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Escuelas Linux Celebrates 20th Anniversary with Major Release, Here's What's New

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Linux

Continuing the Edubuntu legacy of delivering Linux-based operating systems and Open Source software projects to schools and other educational institutions around the world, Escuelas Linux 6 has been released earlier this month with major improvements and new features. The biggest highlights of this release being the availability of dedicated English language ISO images for non-Spanish users.

"Escuelas Linux 6 as a massive amount of improvements, but one of them is key around Softpedia," said Alejandro Díaz. "And, at this point came your help, that above improvement would not be worth the effort if English language people are not aware of our existence. In fact, we recognize that most downloads from non-Spanish language countries are due to your nice articles about us."

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LWN's Latest (Today Outside Paywall) Articles About the Kernel, Linux

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Linux
  • Toward better handling of hardware vulnerabilities

    From the kernel development community's point of view, hardware vulnerabilities are not much different from the software variety: either way, there is a bug that must be fixed in software. But hardware vendors tend to take a different view of things. This divergence has been reflected in the response to vulnerabilities like Meltdown and Spectre which was seen by many as being severely mismanaged. A recent discussion on the Kernel Summit discussion list has shed some more light on how things went wrong, and what the development community would like to see happen when the next hardware vulnerability comes around.

    The definitive story of the response to Meltdown and Spectre has not yet been written, but a fair amount of information has shown up in bits and pieces. Intel was first notified of the problem in July 2017, but didn't get around to telling anybody in the the Linux community about it until the end of October. When that disclosure happened, Intel did not allow the community to work together to fix it; instead each distributor (or other vendor) was mostly left on its own and not allowed to talk to the others. Only at the end of December, right before the disclosure (and the year-end holidays), were members of the community allowed to talk to each other.

    The results of this approach were many, and few were good. The developers charged with responding to these problems were isolated and under heavy stress for two months; they still have not been adequately thanked for the effort they put in. Many important stakeholders, including distributions like Debian and the "tier-two" cloud providers, were not informed at all prior to the general disclosure and found themselves scrambling. Different distributors shipped different fixes, many of which had to be massively revised before entry into the mainline kernel. When the dust settled, there was a lot of anger left simmering in its wake.

  • Writing network flow dissectors in BPF

    Network packet headers contain a great deal of information, but the kernel often only needs a subset of that information to be able to perform filtering or associate any given packet with a flow. The piece of code that follows the different layers of packet encapsulation to find the important data is called a flow dissector. In current Linux kernels, the flow dissector is written in C. A patch set has been proposed recently to implement it in BPF with the clear goal of improving security, flexibility, and maybe even performance.

  • Coscheduling: simultaneous scheduling in control groups

    The kernel's CPU scheduler must, as its primary task, determine which process should be executing in each of a system's processors at any given time. Making an optimal decision involves juggling a number of factors, including the priority (and scheduling classes) of the runnable processes, NUMA locality, cache locality, latency minimization, control-group policies, power management, overall fairness, and more. One might think that throwing another variable into the mix — and a complex one at that — would not be something anybody would want to attempt. The recent coscheduling patch set from Jan Schönherr does exactly that, though, by introducing the concept of processes that should be run simultaneously.

    The core idea behind coscheduling is the marking of one or more control groups as containing processes that should be run together. If one process in a coscheduled group is running on a specific set of CPUs (more on that below), only processes from that group will be allowed to run on those CPUs. This rule holds even to the point of forcing some of the CPUs to go idle if the given control group lacks runnable processes, regardless of whether processes outside the group are runnable.

    Why might one want to do such a thing? Schönherr lists four motivations for this work, the first of which is virtualization. That may indeed be the primary motivation, given that Schönherr is posting from an Amazon address, and Amazon is rumored to be running a virtualized workload or two. A virtual machine usually contains multiple processes that interact with each other; these machines will run more efficiently (and with lower latencies) if those processes can run simultaneously. Coscheduling would ensure that all of a virtual machine's processes are run together, maximizing locality and minimizing the latencies of the interactions between them.

  • Machine learning and stable kernels

    There are ways to get fixes into the stable kernel trees, but they require humans to identify which patches should go there. Sasha Levin and Julia Lawall have taken a different approach: use machine learning to distinguish patches that fix bugs from others. That way, all bug-fix patches could potentially make their way into the stable kernels. Levin and Lawall gave a talk describing their work at the 2018 Open Source Summit North America in Vancouver, Canada.

