LWN.net

The addition of realtime support to Linux is a long story; it first shows up in LWN in 2004. For much of thattime, it has seemed like only a little more work was needed to get acrossthe finish line; thus we ran headlines like therealtime preemption endgame - in 2009. At the 2023 Linux Plumbers Conference, ThomasGleixner informed the group that, now, the end truly is near. There isreally only one big problem left to be solved before all of that work canland in the mainline.

Security updates have been issued by Debian (chromium and openvpn), Oracle (kernel, microcode_ctl, plexus-archiver, and python), Red Hat (.NET 6.0, dotnet6.0, dotnet7.0, dotnet8.0, kernel, linux-firmware, and open-vm-tools), SUSE (apache2, chromium, jhead, postgresql12, postgresql13, and qemu), and Ubuntu (dotnet6, dotnet7, dotnet8, frr, python-pip, quagga, and tidy-html5).

The LWN.net Weekly Edition for November 16, 2023 is available.

Building new kernels and booting into them is an unavoidable-andtime-consuming-part of kernel development. Andrea Righi works forCanonical on the Ubuntu kernel team, so he does a lot of that and wanted tofind a way to speed up the task. To that end, he has been workingon virtme-ng, which is away to boot a new kernel in a virtual machine, and it doesso quickly. He came to the 2023Linux Plumbers Conference (LPC) in Richmond, Virginia to introduce theproject to a wider audience.

Tavis Ormandy has described a bugin some Intel CPUs that can lead to a crash (or worse):

For the COBOL users out there, James K. Lowden has postedan update on the current status of the GNU COBOL compiler.

Security updates have been issued by Debian (libclamunrar and ruby-sanitize), Fedora (frr, roundcubemail, and webkitgtk), Mageia (freerdp and tomcat), Red Hat (avahi, bind, c-ares, cloud-init, container-tools:4.0, container-tools:rhel8, cups, dnsmasq, edk2, emacs, flatpak, fwupd, ghostscript, grafana, java-21-openjdk, kernel, kernel-rt, libfastjson, libmicrohttpd, libpq, librabbitmq, libreoffice, libreswan, libX11, linux-firmware, mod_auth_openidc:2.3, nodejs:20, opensc, perl-HTTP-Tiny, procps-ng, protobuf-c, python-cryptography, python-pip, python27:2.7, python3, python3.11, python3.11-pip, python38:3.8, python38-devel:3.8, python39:3.9, python39-devel:3.9, qt5-qtbase, qt5-qtsvg, rhc, ruby:2.5, shadow-utils, squid:4, sysstat, tang, tomcat, tpm2-tss, virt:rhel, virt-devel:rhel, webkit2gtk3, wireshark, xorg-x11-server, xorg-x11-server-Xwayland, and yajl), Slackware (mariadb), SUSE (chromium, connman, exfatprogs, ucode-intel, and w3m), and Ubuntu (cobbler, ffmpeg, linux-oem-6.5, procps, and traceroute).

Lispis one of the oldest programming languages still in use today, but it has evolved in multiple directions over its more than 60-year history. Two ofthe more prominent descendants, Common Lisp and Emacs Lisp (or Elisp),are fairly closely related at some level, but there is still something of adivide between them. Some recent discussion in the emacs-devel mailinglist have shown that some elements from Common Lisp are not completelywelcome in Elisp-at least in the code that is maintained by the Emacs project itself.

Security updates have been issued by Debian (postgresql-11, postgresql-13, and postgresql-15), Fedora (chromium, optipng, and radare2), Scientific Linux (plexus-archiver and python), Slackware (tigervnc), SUSE (apache2, containerized-data-importer, kernel-firmware-nvidia-gspx-G06, nvidia-open- driver-G06-signed, postgresql, postgresql15, postgresql16, postgresql12, postgresql13, python-Django1, squashfs, and xterm), and Ubuntu (firefox and memcached).

By the time that the 6.7 merge window closed on November 12, 15,418non-merge changesets had been pulled into the mainline kernel. That makesthis one of the busiest merge windows ever; if one discounts the lengthybcachefs development history (some 2,800 commits), though, then the patchvolume is roughly in line with other recent kernels. Over 5,000 of thosecommits were merged after our first-halfmerge-window summary was written.

Security updates have been issued by Debian (audiofile and ffmpeg), Fedora (keylime, python-pillow, and tigervnc), Mageia (quictls and vorbis-tools), Oracle (grub2), Red Hat (galera, mariadb, plexus-archiver, python, squid, and squid34), and SUSE (clamav, kernel, mupdf, postgresql14, tomcat, tor, and vlc).

