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LWN.net is a comprehensive source of news and opinions from and about the Linux community. This is the main LWN.net feed, listing all articles which are posted to the site front page.
Updated: 44 min 7 sec ago

[$] Fixing getrandom()

Friday 27th of September 2019 03:39:54 PM
A report of a boot hang in the 5.3 series has led to an enormous, somewhat contentious thread on the linux-kernel mailing list. The proximate cause was some changes that made the ext4 filesystem do less I/O early in the boot phase, incidentally causing fewer interrupts, but the underlying issue was the getrandom() system call, which was blocking until the /dev/urandom pool was initialized—as designed. Since the system in question was not gathering enough entropy due to the lack of unpredictable interrupt timings, that would hang more or less forever. That has called into question the design and implementation of getrandom().

Security updates for Friday

Friday 27th of September 2019 01:25:01 PM
Security updates have been issued by Fedora (dcmtk), openSUSE (rust), Red Hat (redhat-virtualization-host), and SUSE (ghostscript, nghttp2, and u-boot).

[$] Upstreaming multipath TCP

Thursday 26th of September 2019 03:38:27 PM
The multipath TCP (MPTCP) protocol (and the Linux implementation of it) have been under development for a solid decade; MPTCP offers a number of advantages for devices that have more than one network interface available. Despite having been deployed widely, though, MPTCP is still not supported by the upstream Linux kernel. At the 2019 Linux Plumbers Conference, Matthieu Baerts and Mat Martineau discussed the current state of the Linux MPTCP implementation and what will be required to get it into the mainline kernel.

Security updates for Thursday

Thursday 26th of September 2019 02:32:54 PM
Security updates have been issued by CentOS (dovecot), Debian (lemonldap-ng, openssl, and ruby-nokogiri), openSUSE (fish3, ibus, nmap, and openssl-1_1), Slackware (mozilla), SUSE (mariadb, python-numpy, and SDL2), and Ubuntu (firefox).

[$] LWN.net Weekly Edition for September 26, 2019

Thursday 26th of September 2019 01:58:16 AM
The LWN.net Weekly Edition for September 26, 2019 is available.

[$] Monitoring the internal kernel ABI

Wednesday 25th of September 2019 04:23:52 PM
As part of the Distribution Kernels microconference at Linux Plumbers Conference 2019, Matthias Männich described how the Android project monitors changes to the internal kernel ABI. As Android kernels evolve, typically by adding features and bug fixes from more recent kernel versions, the project wants to ensure that the ABI remains the same so that out-of-tree modules will still function. While the talk was somewhat Android-specific, the techniques and tools used could be applied to other distributions with similar needs (e.g. enterprise distributions).

Security updates for Wednesday

Wednesday 25th of September 2019 03:12:23 PM
Security updates have been issued by Debian (kernel, libgcrypt20, and spip), Fedora (compat-openssl10, expat, ghostscript, ibus, java-1.8.0-openjdk-aarch32, and SDL2_image), openSUSE (bird, chromium, kernel, libreoffice, links, and varnish), Oracle (httpd:2.4 and qemu-kvm), Red Hat (kernel), Scientific Linux (qemu-kvm), SUSE (djvulibre, dovecot22, ghostscript, kernel, libxml2, and python-Twisted), and Ubuntu (file-roller and libreoffice).

A patent lawsuit against GNOME

Wednesday 25th of September 2019 02:47:08 PM
A company called Rothschild Patent Imaging LLC has filed a lawsuit [PDF] against the GNOME Foundation, alleging that the Shotwell photo manager violates patent 9,936,086. Stay tuned, more details will surely emerge.

Google Code‑in 2019

Tuesday 24th of September 2019 08:34:37 PM
Google Code-in (GCI) provides students ages 13 to 17 the opportunity to participate in open source projects. Google has announced the 2019 round of GCI. "New contributors bring fresh perspectives, ideas, and enthusiasm into their open source communities, helping them thrive. Throughout the last 9 years, 58 GCI organizations helped 11,000 students from 108 countries make real contributions to open source projects; and to this day many of those students continue to participate in various open source communities and many have become mentors themselves! Some have even gone on to join Google Summer of Code (GSoC)." Organizations that are interested in mentoring students can apply for GCI starting October 10. GCI begins December 2, 2019 and ends January 23, 2020.

