Update wasmtime to 0.27 (#8913)

* Update wasmtime to 0.27

A couple of notes:

- Now we are fair about unsafeness of runtime creation via an compiled artifact.
  This change was prompted by the change in wasmtime which made
  `deserialize` rightfully unsafe. Now `CodeSupplyMode` was hidden and
  the `create_runtime` now takes the blob again and there is now a new
  fn for creating a runtime with a compiled artifact.
- This is a big change for wasmtime. They switched to the modern backend
  for code generation. While this can bring performance improvements, it
  can also introduce some problems. In fact, 0.27 fixed a serious issue
  that could lead to sandbox escape. Hence we need a proper burn in.

This would require a change to PVF validation host as well.

* Filter regalloc logging

substrate/client/executor/wasmtime/src/imports.rs

@@ -118,7 +118,12 @@ fn resolve_memory_import(
 	}
 
 	let memory_ty = MemoryType::new(Limits::new(initial, requested_memory_ty.limits().max()));
-	let memory = Memory::new(store, memory_ty);
+	let memory = Memory::new(store, memory_ty).map_err(|e| {
+		WasmError::Other(format!(
+			"failed to create a memory during resolving of memory import: {}",
+			e,
+		))
+	})?;
 	Ok(Extern::Memory(memory))
 }
 

substrate/client/executor/wasmtime/src/lib.rs

@@ -24,4 +24,6 @@ mod runtime;
 mod state_holder;
 mod util;
 
-pub use runtime::{create_runtime, prepare_runtime_artifact, CodeSupplyMode, Config, Semantics};
+pub use runtime::{
+	create_runtime, create_runtime_from_artifact, prepare_runtime_artifact, Config, Semantics,
+};

substrate/client/executor/wasmtime/src/runtime.rs

@@ -272,7 +272,7 @@ pub struct Config {
 	pub semantics: Semantics,
 }
 
-pub enum CodeSupplyMode<'a> {
+enum CodeSupplyMode<'a> {
 	/// The runtime is instantiated using the given runtime blob.
 	Verbatim {
 		// Rationale to take the `RuntimeBlob` here is so that the client will be able to reuse
@@ -295,9 +295,42 @@ pub enum CodeSupplyMode<'a> {
 
 /// Create a new `WasmtimeRuntime` given the code. This function performs translation from Wasm to
 /// machine code, which can be computationally heavy.
-///
-/// The `cache_path` designates where this executor implementation can put compiled artifacts.
 pub fn create_runtime(
+	blob: RuntimeBlob,
+	config: Config,
+	host_functions: Vec<&'static dyn Function>,
+) -> std::result::Result<WasmtimeRuntime, WasmError> {
+	// SAFETY: this is safe because it doesn't use `CodeSupplyMode::Artifact`.
+	unsafe { do_create_runtime(CodeSupplyMode::Verbatim { blob }, config, host_functions) }
+}
+
+/// The same as [`create_runtime`] but takes a precompiled artifact, which makes this function
+/// considerably faster than [`create_runtime`].
+///
+/// # Safety
+///
+/// The caller must ensure that the compiled artifact passed here was produced by [`prepare_runtime_artifact`].
+/// Otherwise, there is a risk of arbitrary code execution with all implications.
+///
+/// It is ok though if the `compiled_artifact` was created by code of another version or with different
+/// configuration flags. In such case the caller will receive an `Err` deterministically.
+pub unsafe fn create_runtime_from_artifact(
+	compiled_artifact: &[u8],
+	config: Config,
+	host_functions: Vec<&'static dyn Function>,
+) -> std::result::Result<WasmtimeRuntime, WasmError> {
+	do_create_runtime(
+		CodeSupplyMode::Artifact { compiled_artifact },
+		config,
+		host_functions,
+	)
+}
+
+/// # Safety
+///
+/// This is only unsafe if called with [`CodeSupplyMode::Artifact`]. See [`create_runtime_from_artifact`]
+/// to get more details.
+unsafe fn do_create_runtime(
 	code_supply_mode: CodeSupplyMode<'_>,
 	config: Config,
 	host_functions: Vec<&'static dyn Function>,
@@ -313,7 +346,8 @@ pub fn create_runtime(
 		}
 	}
 
-	let engine = Engine::new(&wasmtime_config);
+	let engine = Engine::new(&wasmtime_config)
+		.map_err(|e| WasmError::Other(format!("cannot create the engine for runtime: {}", e)))?;
 
 	let (module, snapshot_data) = match code_supply_mode {
 		CodeSupplyMode::Verbatim { mut blob } => {
@@ -341,6 +375,8 @@ pub fn create_runtime(
 			}
 		}
 		CodeSupplyMode::Artifact { compiled_artifact } => {
+			// SAFETY: The unsafity of `deserialize` is covered by this function. The
+			//         responsibilities to maintain the invariants are passed to the caller.
 			let module = wasmtime::Module::deserialize(&engine, compiled_artifact)
 				.map_err(|e| WasmError::Other(format!("cannot deserialize module: {}", e)))?;
 
@@ -375,12 +411,12 @@ pub fn prepare_runtime_artifact(
 ) -> std::result::Result<Vec<u8>, WasmError> {
 	instrument(&mut blob, semantics);
 
-	let engine = Engine::new(&common_config());
-	let module = wasmtime::Module::new(&engine, &blob.serialize())
-		.map_err(|e| WasmError::Other(format!("cannot compile module: {}", e)))?;
-	module
-		.serialize()
-		.map_err(|e| WasmError::Other(format!("cannot serialize module: {}", e)))
+	let engine = Engine::new(&common_config())
+		.map_err(|e| WasmError::Other(format!("cannot create the engine: {}", e)))?;
+
+	engine
+		.precompile_module(&blob.serialize())
+		.map_err(|e| WasmError::Other(format!("cannot precompile module: {}", e)))
 }
 
 fn perform_call(