Linus Torvalds has released 6.7-rc1, thus closing the merge windowfor this release. It is the largest merge window ever, but some of thatwas due to the bcachefs history that came with merge of that filesystem.

For folks with an interest in how extended BPF came to be and a half-hourto spare, the announcementhas gone out of a new film called "eBPF: Unlocking the kernel", released atthe KubeCon+CloudNativeCon event. The documentary is available onYouTube.

Years ago, the list of mounted filesystems on a Unix or Linux machine wasrelatively short and static. Adding a filesystem, which typically involvedbuying a new drive, happened rarely. In contrast, contemporary systemswith a large number of containers can have a long and dynamic list ofmounted filesystems. As was discussed atthe 2023 LSFMM+BPF Summit, the Linuxkernel's mechanism for providing information about mounted filesystems hasnot kept up with this change, leading to system-management headaches. Now,two new system calls proposedby Miklos Szeredi look set to provide some much-needed pain relief.

The GNOME Foundation has announcedthe receipt of a 1million award from the German Sovereign Tech Fund. Thefunding will support work on accessibility, privacy, hardware support, and more.

Security updates have been issued by Fedora (community-mysql, matrix-synapse, and xorg-x11-server-Xwayland), Mageia (squid and vim), Oracle (dnsmasq, python3, squid, squid:4, and xorg-x11-server), Red Hat (fence-agents, insights-client, kernel, kpatch-patch, mariadb:10.5, python3, squid, squid:4, tigervnc, and xorg-x11-server), Scientific Linux (bind, firefox, java-1.8.0-openjdk, java-11-openjdk, kernel, libssh2, python-reportlab, python3, squid, thunderbird, and xorg-x11-server), SUSE (go1.21), and Ubuntu (linux-gke and linux-iot).

It is (relatively) easy to add code to the kernel; it tends to be muchharder to remove that code later. The most recent example of this dynamiccan be seen in the story of the ia64 ("Itanium") architecture, support forwhich was removed during the 6.7 merge window. That removal has left asmall group of dedicated ia64 users unhappy and clinging to a faint hopethat this support could return in a year's time.

Security updates have been issued by Debian (cacti and chromium), Fedora (CuraEngine, podman, and rubygem-rmagick), Mageia (gnome-shell, openssl, and zlib), SUSE (salt), and Ubuntu (xrdp).

The LWN.net Weekly Edition for November 9, 2023 is available.

The reminderhas gone out: the deadline for nominations for the Linux FoundationTechnical Advisory Board is November13. If you are interested inrepresenting the kernel community on the TAB, now is the time to puttogether a self-nomination and get onto the ballot.

The linux-kernel mailing list famously gets an enormous amount of email on adaily basis; the volume is so high that various email providers try torate-limit it, which can lead to huge backlogs on the sending side and, of course, delayed mail. Part of the reason there is so muchtraffic is that nearly every patch gets copied to the mailing list, evenwhen it may be unnecessary to do so. A proposed changewould start shunting some of that patch email aside and, as might beguessed, has both supporters and detractors, but the discussion doeshighlight some of thedifferent ways the mailing list is used by kernel developers.

The6.6.1,6.5.11,6.1.62,5.4.260,4.19.298, and4.14.329stable kernel updates have all been released, each contains another set ofimportant fixes.Note that 5.15.138and 5.10.200ended up going into a second round of review; they can be expected in thenear future.Update:5.15.138 and5.10.200are now available as well.

The developers of Home Assistant, which has recently been covered here, have announcedthat they will be removing support for Chamberlain and Liftmastergarage-door openers after being locked out by the company.

The Register attendeda talk about Ubuntu's upcoming Core Desktop immutable distribution.

Security updates have been issued by Debian (python-urllib3 and tang), Fedora (chromium, mlpack, open-vm-tools, and salt), Red Hat (avahi, binutils, buildah, c-ares, cloud-init, containernetworking-plugins, cups, curl, dnsmasq, edk2, flatpak, frr, gdb, ghostscript, glib2, gmp, grafana, haproxy, httpd, mod_http2, java-21-openjdk, kernel, krb5, libfastjson, liblouis, libmicrohttpd, libpq, libqb, librabbitmq, LibRaw, libreoffice, libreswan, libssh, libtiff, libvirt, libX11, linux-firmware, mod_auth_openidc, ncurses, nghttp2, opensc, pcs, perl-CPAN, perl-HTTP-Tiny, podman, procps-ng, protobuf-c, python-cryptography, python-pip, python-tornado, python-wheel, python3.11, python3.11-pip, python3.9, qemu-kvm, qt5 stack, runc, samba, samba, evolution-mapi, openchange, shadow-utils, skopeo, squid, sysstat, tang, tomcat, toolbox, tpm2-tss, webkit2gtk3, wireshark, xorg-x11-server, xorg-x11-server-Xwayland, and yajl), Slackware (sudo), SUSE (squid), and Ubuntu (python-urllib3).

