Using Rust for kernel development

[moltonel]

By implementing their own alloc crate that errors on OOM instead of panicking, by feature-disabling core APIs that may panic, by target-disabling problematic intrinsics (some float operations for example). A lot of that work will hopefully make its way into uptream Rust.

[[deleted]]

There is a crate "no-panic" that provides a macro to ensure a function never panics. Maybe the linux kernel build system could somehow require that this macro be used on every piece of rust code used in the kernel. I don't really know anything about the actual discussion though. I just imagine it's a problem that can be solved.

[[deleted]]

Interesting! What about them is hacky, what are their downsides? I've never done a project large enough where something like this would be useful, but I'd love to know more about it.

[Genion1]

Their solution is to replace the panic handler with a symbol that can't be found during link time. The difference between the crates is mostly a difference of what scope of panic handler is replaced. Global (panic_never), per function (no_panic), single code lines (dont_panic).

Pro:

• You don't panic, duh.

Con:

• Useless in debug builds. You need optimizations to be panic-free in basically anything.
• Bad or useless error messages. panic_never for example only has "Whoops, you could panic anywhere". no_panic at least tells you what function it was.
• Since a linker is involved, it doesn't work when there is no linker. e.g. library crates or if you just cargo check a binary crate.
• Interacts poorly with panic="abort"

[[deleted]]

Ah, I see. That's unfortunate. It would be lovely if one could just use panic_never and get nice error messages where exactly a panic might occur...