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The LWN.net Weekly Edition for September 16, 2021 is available.

Back in January 2020, we looked at someoddities in Python's handling of Not a Number (NaN) values inits statisticsmodule. The conversation went quiet after that, but it has beenrevived recently with an eye toward fixing the problems that were reported.As detailed in that earlier article, NaNs are rather strange beasts in thefloating-point universe, so figuring out how best to deal with theirpresence is less straightforward than it might seem.

Stable kernels 5.14.4, 5.13.17, 5.10.65, and 5.4.146 have been released. There areimportant fixes throughout the tree and users should upgrade.

Security updates have been issued by Arch Linux (chromium, element-desktop, element-web, firefox, ghostscript, and hedgedoc), Fedora (kernel and openssl), openSUSE (ghostscript, htmldoc, and openssl-1_0_0), Oracle (libtirpc), Red Hat (cyrus-imapd, kernel, and kernel-rt), SUSE (ghostscript), and Ubuntu (apport, curl, and squashfs-tools).

The Roundup Issue Trackeris a flexible tool for managing issues via the web oremail. However, Roundup is useful for more thanweb-based bug tracking or help-desk ticketing; it can be used as a simple wiki or to manage taskswith the Getting ThingsDone (GTD) methodology. The 20th-anniversaryedition ofRoundup,version 2.1.0, wasreleased in July; it is a maintenance release, but there have been a numberof larger improvements in the last year or so. Here we introduce Roundup'sfeatures along with therecent developments that have helped make Roundup even more useful for trackingissues to their resolution.

Security updates have been issued by openSUSE (libaom and nextcloud), Oracle (cyrus-imapd, firefox, and thunderbird), Red Hat (kernel and kpatch-patch), Scientific Linux (firefox and thunderbird), and Ubuntu (apport).

Thisrelease on PostgreSQL.org describes an ongoing disagreement over thePostgreSQL trademark:

Linus Torvalds released 5.15-rc1 and closedthe merge window for this release on September 12; at that point, 10,471 non-mergechangesets had found their way into the mainline repository. Thosechangesets contain a lot of significant changes and improvements. Read onfor a summary of what came into the mainline in the roughly 7,000changesets pulled since our first-halfsummary was written.

Security updates have been issued by Debian (qemu and thunderbird), Fedora (chromium, firefox, and mosquitto), openSUSE (apache2-mod_auth_openidc, gifsicle, openssl-1_1, php7-pear, and wireshark), Oracle (oswatcher), Red Hat (cyrus-imapd, firefox, and thunderbird), SUSE (apache2-mod_auth_openidc, compat-openssl098, php7-pear, and wireshark), and Ubuntu (git and linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-hwe, linux-kvm, linux-oracle, linux-snapdragon).

Version 11.1 of the GDB debugger is out. There are a number of newfeatures, and somebody will surely be disappointed to see that support fordebugging Arm Symbian programs has been removed.

Linus has released 5.15-rc1 and closed themerge window for this development cycle.

The5.14.3,5.13.16,5.10.64, and5.4.145stable kernel updates have been released; each contains another set ofimportant fixes.

The Linux Foundation has announced that Software Package Data Exchange (SPDX) has become an international standard (ISO/IEC 5962:2021). SPDX has been used in the kernel and other projects to identify the licenses and attach other metadata to software components.

When we last caught up with the page folio patch set, it appeared to be ontrack to be pulled into the mainline during the 5.15 merge window. MatthewWilcox duly sent a pullrequest in August to make that happen. While it is possible thatfolios could still end up in 5.15, that has not happened as of this writingand appears increasingly unlikely. What we got instead was a lengthydiscussion on the merits of the folio approach.

Security updates have been issued by Debian (firefox-esr, ghostscript, ntfs-3g, and postorius), Fedora (java-1.8.0-openjdk-aarch32, libtpms, and salt), openSUSE (libaom, libtpms, and openssl-1_0_0), Red Hat (openstack-neutron), SUSE (grilo, java-1_7_0-openjdk, libaom, libtpms, mariadb, openssl-1_0_0, openssl-1_1, and php74-pear), and Ubuntu (firefox and ghostscript).

