fuzz: interpreter

Author: subotic

crates/polkavm-common/src/program.rs

@@ -4303,6 +4303,13 @@ impl ProgramBlob {
         &self.bitmask
     }
 
+    #[cfg(feature = "export-internals-for-testing")]
+    #[doc(hidden)]
+    pub fn set_bitmask(&mut self, bitmask: ArcBytes) {
+        self.bitmask = bitmask;
+    }
+
+    /// Returns the import offsets and symbols.
     pub fn imports(&self) -> Imports {
         Imports {
             offsets: &self.import_offsets,
@@ -4363,7 +4370,7 @@ impl ProgramBlob {
         }
     }
 
-    /// Visits every instrution in the program.
+    /// Visits every instruction in the program.
     #[cfg_attr(not(debug_assertions), inline(always))]
     pub fn visit<T>(&self, dispatch_table: T, visitor: &mut T::State)
     where

fuzz/Cargo.lock

@@ -15,6 +15,10 @@ libfuzzer-sys = "0.4"
 path = "../crates/polkavm"
 features = ["export-internals-for-testing"]
 
+[dependencies.polkavm-common]
+path = "../crates/polkavm-common"
+features = ["export-internals-for-testing"]
+
 [[bin]]
 name = "fuzz_shm_allocator"
 path = "fuzz_targets/fuzz_shm_allocator.rs"

fuzz/Cargo.toml

@@ -1,11 +1,11 @@
 #![no_main]
 
 use libfuzzer_sys::fuzz_target;
+use polkavm::Engine;
 use polkavm::InterruptKind;
 use polkavm::ModuleConfig;
-use polkavm::ProgramBlob;
 use polkavm::ProgramCounter;
-use polkavm::{ArcBytes, Engine};
+use polkavm_common::program::ProgramBlob;
 
 fn harness(data: &[u8]) {
     // configure the polkavm engine
@@ -21,15 +21,12 @@ fn harness(data: &[u8]) {
     module_config.set_step_tracing(true);
 
     // create a polkavm program blob (eventually to be filled with the fuzzed data)
-    let blob = ProgramBlob::default();
+    let mut fuzzed_blob = ProgramBlob::default();
 
     let bitmask = vec![0xff; data.len() / 8 + 1];
 
-    let fuzzed_blob = ProgramBlob {
-        code: data.into(),
-        bitmask: bitmask.into(),
-        ..blob
-    };
+    fuzzed_blob.set_code(data.into());
+    fuzzed_blob.set_bitmask(bitmask.into());
 
     // create a polkavm module from the engine, module config, and program blob
     let module = polkavm::Module::from_blob(&engine, &module_config, fuzzed_blob).unwrap();