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The LWN.net Weekly Edition for October 6, 2022 is available.

The release of source code for NVIDIA graphics hardware was perhaps something of a surprise; at least at a quick glance, it seems like that could lead to an in-tree, officially supported driver. For many years, though, the nouveau project has been working on an upstream driver for NVIDIA hardware, so an obvious question is what happens with nouveau in light of the NVIDIA announcement. Kernel graphics maintainer Dave Airlie gave a talk at the 2022 Linux Plumbers Conference (LPC) to help shed some light on that subject.

The New Yorker has a lengthy article on the Network Time Protocol and its creator David Mills.

Coders sometimes joke, morbidly, about the “bus factor.” How many people need to get hit by a bus before a given project is endangered? It’s difficult to determine the bus factor for N.T.P., and time synchronization more broadly, especially now that companies such as Google have developed their own N.T.P.-inspired proprietary code. But it seems reasonable to say that N.T.P.’s bus factor is rather small.

Mahmoud Al-Qudsi provides extensive details on what it takes to implement a safe semaphore type in the Rust language.

The problem is that with n > 1, there’s no concept of a “privileged” owning thread and all threads that have “obtained” the semaphore do so equally. Therefore, a rust semaphore can only ever provide read-only (&T) access to an underlying resource, limiting the usefulness of such a semaphore almost to the point of having no utility. As such, the only safe “owning” semaphore with read-write access that can exist in the rust world would be Semaphore<()>, or one that actually owns no data and can only be used for its side effect of limiting concurrency while the semaphore is “owned,” so to speak.

The 5.19.14, 5.15.72, 5.10.147, 5.4.216, and 4.19.261 stable kernel updates have been released; each contains another set of important fixes.

Security updates have been issued by Debian (barbican, mediawiki, and php-twig), Fedora (bash, chromium, lighttpd, postgresql-jdbc, and scala), Mageia (bash, chromium-browser-stable, and golang), Oracle (bind, bind9.16, and squid:4), Red Hat (bind, bind9.16, RHSSO, and squid:4), Scientific Linux (bind), SUSE (cifs-utils, libjpeg-turbo, nodejs14, and nodejs16), and Ubuntu (jackd2, linux-gke, and linux-intel-iotg).

The kernel's print function, printk(), has been the target of numerous improvement efforts over the years for a variety of reasons. One persistent problem with printk() has been that its latency is unacceptably high for the realtime Linux kernel; at this point, printk() represents the last piece needing changes before the RT_PREEMPT patches can be fully merged. So there have been efforts to rework printk() for latency and lots of other reasons, but those have not made it into the mainline; a recent discussion at the 2022 Linux Plumbers Conference (LPC) seems to have paved the way for new solution to land in the mainline before too long.

Jason Ekstrand announces a new Vulkan driver for NVIDIA hardware on the Collabora blog. It seems to be off to a good start, but there is some work yet to do:

Normally, I would have submitted the merge request long ago. There are far more alpha-quality drivers already in Mesa. The problem is that we really need a new kernel uAPI to support Vulkan properly and I don't want to be stuck supporting the current nouveau uAPI for the next five years.

The 5.19.13 stable kernel update is out. "This release is to resolve a regression on some Intel graphics systems that had problems with 5.19.12. If you do not have this problem with 5.19.12, there is no need to upgrade."

OpenSSH 9.1 has been released. It is advertised as a bug-fix release (and it addresses a few low-priority memory-safety bugs), but there's also a new option to set the minimum RSA key size for authentication, a few sftp extensions, and more.

Security updates have been issued by Debian (barbican), Fedora (libdxfrw, librecad, and python-oauthlib), Oracle (bind), Red Hat (bind and rh-python38-python), SUSE (bind, chromium, colord, libcroco, libgit2, lighttpd, nodejs12, python, python3, slurm, slurm_20_02, and webkit2gtk3), and Ubuntu (linux-azure, python-django, strongswan, and wayland).