Release for CentOS Linux 8 and CentOS Streams

Tuesday 24th of September 2019 05:40:53 PM
CentOS Linux 8.0-1905 has been released. The release notes have more details. The CentOS project also introduces CentOS Stream. "CentOS Stream is a rolling-release Linux distro that exists as a midstream between the upstream development in Fedora Linux and the downstream development for Red Hat Enterprise Linux (RHEL). It is a cleared-path to contributing into future minor releases of RHEL while interacting with Red Hat and other open source developers. This pairs nicely with the existing contribution path in Fedora for future major releases of RHEL."

[$] Better guidance for database developers

Tuesday 24th of September 2019 05:05:24 PM
At the inaugural Databases microconference at the 2019 Linux Plumbers Conference (LPC), two developers who work on rather different database systems had similar complaints about developing for Linux. Richard Hipp, creator of the SQLite database, and Andres Freund from the PostgreSQL project both lamented the lack of definitive documentation on how to best use the kernel's I/O interfaces, especially for corner cases. Both of the sessions, along with others in the microconference, pointed to a strong need for more interaction between user-space and kernel developers.

Security updates for Tuesday

Tuesday 24th of September 2019 02:42:25 PM
Security updates have been issued by Debian (php5), Fedora (blis, kernel, and kernel-headers), openSUSE (bird, curl, fish3, ghostscript, ibus, kernel, libgcrypt, openldap2, openssl-1_1, skopeo, and util-linux and shadow), Oracle (dovecot and kernel), Red Hat (dovecot, httpd:2.4, qemu-kvm, and redhat-virtualization-host), Scientific Linux (dovecot), SUSE (djvulibre, expat, firefox, libopenmpt, and rust), and Ubuntu (ibus and Mosquitto).

[$] 5.4 Merge window, part 1

Monday 23rd of September 2019 03:52:43 PM
As of this writing, 9,632 non-merge changesets have been merged for the 5.4 kernel. This merge window is thus off to a strong start. There has been a wide range of changes merged across the kernel tree, including vast numbers of cleanups and fixes.

Security updates for Monday

Monday 23rd of September 2019 02:48:55 PM
Security updates have been issued by Debian (expat, php-pecl-http, and php7.0), Fedora (ImageMagick, jackson-annotations, jackson-bom, jackson-core, jackson-databind, and rubygem-rmagick), Mageia (chromium-browser-stable, ibus, kernel, samba, and thunderbird), openSUSE (chromium), Oracle (dovecot and kernel), Red Hat (dbus, kernel, kernel-alt, and kpatch-patch), Scientific Linux (dovecot and kernel), and SUSE (expat, ibus, kernel, kernel-source-rt, nmap, openssl, and webkit2gtk3).

Stable kernels for the weekend

Saturday 21st of September 2019 09:03:21 PM
The 5.3.1, 5.2.17, 4.19.75, 4.14.146, 4.9.194, and 4.4.194 stable kernels are all available; each contains another set of important fixes.

LLVM 9.0.0 released

Saturday 21st of September 2019 07:44:48 PM
Version 9.0.0 of the LLVM compiler suite is out. Headline changes include asm goto support — fixing one of the main impediments to compiling the kernel on x86 with LLVM — and non-experimental support for the RISC-V architecture.

[$] Many uses for Core scheduling

Friday 20th of September 2019 07:23:06 PM
Some new kernel features are welcomed by the kernel development community, while others are a rather harder sell. It is fair to say that core scheduling, which makes CPU scheduling harder by placing constraints on which processes may run simultaneously in a core, is of the latter variety. Core scheduling was the topic of (at least) three different sessions at the 2019 Linux Plumbers Conference. One of the most interesting outcomes, perhaps, is that there are use cases for this feature beyond protection from side-channel attacks.

