alt Hacker NewsThis is great work by the Redox team. This might be over the heads of many HNers who are undergoing skill atrophy in real time and addicted to agents, given that 4 hours and less than 10 comments on a highly technical blog post about Rust and asynchronous I/O in Redox.
This project is vehemently against AI usage of any kind, so I can trust that the contents of this post has been checked and written by someone who has read the code and knows what they are doing.
> The Linux io_uring interface allows the user to submit one or more I/O operations to the kernel, which are then processed in an asynchronous fashion without blocking the userspace process. Redox, being a microkernel, handles I/O in userspace scheme processes rather than in the kernel.
io_uring is incredibly fast for async I/O but is also a massive security disaster in the Linux kernel. As long as Redox is able to show a secure interface for async I/O the better. Likely part of their long term goals for the OS.
> While it has substantially improved over the years, IPC is still quite slow on Redox, and this is important to optimize as ring buffers can only offset this overhead to a certain extent. This has been a focus of our work to improve system performance.
I quite like this targeted and thoughtful approach for a wholistic improvement starting with ring buffers in redox. They need to compare the async executor benchmark results with Linux and continue from there for improvements.
> The optimization made here is that the kernel zeroes the vector registers if the caller and callee entered the kernel through syscalls, rather than saving/restoring (using vzeroall, ldmxcsr etc. as required for correctness).
Interesting approach for complete correctness over performance in this area and this tells me that they are not taking going to risk on overlying on rust's "guarantees" to help them prevent races or data reuse after free bugs in the Redox kernel.
One of the most technically sound and researched posts I've read, but unfortunately it has been buried under low effort slop posts on HN.
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>io_uring is incredibly fast for async I/O but is also a massive security disaster in the Linux kernel
Torvalds bound it up with... DMABUF. Guess what will happen.
On Linux' future memory subsystem imported from a branch, the Asterinas' one in Rust it's miles ahead and far more secure. Like Windows 98 compared to NT.
Could you elaborate on io_uring being a security disaster? The Redox article has the following to say:
> In its early days, io_uring did have a few security issues and memory leaks, but these have since been addressed
The article also links to a GitHub discussion where someone explains how io_uring is actually all right (see https://github.com/axboe/liburing/discussions/1047#discussio... ).
(I don't have a horse in this race, I just like being well informed and had reconciled myself with io_uring being secure as a consequence of the Redox article.)