It is time to standardize principles and practices for software memory safety

- out-of-bounds on array read/write

- stack corruption such as overwriting the return address

It doesn't directly say "you can't use C", but achieving this level of soundness in C is quite hard (see sel4 and its Coq proof).

Just sharing an anecdote: recently, I had to create Linux images for x86 on ARM machine using QEMU. During this process, I discovered that, for example, creation of initrd fails because of memory page size (some code makes assumption about page size and calculates the memory location to access instead of using system interface to discover that location). There's a similar problem when using "locate" utility. Probably a bunch more programs that have been successfully used millions, well, probably trillions times. This manifests itself in QEMU segfaulting when trying to perform these operations.

But, to answer the question: I think, one way to define memory safety is to ensure that the language doesn't have the ability to do I/O to a memory address not obtained through system interface. Not sure if this is too much to ask. Feels like for application development purposes this should be OK, and for system development this obviously will not work (someone has to create the system interface that supplies valid memory addresses).

Not really.

It's just out of fashion. But there are really high quality current day implementation, like the one from Embarcadero (i think they acquired Borland a while ago?): https://www.embarcadero.com/products/delphi/features/design

Here is my favourite quote, every time we discuss bounds checking.

"A consequence of this principle is that every occurrence of every subscript of every subscripted variable was on every occasion checked at run time against both the upper and the lower declared bounds of the array. Many years later we asked our customers whether they wished us to provide an option to switch off these checks in the interests of efficiency on production runs. Unanimously, they urged us not to--they already knew how frequently subscript errors occur on production runs where failure to detect them could be disastrous. I note with fear and horror that even in 1980 language designers and users have not learned this lesson. In any respectable branch of engineering, failure to observe such elementary precautions would have long been against the law."

-- C.A.R Hoare's "The 1980 ACM Turing Award Lecture"

Guess what programming language he is referring to by "1980 language designers and users have not learned this lesson".

Having a well-defined memory model is important when running on infra with very different models, such as x86 and aarch64.

Oh, wait, it exists https://docs.oracle.com/javase/8/docs/api/java/util/Optional...

I haven't tested this code, and definitely don't do this.

This code is intended to lets attackers run any shell command by sending JSON with a "debug_command" field - similar to Log4J, it's a "feature" being misused rather than a memory bug that Rust would catch.

      ```rust
   use serde_json::Value;
   use std::process::Command;
   
   fn process_log_entry(log: &str) {
       //  UNSAFE: Allows command injection
       if let Ok(json) = serde_json::from_str::<Value>(log) {
           if let Some(cmd) = json.get("debug_command") {
               Command::new("sh")
                   .arg("-c")
                   .arg(cmd.as_str().unwrap_or(""))
                   .output()
                   .unwrap();
           }
       }
   }
   ```

That's a sound deduction. The JVM had such a vulnerability because it's full of ambient authority and rights amplification patterns. More such vulnerabilities probably exist, they're just hard to see.

My experience is that Rust guides you towards defaults that tend to not hit those things and for the cases where you really do need that fine grained control unsafe blocks with direct pointer access are available(and I've used them when needed).

2. Even when they exist, Rust lets you use unsafe code but only where needed. It's still much better than having your entire program be unsafe.

3. In practice Rust versions of programs are as fast, if not faster than C/C++ ones.

One of the reason is you get the whole program optimization automatically in Rust while C/C++ you need to use put the function that need to be inline in the header or enable LTO at the link time. Bound checking in Rust that people keep using as an example for performance problem is not actually a problem. For example, if you need to access the same index multiple times Rust will perform bound-checking only on the first access (e.g. https://play.rust-lang.org/?version=stable&mode=release&edit...).

Borrow checker is your friend, not an enemy once you know how work with it.

This is moving the goalposts. "Safe rust" isn't a distinct language. The unsafe escape hatch is there to make sure that all programs can be implemented safely.

Isn't Rusts's async situation "somewhat broken" in the exact same way the C++'s async situation is?

Moreover, if I remember correctly, they all are made possible by a single (long-standing) compiler bug that eventually will be fixed.

Previously discussed: https://news.ycombinator.com/item?id=39440808

I think this mindset is the big difference. We're not perfect, but we're working on it.

Meanwhile the rest of the population gets pushed towards authoritarian dystopia.

Users should have control and trust in their devices.

I think that already went away once they started adding spyware ("telemetry" being the usual euphemism) and forced automatic updates ("remotely compromised", as you put it.)

Meanwhile, everything else passes under the guise of "safety and security".