More LLVM passes from AFL++ (#394)

* afl coverage pass

* working ctx coverage

* MAYBE_THREAD_LOCAL

* doh

* fix for msvc

* ci

* clippy

* atheris

* thread_local

.github/workflows/build_and_test.yml

@@ -63,10 +63,10 @@ jobs:
     # cargo-hack's --feature-powerset would be nice here but libafl has a too many knobs
     - name: Check each feature
       # Skipping python as it has to be built with the `maturin` tool
-      run: cargo hack check --feature-powerset --depth=2 --exclude-features=agpl,nautilus,python,sancov_pcguard_edges,sancov_pcguard_edges_ptr --no-dev-deps
+      run: cargo hack check --feature-powerset --depth=2 --exclude-features=agpl,nautilus,python,sancov_pcguard_edges --no-dev-deps
     # pcguard edges and pcguard hitcounts are not compatible and we need to build them seperately
     - name: Check pcguard edges
-      run: cargo check --features=sancov_pcguard_edges,sancov_pcguard_edges_ptr
+      run: cargo check --features=sancov_pcguard_edges
     - name: Build examples
       run: cargo build --examples --verbose
     - uses: actions/checkout@v2

fuzzers/libafl_atheris/Cargo.toml

@@ -21,7 +21,7 @@ num_cpus = "1.0"
 
 [dependencies]
 libafl = { path = "../../libafl/" }
-libafl_targets = { path = "../../libafl_targets/", features = ["sancov_pcguard_hitcounts_ptr", "sancov_cmplog", "libfuzzer"] }
+libafl_targets = { path = "../../libafl_targets/", features = ["pointer_maps", "sancov_cmplog", "libfuzzer"] }
 clap = { version = "3.0.0-beta.4", features = ["default", "yaml"] }
 
 [lib]

fuzzers/libfuzzer_libpng_ctx/.gitignore

@@ -0,0 +1 @@
+libpng-*

fuzzers/libfuzzer_libpng_ctx/Cargo.toml

@@ -0,0 +1,31 @@
+[package]
+name = "libfuzzer_libpng_launcher"
+version = "0.6.1"
+authors = ["Andrea Fioraldi <andreafioraldi@gmail.com>", "Dominik Maier <domenukk@gmail.com>"]
+edition = "2021"
+
+[features]
+default = ["std"]
+std = []
+
+[profile.release]
+lto = true
+codegen-units = 1
+opt-level = 3
+debug = true
+
+[build-dependencies]
+cc = { version = "1.0", features = ["parallel"] }
+which = { version = "4.0.2" }
+num_cpus = "1.0"
+
+[dependencies]
+libafl = { path = "../../libafl/", features = ["std", "anymap_debug", "derive", "llmp_compression", "introspection"] }
+libafl_targets = { path = "../../libafl_targets/", features = ["libfuzzer"] }
+# TODO Include it only when building cc
+libafl_cc = { path = "../../libafl_cc/" }
+clap = { version = "3.0.0-beta.2", features = ["yaml"] }
+
+[lib]
+name = "libfuzzer_libpng"
+crate-type = ["staticlib"]

fuzzers/libfuzzer_libpng_ctx/Makefile

@@ -0,0 +1,50 @@
+FUZZER_NAME="fuzzer_libpng"
+PROJECT_DIR=$(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))
+UNAME := $(shell uname)
+
+PHONY: all
+
+all: fuzzer
+
+libpng-1.6.37:
+	wget https://deac-fra.dl.sourceforge.net/project/libpng/libpng16/1.6.37/libpng-1.6.37.tar.xz
+	tar -xvf libpng-1.6.37.tar.xz
+
+target/release/libafl_cxx: src/* src/bin/*
+	# Build the libpng libfuzzer library
+	cargo build --release
+
+libafl_cxx: target/release/libafl_cxx
+
+libafl_cc: target/release/libafl_cxx
+
+libpng-1.6.37/.libs/libpng16.a: libpng-1.6.37 libafl_cc
+	cd libpng-1.6.37 && ./configure --enable-shared=no --with-pic=yes --enable-hardware-optimizations=yes
+	$(MAKE) -C libpng-1.6.37 CC="$(PROJECT_DIR)/target/release/libafl_cc" CXX="$(PROJECT_DIR)/target/release/libafl_cxx"
+	
+
+fuzzer: libpng-1.6.37/.libs/libpng16.a libafl_cxx
+	# Build the libpng libfuzzer library
+	cargo build --release
+
+	# Build the libpng harness	
+	target/release/libafl_cxx \
+		$(PROJECT_DIR)/harness.cc \
+		$(PROJECT_DIR)/libpng-1.6.37/.libs/libpng16.a \
+		-I$(PROJECT_DIR)/libpng-1.6.37/ \
+		-o $(FUZZER_NAME) \
+		-lm -lz
+
+clean:
+	rm ./$(FUZZER_NAME)
+	$(MAKE) -C libpng-1.6.37 clean
+
+run: all
+	./$(FUZZER_NAME) --cores 0 &
+
+short_test: all
+	rm -rf libafl_unix_shmem_server || true
+	timeout 10s ./$(FUZZER_NAME) --cores 0 &
+
+test: all
+	timeout 60s ./$(FUZZER_NAME) --cores 0 &

fuzzers/libfuzzer_libpng_ctx/README.md

@@ -0,0 +1,47 @@
+# Libfuzzer for libpng, with launcher
+
+This folder contains an example fuzzer for libpng, using LLMP for fast multi-process fuzzing and crash detection.
+To show off crash detection, we added a `ud2` instruction to the harness, edit harness.cc if you want a non-crashing example.
+It has been tested on Linux.
+
+In contrast to the normal libfuzzer libpng example, this uses the `launcher` feature, that automatically spawns `n` child processes, and binds them to a free core.
+
+## Build
+
+To build this example, run
+
+```bash
+cargo build --release
+```
+
+This will build the library with the fuzzer (src/lib.rs) with the libfuzzer compatibility layer and the SanitizerCoverage runtime functions for coverage feedback.
+In addition, it will also build two C and C++ compiler wrappers (bin/libafl_c(libafl_c/xx).rs) that you must use to compile the target.
+
+Then download libpng, and unpack the archive:
+```bash
+wget https://deac-fra.dl.sourceforge.net/project/libpng/libpng16/1.6.37/libpng-1.6.37.tar.xz
+tar -xvf libpng-1.6.37.tar.xz
+```
+
+Now compile libpng, using the libafl_cc compiler wrapper:
+
+```bash
+cd libpng-1.6.37
+./configure
+make CC=../target/release/libafl_cc CXX=../target/release/libafl_cxx -j `nproc`
+```
+
+You can find the static lib at `libpng-1.6.37/.libs/libpng16.a`.
+
+Now, we have to build the libfuzzer harness and link all together to create our fuzzer binary.
+
+```
+cd ..
+./target/release/libafl_cxx ./harness.cc libpng-1.6.37/.libs/libpng16.a -I libpng-1.6.37/ -o fuzzer_libpng -lz -lm
+```
+
+Afterwards, the fuzzer will be ready to run.
+
+## Run
+
+Just run once, the launcher feature should do the rest.

