add RandGraphSnippetMutator

fuzzers/wcet_qemu_sys/src/bin/fuzzer.rs

@@ -1,5 +1,6 @@
 //! A singlethreaded QEMU fuzzer that can auto-restart.
 
+use wcet_qemu_sys::sysstate::graph::RandGraphSnippetMutator;
 use wcet_qemu_sys::sysstate::graph::GraphMaximizerCorpusScheduler;
 use wcet_qemu_sys::sysstate::graph::SysMapFeedback;
 use wcet_qemu_sys::sysstate::graph::SysGraphFeedbackState;
@@ -391,7 +392,10 @@ 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())
+        .merge(tuple_list!(RandGraphSnippetMutator::new())),
+        5)?;
 
     // let power = PowerMutationalStage::new(mutator, PowerSchedule::FAST, &edges_observer);
     let mutation = StdMutationalStage::new(mutator);

fuzzers/wcet_qemu_sys/src/sysstate/graph.rs

@@ -1,5 +1,14 @@
 
 /// Feedbacks organizing SystemStates as a graph
+use libafl::inputs::HasBytesVec;
+use libafl::bolts::rands::RandomSeed;
+use libafl::bolts::rands::StdRand;
+use libafl::mutators::Mutator;
+use libafl::mutators::MutationResult;
+use core::marker::PhantomData;
+use libafl::state::HasCorpus;
+use libafl::state::HasSolutions;
+use libafl::state::HasRand;
 use crate::worst::MaxExecsLenFavFactor;
 use libafl::corpus::MinimizerCorpusScheduler;
 use libafl::bolts::HasRefCnt;
@@ -32,6 +41,10 @@ use petgraph::graph::NodeIndex;
 use petgraph::Direction;
 use std::cmp::Ordering;
 
+use libafl::bolts::rands::Rand;
+use rand::SeedableRng;
+use rand::seq::SliceRandom;
+
 //============================= Data Structures
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
 struct VariantTuple
@@ -100,12 +113,13 @@ impl PartialEq for SysGraphNode {
 // Wrapper around Vec<RefinedFreeRTOSSystemState> to attach as Metadata
 #[derive(Debug, Default, Serialize, Deserialize, Clone)]
 pub struct SysGraphMetadata {
-    indices: Vec<usize>,    // Hashed enumeration of States
+    inner: Vec<NodeIndex>,
+    indices: Vec<usize>,
     tcref: isize,
 }
 impl SysGraphMetadata {
     pub fn new(inner: Vec<NodeIndex>) -> Self{
-        Self {indices: inner.into_iter().map(|x| x.index()).collect(), tcref: 0}
+        Self {indices: inner.iter().map(|x| x.index()).collect(), inner: inner, tcref: 0}
     }
 }
 impl AsSlice<usize> for SysGraphMetadata {
@@ -278,3 +292,106 @@ impl Named for SysMapFeedback
         &self.name
     }
 }
+
+//============================= Mutators
+
+pub struct RandGraphSnippetMutator<I, S>
+where
+    I: Input + HasBytesVec,
+    S: HasRand + HasMetadata + HasCorpus<I> + HasSolutions<I>,
+{
+    phantom: PhantomData<(I, S)>,
+}
+impl<I, S> RandGraphSnippetMutator<I, S>
+where
+    I: Input + HasBytesVec,
+    S: HasRand + HasMetadata + HasCorpus<I> + HasSolutions<I>,
+{
+    pub fn new() -> Self {
+        RandGraphSnippetMutator{phantom: PhantomData}
+    }
+}
+impl<I, S> Mutator<I, S> for RandGraphSnippetMutator<I, S>
+where
+    I: Input + HasBytesVec,
+    S: HasRand + HasMetadata + HasCorpus<I> + HasSolutions<I> + HasFeedbackStates,
+{
+    fn mutate(
+        &mut self, 
+        state: &mut S, 
+        input: &mut I, 
+        _stage_idx: i32
+    ) -> Result<MutationResult, Error>
+    {
+        // need our own random generator, because borrowing rules
+        let mut myrand = StdRand::new();
+        let tmp = &mut state.rand_mut();
+        myrand.set_seed(tmp.next());   
+        drop(tmp);
+
+        let feedbackstate = state
+            .feedback_states()
+            .match_name::<SysGraphFeedbackState>("SysMap")
+            .unwrap();
+        let g = &feedbackstate.graph;
+        let tmp = state.metadata().get::<SysGraphMetadata>();
+        if tmp.is_none() {  // if there are no metadata it was probably not interesting anyways
+            return Ok(MutationResult::Skipped);
+        }
+        let trace =tmp.expect("SysGraphMetadata not found");
+        // follow the path, extract snippets from last reads, find common snippets.
+        // those are likley keys parts. choose random parts from other sibling traces
+        let sibling_inputs : Vec<&Vec<u8>>= g[*trace.inner.last().unwrap()].variants.iter().map(|x| &x.input).collect();
+        let mut snippet_collector = vec![];
+        let mut per_input_counters = HashMap::<&Vec<u8>,usize>::new(); // ugly workaround to track multiple inputs
+        for t in &trace.inner {
+            let node = &g[*t];
+            let mut per_node_snippets = HashMap::<&Vec<u8>,&[u8]>::new();
+            for v in &node.variants {
+                match per_input_counters.get_mut(&v.input) {
+                    None => {
+                        if sibling_inputs.iter().any(|x| *x==&v.input) {    // only collect info about siblin inputs from target
+                            per_input_counters.insert(&v.input, v.input_counter.try_into().unwrap());
+                        }
+                    },
+                    Some(x) => {
+                        let x_u = *x;
+                        if x_u<v.input_counter as usize {
+                            *x=v.input_counter as usize;
+                            per_node_snippets.insert(&v.input,&v.input[x_u..v.input_counter as usize]);
+                        }
+                    }
+                }
+            }
+            snippet_collector.push(per_node_snippets);
+        }
+        let mut new_input : Vec<u8> = vec![];
+        for c in snippet_collector {
+            new_input.clone_from_slice(myrand.choose(c).1);
+        }
+        for i in new_input.iter().enumerate() {
+            input.bytes_mut()[i.0]=*i.1;
+        }
+
+        Ok(MutationResult::Mutated)
+    }
+
+    fn post_exec(
+        &mut self, 
+        _state: &mut S, 
+        _stage_idx: i32, 
+        _corpus_idx: Option<usize>
+    ) -> Result<(), Error> {
+        Ok(())
+    }
+}
+
+impl<I, S> Named for RandGraphSnippetMutator<I, S>
+where
+    I: Input + HasBytesVec,
+    S: HasRand + HasMetadata + HasCorpus<I> + HasSolutions<I> + HasFeedbackStates,
+{
+    fn name(&self) -> &str {
+        "RandGraphSnippetMutator"
+    }
+}