    Levin began with a quick introduction to the stable tree and how patches get into it. When a developer fixes a bug in a patch they can add a "stable tag" to the commit or send a mail to the stable mailing list; Greg Kroah-Hartman will then pick up the fix, evaluate it, and add it to the stable tree. But that means that the stable tree is only getting the fixes that are pointed out to the stable maintainers. No one has time to check all of the commits to the kernel for bug fixes but, in an ideal world, all of the bug fixes would go into the stable kernels. Missing out on some fixes means that the stable trees will have more security vulnerabilities because the fixes often close those holes—even if the fixer doesn't realize it.

  • Trying to get STACKLEAK into the kernel

    The STACKLEAK kernel security feature has been in the works for quite some time now, but has not, as yet, made its way into the mainline. That is not for lack of trying, as Alexander Popov has posted 15 separate versions of the patch set since May 2017. He described STACKLEAK and its tortuous path toward the mainline in a talk [YouTube video] at the 2018 Linux Security Summit.

    STACKLEAK is "an awesome security feature" that was originally developed by The PaX Team as part of the PaX/grsecurity patches. The last public version of the patch set was released in April 2017 for the 4.9 kernel. Popov set himself on the goal of getting STACKLEAK into the kernel shortly after that; he thanked both his employer (Positive Technologies) and his family for giving him working and free time to push STACKLEAK.

    The first step was to extract STACKLEAK from the more than 200K lines of code in the grsecurity/PaX patch set. He then "carefully learned" about the patch and what it does "bit by bit". He followed the usual path: post the patch, get feedback, update the patch based on the feedback, and then post it again. He has posted 15 versions and "it is still in progress", he said.

WireGuard Picks Up A Simpler Kconfig, Zinc Crypto Performance Fix

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Linux
Security

WireGuard lead developer Jason Donenfeld sent out the fifth revision of the WireGuard and Zinc crypto library patches this week. They've been coming in frequently with a lot of changes with it looking like this "secure VPN tunnel" could reach the Linux 4.20~5.0 kernel.

With the WireGuard v5 patches there are various low-level code improvements, a "saner" and simpler Kconfig build-time configuration options, a performance regression for tcrypt within the Zinc crypto code has been fixed and is now even faster than before, and there is also now a nosimd module parameter to disable the use of SIMD instructions.

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Variscite’s latest DART module taps headless i.MX6 ULZ

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Linux

Variscite is prepping a headless version of its Linux-friendly DART-6UL module with NXP’s new i.MX6 ULZ SoC, a cheaper version of the i.MX6 UL without display or Ethernet features.

Variscite is spinning out yet another pin-compatible version of its 50 x 25mm DART-6UL computer-on-module, this time loaded with NXP’s headless new i.MX6 ULZ variant of the single Cortex-A7 core i.MX6 UL. Due for a Q4 launch, the unnamed module lacks display or LAN support. It’s billed as “a native solution for headless Linux-based embedded products such as IoT devices and smart home sensors requiring low power, low size, and rich connectivity options.”

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Stable kernels 4.18.9, 4.14.71, 4.9.128 and 4.4.157

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Linux

Kernel: Virtme, 2018 Linux Audio Miniconference and Linux Foundation Articles

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Linux
  • Virtme: The kernel developers' best friend

    When working on the Linux Kernel, testing via QEMU is pretty common. Many virtual drivers have been recently merged, useful either to test the kernel core code, or your application. These virtual drivers make QEMU even more attractive.

  • 2018 Linux Audio Miniconference

    As in previous years we’re trying to organize an audio miniconference so we can get together and talk through issues, especially design decisons, face to face. This year’s event will be held on Sunday October 21st in Edinburgh, the day before ELC Europe starts there.

  • How Writing Can Expand Your Skills and Grow Your Career [Ed: Linux Foundation article]

    At the recent Open Source Summit in Vancouver, I participated in a panel discussion called How Writing can Change Your Career for the Better (Even if You don't Identify as a Writer. The panel was moderated by Rikki Endsley, Community Manager and Editor for Opensource.com, and it included VM (Vicky) Brasseur, Open Source Strategy Consultant; Alex Williams, Founder, Editor in Chief, The New Stack; and Dawn Foster, Consultant, The Scale Factory.

  • At the Crossroads of Open Source and Open Standards [Ed: Another Linux Foundation article]

    A new crop of high-value open source software projects stands ready to make a big impact in enterprise production, but structural issues like governance, IPR, and long-term maintenance plague OSS communities at every turn. Meanwhile, facing significant pressures from open source software and the industry groups that support them, standards development organizations are fighting harder than ever to retain members and publish innovative standards. What can these two vastly different philosophies learn from each other, and can they do it in time to ensure they remain relevant for the next 10 years?

BlackArch Linux Ethical Hacking OS Now Has More Than 2000 Hacking Tools

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GNU
Linux
Security

The BlackArch Linux penetration testing and ethical hacking computer operating system now has more than 2000 tools in its repositories, announced the project's developers recently.