fuzzers/libfuzzer_libpng_ctx/harness.cc

@@ -0,0 +1,197 @@
+// libpng_read_fuzzer.cc
+// Copyright 2017-2018 Glenn Randers-Pehrson
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that may
+// be found in the LICENSE file https://cs.chromium.org/chromium/src/LICENSE
+
+// Last changed in libpng 1.6.35 [July 15, 2018]
+
+// The modifications in 2017 by Glenn Randers-Pehrson include
+// 1. addition of a PNG_CLEANUP macro,
+// 2. setting the option to ignore ADLER32 checksums,
+// 3. adding "#include <string.h>" which is needed on some platforms
+//    to provide memcpy().
+// 4. adding read_end_info() and creating an end_info structure.
+// 5. adding calls to png_set_*() transforms commonly used by browsers.
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <vector>
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#define PNG_CLEANUP \
+  if(png_handler.png_ptr) \
+  { \
+    if (png_handler.row_ptr) \
+      png_free(png_handler.png_ptr, png_handler.row_ptr); \
+    if (png_handler.end_info_ptr) \
+      png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
+        &png_handler.end_info_ptr); \
+    else if (png_handler.info_ptr) \
+      png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
+        nullptr); \
+    else \
+      png_destroy_read_struct(&png_handler.png_ptr, nullptr, nullptr); \
+    png_handler.png_ptr = nullptr; \
+    png_handler.row_ptr = nullptr; \
+    png_handler.info_ptr = nullptr; \
+    png_handler.end_info_ptr = nullptr; \
+  }
+
+struct BufState {
+  const uint8_t* data;
+  size_t bytes_left;
+};
+
+struct PngObjectHandler {
+  png_infop info_ptr = nullptr;
+  png_structp png_ptr = nullptr;
+  png_infop end_info_ptr = nullptr;
+  png_voidp row_ptr = nullptr;
+  BufState* buf_state = nullptr;
+
+  ~PngObjectHandler() {
+    if (row_ptr)
+      png_free(png_ptr, row_ptr);
+    if (end_info_ptr)
+      png_destroy_read_struct(&png_ptr, &info_ptr, &end_info_ptr);
+    else if (info_ptr)
+      png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
+    else
+      png_destroy_read_struct(&png_ptr, nullptr, nullptr);
+    delete buf_state;
+  }
+};
+
+void user_read_data(png_structp png_ptr, png_bytep data, size_t length) {
+  BufState* buf_state = static_cast<BufState*>(png_get_io_ptr(png_ptr));
+  if (length > buf_state->bytes_left) {
+    png_error(png_ptr, "read error");
+  }
+  memcpy(data, buf_state->data, length);
+  buf_state->bytes_left -= length;
+  buf_state->data += length;
+}
+
+static const int kPngHeaderSize = 8;
+
+// Entry point for LibFuzzer.
+// Roughly follows the libpng book example:
+// http://www.libpng.org/pub/png/book/chapter13.html
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  if (size < kPngHeaderSize) {
+    return 0;
+  }
+
+  std::vector<unsigned char> v(data, data + size);
+  if (png_sig_cmp(v.data(), 0, kPngHeaderSize)) {
+    // not a PNG.
+    return 0;
+  }
+
+  PngObjectHandler png_handler;
+  png_handler.png_ptr = nullptr;
+  png_handler.row_ptr = nullptr;
+  png_handler.info_ptr = nullptr;
+  png_handler.end_info_ptr = nullptr;
+
+  png_handler.png_ptr = png_create_read_struct
+    (PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
+  if (!png_handler.png_ptr) {
+    return 0;
+  }
+
+  png_handler.info_ptr = png_create_info_struct(png_handler.png_ptr);
+  if (!png_handler.info_ptr) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  png_handler.end_info_ptr = png_create_info_struct(png_handler.png_ptr);
+  if (!png_handler.end_info_ptr) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  png_set_crc_action(png_handler.png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
+#ifdef PNG_IGNORE_ADLER32
+  png_set_option(png_handler.png_ptr, PNG_IGNORE_ADLER32, PNG_OPTION_ON);
+#endif
+
+  // Setting up reading from buffer.
+  png_handler.buf_state = new BufState();
+  png_handler.buf_state->data = data + kPngHeaderSize;
+  png_handler.buf_state->bytes_left = size - kPngHeaderSize;
+  png_set_read_fn(png_handler.png_ptr, png_handler.buf_state, user_read_data);
+  png_set_sig_bytes(png_handler.png_ptr, kPngHeaderSize);
+
+  if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  // Reading.
+  png_read_info(png_handler.png_ptr, png_handler.info_ptr);
+
+  // reset error handler to put png_deleter into scope.
+  if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  png_uint_32 width, height;
+  int bit_depth, color_type, interlace_type, compression_type;
+  int filter_type;
+
+  if (!png_get_IHDR(png_handler.png_ptr, png_handler.info_ptr, &width,
+                    &height, &bit_depth, &color_type, &interlace_type,
+                    &compression_type, &filter_type)) {
+    PNG_CLEANUP
+    return 0;
+  }
+
+  // This is going to be too slow.
+  if (width && height > 100000000 / width) {
+    PNG_CLEANUP
+#ifdef HAS_DUMMY_CRASH
+ #ifdef __aarch64__
+      asm volatile (".word 0xf7f0a000\n");
+ #else
+      asm("ud2");
+ #endif
+#endif
+    return 0;
+  }
+
+  // Set several transforms that browsers typically use:
+  png_set_gray_to_rgb(png_handler.png_ptr);
+  png_set_expand(png_handler.png_ptr);
+  png_set_packing(png_handler.png_ptr);
+  png_set_scale_16(png_handler.png_ptr);
+  png_set_tRNS_to_alpha(png_handler.png_ptr);
+
+  int passes = png_set_interlace_handling(png_handler.png_ptr);
+
+  png_read_update_info(png_handler.png_ptr, png_handler.info_ptr);
+
+  png_handler.row_ptr = png_malloc(
+      png_handler.png_ptr, png_get_rowbytes(png_handler.png_ptr,
+                                            png_handler.info_ptr));
+
+  for (int pass = 0; pass < passes; ++pass) {
+    for (png_uint_32 y = 0; y < height; ++y) {
+      png_read_row(png_handler.png_ptr,
+                   static_cast<png_bytep>(png_handler.row_ptr), nullptr);
+    }
+  }
+
+  png_read_end(png_handler.png_ptr, png_handler.end_info_ptr);
+
+  PNG_CLEANUP
+  return 0;
+}
+

