Joshua Liebow-Feeser

"I don't quite know how to put this, but our entire field is bad at what we do, and if you rely on us, everyone will die." Fuchsia Security. Adjunct prof @ USF.

[Joshua Liebow-Feeser @joshlf_]

My #rustconf24 talk, Safety in an Unsafe World, is now available! I argue that we can move Rust beyond memory safety to guarantee freedom from *any* class of bugs.

[This is a re-post of my original tweet; the video's fixed to remove hard-coded subtitles]

https://t.co/PKN935jZp6

[Joshua Liebow-Feeser @joshlf_]

“Sophist futurists be like: ‘The arc of the moral universe is long, but it bends toward dopeness.’” - my friend George

[Joshua Liebow-Feeser @joshlf_]

Zerocopy can’t support IntoBytes on a surprising set of types today for this reason. Unsupported types you may not have known about:
- Most DSTs
- Unions whose fields are of different lengths*
- Many generic struct types

*adds implicit trailing padding after some fields

[Joshua Liebow-Feeser @joshlf_]

Would anyone use this @rustlang attribute?

#[repr(padded)]

All padding bytes guaranteed initialized (represented as u8).

Would permit T: zerocopy::IntoBytes for any struct or union type - even those with padding.

[Sam Bowman @s8mb]

The Hanseatic League was a coalition of merchant cities that grew to dominate trade in Europe and even fought and won wars.

The League's rise and fall is a story of building and holding together a coalition, and of how technology shapes war & economics.

https://t.co/mzsBvVvt3f

[Joshua Liebow-Feeser @joshlf_]

Can anyone solve this #rustlang type puzzle? I *think* it's impossible to solve, but I'm hoping I'm wrong.

https://t.co/qby7dOXhvv

[Joshua Liebow-Feeser @joshlf_]

@mitsuhiko Context: I work on the Fuchsia Security team, where ~50% of our Rust code is from third-party https://t.co/9XfOAcvD1r deps. Part of my job is to improve the soundness of that code by reducing instances of `unsafe`. This doesn't all involve zerocopy; eg: https://t.co/FPuK2TT6Oa

[Joshua Liebow-Feeser @joshlf_]

This was a great talk!

[Predrag Gruevski @PredragGruevski]

It would have been much worse if the data showed that most breakage is "long tail" problems.

We would have needed hundreds of lints to make even a dent in the problem!

Find more data and examples in my #rustconf24 talk:
https://t.co/kpuP9zj3gW

[Joshua Liebow-Feeser @joshlf_]

@tenellous @ManishEarth @pcwalton Unless I'm missing something, the impl of `Hash for [u8]` bottoms out generically in `Hash for u8` via https://t.co/2DBdDURMhl

So I'd expect optimizations would be helpful relative to that naive implementation.

[Joshua Liebow-Feeser @joshlf_]

Anyone got any galaxy-brain #rustlang type system ideas for how to solve this?

https://t.co/WxiY8FZDtb

[Joshua Liebow-Feeser @joshlf_]

@OmniFocus And the same error on https://t.co/KldvBAf8IS:

[Joshua Liebow-Feeser @joshlf_]

@burntsushi5 @tenellous @Lokathor @dj_d_sol @jswrenn But I think the diversity is important in itself. Both of us have taken inspiration from each other at points (eg we had a custom derive first, while bytemuck had fallible conversions first, just to name two examples). I suspect this will continue.

[Joshua Liebow-Feeser @joshlf_]

@burntsushi5 @tenellous @Lokathor @dj_d_sol @jswrenn Mostly I think the differences are around stability (bytemuck at 1.0 and w/ a very low MSRV, while zerocopy releases breaking changes) and API design tradeoffs (bytemuck prioritizes simple, panicking APIs, while zerocopy returns rich error types that the caller must handle).

[Joshua Liebow-Feeser @joshlf_]

Announcing a pre-release of zerocopy 0.8! Please kick the tires and give us feedback! 0.8 is chock-full of new features, so there’s fun for the whole family.

https://t.co/vLywI4lukJ

[RustConf @rustconf]

@aevavoom @nikomatsakis @me_diru @adam_chal @nick_r_cameron 🥽 Excited to have Jack Wrenn, Applied Scientist at AWS, presenting at #rustconf 2024!

Join us for "Safety Goggles for Alchemists" as Jack unveils Rust's journey towards transmutation safety.

[RustConf @rustconf]

@aevavoom @nikomatsakis @me_diru 🔐 Delve into the realm of safety with Google software engineer Joshua Liebow-Feeser at #rustconf 2024!
Join us for his session on "Safety in an Unsafe World"

[Joshua Liebow-Feeser @joshlf_]

Happy to announce that I'll be speaking at @rustconf 2024 about pushing the boundaries of safety and security in safety-critical domains; hope to see you there!

[Joshua Liebow-Feeser @joshlf_]

Looking to dip your toes in @rustlang? Check out zerocopy’s Hacktoberfedt issues! Spooky fun for the whole family!

https://t.co/XaHA0QvfHv

[Joshua Liebow-Feeser @joshlf_]

Time for binary transparency in Cargo?

[Joshua Liebow-Feeser @joshlf_]

Anyone know how to find the SHA for Miri in a particular nightly #rustlang release? Context: https://t.co/OeuqRutt66