There has been a lot of action for the Python C API in the last month orso-much of it organizational in nature. As predicted in our late September article on using the "limited"C API in the standard library, the core developer sprint in October was thescene of some discussions about the API and the plans for it. Out of those discussions have come two PEPs, one of which describes the API,its purposes, strengths, and weaknesses, while the other would establish a CAPI working group to coordinate and oversee the development and maintenanceof it.

Alexander "Solar Designer" Peslyak, the longtime maintainer of theoss-security and linux-distros mailing lists, has announcedthat this work has gained a sponsor:

Fedora39 has been released, one day after the Fedora project's 20thanniversary. See the list ofapproved changes and this FedoraMagazine article for more information.

Security updates have been issued by Debian (trapperkeeper-webserver-jetty9-clojure), Mageia (libsndfile, packages, thunderbird, and x11-server), Oracle (.NET 6.0), SUSE (kernel, kubevirt, virt-api-container, virt-controller-container, virt-handler-container, virt-launcher-container, virt-libguestfs-tools- container, virt-operator-container, redis, and squid), and Ubuntu (gsl).

Containers and virtual machines on Linux communicate with the world viavirtual network devices. This arrangement makes the full power of theLinux networking stack available, but it imposes the full overhead of thatstack as well. Often, the routing of this networking traffic can behandled with relatively simple logic; the BPF-programmable network device,which was merged for the 6.7 kernel release, makes it possible to avoidexpensive network processing, in at least some cases.

Security updates have been issued by Debian (chromium, open-vm-tools, openjdk-17, pmix, and trafficserver), Fedora (netconsd, podman, suricata, and usd), Oracle (.NET 6.0, .NET 7.0, binutils, ghostscript, java-1.8.0-openjdk, kernel, and squid), SUSE (apache-ivy, gstreamer-plugins-bad, kernel, nodejs12, opera, poppler, rubygem-activesupport-5.2, tiff, util-linux, and virtualbox), and Ubuntu (krb5).

The Google Project Zero blog celebratesthe launch of the Pixel8 handset, the first to make use of Arm'sMemory Tagging Extension (MTE). Linux has supported MTE since the 5.10 release in 2020,but that support has only now shown up (in experimental form) in anavailable handset.

The Open Enterprise Linux Association, ajoint venture founded by CIQ, Oracle, and SUSE, has announcedits first code release.

As of this writing, 9,842 non-merge changesets have found their way intothe mainline repository since the 6.7 merge window opened. Nearly a thirdof those consist of the entire bcachefs development history but, evendiscounting that, there has been a lot of material landing for the nextrelease. Read on for a summary of the most interesting changes pulled sofar in this development cycle.

Security updates have been issued by Debian (phppgadmin and vlc), Fedora (attract-mode, chromium, and netconsd), Red Hat (.NET 7.0, c-ares, curl, ghostscript, insights-client, python, squid, and squid:4), SUSE (kernel and roundcubemail), and Ubuntu (libsndfile).

One of the core objectives of any confidential-computing implementation isto protect a guest system's memory from access by actors outside of theguest itself. The host computer and hypervisor are part of the group thatis to be excluded from such access; indeed, they are often seen as threat in their own right. Hardware vendors have added features like memoryencryption to make memory inaccessible to the host, but such features canbe difficult to use and are not available on all CPUs, so there is ongoinginterest in software-only solutions that can improve confidentiality. Theguest-firstmemory patch set, posted by Sean Christopherson and containing work byseveral developers, looks poised to bring some software-based protection toan upcoming kernel release.

Julia Evans has posted a list ofconfusing Git terms and behavior along with explanations of what isactually going on.

HomeAssistant 2023.11 is available. New features include a to-do listmanager, Matter1.2 support, customizable tile cards, new integrations, and more. (LWNlooked at Home Assistant last month).

The GNU awk text-processing utility, gawk, has released version5.3.0. The main new features add compatibility with "The One True Awk" (also knownas "BWK awk"); version 5.3.0 adds CSV (comma-separated values) parsing andthe ability to use \u escape sequences for Unicode code points.Read on for other changes in the release.