fuzzers/libfuzzer_libpng_ctx/src/bin/libafl_cc.rs

@@ -0,0 +1,37 @@
+use libafl_cc::{ClangWrapper, CompilerWrapper, LLVMPasses};
+use std::env;
+
+pub fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() > 1 {
+        let mut dir = env::current_exe().unwrap();
+        let wrapper_name = dir.file_name().unwrap().to_str().unwrap();
+
+        let is_cpp = match wrapper_name[wrapper_name.len()-2..].to_lowercase().as_str() {
+            "cc" => false,
+            "++" | "pp" | "xx" => true,
+            _ => panic!("Could not figure out if c or c++ warpper was called. Expected {:?} to end with c or cxx", dir),
+        };
+
+        dir.pop();
+
+        let mut cc = ClangWrapper::new();
+        if let Some(code) = cc
+            .cpp(is_cpp)
+            // silence the compiler wrapper output, needed for some configure scripts.
+            .silence(true)
+            .from_args(&args)
+            .expect("Failed to parse the command line")
+            .add_pass(LLVMPasses::AFLCoverage)
+            .add_arg("-mllvm")
+            .add_arg("-ctx") // Context sensitive coverage
+            .link_staticlib(&dir, "libfuzzer_libpng")
+            .run()
+            .expect("Failed to run the wrapped compiler")
+        {
+            std::process::exit(code);
+        }
+    } else {
+        panic!("LibAFL CC: No Arguments given");
+    }
+}

fuzzers/libfuzzer_libpng_ctx/src/bin/libafl_cxx.rs

@@ -0,0 +1,5 @@
+pub mod libafl_cc;
+
+fn main() {
+    libafl_cc::main()
+}

fuzzers/libfuzzer_libpng_ctx/src/clap-config.yaml

@@ -0,0 +1,12 @@
+name: libfuzzer libpng
+version: "0.1.0"
+author: "Andrea Fioraldi <andreafioraldi@gmail.com>, Dominik Maier <domenukk@gmail.com>"
+about: A clone of libfuzzer using libafl for a libpng harness.
+args:
+    - cores:
+        short: c
+        long: cores
+        about: "spawn a client in each of the provided cores. Broker runs in the 0th core. 'all' to select all available cores. 'none' to run a client without binding to any core. eg: '1,2-4,6' selects the cores 1,2,3,4,6." 
+        value_name: CORES
+        required: true
+        takes_value: true

