Set the number of stacked mutations in MOpt mutator (#587)

* max_stack_pow

* fix

* fix

* fmt

* rename

fuzzers/baby_fuzzer_gramatron/src/main.rs

@@ -145,7 +145,7 @@ pub fn main() {
         .expect("Failed to generate the initial corpus");
 
     // Setup a mutational stage with a basic bytes mutator
-    let mutator = StdScheduledMutator::with_max_iterations(
+    let mutator = StdScheduledMutator::with_max_stack_pow(
         tuple_list!(
             GramatronRandomMutator::new(&generator),
             GramatronRandomMutator::new(&generator),

fuzzers/baby_fuzzer_grimoire/src/main.rs

@@ -145,8 +145,8 @@ pub fn main() {
     .expect("Failed to create the Executor");
 
     // Setup a mutational stage with a basic bytes mutator
-    let mutator = StdScheduledMutator::with_max_iterations(havoc_mutations(), 2);
+    let mutator = StdScheduledMutator::with_max_stack_pow(havoc_mutations(), 2);
-    let grimoire_mutator = StdScheduledMutator::with_max_iterations(
+    let grimoire_mutator = StdScheduledMutator::with_max_stack_pow(
         tuple_list!(
             GrimoireExtensionMutator::new(),
             GrimoireRecursiveReplacementMutator::new(),

fuzzers/baby_fuzzer_nautilus/src/main.rs

@@ -141,7 +141,7 @@ pub fn main() {
         .expect("Failed to generate the initial corpus");
 
     // Setup a mutational stage with a basic bytes mutator
-    let mutator = StdScheduledMutator::with_max_iterations(
+    let mutator = StdScheduledMutator::with_max_stack_pow(
         tuple_list!(
             NautilusRandomMutator::new(&context),
             NautilusRandomMutator::new(&context),

fuzzers/baby_fuzzer_tokens/src/main.rs

@@ -116,7 +116,7 @@ pub fn main() {
     .expect("Failed to create the Executor");
 
     // Setup a mutational stage with a basic bytes mutator
-    let mutator = StdScheduledMutator::with_max_iterations(encoded_mutations(), 2);
+    let mutator = StdScheduledMutator::with_max_stack_pow(encoded_mutations(), 2);
     let mut stages = tuple_list!(StdMutationalStage::new(mutator));
 
     println!("Decoder {:?} ...", &encoder_decoder);

fuzzers/fuzzbench/src/lib.rs

@@ -306,7 +306,12 @@ fn fuzz(
     let i2s = StdMutationalStage::new(StdScheduledMutator::new(tuple_list!(I2SRandReplace::new())));
 
     // Setup a MOPT mutator
-    let mutator = StdMOptMutator::new(&mut state, havoc_mutations().merge(tokens_mutations()), 5)?;
+    let mutator = StdMOptMutator::new(
+        &mut state,
+        havoc_mutations().merge(tokens_mutations()),
+        7,
+        5,
+    )?;
 
     let power =
         StdPowerMutationalStage::new(&mut state, mutator, &edges_observer, PowerSchedule::FAST);

fuzzers/fuzzbench_fork_qemu/src/fuzzer.rs

@@ -277,7 +277,12 @@ fn fuzz(
     let i2s = StdMutationalStage::new(StdScheduledMutator::new(tuple_list!(I2SRandReplace::new())));
 
     // Setup a MOPT mutator
-    let mutator = StdMOptMutator::new(&mut state, havoc_mutations().merge(tokens_mutations()), 5)?;
+    let mutator = StdMOptMutator::new(
+        &mut state,
+        havoc_mutations().merge(tokens_mutations()),
+        7,
+        5,
+    )?;
 
     let power =
         StdPowerMutationalStage::new(&mut state, mutator, &edges_observer, PowerSchedule::FAST);

fuzzers/fuzzbench_qemu/src/fuzzer.rs

@@ -290,7 +290,12 @@ fn fuzz(
     let i2s = StdMutationalStage::new(StdScheduledMutator::new(tuple_list!(I2SRandReplace::new())));
 
     // Setup a MOPT mutator
-    let mutator = StdMOptMutator::new(&mut state, havoc_mutations().merge(tokens_mutations()), 5)?;
+    let mutator = StdMOptMutator::new(
+        &mut state,
+        havoc_mutations().merge(tokens_mutations()),
+        7,
+        5,
+    )?;
 
     let power =
         StdPowerMutationalStage::new(&mut state, mutator, &edges_observer, PowerSchedule::FAST);

fuzzers/fuzzbench_text/src/lib.rs

@@ -367,7 +367,12 @@ fn fuzz_binary(
     let i2s = StdMutationalStage::new(StdScheduledMutator::new(tuple_list!(I2SRandReplace::new())));
 