The 6.5.10 and 6.1.61 stable kernels have been released. Asusual, they contain important fixes throughout the kernel tree; users ofthose series should upgrade.

Security updates have been issued by Gentoo (Netatalk), Oracle (firefox), Red Hat (.NET 6.0, .NET 6.0, .NET 7.0, binutils, and qemu-kvm), SUSE (gcc13, tomcat, and xorg-x11-server), and Ubuntu (axis, libvpx, linux-starfive, thunderbird, and xrdp).

The LWN.net Weekly Edition for November 2, 2023 is available.

LWN.net is looking to hire a full-time writer/editor to help us keep thenews flowing and to expand our content in areas of interest to our readers.We are certain that the person we need is out there somewhere, and arecounting on help from LWN readers to find them. Read on for details on whowe are looking for and how we see them fitting in here.

Python functions can use both positional and keyword arguments; the latterprovide a certain level of documentation for an argument and its meaning,while allowing them to be given in any order in a call. But it is oftenthe case that the name of the local variable to be passed is the same asthe keyword, which can lead to overly repetitive argument lists, at leastin some eyes. A recent proposal to shorten the syntax for calls withthese duplicate names seems to be gaining some steam-a Python EnhancementProposal (PEP) is forthcoming-though there are some who find it to be anunnecessary and unwelcome complication for the language.

LWN editor Jonathan Corbet was asked to give a brief talk about kernelmaintainership at the recently concluded LinuxFoundation Member Summit. That talk was recorded and has now been made availableon YouTube. There is little in it that will be news to regular LWNreaders, but it may be instructive to folks who are less well versed in howkernel development works.

Matthew Garrett explainswhy ACPI exists and why it is not as bad a thing as some think.

Security updates have been issued by Debian (h2o, open-vm-tools, pmix, and zookeeper), Gentoo (GitPython), Oracle (firefox, java-11-openjdk, java-17-openjdk, libguestfs-winsupport, nginx:1.22, and thunderbird), Red Hat (samba), SUSE (container-suseconnect, libsndfile, and slurm), and Ubuntu (krb5, linux, linux-aws, linux-aws-5.15, linux-azure, linux-azure-5.15, linux-azure-fde, linux-azure-fde-5.15, linux-gcp, linux-gcp-5.15, linux-gkeop, linux-gkeop-5.15, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-oracle, linux-oracle-5.15, linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-bluefield, linux-gcp, linux-gcp-5.4, linux-gkeop, linux-hwe-5.4, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4, linux-xilinx-zynqmp, linux, linux-aws, linux-aws-6.2, linux-azure, linux-azure-6.2, linux-azure-fde-6.2, linux-gcp, linux-gcp-6.2, linux-hwe-6.2, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-6.2, linux-oracle, linux-raspi, linux-starfive, linux-laptop, linux-nvidia-6.2, linux-oem-6.1, linux-raspi, open-vm-tools, and xorg-server).

A fast-moving patch set-seemingly the norm for Linux networkingdevelopment-seeks to add some Rust abstractions for physical layer(PHY) drivers. Lots of review has been done, and the patch set has been reworkedfrequently in response to those comments. Unfortunately, the Rust-for-Linux developers arehaving trouble keeping up with that pace. There is, it would appear, something of a disconnect between the two communities'development practices.

Version0.2 of Incus, an LXD fork, has been released. "This versionincorporates most changes that went into LXD 5.19 as well as introduce afew additional features and improvements." Changes include NVMEstorage support, support for migrating clustered environments from LXD, andmore.

Security updates have been issued by Debian (jetty9, node-browserify-sign, request-tracker4, and request-tracker5), Fedora (golang-github-altree-bigfloat, golang-github-seancfoley-bintree, golang-github-seancfoley-ipaddress, kitty, slurm, and thunderbird), Gentoo (ConnMan, libxslt, and Salt), Mageia (chromium-browser-stable), Red Hat (firefox, libguestfs-winsupport, and thunderbird), SUSE (clamav, gcc13, gstreamer-plugins-bad, icu73_2, java-17-openjdk, nodejs10, poppler, python-Werkzeug, redis, thunderbird, webkit2gtk3, xorg-x11-server, and xwayland), and Ubuntu (kernel, linux-aws, linux-azure, linux-gcp, linux-oracle, linux-raspi, linux-iot, linux-raspi, linux-raspi-5.4, and mysql-8.0).