fuzzers/libfuzzer_libpng_ctx/src/lib.rs

@@ -0,0 +1,183 @@
+//! A libfuzzer-like fuzzer with llmp-multithreading support and restarts
+//! The example harness is built for libpng.
+//! In this example, you will see the use of the `launcher` feature.
+//! The `launcher` will spawn new processes for each cpu core.
+
+use clap::{load_yaml, App};
+use core::time::Duration;
+use std::{env, path::PathBuf};
+
+use libafl::{
+    bolts::{
+        current_nanos,
+        launcher::Launcher,
+        os::parse_core_bind_arg,
+        rands::StdRand,
+        shmem::{ShMemProvider, StdShMemProvider},
+        tuples::{tuple_list, Merge},
+    },
+    corpus::{
+        Corpus, InMemoryCorpus, IndexesLenTimeMinimizerCorpusScheduler, OnDiskCorpus,
+        QueueCorpusScheduler,
+    },
+    events::EventConfig,
+    executors::{inprocess::InProcessExecutor, ExitKind, TimeoutExecutor},
+    feedback_or, feedback_or_fast,
+    feedbacks::{CrashFeedback, MapFeedbackState, MaxMapFeedback, TimeFeedback, TimeoutFeedback},
+    fuzzer::{Fuzzer, StdFuzzer},
+    inputs::{BytesInput, HasTargetBytes},
+    monitors::MultiMonitor,
+    mutators::scheduled::{havoc_mutations, tokens_mutations, StdScheduledMutator},
+    mutators::token_mutations::Tokens,
+    observers::{HitcountsMapObserver, StdMapObserver, TimeObserver},
+    stages::mutational::StdMutationalStage,
+    state::{HasCorpus, HasMetadata, StdState},
+    Error,
+};
+
+use libafl_targets::{edges_map_from_ptr, libfuzzer_initialize, libfuzzer_test_one_input};
+
+/// The main fn, `no_mangle` as it is a C symbol
+#[no_mangle]
+pub fn libafl_main() {
+    // Registry the metadata types used in this fuzzer
+    // Needed only on no_std
+    //RegistryBuilder::register::<Tokens>();
+    let yaml = load_yaml!("clap-config.yaml");
+    let matches = App::from(yaml).get_matches();
+
+    let broker_port = 1337;
+
+    let cores = parse_core_bind_arg(matches.value_of("cores").unwrap())
+        .expect("No valid core count given!");
+
+    println!(
+        "Workdir: {:?}",
+        env::current_dir().unwrap().to_string_lossy().to_string()
+    );
+
+    let shmem_provider = StdShMemProvider::new().expect("Failed to init shared memory");
+
+    let monitor = MultiMonitor::new(|s| println!("{}", s));
+
+    let mut run_client = |state: Option<StdState<_, _, _, _, _>>, mut restarting_mgr, _core_id| {
+        let corpus_dirs = &[PathBuf::from("./corpus")];
+        let objective_dir = PathBuf::from("./crashes");
+
+        // Create an observation channel using the coverage map
+        let edges = edges_map_from_ptr();
+        let edges_observer = HitcountsMapObserver::new(StdMapObserver::new("edges", edges));
+
+        // Create an observation channel to keep track of the execution time
+        let time_observer = TimeObserver::new("time");
+
+        // The state of the edges feedback.
+        let feedback_state = MapFeedbackState::with_observer(&edges_observer);
+
+        // Feedback to rate the interestingness of an input
+        // This one is composed by two Feedbacks in OR
+        let feedback = feedback_or!(
+            // New maximization map feedback linked to the edges observer and the feedback state
+            MaxMapFeedback::new_tracking(&feedback_state, &edges_observer, true, false),
+            // Time feedback, this one does not need a feedback state
+            TimeFeedback::new_with_observer(&time_observer)
+        );
+
+        // A feedback to choose if an input is a solution or not
+        let objective = feedback_or_fast!(CrashFeedback::new(), TimeoutFeedback::new());
+
+        // If not restarting, create a State from scratch
+        let mut state = state.unwrap_or_else(|| {
+            StdState::new(
+                // RNG
+                StdRand::with_seed(current_nanos()),
+                // Corpus that will be evolved, we keep it in memory for performance
+                InMemoryCorpus::new(),
+                // Corpus in which we store solutions (crashes in this example),
+                // on disk so the user can get them after stopping the fuzzer
+                OnDiskCorpus::new(objective_dir).unwrap(),
+                // States of the feedbacks.
+                // They are the data related to the feedbacks that you want to persist in the State.
+                tuple_list!(feedback_state),
+            )
+        });
+
+        println!("We're a client, let's fuzz :)");
+
+        // Create a PNG dictionary if not existing
+        if state.metadata().get::<Tokens>().is_none() {
+            state.add_metadata(Tokens::new(vec![
+                vec![137, 80, 78, 71, 13, 10, 26, 10], // PNG header
+                "IHDR".as_bytes().to_vec(),
+                "IDAT".as_bytes().to_vec(),
+                "PLTE".as_bytes().to_vec(),
+                "IEND".as_bytes().to_vec(),
+            ]));
+        }
+
+        // Setup a basic mutator with a mutational stage
+        let mutator = StdScheduledMutator::new(havoc_mutations().merge(tokens_mutations()));
+        let mut stages = tuple_list!(StdMutationalStage::new(mutator));
+
+        // A minimization+queue policy to get testcasess from the corpus
+        let scheduler = IndexesLenTimeMinimizerCorpusScheduler::new(QueueCorpusScheduler::new());
+
+        // A fuzzer with feedbacks and a corpus scheduler
+        let mut fuzzer = StdFuzzer::new(scheduler, feedback, objective);
+
+        // The wrapped harness function, calling out to the LLVM-style harness
+        let mut harness = |input: &BytesInput| {
+            let target = input.target_bytes();
+            let buf = target.as_slice();
+            libfuzzer_test_one_input(buf);
+            ExitKind::Ok
+        };
+
+        // Create the executor for an in-process function with one observer for edge coverage and one for the execution time
+        let mut executor = TimeoutExecutor::new(
+            InProcessExecutor::new(
+                &mut harness,
+                tuple_list!(edges_observer, time_observer),
+                &mut fuzzer,
+                &mut state,
+                &mut restarting_mgr,
+            )?,
+            // 10 seconds timeout
+            Duration::new(10, 0),
+        );
+
+        // The actual target run starts here.
+        // Call LLVMFUzzerInitialize() if present.
+        let args: Vec<String> = env::args().collect();
+        if libfuzzer_initialize(&args) == -1 {
+            println!("Warning: LLVMFuzzerInitialize failed with -1")
+        }
+
+        // In case the corpus is empty (on first run), reset
+        if state.corpus().count() < 1 {
+            state
+                .load_initial_inputs(&mut fuzzer, &mut executor, &mut restarting_mgr, corpus_dirs)
+                .unwrap_or_else(|_| panic!("Failed to load initial corpus at {:?}", corpus_dirs));
+            println!("We imported {} inputs from disk.", state.corpus().count());
+        }
+
+        fuzzer.fuzz_loop(&mut stages, &mut executor, &mut state, &mut restarting_mgr)?;
+        Ok(())
+    };
+
+    match Launcher::builder()
+        .shmem_provider(shmem_provider)
+        .configuration(EventConfig::from_name("default"))
+        .monitor(monitor)
+        .run_client(&mut run_client)
+        .cores(&cores)
+        .broker_port(broker_port)
+        .stdout_file(Some("/dev/null"))
+        .build()
+        .launch()
+    {
+        Ok(()) => (),
+        Err(Error::ShuttingDown) => println!("Fuzzing stopped by user. Good bye."),
+        Err(err) => panic!("Failed to run launcher: {:?}", err),
+    }
+}

libafl_cc/build.rs

@@ -62,9 +62,17 @@ fn main() {
     let out_dir = Path::new(&out_dir);
     let src_dir = Path::new("src");
 
+    let mut custom_flags = vec![];
+
     let dest_path = Path::new(&out_dir).join("clang_constants.rs");
     let mut clang_constants_file = File::create(&dest_path).expect("Could not create file");
 
+    let edges_map_size: usize = option_env!("LIBAFL_EDGES_MAP_SIZE")
+        .map_or(Ok(65536), str::parse)
+        .expect("Could not parse LIBAFL_EDGES_MAP_SIZE");
+    println!("cargo:rerun-if-env-changed=LIBAFL_EDGES_MAP_SIZE");
+    custom_flags.push(format!("-DLIBAFL_EDGES_MAP_SIZE={}", edges_map_size));
+
     let llvm_config = find_llvm_config();
 
     if let Ok(output) = Command::new(&llvm_config).args(&["--bindir"]).output() {
@@ -80,14 +88,16 @@ fn main() {
 
             pub const CLANG_PATH: &str = {:?};
             pub const CLANGXX_PATH: &str = {:?};
+            
+            /// The size of the edges map
+            pub const EDGES_MAP_SIZE: usize = {};
             ",
             llvm_bindir.join("clang"),
-            llvm_bindir.join("clang++")
+            llvm_bindir.join("clang++"),
+            edges_map_size
         )
         .expect("Could not write file");
 
-        println!("cargo:rerun-if-changed=src/cmplog-routines-pass.cc");
-
         let output = Command::new(&llvm_config)
             .args(&["--cxxflags"])
             .output()
@@ -110,14 +120,28 @@ fn main() {
             ldflags.push("dynamic_lookup");
         };
 
