Linux Weekly News

The 5.7.4 stable kernel has been released. It contains a single fix for a problem introduced in the rework of the VDSO clock code that affects paravirtualized guests. Users should upgrade.

ESPHome is a project that brings together two recent subjects at LWN: The open-source smart hub Home Assistant, and the Espressif ESP8266 microcontroller. With this project, smart home devices can be created and integrated quickly — without needing to write a single line of code.

Version 4.3.0 of the Krita painting application is out. "There’s a whole new set of brush presets that evoke watercolor painting. There’s a color mode in the gradient map filter and a brand new palettize filter and a high pass filter. The scripting API has been extended. It’s now possible to adjust the opacity and lightness on colored brush tips separately. You can now create animated brush tips that select brush along multiple dimensions. We’ve made it possible to put the canvas area in a window of its own, so on a multi monitor setup, you can have all the controls on one monitor, and your images on the other. The color selector has had a big update. There’s a new snapshot docker that stores states of your image, and you can switch between those. There’s a brand new magnetic selection tool. Gradients can now be painting as spirals."

Security updates have been issued by Debian (drupal7 and python-django), Fedora (glib-networking, kernel, kernel-headers, and nghttp2), openSUSE (adns, chromium, file-roller, and libEMF), SUSE (java-1_7_1-ibm), and Ubuntu (bind9 and nss).

The LWN.net Weekly Edition for June 18, 2020 is available.

More and more web-site owners are concerned about the "all-seeing Google" tracking users as they browse around the web. Google Analytics (GA) is a full-featured web-analytics system that is available for free and, despite the privacy concerns, has become the de facto analytics tool for small and large web sites alike. However, in recent years, a growing number of alternatives are helping break Google's dominance. In this article we'll look at two of the lightweight open-source options, namely GoatCounter and Plausible. In a subsequent article, we'll look at a few of the larger tools.

Stable kernels 5.7.3, 5.6.19, and 5.4.47 have been released with important fixes throughout the tree. This is the last 5.6.y release and users should move to 5.7.y.

Arguments about terminology are not rare in our community; words are powerful tools, so we want to be sure that we are using them in the correct way. But, naturally, opinions on what is "correct" may (and do) differ. Discussions on the use of loaded terms like "master" and "slave" have been ongoing in the community for some time, but recent world events have given them a new urgency. Some projects have made changes in the past, but the current wave of changes seems likely to be far larger.

Security updates have been issued by Arch Linux (dbus and intel-ucode), CentOS (libexif), Debian (vlc), SUSE (xen), and Ubuntu (dbus, libexif, and nss).

Nikita Prokopov reviews Syncthing (a file-synchronization system) and, seemingly, rediscovers free software: "Syncthing is everything I used to love about computers. It’s amazing how great computer products can be when they don’t need to deal with corporate bullshit, don’t have to promote a brand or to sell its users. Frankly, I almost ceased to believe it’s still possible. But it is."

Open-source developers put a lot of emphasis on quality and have created many tools to improve source code, such as linters and code formatters. Documentation, on the other hand, doesn't receive the attention it deserves. LWN reviewed several grammar and style-checking tools back in 2016. It seems like a good time to evaluate progress in this area.

Security updates have been issued by Fedora (galera, grafana, libjcat, libvirt, mariadb-connector-c, and perl), Gentoo (asterisk, bubblewrap, cyrus-imapd, faad2, json-c, openconnect, openjdk-bin, pcre2, PEAR-Archive_Tar, thunderbird, and tomcat), Mageia (mbedtls and scapy), openSUSE (libntlm, libupnp, prboom-plus, varnish, and xen), Oracle (libexif), Red Hat (kpatch-patch), Scientific Linux (libexif), SUSE (mariadb, nodejs6, and poppler), and Ubuntu (apport).

The Internet of Things (IoT) world is filled with countless microprocessors. One option we have covered in various ways before is the Arduino ecosystem. In the same vein, we now will look at another interesting segment of that community: The WiFi-enabled Espressif ESP8266 chip.