     // Setup a MOPT mutator
-    let mutator = StdMOptMutator::new(&mut state, havoc_mutations().merge(tokens_mutations()), 5)?;
+    let mutator = StdMOptMutator::new(
+        &mut state,
+        havoc_mutations().merge(tokens_mutations()),
+        7,
+        5,
+    )?;
 
     let power =
         StdPowerMutationalStage::new(&mut state, mutator, &edges_observer, PowerSchedule::FAST);
@@ -572,12 +577,17 @@ fn fuzz_text(
     let i2s = StdMutationalStage::new(StdScheduledMutator::new(tuple_list!(I2SRandReplace::new())));
 
     // Setup a MOPT mutator
-    let mutator = StdMOptMutator::new(&mut state, havoc_mutations().merge(tokens_mutations()), 5)?;
+    let mutator = StdMOptMutator::new(
+        &mut state,
+        havoc_mutations().merge(tokens_mutations()),
+        7,
+        5,
+    )?;
 
     let power =
         StdPowerMutationalStage::new(&mut state, mutator, &edges_observer, PowerSchedule::FAST);
 
-    let grimoire_mutator = StdScheduledMutator::with_max_iterations(
+    let grimoire_mutator = StdScheduledMutator::with_max_stack_pow(
         tuple_list!(
             GrimoireExtensionMutator::new(),
             GrimoireRecursiveReplacementMutator::new(),

fuzzers/fuzzbench_weighted/src/lib.rs

@@ -306,7 +306,12 @@ fn fuzz(
     let i2s = StdMutationalStage::new(StdScheduledMutator::new(tuple_list!(I2SRandReplace::new())));
 
     // Setup a MOPT mutator
-    let mutator = StdMOptMutator::new(&mut state, havoc_mutations().merge(tokens_mutations()), 5)?;
+    let mutator = StdMOptMutator::new(
+        &mut state,
+        havoc_mutations().merge(tokens_mutations()),
+        7,
+        5,
+    )?;
 
     let power =
         StdPowerMutationalStage::new(&mut state, mutator, &edges_observer, PowerSchedule::FAST);

libafl/src/mutators/mopt_mutator.rs

@@ -369,6 +369,7 @@ where
     mode: MOptMode,
     finds_before: usize,
     mutations: MT,
+    max_stack_pow: u64,
     phantom: PhantomData<(I, S)>,
 }
 
@@ -531,7 +532,12 @@ where
     S: HasRand + HasMetadata + HasCorpus<I> + HasSolutions<I>,
 {
     /// Create a new [`StdMOptMutator`].
-    pub fn new(state: &mut S, mutations: MT, swarm_num: usize) -> Result<Self, Error> {
+    pub fn new(
+        state: &mut S,
+        mutations: MT,
+        max_stack_pow: u64,
+        swarm_num: usize,
+    ) -> Result<Self, Error> {
         if !state.has_metadata::<MOpt>() {
             state.add_metadata::<MOpt>(MOpt::new(mutations.len(), swarm_num)?);
         }
@@ -539,6 +545,7 @@ where
             mode: MOptMode::Pilotfuzzing,
             finds_before: 0,
             mutations,
+            max_stack_pow,
             phantom: PhantomData,
         })
     }
@@ -637,7 +644,7 @@ where
 {
     /// Compute the number of iterations used to apply stacked mutations
     fn iterations(&self, state: &mut S, _: &I) -> u64 {
-        1 << (1 + state.rand_mut().below(6))
+        1 << (1 + state.rand_mut().below(self.max_stack_pow))
     }
 
     /// Get the next mutation to apply

libafl/src/mutators/scheduled.rs

@@ -109,7 +109,7 @@ where
     S: HasRand,
 {
     mutations: MT,
-    max_iterations: u64,
+    max_stack_pow: u64,
     phantom: PhantomData<(I, S)>,
 }
 
@@ -173,7 +173,7 @@ where
 {
     /// Compute the number of iterations used to apply stacked mutations
     fn iterations(&self, state: &mut S, _: &I) -> u64 {
-        1 << (1 + state.rand_mut().below(self.max_iterations))
+        1 << (1 + state.rand_mut().below(self.max_stack_pow))
     }
 
     /// Get the next mutation to apply
@@ -193,16 +193,16 @@ where
     pub fn new(mutations: MT) -> Self {
         StdScheduledMutator {
             mutations,
-            max_iterations: 6,
+            max_stack_pow: 7,
             phantom: PhantomData,
         }
     }
 
     /// Create a new [`StdScheduledMutator`] instance specifying mutations and the maximun number of iterations
-    pub fn with_max_iterations(mutations: MT, max_iterations: u64) -> Self {
+    pub fn with_max_stack_pow(mutations: MT, max_stack_pow: u64) -> Self {
         StdScheduledMutator {
             mutations,
-            max_iterations,
+            max_stack_pow,
             phantom: PhantomData,
         }
     }