+        println!("cargo:rerun-if-changed=src/cmplog-routines-pass.cc");
+        println!("cargo:rerun-if-changed=src/afl-coverage-pass.cc");
+
         let _ = Command::new(llvm_bindir.join("clang++"))
             .args(&cxxflags)
+            .args(&custom_flags)
             .arg(src_dir.join("cmplog-routines-pass.cc"))
             .args(&ldflags)
             .args(&["-fPIC", "-shared", "-o"])
             .arg(out_dir.join(format!("cmplog-routines-pass.{}", dll_extension())))
             .status()
             .expect("Failed to compile cmplog-routines-pass.cc");
+
+        let _ = Command::new(llvm_bindir.join("clang++"))
+            .args(&cxxflags)
+            .args(&custom_flags)
+            .arg(src_dir.join("afl-coverage-pass.cc"))
+            .args(&ldflags)
+            .args(&["-fPIC", "-shared", "-o"])
+            .arg(out_dir.join(format!("afl-coverage-pass.{}", dll_extension())))
+            .status()
+            .expect("Failed to compile afl-coverage-pass.cc");
     } else {
         write!(
             &mut clang_constants_file,

libafl_cc/src/afl-coverage-pass.cc

@@ -0,0 +1,842 @@
+/*
+   american fuzzy lop++ - LLVM-mode instrumentation pass
+   ---------------------------------------------------
+
+   Written by Laszlo Szekeres <lszekeres@google.com>,
+              Adrian Herrera <adrian.herrera@anu.edu.au>,
+              Michal Zalewski
+
+   LLVM integration design comes from Laszlo Szekeres. C bits copied-and-pasted
+   from afl-as.c are Michal's fault.
+
+   NGRAM previous location coverage comes from Adrian Herrera.
+
+   Copyright 2015, 2016 Google Inc. All rights reserved.
+   Copyright 2019-2020 AFLplusplus Project. All rights reserved.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at:
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   This library is plugged into LLVM when invoking clang through afl-clang-fast.
+   It tells the compiler to add code roughly equivalent to the bits discussed
+   in ../afl-as.h.
+
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <list>
+#include <string>
+#include <fstream>
+
+#include "llvm/Config/llvm-config.h"
+#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR < 5
+typedef long double max_align_t;
+#endif
+
+#if LLVM_VERSION_MAJOR >= 7 /* use new pass manager */
+//#define USE_NEW_PM 1
+#endif
+
+#include "llvm/Support/CommandLine.h"
+#include "llvm/IR/IRBuilder.h"
+#ifdef USE_NEW_PM
+#include "llvm/Passes/PassPlugin.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/IR/PassManager.h"
+#else
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+#endif
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MathExtras.h"
+
+#if LLVM_VERSION_MAJOR > 3 || \
+    (LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 4)
+  #include "llvm/IR/DebugInfo.h"
+  #include "llvm/IR/CFG.h"
+#else
+  #include "llvm/DebugInfo.h"
+  #include "llvm/Support/CFG.h"
+#endif
+
+typedef uint32_t prev_loc_t;
+
+/* Maximum ngram size */
+#define NGRAM_SIZE_MAX 16U
+
+/* Maximum K for top-K context sensitivity */
+#define CTX_MAX_K 32U
+
+#define MAP_SIZE LIBAFL_EDGES_MAP_SIZE
+
+#define FATAL(...) do { fprintf(stderr, "FATAL: " __VA_ARGS__); exit(1); } while (0)
+
+using namespace llvm;
+
+static cl::opt<bool> Debug("debug", cl::desc("Debug prints"), cl::init(false), cl::NotHidden);
+static cl::opt<uint32_t> InstRatio("inst_ratio", cl::desc("Instrumentation ratio in percentage"), cl::init(100), cl::NotHidden);
+static cl::opt<bool> NotZero("not_zero", cl::desc("Never hit 0 again in the hitcount"), cl::init(true), cl::NotHidden);
+static cl::opt<uint32_t> Ngram("ngram", cl::desc("Size of the Ngram instrumentation (0 to disable)"), cl::init(0), cl::NotHidden);
+static cl::opt<uint32_t> CtxK("ctx_k", cl::desc("Size of the context for K-Ctx context sensitivity (0 to disable)"), cl::init(0), cl::NotHidden);
+static cl::opt<bool> Ctx("ctx", cl::desc("Enable full context sensitive coverage"), cl::init(false), cl::NotHidden);
+static cl::opt<bool> ThreadSafe("thread_safe", cl::desc("Use the thread safe instrumentation"), cl::init(false), cl::NotHidden);
+
+namespace {
+
+#ifdef USE_NEW_PM
+class AFLCoverage : public PassInfoMixin<AFLCoverage> {
+ public:
+  AFLCoverage() {
+#else
+class AFLCoverage : public ModulePass {
+ public:
+  static char ID;
+  AFLCoverage() : ModulePass(ID) {
+#endif
+
+    // initInstrumentList();
+
+  }
+
+#ifdef USE_NEW_PM
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM);
+#else
+  bool runOnModule(Module &M) override;
+#endif
+
+ protected:
+  uint32_t    map_size = MAP_SIZE;
+  uint32_t    function_minimum_size = 1;
+
+};
+
+}  // namespace
+
+#ifdef USE_NEW_PM
+extern "C" ::llvm::PassPluginLibraryInfo LLVM_ATTRIBUTE_WEAK
+llvmGetPassPluginInfo() {
+  return {
+    LLVM_PLUGIN_API_VERSION, "AFLCoverage", "v0.1",
+    /* lambda to insert our pass into the pass pipeline. */
+    [](PassBuilder &PB) {
+#if 1
+       using OptimizationLevel = typename PassBuilder::OptimizationLevel;
+       PB.registerOptimizerLastEPCallback(
+         [](ModulePassManager &MPM, OptimizationLevel OL) {
+           MPM.addPass(AFLCoverage());
+         }
+       );
+/* TODO LTO registration */
+#else
+       using PipelineElement = typename PassBuilder::PipelineElement;
+       PB.registerPipelineParsingCallback(
+         [](StringRef Name, ModulePassManager &MPM, ArrayRef<PipelineElement>) {
