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Comment by KronisLV | Hacker News Reader

I wonder whether we'll ever get to a point where the kernel, the drivers and the userland software are all written in memory safe languages, possibly with other safe mechanisms and abstractions thrown in; yet to have it become mainstream and as popular as Linux is now.

Might take decades of work though and probably nobody cares enough for something like that.

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Android has been replacing a lot of core components with Rust and other memory safe languages. The Asahi team built a GPU driver in Rust recently. Seems like things are moving in the right direction.

Is Rust memory safe if you have to use unsafe everywhere, like in the kernel?

Android makes frequent use of unsafe but in their blog post they claim an unsafe rust line has never caused a memory issue. Because they are such a small and focused selection of the code, full scrutiny can be used for any unsafe lines.

Google has actually audited using cargo-vet every crate that chromiumos and fucshia depend on that have unsafe in it. They also have some additional rules related to cryptographic algorithms. I'm pretty surprised they haven't done the same for rust usage in android. https://github.com/google/rust-crate-audits

Kernels and device drivers have to read and write from hardware registers. Doing so is fundamentally "unsafe", by Rust's definition. Hardware is a big bag of external state which can often be mutated external to any software running on the CPU. It's a device driver's job to abstract away this unsafe interface and (ideally) try to present a safe one.

That's not to say there aren't benefits to using languages other than C for this stuff. But a Rust kernel will necessarily rely on `unsafe` blocks to do its job.

I feel that a sort of universal sandboxing is more likely

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