New Linux Kernel Rules Put The Onus On Humans For AI Tool Usage

April 14, 2026 by Maya Posch 2 Comments

It’s fair to say that the topic of so-called ‘AI coding assistants’ is somewhat controversial. With arguments against them ranging from code quality to copyright issues, there are many valid reasons to be at least hesitant about accepting their output in a project, especially one as massive as the Linux kernel. With a recent update to the Linux kernel documentation the use of these tools has now been formalized.

The upshot of the use of such Large Language Models (LLM) tools is that any commit that uses generated code has to be signed off by a human developer, and this human will ultimately bear responsibility for the code quality as well as any issues that the code may cause, including legal ones. The use of AI tools also has to be declared with the Assisted-by: tag in contributions so that their use can be tracked.

When it comes to other open source projects the approach varies, with NetBSD having banished anything tainted by ‘AI’, cURL shuttering its bug bounty program due to AI code slop, and Mesa’s developers demanding that you understand generated code which you submit, following a tragic slop-cident.

Meanwhile there are also rising concerns that these LLM-based tools may be killing open source through ‘vibe-coding’, along with legal concerns whether LLM-generated code respects the original license of the code that was ingested into the training model. Clearly we haven’t seen the end of these issues yet.

Hackaday Links: April 12, 2026

April 12, 2026 by Tom Nardi 1 Comment

At this point, we’ll assume you already know that four humans took a sightseeing trip around the Moon and made their triumphant return to Earth on Friday. Even if you somehow avoided hearing about it through mainstream channels, we kept a running account of the mission’s highlights stuck to the front page of the site for the ten days that the crew was in space.

On the assumption that you might be a bit burned out with space news at this point, we won’t bring up it up in this post… other than to point out that excitement for the lunar flyby has driven the number of simultaneous players of Kerbal Space Program to its highest count ever — nearly 20,000 armchair astronauts spent this weekend trying to cobble together their own rocket in honor of the Artemis II mission.

With so many folks focused on the Moon it would be the perfect time for a company to sneak out some bad news, which is perhaps why Amazon picked this week to announce they would be dropping support for Kindles released before 2012. Presumably there aren’t too many first and second generation Kindles still out there in the wild, but the 2012 cutoff does mean the first iteration of the Paperwhite will be one of the devices being put out to pasture come May 20th.

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A hex dump of the first iteration of the small ELF file

How Small Can A Linux Executable Be?

March 31, 2026 by Julian Scheffers 37 Comments

With ever increasing sizes of various programs (video games being notorious for this), the question of size optimization comes up more and more often. [Nathan Otterness] shows us how it’s done by minifying a Linux “Hello, World!” program to the extreme.

A naive attempt at a minimal hello world in C might land you somewhere about 12-15Kb, but [Nathan] can do much better. He starts by writing everything in assembly, using Linux system calls. This initial version without optimization is 383 bytes. The first major thing to go is the section headers; they are not needed to actually run the program. Now he’s down to 173 bytes. And this is without any shenanigans!

A hexdump of the final ELF file, significantly smaller than the original — The final tiny ELF file

The first shenanigans are extreme code size optimizations: by selecting instructions carefully (and in a way a C compiler never would), he shaves another 16 bytes off. But the real shenanigans begin when he starts looking for spaces in the ELF header that he can clobber while the program is still accepted by Linux: now he can move his already tiny x86_64 code into these “vacant” spaces in the ELF and program headers for a final tiny ELF file weighing in at just 120 bytes.

P.S.: We know it is possible to make this smaller, but leave this as an exercise to the viewer.

Linux Fu: UPNP A Port Mapping Odyssey

March 23, 2026 by Al Williams 7 Comments

If you’ve ever run a game server or used BitTorrent, you probably know that life is easier if your router supports UPnP (Universal Plug and Play). This is a fairly old tech — created by a standards group in 1999 — that allows a program to open an incoming port into your home network. Of course, most routers let you do this manually, but outside of the Hackaday universe, most people don’t know how to log into their routers, much less how to configure an open UDP port.