+            if ( Name == "AFLCoverage" ) {
+              MPM.addPass(AFLCoverage());
+              return true;
+            } else {
+              return false;
+            }
+         }
+       );
+#endif
+    }
+  };
+}
+#else
+
+char AFLCoverage::ID = 0;
+#endif
+
+static uint32_t RandBelow(uint32_t max) {
+    return (uint32_t)rand() % (max +1);
+}
+
+/* needed up to 3.9.0 */
+#if LLVM_VERSION_MAJOR == 3 && \
+    (LLVM_VERSION_MINOR < 9 || \
+     (LLVM_VERSION_MINOR == 9 && LLVM_VERSION_PATCH < 1))
+static uint64_t PowerOf2Ceil(unsigned in) {
+
+  uint64_t in64 = in - 1;
+  in64 |= (in64 >> 1);
+  in64 |= (in64 >> 2);
+  in64 |= (in64 >> 4);
+  in64 |= (in64 >> 8);
+  in64 |= (in64 >> 16);
+  in64 |= (in64 >> 32);
+  return in64 + 1;
+
+}
+
+#endif
+
+/* #if LLVM_VERSION_STRING >= "4.0.1" */
+#if LLVM_VERSION_MAJOR > 4 || \
+    (LLVM_VERSION_MAJOR == 4 && LLVM_VERSION_PATCH >= 1)
+  #define HAVE_VECTOR_INTRINSICS 1
+#endif
+
+
+#ifdef USE_NEW_PM
+PreservedAnalyses AFLCoverage::run(Module &M, ModuleAnalysisManager &MAM) {
+#else
+bool AFLCoverage::runOnModule(Module &M) {
+#endif
+
+  LLVMContext &C = M.getContext();
+
+  IntegerType *Int8Ty = IntegerType::getInt8Ty(C);
+  IntegerType *Int32Ty = IntegerType::getInt32Ty(C);
+#ifdef HAVE_VECTOR_INTRINSICS
+  IntegerType *IntLocTy =
+      IntegerType::getIntNTy(C, sizeof(prev_loc_t) * CHAR_BIT);
+#endif
+  uint32_t rand_seed;
+  unsigned int cur_loc = 0;
+
+#ifdef USE_NEW_PM
+  auto PA = PreservedAnalyses::all();
+#endif
+
+  /* Setup random() so we get Actually Random(TM) */
+  rand_seed = time(NULL);
+  srand(rand_seed);
+
+  /*
+    char *ptr;
+    if ((ptr = getenv("AFL_MAP_SIZE")) || (ptr = getenv("AFL_MAPSIZE"))) {
+
+      map_size = atoi(ptr);
+      if (map_size < 8 || map_size > (1 << 29))
+        FATAL("illegal AFL_MAP_SIZE %u, must be between 2^3 and 2^30",
+    map_size); if (map_size % 8) map_size = (((map_size >> 3) + 1) << 3);
+
+    }
+
+  */
+
+  /* Decide instrumentation ratio */
+
+  if (!InstRatio || InstRatio > 100)
+    FATAL("Bad value of the instrumentation ratio (must be between 1 and 100)");
+
+  unsigned PrevLocSize = 0;
+  unsigned PrevCallerSize = 0;
+
+  bool instrument_ctx = Ctx || CtxK > 0;
+  bool instrument_caller = false;
+
+#ifdef HAVE_VECTOR_INTRINSICS
+  /* Decide previous location vector size (must be a power of two) */
+  VectorType *PrevLocTy = NULL;
+
+  if (Ngram && (Ngram < 2 || Ngram > NGRAM_SIZE_MAX))
+      FATAL(
+          "Bad value of the Ngram size (must be between 2 and NGRAM_SIZE_MAX "
+          "(%u))",
+          NGRAM_SIZE_MAX);
+
+  if (Ngram)
+    PrevLocSize = Ngram - 1;
+  else
+    PrevLocSize = 1;
+
+  /* Decide K-Ctx vector size (must be a power of two) */
+  VectorType *PrevCallerTy = NULL;
+
+  if (CtxK > CTX_MAX_K)
+      FATAL("Bad value of K for K-context sensitivity (must be between 1 and CTX_MAX_K (%u))",
+            CTX_MAX_K);
+
+  if (CtxK == 1) {
+
+    CtxK = 0;
+    instrument_ctx = true;
+    instrument_caller = true;  // Enable CALLER instead
+
+  }
+
+  if (CtxK) {
+
+    PrevCallerSize = CtxK;
+    instrument_ctx = true;
+
+  }
+
+#else
+  if (Ngram)
+  #ifndef LLVM_VERSION_PATCH
+    FATAL(
+        "Sorry, NGRAM branch coverage is not supported with llvm version "
+        "%d.%d.%d!",
+        LLVM_VERSION_MAJOR, LLVM_VERSION_MINOR, 0);
+  #else
+    FATAL(
+        "Sorry, NGRAM branch coverage is not supported with llvm version "
+        "%d.%d.%d!",
+        LLVM_VERSION_MAJOR, LLVM_VERSION_MINOR, LLVM_VERSION_PATCH);
+  #endif
+  if (CtxK)
+  #ifndef LLVM_VERSION_PATCH
+    FATAL(
+        "Sorry, K-CTX branch coverage is not supported with llvm version "
+        "%d.%d.%d!",
+        LLVM_VERSION_MAJOR, LLVM_VERSION_MINOR, 0);
+  #else
+    FATAL(
+        "Sorry, K-CTX branch coverage is not supported with llvm version "
+        "%d.%d.%d!",
+        LLVM_VERSION_MAJOR, LLVM_VERSION_MINOR, LLVM_VERSION_PATCH);
+  #endif
+  PrevLocSize = 1;
+#endif
+
+#ifdef HAVE_VECTOR_INTRINSICS
+  int PrevLocVecSize = PowerOf2Ceil(PrevLocSize);
+  if (Ngram)
+    PrevLocTy = VectorType::get(IntLocTy, PrevLocVecSize
+  #if LLVM_VERSION_MAJOR >= 12
+                                ,
+                                false
+  #endif
+    );
+#endif
+
+#ifdef HAVE_VECTOR_INTRINSICS
+  int PrevCallerVecSize = PowerOf2Ceil(PrevCallerSize);
+  if (CtxK)
+    PrevCallerTy = VectorType::get(IntLocTy, PrevCallerVecSize
+  #if LLVM_VERSION_MAJOR >= 12
+                                   ,
+                                   false
+  #endif
+    );
+#endif
+
+  /* Get globals for the SHM region and the previous location. Note that
+     __afl_prev_loc is thread-local. */
+
+  GlobalVariable *AFLMapPtr =
+      new GlobalVariable(M, PointerType::get(Int8Ty, 0), false,
+                         GlobalValue::ExternalLinkage, 0, "__afl_area_ptr");
+  GlobalVariable *AFLPrevLoc;
+  GlobalVariable *AFLPrevCaller;
+  GlobalVariable *AFLContext = NULL;
+
+  if (Ctx || instrument_caller)
+#if defined(__ANDROID__) || defined(__HAIKU__)
+    AFLContext = new GlobalVariable(
+        M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_ctx");
+#else
+    AFLContext = new GlobalVariable(
+        M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_ctx", 0,
+        GlobalVariable::GeneralDynamicTLSModel, 0, false);
+#endif
+
+#ifdef HAVE_VECTOR_INTRINSICS
+  if (Ngram)
