Re: Rust in the kernel

[jbranso]

July 4, 2022 1:36 PM, "Akib Azmain Turja" <akib@disroot.org> wrote:

> Ludovic Courtès <ludo@gnu.org> writes:
> 
>> Hi!
>> 
>> Leo Famulari <leo@famulari.name> skribis:
> 
> The effort to use the Rust programming language within the Linux kernel
> is progressing and may be realized in the next few months:
> 
> https://lwn.net/SubscriberLink/899182/6c831b90eaee015e
> https://www.memorysafety.org/blog/memory-safety-in-linux-kernel
> 
> Within Guix, we'll need to adapt our kernel build processes in order to
> support this.
> 
> Although I help with updating and configuring the kernel builds, I won't
> be able to participate in the "Rust in the kernel" effort for Guix.
>> Understood…
> 
> So, interested volunteers should begin organizing :)
>> Yup!
>> 
>> Now, concretely, how long will it take before key parts of the kernel
>> are written in Rust? Hopefully a long time, no? Per the article above,
>> it’s starting small, with Rust usage in well-defined locations.
>> 
>> This is not to say that we shouldn’t start organizing, but rather that
>> we still have a bit of time ahead.
>> 
>> (During that time, interested readers can also take a stab at improving
>> support for the Hurd, which relies on that revolutionary technology
>> called “address spaces” to ensure Memory Safety™ among other things!)
>> 
>> Ludo’.
> 
> "Address spaces"! What's that? Sorry for asking without searching the
> internet first, but the Hurd designers are so creative that a few
> understand the concepts and join the community, so there is a little
> chance (if any) that I'll find any useful information on that.

>From the Hurd wiki: https://www.gnu.org/software/hurd/advantages.html

The Hurd is built in a very modular fashion. Other Unix-like kernels
(Linux, for example) are also modular in that they allow loading
(and unloading) some components as kernel modules, but the Hurd goes
one step further in that most of the components that constitute the
whole kernel are running as separate user-space processes and are thus
using different address spaces that are isolated from each other.
This is a multi-server design based on a microkernel. It is not
possible that a faulty memory dereference inside the TCP/IP stack
can bring down the whole kernel, and thus the whole system, which
is a real problem in a monolithic Unix kernel architecture.

Some visual explantions:

https://en.wikipedia.org/wiki/Microkernel#/media/File:OS-structure.svg

The Hurd is on the right in this image.

Essentially, if your fileserver somehow gets hacked, the attacker
cannot magically access your TCP/IP stack, because your TCP/IP is not
in the some "software zone" as your fileserver. So microkernels like
the Hurd are usually considered more secure and better designed
than monolithic kernels like Linux. However, monolithic kernels
will usually be faster than microkernels.

> --
> Akib Azmain Turja
> 
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