I recently found myself using a temporary setup where I could not access the router directly, but I needed some open ports. That got me thinking: if a program can open a port using UPnP, why can’t I? Turns out, of course, you can. Maybe.

Caveats

The first thing, of course, is that you need your firewall open, but that’s true no matter how you open up the router. If the firewall is in the router, then you are at the mercy of the router firmware to realize that if UPnP opens something up, it needs to open the firewall, too.

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Remotely Unlocking An Encrypted Hard Disk

March 6, 2026 by Al Williams 22 Comments

Can you remotely unlock an encrypted hard disk? [Jyn] needed to unlock their home server after it rebooted even if they weren’t home. Normally, they used Tailscale to remote in, but you can’t use tailscale to connect to the machine before the hard drive decrypts, right? Well, you can, sort of, and [Jyn] explains how.

The entertaining post points out something you probably knew, but never thought much about. When your Linux box boots, it starts a very tiny compressed Linux in RAM. On [Jyn’s] machine using Arch, this is the initramfs.

That’s not news, but because it is an actual limited Linux system (including systemd), you can add tools to it. In this case, adding dropbear (an ssh server) and Tailscale to the limited boot-time Linux.

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Linux Hotplug Events Explained

March 6, 2026 by Al Williams 9 Comments

There was a time when Linux was much simpler. You’d load a driver, it would find your device at boot up, or it wouldn’t. That was it. Now, though, people plug and unplug USB devices all the time and expect the system to react appropriately. [Arcanenibble] explains all “the gory details” about what really happens when you plug or unplug a device.

You might think, “Oh, libusb handles that.” But, of course, it doesn’t do the actual work. In fact, there are two possible backends: netlink or udev. However, the libusb developers strongly recommend udev. Turns out, udev also depends on netlink underneath, so if you use udev, you are sort of using netlink anyway.

If netlink sounds familiar, it is a generic BSD-socket-like API the kernel can use to send notifications to userspace. The post shows example code for listening to kernel event messages via netlink, just like udev does.

When udev sees a device add message from netlink, it resends a related udev message using… netlink! Turns out, netlink can send messages between two userspace programs, not just between the kernel and userspace. That means that the code to read udev events isn’t much different from the netlink example.

The next hoop is the udev event format. It uses a version number, but it seems stable at version 0xfeedcafe. Part of the structure contains a hash code that allows a bloom filter to quickly weed out uninteresting events, at least most of the time.

The post documents much of the obscure inner workings of USB hotplug events. However, there are some security nuances that aren’t clear. If you can explain them, we bet [Arcanenibble] would like to hear from you.

If you like digging into the Linux kernel and its friends, you might want to try creating kernel modules. If you get overwhelmed trying to read the kernel source, maybe go back a few versions.

A Live ISO For Those Vibe Coding Experiments

March 5, 2026 by Jenny List 18 Comments

Vibe coding is all the rage at the moment if you follow certain parts of the Internet. It’s very easy to dunk upon it, whether it’s to mock the sea of people who’ve drunk the Kool-Aid and want the magic machine to make them a million dollar app with no work, or the vibe coded web apps with security holes you could drive a bus through.

But AI-assisted coding is now a thing that will stick around whether you like it or not, and there are many who want to dip a toe in the water to see what the fuss is about. For those who don’t quite trust the magic machines in their inner sanctum, [jscottmiller] is here with Clix, a bootable live Linux environment which puts Claude Code safely in a sandbox away from your family silver.

Physically it’s a NixOS live USB image with the Sway tiling Wayland compositor, and as he puts it: “Claude Code ready to go”. It has a shared partition for swapping files with Windows or macOS machines, and it’s persistent. The AI side of it has permissive settings, which means the mechanical overlord can reach parts of the OS you wouldn’t normally let it anywhere near; the point of having it in a live environment in the first place.

We can see the attraction of using an environment such as this one for experimenting without commitment, but we’d be interested to hear your views in the comments. It’s about a year since we asked you all about vibe coding, has the art moved forward in that time?