+  #if defined(__ANDROID__) || defined(__HAIKU__)
+    AFLPrevLoc = new GlobalVariable(
+        M, PrevLocTy, /* isConstant */ false, GlobalValue::ExternalLinkage,
+        /* Initializer */ nullptr, "__afl_prev_loc");
+  #else
+    AFLPrevLoc = new GlobalVariable(
+        M, PrevLocTy, /* isConstant */ false, GlobalValue::ExternalLinkage,
+        /* Initializer */ nullptr, "__afl_prev_loc",
+        /* InsertBefore */ nullptr, GlobalVariable::GeneralDynamicTLSModel,
+        /* AddressSpace */ 0, /* IsExternallyInitialized */ false);
+  #endif
+  else
+#endif
+#if defined(__ANDROID__) || defined(__HAIKU__)
+    AFLPrevLoc = new GlobalVariable(
+        M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_loc");
+#else
+  AFLPrevLoc = new GlobalVariable(
+      M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_loc", 0,
+      GlobalVariable::GeneralDynamicTLSModel, 0, false);
+#endif
+
+#ifdef HAVE_VECTOR_INTRINSICS
+  if (CtxK)
+  #if defined(__ANDROID__) || defined(__HAIKU__)
+    AFLPrevCaller = new GlobalVariable(
+        M, PrevCallerTy, /* isConstant */ false, GlobalValue::ExternalLinkage,
+        /* Initializer */ nullptr, "__afl_prev_caller");
+  #else
+    AFLPrevCaller = new GlobalVariable(
+        M, PrevCallerTy, /* isConstant */ false, GlobalValue::ExternalLinkage,
+        /* Initializer */ nullptr, "__afl_prev_caller",
+        /* InsertBefore */ nullptr, GlobalVariable::GeneralDynamicTLSModel,
+        /* AddressSpace */ 0, /* IsExternallyInitialized */ false);
+  #endif
+  else
+#endif
+#if defined(__ANDROID__) || defined(__HAIKU__)
+    AFLPrevCaller =
+        new GlobalVariable(M, Int32Ty, false, GlobalValue::ExternalLinkage, 0,
+                           "__afl_prev_caller");
+#else
+  AFLPrevCaller = new GlobalVariable(
+      M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_caller",
+      0, GlobalVariable::GeneralDynamicTLSModel, 0, false);
+#endif
+
+#ifdef HAVE_VECTOR_INTRINSICS
+  /* Create the vector shuffle mask for updating the previous block history.
+     Note that the first element of the vector will store cur_loc, so just set
+     it to undef to allow the optimizer to do its thing. */
+
+  SmallVector<Constant *, 32> PrevLocShuffle = {UndefValue::get(Int32Ty)};
+
+  for (unsigned I = 0; I < PrevLocSize - 1; ++I)
+    PrevLocShuffle.push_back(ConstantInt::get(Int32Ty, I));
+
+  for (int I = PrevLocSize; I < PrevLocVecSize; ++I)
+    PrevLocShuffle.push_back(ConstantInt::get(Int32Ty, PrevLocSize));
+
+  Constant *PrevLocShuffleMask = ConstantVector::get(PrevLocShuffle);
+
+  Constant *                  PrevCallerShuffleMask = NULL;
+  SmallVector<Constant *, 32> PrevCallerShuffle = {UndefValue::get(Int32Ty)};
+
+  if (CtxK) {
+
+    for (unsigned I = 0; I < PrevCallerSize - 1; ++I)
+      PrevCallerShuffle.push_back(ConstantInt::get(Int32Ty, I));
+
+    for (int I = PrevCallerSize; I < PrevCallerVecSize; ++I)
+      PrevCallerShuffle.push_back(ConstantInt::get(Int32Ty, PrevCallerSize));
+
+    PrevCallerShuffleMask = ConstantVector::get(PrevCallerShuffle);
+
+  }
+
+#endif
+
+  // other constants we need
+  ConstantInt *One = ConstantInt::get(Int8Ty, 1);
+
+  Value *   PrevCtx = NULL;     // CTX sensitive coverage
+  LoadInst *PrevCaller = NULL;  // K-CTX coverage
+
+  /* Instrument all the things! */
+
+  int inst_blocks = 0;
+  // scanForDangerousFunctions(&M);
+
+  for (auto &F : M) {
+
+    int has_calls = 0;
+    if (Debug)
+      fprintf(stderr, "FUNCTION: %s (%zu)\n", F.getName().str().c_str(),
+              F.size());
+
+    // if (!isInInstrumentList(&F)) { continue; }
+
+    if (F.size() < function_minimum_size) { continue; }
+
+    std::list<Value *> todo;
+    for (auto &BB : F) {
+
+      BasicBlock::iterator IP = BB.getFirstInsertionPt();
+      IRBuilder<>          IRB(&(*IP));
+
+      // Context sensitive coverage
+      if (instrument_ctx && &BB == &F.getEntryBlock()) {
+
+#ifdef HAVE_VECTOR_INTRINSICS
+        if (CtxK) {
+
+          PrevCaller = IRB.CreateLoad(AFLPrevCaller);
+          PrevCaller->setMetadata(M.getMDKindID("nosanitize"),
+                                  MDNode::get(C, None));
+          PrevCtx =
+              IRB.CreateZExt(IRB.CreateXorReduce(PrevCaller), IRB.getInt32Ty());
+
+        } else
+
+#endif
+        {
+
+          // load the context ID of the previous function and write to to a
+          // local variable on the stack
+          LoadInst *PrevCtxLoad = IRB.CreateLoad(AFLContext);
+          PrevCtxLoad->setMetadata(M.getMDKindID("nosanitize"),
+                                   MDNode::get(C, None));
+          PrevCtx = PrevCtxLoad;
+
+        }
+
+        // does the function have calls? and is any of the calls larger than one
+        // basic block?
+        for (auto &BB_2 : F) {
+
+          if (has_calls) break;
+          for (auto &IN : BB_2) {
+
+            CallInst *callInst = nullptr;
+            if ((callInst = dyn_cast<CallInst>(&IN))) {
+
+              Function *Callee = callInst->getCalledFunction();
+              if (!Callee || Callee->size() < function_minimum_size)
+                continue;
+              else {
+
+                has_calls = 1;
+                break;
+
+              }
+
+            }
+
+          }
+
+        }
+
+        // if yes we store a context ID for this function in the global var
+        if (has_calls) {
+
