Rust in the kernel is no longer experimental

Post by ls-a » Wed, Dec 10, 2025, 7:06 PM UTC

School-Cotton wrote: post #688

ls-a wrote: post #588

Earlier quoted context omitted.

That's not the case. It's using Rust as a selling point. All the noise around using Rust is marketing. The fact that you think linux machines are enjoyed by only a specific group of people makes me happier with my choice

> It's using Rust as a selling point. That's just not true. Neither Linus Torvalds, nor the Linux Foundation, nor any major distro, nor anyone else who could conceivably be considered responsible for "marketing" Linux is saying you should use it because a small part of it is written in Rust. I just went to ubuntu.com and the word "rust" does not appear anywhere on the front page. So what are you talking about?

Post by johncolanduoni » Wed, Dec 10, 2025, 7:12 PM UTC

School-Cotton wrote: post #593

johncolanduoni wrote: post #283

Earlier quoted context omitted.

Drivers are interesting from a safety perspective, because on systems without an IOMMU sending the wrong command to devices can potentially overwrite most of RAM. For example, if the safe wrappers let you write arbitrary data to a PCIe network card’s registers you could retarget a receive queue to the middle of a kernel memory page.

In normal user-mode rust, not running inside the kernel at all, you can open /dev/mem and write whatever you want to any process's memory (assuming you are root). This does not require "unsafe" at all. Another thing you can do from rust without "unsafe": output some buggy source code that invokes UB in a language like C to a file, then shell out to the compiler to compile that file and run it.

Post by [deleted] » Wed, Dec 10, 2025, 7:26 PM UTC

NetMageSCW wrote: post #674

0xbadcafebee wrote: post #115

Earlier quoted context omitted.

It's a bit like asking if there is any significant advantage to ICE motors over electric motors. They both have advantages and disadvantages. Every person who uses one or the other, will tell you about their own use case, and why nobody could possibly need to use the alternative. There's already applications out there for the "old thing" that need to be maintained, and they're way too old for anyone to bother with re…

Machine code: Yes. Punched cards: easy - every punch has the character it represents at the top of the card.

Post by [deleted] » Wed, Dec 10, 2025, 7:29 PM UTC

jacquesm wrote: post #510

acdha wrote: post #491

Earlier quoted context omitted.

It’s an interesting list from the perspective of what kind of project Linux is. Things like PA-RISC and Alpha were dead even in the 90s (thanks to the successful Itanium marketing push convincing executives not to invest in their own architectures), and SuperH was only relevant in the 90s due to the Dreamcast pushing volume. That creates an interesting dynamic where Linux as a hobbyist OS has people who want to suppo…

There was a time when it came to 64 bit support Alpha really was the only game in town where you could buy a server without adding a sixth zero to the bill. It was AMD, not Itanium that killed Alpha.

Post by dwattttt » Wed, Dec 10, 2025, 7:33 PM UTC

viraptor wrote: post #658

aw1621107 wrote: post #577

Earlier quoted context omitted.

It is how it's supposed to work. `unsafe` is intended to be used on functions where the caller must uphold some precondition(s) in order to not invoke UB, even if the keyword is not strictly required to get the code to compile. The general rule of thumb is that safe code must not be able to invoke UB.

Yes. I was objecting to the parent poster's "can and should be" which sounds like they think people just randomly choose where to use the unsafe decoration.