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CompCert | seL4 | |
---|---|---|
36 | 60 | |
1,761 | 4,530 | |
1.8% | 1.5% | |
7.3 | 9.0 | |
25 days ago | 4 days ago | |
Coq | C | |
GNU General Public License v3.0 or later | GNU General Public License v3.0 or later |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
CompCert
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Differ: Tool for testing and validating transformed programs
A big problem is that proving that transformations preserve semantics is very hard. Formal methods has huge potential and I believe it will be a big part of the future, but it hasn't become mainstream yet. Probably a big reason why is that right now it's simply not practical: the things you can prove are much more limited than the things you can do, and it's a lot less work to just create a large testsuite.
Example: CompCert (https://compcert.org/), a formally-verified compiler AKA formally-verified sequence of semantics-preserving transformations from C code to Assembly. It's a great accomplishment, but few people are actually compiling their code with CompCert. Because GCC and LLVM are much faster[1], and have been used so widely that >99.9% of code is going to be compiled correctly, especially code which isn't doing anything extremely weird.
But as articles like this show, no matter how large a testsuite there may always be bugs, tests will never provide the kind of guarantees formal verification does.
[1] From CompCert, "Performance of the generated code is decent but not outstanding: on PowerPC, about 90% of the performance of GCC version 4 at optimization level 1"
- So you think you know C?
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Can the language of proof assistants be used for general purpose programming?
Also a C compiler (https://compcert.org/). I did exaggerate bit in saying that anything non-trivial is "nearly impossible".
However, both CompCert and sel4 took a few years to develop, whereas it would only take months if not weeks to make versions of both which aren't formally verified but heavily tested.
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A Guide to Undefined Behavior in C and C++
From my experience, while many MCUs have settled for the big compilers (GCC and Clang), DSPs and some FPGAs (not Intel and Xilinx, those have lately settled for Clang and a combination of Clang and GCC respectively) use some pretty bespoke compilers (just running ./ --version is enough to verify this, if the compiler even offers that option). That's not necessarily bad, since many of them offer some really useful features, but error messages can be really cryptic in some cases. Also some industries require use of verified compilers, like CompCert[1], and in such cases GCC and Clang just don't cut it.
[1]: https://compcert.org/
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Recently I am having too much friction with the borrow checker... Would you recommend I rewrite the compiler in another language, or keep trying to implement it in rust?
CompCert sends its regards
- Rosenpass – formally verified post-quantum WireGuard
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OpenAI might be training its AI technology to replace some software engineers, report says
But that's fine, because we can do even better with things like the CompCert C compiler, which is formally proven to produce correct asm output for ISO C 2011 source. It's designed for high-reliability, safety-critical applications; it's used for things like Airbus A380 avionics software, or control software for emergency generators at nuclear power plants. Software that's probably not overly sophisticated and doesn't need to be highly optimized, but does need to work ~100% correctly, ~100% of the time.
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There is such thing called bugfree code.
For context, CompCert is a formally verified compiler. My former advisor helped with a fuzzer called CSmith which found plenty of bugs in GCC and LLVM but not in CompCert.
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Checked C
Does anybody know how does this compare to https://compcert.org/ ?
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Proofs about Programs
This is a common property for proof-oriented languages. Coq shares this property for instance, and you can write an optimizing C compiler in Coq: https://github.com/AbsInt/CompCert .
seL4
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From L3 to seL4 what have we learnt in 20 years of L4 microkernels? [video]
> People like to snob Unix but the fact is: the world runs on Unix.
The world you are aware of runs on it.
> Can we really do that much better or is it just hubris?
Yes. Have a look at seL4[1] and Barrelfish too[2], even though that's no longer active. seL4 in particular is powering a lot of highly secure computing systems. There is a surprisingly large sphere outside of Unix/POSIX.
[1] https://sel4.systems/
[2] https://barrelfish.org/
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On the Costs of Syscalls
There are also RTOS-capable microkernels such as seL4[0], with few but extremely fast syscalls[1]. Note times are in cycles, not usec.
0. https://sel4.systems/
1. https://sel4.systems/About/Performance/
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Can the language of proof assistants be used for general purpose programming?
https://sel4.systems
Working on a number of platforms, verified on some. Multicore support is an ongoing effort afaict.
On OS built on this kernel is still subject to some assumptions (like, hardware working correctly, bootloader doing its job, etc). But mostly those assumptions are less of a problem / easier to prove than the properties of a complex software system.
As I understand it, guarantees that seL4 does provide, go well beyond anything else currently out there.
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How to write TEE/Trusted OS for ARM microcontrollers?
Take a look at this: https://sel4.systems/
- Simulation: KI-Drohne der US Air Force eliminiert Operator für Punktemaximierung
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Paragon Graphite is a Pegasus spyware clone used in the US
It's probably have to be seL4 (https://sel4.systems), running on some fully OSS hardware.
There are question marks over much of available RISC-V chips due to chinese producers, so maybe OpenPower based hardware?
Plus, the entire system (motherboard, etc) would need to be manufactured using a good supply chain.
Hmmm, this has probably all been thought through in depth before by others. :)
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Basic SAT model of x86 instructions using Z3, autogenerated from Intel docs
You can use it to (mostly) validate small snippets are the same. See Alive2 for the application of Z3/formalization of programs as SMT for that [1]. As far as I'm aware there are some problems scaling up to arbitrarily sized programs due to a lack of formalization in higher level languages in addition to computational constraints. With a lot of time and effort it can be done though [2].
1. https://github.com/AliveToolkit/alive2
2. https://sel4.systems/
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What are the current hot topics in type theory and static analysis?
Formal methods. This is not in most general-purpose programming languages and probably never will be (maybe we'll see formal methods to verify unsafe code in Rust...) because it's a ton of boilerplate (you have to help the compiler type-check your code) and also extremely complicated. However, formal methods is very important for proving code secure, such as sel4 (microkernel formally verified to not have bugs or be exploitable) which has just received the ACM Software Systems Award 3 days ago.
- Rust Now Available for Real-Time Operating System and Hypervisor PikeOS
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Amiga and AmigaOS should move to ARM.
Today we'd look at seL4.
What are some alternatives?
coq - Coq is a formal proof management system. It provides a formal language to write mathematical definitions, executable algorithms and theorems together with an environment for semi-interactive development of machine-checked proofs.
l4v - seL4 specification and proofs
unbound - Replib: generic programming & Unbound: generic treatment of binders
fprime - F´ - A flight software and embedded systems framework
gcc
nomicon - The Dark Arts of Advanced and Unsafe Rust Programming
corn - Coq Repository at Nijmegen [maintainers=@spitters,@VincentSe]
InitWare - The InitWare Suite of Middleware allows you to manage services and system resources as logical entities called units. Its main component is a service management ("init") system.
vericert - A formally verified high-level synthesis tool based on CompCert and written in Coq.
4.4BSD-Lite2 - 4.4BSD Lite Release 2: last Unix operating system from Berkeley
koika - A core language for rule-based hardware design 🦑
openc910 - OpenXuantie - OpenC910 Core