Version 2.38.0 of the Git distributed version-control system has been released. It comes with lots of new features and bug fixes, some of the former are described in a GitHub blog post by Taylor Blau. Highlights include the promotion of the scalar addition for large repositories into Git core, improvements to multi-branch rebase operations with --update-refs, performance improvements, a bash prompt indication for unmerged indexes, and lots more.

The accepted sessions for the upcoming Netdev 0x16 have been posted. The conference will be held virtually and in-person in Lisbon, Portugal October 24-28. In addition, early-bird registration rates have been extended to October 4. Netdev 0x16, like all the previous netdev conferences, is a conference of the netdev community, by the netdev community, for the netdev community. Linux kernel networking and user space utilization of the interfaces to the Linux kernel networking subsystem are the focus. If you are using Linux as a boot system for proprietary networking, then this conference _may not be for you_.

Linus Torvalds released the 6.0 kernel on October 2. There were 15,402 non-merge changesets pulled into the mainline for this release, growing the kernel by just over 1.1 million lines of code. As usual, a lot went into the creation of this kernel release; read on for a look at where some of that work came from.

Security updates have been issued by Debian (chromium, gdal, kernel, libdatetime-timezone-perl, libhttp-daemon-perl, lighttpd, mariadb-10.3, node-thenify, snakeyaml, tinyxml, and tzdata), Fedora (enlightenment, kitty, and thunderbird), Mageia (expat, firejail, libjpeg, nodejs, perl-HTTP-Daemon, python-mako, squid, and thunderbird), Scientific Linux (firefox and thunderbird), SUSE (buildah, connman, cosign, expat, ImageMagick, python36, python39, slurm, and webkit2gtk3), and Ubuntu (linux, linux-aws, linux-kvm, linux-lts-xenial and linux-gke-5.15).

Linus has released the 6.0 kernel as expected.

So, as is hopefully clear to everybody, the major version number change is more about me running out of fingers and toes than it is about any big fundamental changes.

But of course there's a lot of various changes in 6.0 - we've got over 15k non-merge commits in there in total, after all, and as such 6.0 is one of the bigger releases at least in numbers of commits in a while.

Headline features in 6.0 include a number of io_uring improvements including support for buffered writes to XFS filesystems and zero-copy network transmission, an io_uring-based block driver mechanism, the runtime verification subsystem, and much more; see the LWN merge-window summaries (part 1, part 2) for more information.

The results are in on the Debian project's general-resolution vote regarding non-free firmware in the installer image. The winning option allows the installer image to include firmware necessary to use the system:

We will include non-free firmware packages from the "non-free-firmware" section of the Debian archive on our official media (installer images and live images). The included firmware binaries will normally be enabled by default where the system determines that they are required, but where possible we will include ways for users to disable this at boot (boot menu option, kernel command line etc.).

The vote also changes the Debian Social Contract to make it clear that including non-free firmware in this manner is allowed.

Just over ten years ago, the Arm big.LITTLE architecture posed a challenge for the kernel's CPU scheduler: how should processes be assigned to CPUs when not all CPUs have the same capacity? The situation has not gotten simpler since then; new systems bring new quirks that must be kept in mind for optimal scheduling. At the 2022 Linux Plumbers Conference, Len Brown and Ricardo Neri talked about Intel's hybrid systems and the work that is being done to schedule properly on those systems.

Security updates have been issued by Debian (libsndfile and libvncserver), Fedora (bash), Red Hat (httpd24-httpd, java-1.7.1-ibm, and java-1.8.0-ibm), and SUSE (krb5-appl, libjpeg-turbo, python310, and slurm_20_02).

An important message from Damien Miller (djm@) turned up on mailing lists and elsewhere, saying,

From: Damien Miller <djm () mindrot ! org> Date: Wed, 28 Sep 2022 00:03:37 +0000 To: openssh-unix-dev Subject: Call for testing: openssh-9.1 Hi, OpenSSH 9.1p1 is almost ready for release, so we would appreciate testing on as many platforms and systems as possible. This is a bugfix release. Snapshot releases for portable OpenSSH are available from http://www.mindrot.org/openssh_snap/

You can read the whole message here or continue after the fold -

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