Security updates for Friday

Friday 20th of September 2019 03:07:22 PM
Security updates have been issued by Debian (bird, opendmarc, php7.3, and qemu), Fedora (bird, dino, nbdkit, and openconnect), Oracle (nginx:1.14, patch, and thunderbird), Red Hat (dovecot, kernel, kernel-alt, and kernel-rt), Scientific Linux (thunderbird), and SUSE (kernel, openssl, openssl-1_1, python-SQLAlchemy, and python-Werkzeug).

[$] System-call wrappers for glibc

Thursday 19th of September 2019 03:42:39 PM
The GNU C Library has long had a reputation for being hostile to the addition of wrappers for new Linux system calls; that has resulted in many system calls being unsupported by the library for years. That situation is changing, though. During the Toolchain microconference at the 2019 Linux Plumbers Conference, Maciej Rozycki talked about glibc's new attitude toward system-call wrappers, but also served notice that there is still significant work to do for the addition of any new system call.

Stable kernels 5.2.16, 4.19.74, and 4.14.145

Thursday 19th of September 2019 02:39:50 PM
Greg Kroah-Hartman has announced the release of the 5.2.16, 4.19.74, and 4.14.145 stable kernels. Important fixes are contained within; users should upgrade.

More in Tux Machines

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Python Programming Leftovers

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  • Daudin – a Python shell

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  • How to Convert Python String to Int and Back to String

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  • Thousands of Scientific Papers May be Invalid Due to Misunderstanding Python

    It was recently discovered that several thousand scientific articles could be invalid in their conclusions because scientists did not understand that Python’s glob.glob() does not return sorted results. This is being reported on by Vice, Slashdot and there’s an interesting discussion going on over on Reddit as well.

Audiocasts/Shows/Screencasts: Open Source Security Podcast, Linux Action News and Manjaro 19.09.28 KDE-DEV Run Through

  • Open Source Security Podcast: Episode 165 - Grab Bag of Microsoft Security News

    Josh and Kurt about a number of Microsoft security news items. They've changed how they are handling encrypted disks and are now forcing cloud logins on Windows users.

  • Linux Action News 127

    Richard Stallman's GNU leadership is challenged by an influential group of maintainers, SUSE drops OpenStack "for the customer," and Google claims Stadia will be faster than a gaming PC. Plus OpenLibra aims to save us from Facebook but already has a miss, lousy news for Telegram, and enormous changes for AMP.

  • GNU World Order 13x42

    On the road during the **All Things Open** conference, Klaatu talks about how to make ebooks from various sources, with custom CSS, using the Pandoc command.

  • Manjaro 19.09.28 KDE-DEV Run Through

    In this video, we are looking at Manjaro 19.09.28 KDE-DEV.

Apple of 2019 is the Linux of 2000

Last week the laptop I use for macOS development said that there is an XCode update available. I tried to install it but it said that there is not enough free space available to run the installer. So I deleted a bunch of files and tried again. Still the same complaint. Then I deleted some unused VM images. Those would free a few dozen gigabytes, so it should make things work. I even emptied the trash can to make sure nothing lingered around. But even this did not help, I still got the same complaint. At this point it was time to get serious and launch the terminal. And, true enough, according to df the disk had only 8 gigabytes of free space even though I had just deleted over 40 gigabytes of files from it (using rm, not the GUI, so things really should have been gone). A lot of googling and poking later I discovered that all the deleted files had gone to "reserved space" on the file system. There was no way to access those files or delete them. According to documentation the operating system would delete those files "on demand as more space is needed". This was not very comforting because the system most definitely was not doing that and you'd think that Apple's own software would get this right. After a ton more googling I managed to find a chat buried somewhere deep in Reddit which listed the magical indentation that purges reserved space. It consisted of running tmutil from the command line and giving it a bunch of command line arguments that did not seem to make sense or have any correlation to the thing that I wanted to do. But it did work and eventually I got XCode updated. After my blood pressure dropped to healthier levels I got the strangest feeling of déjà vu. This felt exactly like using Linux in the early 2000s. Things break at random for reasons you can't understand and the only way to fix it is to find terminal commands from discussion forums, type them in and hope for the best. Then it hit me. Read more