Security updates have been issued by Debian (intel-microcode, libexif, mysql-connector-java, and thunderbird), Fedora (gnutls, grafana, kernel, kernel-headers, mingw-gnutls, mod_auth_openidc, NetworkManager, and pdns-recursor), Gentoo (adobe-flash, ansible, chromium, firefox, glibc, mailutils, nokogiri, readline, ssvnc, and webkit-gtk), Mageia (axel, bind, dbus, flash-player-plugin, libreoffice, networkmanager, and roundcubemail), openSUSE (java-1_8_0-openjdk, kernel, nodejs8, rubygem-bundler, texlive-filesystem, and thunderbird), Oracle (libexif and tomcat6), Red Hat (chromium-browser, flash-plugin, and libexif), Scientific Linux (tomcat6), SUSE (libEMF), and Ubuntu (fwupd).

By the time Linus Torvalds released 5.8-rc1 and closed the merge window for this development cycle, 14,206 non-merge changesets had been pulled into the repository for 5.8. That is more work than was pulled for the entire 5.7 cycle; clearly development work on the kernel has not (yet) slowed down in response to events in the wider world. The nearly 6,700 changes pulled since the previous summary include huge numbers of fixes and internal cleanups, but there were a number of significant features added as well.

Linus has released 5.8-rc1 and closed the merge window for this release. By the end, 14,206 non-merge changesets found their way into the mainline repository, making this one of the busiest development cycles ever. "So in the 5.8 merge window we have modified about 20% of all the files in the kernel source repository. That's really a fairly big percentage, and while some of it _is_ scripted, on the whole it's really just the same pattern: 5.8 has simply seen a lot of development. IOW, 5.8 looks big. Really big."

Over at TechNewsWorld, Jack M. Germain reviews the rather ... different ... distribution, PsychOS Linux. Just taking a peek at the home page may be enough to cause flashbacks to a misspent youth, or perhaps that of one's parents at this point. Bucking the trend for modern distributions, PsychOS is only built for 32-bit systems; the main focus seems to be DOS-oriented: "Retro comes alive in PsychOS and is the main driving point in its development. The distro creator still uses DOS software, which is launched easily from the applications menu via emulators such as DOSBox. Anyone with PsychOS 3.4.6 and higher who uses RetroGrab to install older software can do the same, noted the developer. The corresponding emulators must be installed first. PsychOS lets you run more than one DOS program at a time, too. Other programming influences include BASIC and BBC BASIC, due to shortcomings that helped the PsychOS developer learn more about Python. Other BASIC flavors are FreeBASIC, QB45, and QB64."

The bpfilter subsystem, along with its "user-mode blobs" infrastructure, attracted a lot of attention when it was merged for the 4.18 kernel in 2018. Since then, however, development in this effort has been, to put it charitably, subdued. Now, two years after its merging, bpfilter may be in danger of being removed from the kernel as a failed experiment.

Security updates have been issued by CentOS (tomcat), Debian (intel-microcode, libphp-phpmailer, mysql-connector-java, python-django, thunderbird, and xawtv), Fedora (kernel and thunderbird), Gentoo (perl), openSUSE (libexif and vim), Oracle (dotnet, kernel, microcode_ctl, and tomcat), Red Hat (net-snmp), Scientific Linux (libexif and tomcat), Slackware (kernel), and SUSE (adns, audiofile, ed, kvm, nodejs12, and xen).

Part 1 of this series, covered some background on ION, DMA-BUF heaps, the DMA API, and the concept of "ownership" when it comes to handling CPU-cache maintenance, finally ending on a conventional DMA API view of how DMA-BUF cache handling should be done. The article concluded with a discussion of why the traditional DMA APIs can perform poorly on contemporary systems. This article completes the series with an exploration of some of the approaches that DMA-BUF exporters can use to avoid unnecessary cache operations along with some rough proposals for how we might improve things.