This blog post byLoris Cro makes the claim that the Ziglanguage isthe solution to a lot of low-level programming problems:

The Linux extended-attribute mechanism allows the attachment of metadata tofiles within a filesystem. It tends to be little used — at least, in theabsence of a security module like SELinux. There is interest in how theseattributes work, though, as evidenced by the discussions that havefollowed the posting of revisions of thispatch by Vivek Goyal, which seeks to make a seemingly small change tothe rules regarding extended attributes and special files.

The Open Source Initiative has announced theappointment of Stefano Maffulli as its executive director."'Bringing Stefano Maffulli on board as OSI’s first ExecutiveDirector is the culmination of a years-long march towardprofessionalization, so that OSI can be a stronger and more responsiveadvocate for open source,' says Joshua Simmons, Board Chair of OSI."

Security updates have been issued by Fedora (lynx, matrix-synapse, and proftpd), openSUSE (ntfs-3g_ntfsprogs), Oracle (kernel), Red Hat (RHV-H), Scientific Linux (kernel), and Ubuntu (libapache2-mod-auth-mellon, linux, linux-aws, linux-aws-5.11, linux-azure, linux-azure-5.11, linux-gcp, linux-hwe-5.11, linux-kvm, linux-oracle, linux-oracle-5.11, linux-raspi, linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, and linux-azure-5.8, linux-oem-5.10).

The LWN.net Weekly Edition for September 9, 2021 is available.

Two recent threads on the python-ideas mailing list have overlapped to acertain extent; both referred to Python's style guide, but the discussionindicates that the advice in it may have been stretched further than intended. PEP 8("Style Guide for Python Code") is the longstanding set ofguidelines and suggestions for code that is going into the standardlibrary, but the "rules" in the PEP have been applied in settings and tools well outside of thatrealm. There may be reasons to update the PEP—some unrelated work of that nature isongoing, in fact—but Pythonistas need to remember that the suggestions init are not carved in stone.

Stable kernels 5.14.2, 5.13.15, and 5.10.63 have been released. As usual, thereare important fixes and users should upgrade.

Security updates have been issued by Debian (haproxy), Fedora (libguestfs, ntfs-3g, ntfs-3g-system-compression, partclone, testdisk, vim, and wimlib), Mageia (kernel and kernel-linus), openSUSE (haproxy), Oracle (kernel), Red Hat (kernel, kernel-rt, and kpatch-patch), SUSE (haproxy), and Ubuntu (cpio, haproxy, libapache2-mod-auth-mellon, libgd2, linux, linux-aws, linux-kvm, linux-lts-xenial, openvswitch, python-pysaml2, and sssd).

Firefox 92.0 has been released. Inthis version Firefox can now automatically upgrade to HTTPS using HTTPS RRas Alt-Svc headers, support full-range color levels for video playback onmany systems, and more.Firefox78.14.0 ESR and Firefox91.1.0 have also been released. ESR78 will reach end-of-life inNovember.

Amateur ("ham") radio operators have been experimenting with ways to usecomputers in their hobby since PCs became widely available—perhaps evenbefore then. While manypeople picture hams either talking into a microphone or tapping a telegraphkey, many hams now type on a keyboard or even click buttons on a computer screen to makecontacts. Even hams who still prefer to talk or use Morse code may stilluse computers for some things, such as logging contacts or predictingradio conditions. While most hams use Windows, there is no shortage of hamradio software for Linux.

Security updates have been issued by openSUSE (apache2, java-11-openjdk, libesmtp, nodejs10, ntfs-3g_ntfsprogs, openssl-1_1, xen, and xerces-c), Red Hat (kernel-rt and kpatch-patch), and SUSE (ntfs-3g_ntfsprogs and openssl-1_1).

Version 3.0 of the OpenSSL TLS library has been released; the largeversion-number jump (from 1.1.1) reflects a new versioning scheme.

The linux.conf.au organizers have put out a second, extended call forproposals for the 2022 event, which will be held online startingJanuary 14.

