Ethernet controller. At slightly more than 100 lines,it's about as simple as a driver can be, and therefore is a useful touchstone forthe differences between writing Rust and C in the kernel. Looking at the Rustsyntax, types, and APIs used by the driver and contrasting them with the Cversion will help illustrate those differences.
The history of the bcachefs filesystem in the kernel has been turbulent,most recently with Linus Torvalds refusinga pull request for the 6.16-rc3 release. Torvalds has now pulledthe code in question, but also said:
Security updates have been issued by Debian (freeradius and icu), Fedora (clamav, glow, libssh, perl-Crypt-OpenSSL-RSA, perl-CryptX, podman, trafficserver, and xorg-x11-server), Mageia (gdk-pixbuf2.0 and thunderbird), Red Hat (osbuild-composer and weldr-client), SUSE (afterburn, google-osconfig-agent, libblockdev, pam, python-tornado6, screen, and yelp-xsl), and Ubuntu (libxslt and python-pip).
Version1.88.0 of the Rust language has been released. Changes include theability to chain let expressions, "naked" functions that have nocompiler-generated prologue or epilogue, automatic garbage collection incargo, a set of stabilized APIs, and more.
Over on the Collabora blog, Tathagata Roy has an updateon the progress of targeting the Coccinelle toolfor matching and transforming source code to Rust. The Coccinelle for Rustproject, which we covered in a 2024talk by Roy at Kangrejos, is addingthe ability to transform Rust programs and the goal is "to bringCoccinelle For Rust at par with Coccinelle For C in terms of basicfunctionalities". There is still work to be done to get there, butprogress is being made in various areas.
Kernel development and machine learning seem like vastly different areas ofendeavor; there are not, yet, stories circulating about the vibe-coding ofnew memory-management algorithms. There may well be places where machinelearning (and large language models - LLMs - in particular) prove to behelpful on the edges of the kernel project, though. At the 2025North-American edition of the Open Source Summit, Sasha Levin presentedsome of the work he has done putting LLMs to work to make the kernel better
Security updates have been issued by Debian (firefox-esr and libxml2), Fedora (firefox, libtpms, and tigervnc), Mageia (chromium-browser-stable and nss & firefox), Oracle (emacs, iputils, kernel, krb5, libarchive, mod_proxy_cluster, pam, perl-File-Find-Rule, perl-YAML-LibYAML, and qt5-qtbase), Red Hat (opentelemetry-collector, osbuild-composer, and weldr-client), SUSE (clamav, firefox, go1.24-openssl, and helm), and Ubuntu (libarchive, linux-azure, linux-azure-5.4, linux-azure-fips, linux-fips, linux-azure-nvidia, linux-oracle, linux-oracle-6.8, linux-raspi, linux-raspi-realtime, linux-xilinx-zynqmp, and python-urllib3).
Libxml2, anXML parser and toolkit, is an almost perfect example of the successesand failures of the open-source movement. In the 25 years since itsfirst release, it has been widely adopted by open-source projects, foruse in commercial software, and for government use. It alsoillustrates that while many organizations love using open-source software,far fewer have yet to see value in helping to sustain it. That has ledlibxml2's current maintainer to reject security embargoes and sparkeda discussion about maintenance terms for free and open-sourceprojects.
One of the biggest changes to come to the Python world is the addition of the free-threadinginterpreter, which eliminates the globalinterpreter lock (GIL) that kept the interpreter thread-safe, but alsoserialized multi-threaded Python code. Over the years, the GIL has been asource of complaints about the scalability of Python code usingthreads, so many developers have been looking forward to the change, whichhas been an experimental feature since Python 3.13was released in October 2024. Making the free-threaded version workwith the rest of the Python ecosystem, especially native extensions, is anongoing effort, however; Nathan Goldbaum and Lysandros Nikolaou spoke at PyCon US 2025 about those efforts.
It took time and the writing of over 60 articles, but LWN's coverage fromthe 2025 Linux Storage, Filesystem,Memory-Management, and BPF Summit is now complete. We have also madean EPUB book (13MB) containingthe full set of coverage available to all readers. This coverageconstitutes the definitive guide to the challenges that these core-kernelcommunities are facing and their development plans for the coming year.Documenting an event of this intensity at such a detailed level is not asmall undertaking. We are grateful to the Linux Foundation for funding ourtravel to our event and, especially, to LWN's subscribers for making thewhole thing possible. If you appreciate this type of coverage and have notyet subscribed, please sign up today to help makemore of it possible.
Version140.0 of the Firefox browser has been released. Changes include morecontrol over vertical tabs, a dialog to add custom search engines,improvements to translation performance, and more.
Working on the kernel can be a challenging task but, for many,configuring a kernel build can be the largest obstacle to gettingstarted. The kernel has thousands of configuration options; many of those,if set incorrectly, will result in a kernel that does not work on thetarget system. The key to helping users with complex configurationproblems is to provide reasonable defaults but, in the kernel community,there is currently little consensus around what those defaults should be.
KDE contributor Nate Graham recently wroteabout the KDE Project's plans for Plasma's X11 session. He notes thatthe project will continue to ensure that Plasma "continues tocompile and deploy on X11" and isn't horribly broken. Majorregressions will probably be fixed, eventually, but the writing is onthe wall:
The postmarketOS project,which creates a Linux distribution for mobile devices, announcedit was working on adding a version with systemd last March. That dayhas arrived with the announcementof version 25.06:
Adrian Vovk, a GNOME contributor and member of its releaseteam, recently announcedin a blog post that GNOME would be adding new dependencies on systemd, and soon. The idea is to shedGNOME's homegrown service manager in favor of using systemd, and toimprove GNOME's ability to run concurrent user sessions. However, themove is also going to throw a spanner in the works for the BSDs andLinux distributions without systemd when the changes take effect inthe GNOME49 release that is set for September.
The Collabora blog has a summary,written by Nicolas Dufresne, about the LinuxMedia Summit held on May 13 in Nice, France. It was co-located withthe Embedded Recipesconference and had sessions on stateless video encoders, camera support,staging drivers, memory accounting, and a multi-committer model for themedia subsystem."Our largest Media Summit to date brought together around 20 engaged participants. Engagement was strong, marked by thoughtful questions and lively discussions."
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