bufferred_read blows stack

[stevemk14ebr]

Hello, the routine here:

parity-wasm/src/elements/mod.rs

Line 12 in 373f655

let mut buf = [0u8; $buffer_size];

is often called with a size of about 0x4000. In embedded environments this can be over what's a reasonable stack size, and can cause the stack to blow. Even in a non-embedded environment this is a pretty big stack buffer, though it's not going to be an issue in usermode as there's usually a few MB of stack available.

This is currently hidden behind a crate flag reduced-stack-buffer to use a smaller default stack size. I suggest this be made the default. This flag is not being exposed in wasmi so users of that library cannot control this.

[stevemk14ebr]

#283 implemented the feature flag originally.

[athei]

We will merge wasmi-labs/wasmi#243

[stevemk14ebr]

That's very exciting thank you! Any chance of a release soon for this new feature flag. And in the future, potentially making these smaller values default?

[athei]

I will look into the wasmi release. However, won't be changing the default here as we don't want to risk any regressions.