Once upon a time, block storage devices were slow, to the point that theyoften limited the speed of the system as a whole. A great deal of effortwent into carefully ordering requests to get the best performance out ofthe storage device; achieving that goal was well worth expending some CPUtime. But then storage devices got much faster and the equation changed.Fancy I/O-scheduling mechanisms have fallen by the wayside and effort is nowfocused on optimizing code so that the CPU can keep up with its storage. Ablock-layer change that was merged for the 5.15 kernel shows the kinds oftradeoffs that must be made to get the best performance from current hardware.

Security updates have been issued by Debian (btrbk, pywps, and squashfs-tools), Fedora (libguestfs, libss7, ntfs-3g, ntfs-3g-system-compression, partclone, testdisk, wimlib, and xen), Mageia (exiv2, golang, libspf2, and ruby-addressable), openSUSE (apache2, dovecot23, gstreamer-plugins-good, java-11-openjdk, libesmtp, mariadb, nodejs10, opera, python39, sssd, and xerces-c), and SUSE (apache2, java-11-openjdk, libesmtp, mariadb, nodejs10, python39, sssd, xen, and xerces-c).

Version 21.02.0 of the OpenWrt router distribution is out. "Itincorporates over 5800 commits since branching the previous OpenWrt 19.07release and has been under development for about one and a halfyear". Significant changes include WPA3 support by default, TLSsupport in opkg and in the LuCi interface, initial DistributedSwitch Architecture support, new hardware support, and more. See the releasenotes for more information.

Computing terminology can be counterintuitive at times, but even alongtime participant in the industry may have to look twice at the notionof named anonymous memory. That, however, is just the concept that thispatch set posted by Suren Baghdasaryan proposes to add. There are, itseems, developers who find the idea useful enough to not only overcome theinitial cognitive dissonance that comes with it, but also to resurrect aneight-year-old patch to get it into the kernel.

Greg Kroah-Hartman has announced the release of the 5.14.1, 5.13.14, 5.10.62, 5.4.144, 4.19.206, 4.14.246, 4.9.282, and 4.4.283 stable kernels. As usual, these updatescontain important fixes; users of those series should upgrade.

Security updates have been issued by Debian (qemu), Fedora (condor, grilo, libopenmpt, opencryptoki, and php), openSUSE (xen), and SUSE (ffmpeg, file, php72, rubygem-addressable, and xen).

As of this writing, 3,440 non-merge changesets have been pulled into themainline repository for the 5.15 development cycle. A mere 3,440 patchesmay seem like a slow start, but those patches are densely populated withsignificant new features. Read on for a look at what the first part of the5.15 merge window has brought.

On the ADA Logics blog, David Korczynski and Adam Korczynski write about their work integrating 115 open-source projects with Google's OSS-Fuzz project for doing continuous fuzz testing. They describe the process of integrating a project into OSS-Fuzz, and discuss their findings, which include more than 2000 bugs (500+ security relevant), of which 1300+ have been fixed at this point:

Security updates have been issued by openSUSE (ffmpeg and gstreamer-plugins-good), SUSE (apache2, apache2-mod_auth_mellon, ffmpeg, gstreamer-plugins-good, libesmtp, openexr, rubygem-puma, xen, and xerces-c), and Ubuntu (openssl).

The LWN.net Weekly Edition for September 2, 2021 is available.

Discussions on ways to "modernize" the Emacs editor have come up in various guises over the past fewyears. Changes of that nature tend to be somewhat contentious in the Emacscommunity, pitting the "old guard" that values the existing features (andkeybindings) against those who argue for changes to make Emacs moreapproachable (and aesthetically pleasing) to newcomers. Those discussionstend toward mega-thread status, so it should be no surprise that a queryabout possibly moving Emacs development to a "forge" (e.g. GitHub or GitLab) gotsimilar treatment. As always in Emacs-land, there are multiple facets tothe discussion, including the desirability of moving away from anemail-based workflow, accommodating younger, forge-centric developerswithout forcing existing developers into that model, and—naturally—licensing.

Security updates have been issued by CentOS (bind, GNOME, hivex, kernel, and sssd), Debian (gpac and squashfs-tools), Fedora (c-ares and openssl), openSUSE (dovecot23), Oracle (bind, hivex, kernel, and sssd), Red Hat (kernel), Scientific Linux (bind, hivex, kernel, libsndfile, libX11, and sssd), Slackware (ntfs), SUSE (dovecot23), and Ubuntu (ntfs-3g).