Used by thousands of hundreds of hackers and security researchers all over the world, BlackArch Linux is one of the most acclaimed Linux-based operating systems for hacking and other security-related tasks. It has its own software repositories that contain thousands of tools.

The OS is based on the famous Arch Linux operating system and follows a rolling release model, where users install once and receive updates forever, or at least until they do something that can't be repaired and need to reinstall.

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Moving Compiler Dependency Checks to Kconfig

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Development
Linux

One reason became clear recently when Linus Torvalds asked developers to add an entirely new system of dependency checks to the Kconfig language, specifically testing the capabilities of the GCC compiler.

It's actually an important issue. The Linux kernel wants to support as many versions of GCC as possible—so long as doing so would not require too much insanity in the kernel code itself—but different versions of GCC support different features. The GCC developers always are tweaking and adjusting, and GCC releases also sometimes have bugs that need to be worked around. Some Linux kernel features can only be built using one version of the compiler or another. And, some features build better or faster if they can take advantage of various GCC features that exist only in certain versions.

Up until this year, the kernel build system has had to check all those compiler features by hand, using many hacky methods. The art of probing a tool to find out if it supports a given feature dates back decades and is filled with insanity. Imagine giving a command that you know will fail, but giving it anyway because the specific manner of failure will tell you what you need to know for a future command to work. Now imagine hundreds of hacks like that in the Linux kernel build system.

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Endless OS May Be the Best Linux Version for New Computer Users

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GNU
Linux

Linux appeals to a certain kind of computer user: if you like computers enough to read about or tinker with them in your free time, then there’s a good chance you’ll find something to like about Linux. Otherwise, you will probably consider it too much work to bother.

Endless Computer’s Endless OS aims to provide a complete desktop experience that’s versatile enough to serve families. Is this the ideal way to introduce newcomers to Linux?

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Survey: Console Based Linux File Managers

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GNU
Linux

The term ‘file management functions’ refers to the functions used to manage files, such as creating, deleting, opening, closing, reading from, and writing to files.

In the field of system administration, Linux has bags of graphical file managers. However, some users prefer managing files from the shell, finding it the quickest way to navigate the file system and perform file operations. This is, in part, because console based file managers are more keyboard friendly, enabling users to perform file operations without using a mouse, and make it quicker to navigate the filesystem and issue commands in the console at the same time.

A console application is computer software which can be used with a text-only computer interface, the command line interface, or a text-based interface included within a graphical user interface operating system, such as a terminal emulator. Whereas a graphical user interface application generally involves using the mouse and keyboard (or touch control), with a console application the primary (and often only) input method is the keyboard. Many console applications are command line tools, but there is a wealth of software that has a text-based user interface making use of ncurses, a library which allow programmers to write text-based user interfaces.

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The "Chinese EPYC" Hygon Dhyana CPU Support Still Getting Squared Away For Linux

Back in June is when the Linux kernel patches appeared for the Hygon Dhyana, the new x86 processors based on AMD Zen/EPYC technology licensed by Chengdu Haiguang IC Design Co for use in Chinese data-centers. While the patches have been out for months, they haven't reached the mainline kernel quite yet but that might change next cycle. The Hygon Dyhana Linux kernel patches have gone through several revisions and the code is mostly adapting existing AMD Linux kernel code paths for Zen/EPYC to do the same on these new processors. While these initial Hygon CPUs appear to basically be re-branded EPYC CPUs, the identifiers are different as rather than AMD Family 17h, it's now Family 18h and the CPU Vendor ID is "HygonGenuine" and carries a new PCI Express device vendor ID, etc. So the different areas of the kernel from CPUFreq to KVM/Xen virtualization to Spectre V2 mitigations had to be updated for the correct behavior. Read more

Good Support For Wayland Remote Desktop Handling On Track For KDE Plasma 5.15

The KDE Plasma 5.15 release due out next year will likely be in good shape for Wayland remote desktop handling. The KDE Plasma/KWin developers have been pursuing Wayland remote desktop support along a similar route to the GNOME Shell camp by making use of PipeWire and the XDG-Desktop-Portal. Bits are already in place for KDE Plasma 5.13 and the upcoming 5.14 release, but for the 5.15 release is now where it sounds like the support may be in good shape for end-users. Read more

Linux developers threaten to pull “kill switch”

Linux powers the internet, the Android in your pocket, and perhaps even some of your household appliances. A controversy over politics is now seeing some of its developers threatening to withdraw the license to all of their code, potentially destroying or making the whole Linux kernel unusable for a very long time. Read more

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