dccaa64962
Fuzzing has turned up that module linking can create large amounts of tables and memories in addition to instances. For example if N instances are allowed and M tables are allowed per-instance, then currently wasmtime allows MxN tables (which is quite a lot). This is causing some wasm-smith-generated modules to exceed resource limits while fuzzing! This commits adds corresponding `max_tables` and `max_memories` functions to sit alongside the `max_instances` configuration. Additionally fuzzing now by default configures all of these to a somewhat low value to avoid too much resource usage while fuzzing.
48 lines
1.5 KiB
Rust
48 lines
1.5 KiB
Rust
//! Fuzzing infrastructure for Wasmtime.
|
|
|
|
#![deny(missing_docs, missing_debug_implementations)]
|
|
|
|
pub mod generators;
|
|
pub mod oracles;
|
|
|
|
/// One time start up initialization for fuzzing:
|
|
///
|
|
/// * Enables `env_logger`.
|
|
///
|
|
/// * Restricts `rayon` to a single thread in its thread pool, for more
|
|
/// deterministic executions.
|
|
///
|
|
/// If a fuzz target is taking raw input bytes from the fuzzer, it is fine to
|
|
/// call this function in the fuzz target's oracle or in the fuzz target
|
|
/// itself. However, if the fuzz target takes an `Arbitrary` type, and the
|
|
/// `Arbitrary` implementation is not derived and does interesting things, then
|
|
/// the `Arbitrary` implementation should call this function, since it runs
|
|
/// before the fuzz target itself.
|
|
pub(crate) fn init_fuzzing() {
|
|
static INIT: std::sync::Once = std::sync::Once::new();
|
|
|
|
INIT.call_once(|| {
|
|
let _ = env_logger::try_init();
|
|
|
|
let _ = rayon::ThreadPoolBuilder::new()
|
|
.num_threads(1)
|
|
.build_global();
|
|
})
|
|
}
|
|
|
|
/// Create default fuzzing config with given strategy
|
|
pub fn fuzz_default_config(strategy: wasmtime::Strategy) -> anyhow::Result<wasmtime::Config> {
|
|
init_fuzzing();
|
|
let mut config = wasmtime::Config::new();
|
|
config
|
|
.cranelift_nan_canonicalization(true)
|
|
.wasm_bulk_memory(true)
|
|
.wasm_reference_types(true)
|
|
.wasm_module_linking(true)
|
|
.max_instances(100)
|
|
.max_tables(100)
|
|
.max_memories(100)
|
|
.strategy(strategy)?;
|
|
Ok(config)
|
|
}
|