The Free Software Foundation (FSF) clarifiesthe purpose of its copyright policies and examines the impact ofpotential alternatives.

A longstanding tug-of-war between system package managers and Python's owninstallation mechanisms (primarily pip, but there are others) lookson its way to being resolved—or at least regularized. PEP 668("Graceful cooperation between external and Python packagemanagers") has been created to provide ways for the two types of package installationtowork together, rather than at cross-purposes at times.Since many operating systems depend on Python tools, with package versionsthat may differ from those of users' Python applications, making them play togethernicely should result in more stable systems.

The 5.15 merge window is off to a fast start; stay tuned for our usual fullsummary. It is worth mentioning, though, that the realtime preemptionlocking code has been pulled into themainline with little fanfare. This work began in 2004 and has fundamentallychanged many parts of the core kernel. With this pull, the sleepable locksthat make deterministic realtime response possible have finally joined allof that other work (though the kernel must be built with theREALTIME configuration option to use them).Congratulations are due to all of the realtime developers who pushed thisproject forward for nearly two decades.

Security updates have been issued by CentOS (libsndfile and libX11), Debian (ledgersmb, libssh, and postgresql-9.6), Fedora (squashfs-tools), openSUSE (389-ds, nodejs12, php7, spectre-meltdown-checker, and thunderbird), Oracle (kernel, libsndfile, and libX11), Red Hat (bind, cloud-init, edk2, glibc, hivex, kernel, kernel-rt, kpatch-patch, microcode_ctl, python3, and sssd), SUSE (bind, mysql-connector-java, nodejs12, sssd, and thunderbird), and Ubuntu (apr, squashfs-tools, thunderbird, and uwsgi).

The 5.14 kernel was released on August 29after a nine-week development period. This cycle was not as active as its predecessor, whichset a record for the number of developers involved, but there was still alot going on and a number of long-awaited features were merged. Now thatthe release is out, the time has come for our traditional look at where the code in 5.14 came from and how it got there.

Security updates have been issued by Debian (exiv2, grilo, gthumb, and redis), Fedora (krb5, nbdkit, and rubygem-addressable), Mageia (libass and opencontainers-runc), openSUSE (cacti, cacti-spine, go1.15, opera, qemu, and spectre-meltdown-checker), Red Hat (java-1.7.1-ibm, java-1.8.0-ibm, libsndfile, and libX11), SUSE (389-ds, qemu, and spectre-meltdown-checker), and Ubuntu (grilo).

Linus has released the 5.14 kernel.

The Linux kernel is a fast-moving project, but change can still besurprisingly slow to come at times. The nftables project to replace the kernel'spacket-filtering subsystem has its origins in 2008, but is still not beingused by most (or perhaps even many) production firewalls. The transitionmay be getting closer, though, as highlighted by the release of nftables 1.0.0 onAugust 19.

Security updates have been issued by Fedora (haproxy and libopenmpt), openSUSE (aws-cli, python-boto3, python-botocore,, dbus-1, and qemu), Oracle (rh-postgresql10-postgresql), Red Hat (compat-exiv2-023, compat-exiv2-026, exiv2, libsndfile, microcode_ctl, python27, rh-nodejs12-nodejs and rh-nodejs12-nodejs-nodemon, rh-nodejs14-nodejs and rh-nodejs14-nodejs-nodemon, and rh-python38), Scientific Linux (compat-exiv2-023 and compat-exiv2-026), SUSE (compat-openssl098), and Ubuntu (libssh, openssl, and openssl1.0).

As a general rule, the kernel community is happy to merge working devicedrivers without much concern for the availability of any associateduser-space code. What happens in user space is beyond the kernel's concernand unaffected by the kernel's license. There is an exception, though, inthe form of drivers for graphical processors (GPUs), which cannot be mergedin the absence of a working, freely-licensed user-space component. Thequestion of which drivers are subject to that rule has come up a few timesin recent years; that discussion has now come to a decision point with aneffort to block someHabana Labs driver updates from entry into the 5.15 kernel.