+          Value *NewCtx = ConstantInt::get(Int32Ty, RandBelow(map_size));
+#ifdef HAVE_VECTOR_INTRINSICS
+          if (CtxK) {
+
+            Value *ShuffledPrevCaller = IRB.CreateShuffleVector(
+                PrevCaller, UndefValue::get(PrevCallerTy),
+                PrevCallerShuffleMask);
+            Value *UpdatedPrevCaller = IRB.CreateInsertElement(
+                ShuffledPrevCaller, NewCtx, (uint64_t)0);
+
+            StoreInst *Store =
+                IRB.CreateStore(UpdatedPrevCaller, AFLPrevCaller);
+            Store->setMetadata(M.getMDKindID("nosanitize"),
+                               MDNode::get(C, None));
+
+          } else
+
+#endif
+          {
+
+            if (Ctx) NewCtx = IRB.CreateXor(PrevCtx, NewCtx);
+            StoreInst *StoreCtx = IRB.CreateStore(NewCtx, AFLContext);
+            StoreCtx->setMetadata(M.getMDKindID("nosanitize"),
+                                  MDNode::get(C, None));
+
+          }
+
+        }
+
+      }
+
+      if (RandBelow(100) >= InstRatio) continue;
+
+      /* Make up cur_loc */
+
+      // cur_loc++;
+      cur_loc = RandBelow(map_size);
+
+/* There is a problem with Ubuntu 18.04 and llvm 6.0 (see issue #63).
+   The inline function successors() is not inlined and also not found at runtime
+   :-( As I am unable to detect Ubuntu18.04 heree, the next best thing is to
+   disable this optional optimization for LLVM 6.0.0 and Linux */
+#if !(LLVM_VERSION_MAJOR == 6 && LLVM_VERSION_MINOR == 0) || !defined __linux__
+      // only instrument if this basic block is the destination of a previous
+      // basic block that has multiple successors
+      // this gets rid of ~5-10% of instrumentations that are unnecessary
+      // result: a little more speed and less map pollution
+      int more_than_one = -1;
+      // fprintf(stderr, "BB %u: ", cur_loc);
+      for (pred_iterator PI = pred_begin(&BB), E = pred_end(&BB); PI != E;
+           ++PI) {
+
+        BasicBlock *Pred = *PI;
+
+        int count = 0;
+        if (more_than_one == -1) more_than_one = 0;
+        // fprintf(stderr, " %p=>", Pred);
+
+        for (succ_iterator SI = succ_begin(Pred), E = succ_end(Pred); SI != E;
+             ++SI) {
+
+          BasicBlock *Succ = *SI;
+
+          // if (count > 0)
+          //  fprintf(stderr, "|");
+          if (Succ != NULL) count++;
+          // fprintf(stderr, "%p", Succ);
+
+        }
+
+        if (count > 1) more_than_one = 1;
+
+      }
+
+      // fprintf(stderr, " == %d\n", more_than_one);
+      if (F.size() > 1 && more_than_one != 1) {
+
+        // in CTX mode we have to restore the original context for the caller -
+        // she might be calling other functions which need the correct CTX
+        if (instrument_ctx && has_calls) {
+
+          Instruction *Inst = BB.getTerminator();
+          if (isa<ReturnInst>(Inst) || isa<ResumeInst>(Inst)) {
+
+            IRBuilder<> Post_IRB(Inst);
+
+            StoreInst *RestoreCtx;
+  #ifdef HAVE_VECTOR_INTRINSICS
+            if (CtxK)
+              RestoreCtx = IRB.CreateStore(PrevCaller, AFLPrevCaller);
+            else
+  #endif
+              RestoreCtx = Post_IRB.CreateStore(PrevCtx, AFLContext);
+            RestoreCtx->setMetadata(M.getMDKindID("nosanitize"),
+                                    MDNode::get(C, None));
+
+          }
+
+        }
+
+        continue;
+
+      }
+
+#endif
+
+      ConstantInt *CurLoc;
+
+#ifdef HAVE_VECTOR_INTRINSICS
+      if (Ngram)
+        CurLoc = ConstantInt::get(IntLocTy, cur_loc);
+      else
+#endif
+        CurLoc = ConstantInt::get(Int32Ty, cur_loc);
+
+      /* Load prev_loc */
+
+      LoadInst *PrevLoc = IRB.CreateLoad(AFLPrevLoc);
+      PrevLoc->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+      Value *PrevLocTrans;
+
+#ifdef HAVE_VECTOR_INTRINSICS
+      /* "For efficiency, we propose to hash the tuple as a key into the
+         hit_count map as (prev_block_trans << 1) ^ curr_block_trans, where
+         prev_block_trans = (block_trans_1 ^ ... ^ block_trans_(n-1)" */
+
+      if (Ngram)
+        PrevLocTrans =
+            IRB.CreateZExt(IRB.CreateXorReduce(PrevLoc), IRB.getInt32Ty());
+      else
+#endif
+        PrevLocTrans = PrevLoc;
+
+      if (instrument_ctx)
+        PrevLocTrans =
+            IRB.CreateZExt(IRB.CreateXor(PrevLocTrans, PrevCtx), Int32Ty);
+      else
+        PrevLocTrans = IRB.CreateZExt(PrevLocTrans, IRB.getInt32Ty());
+
+      /* Load SHM pointer */
+
+      LoadInst *MapPtr = IRB.CreateLoad(AFLMapPtr);
+      MapPtr->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+
+      Value *MapPtrIdx;
+#ifdef HAVE_VECTOR_INTRINSICS
+      if (Ngram)
+        MapPtrIdx = IRB.CreateGEP(
+            MapPtr,
+            IRB.CreateZExt(
+                IRB.CreateXor(PrevLocTrans, IRB.CreateZExt(CurLoc, Int32Ty)),
+                Int32Ty));
+      else
+#endif
+        MapPtrIdx = IRB.CreateGEP(MapPtr, IRB.CreateXor(PrevLocTrans, CurLoc));
+
+      /* Update bitmap */
+
+      if (ThreadSafe) {  /* Atomic */
+         /*
+         #if LLVM_VERSION_MAJOR < 9
+                 if (neverZero_counters_str !=
+                     NULL) {  // with llvm 9 we make this the default as the bug
+         in llvm
+                              // is then fixed
+         #else
+                 if (NotZero) {
+
+         #endif
+                   // register MapPtrIdx in a todo list
+                   todo.push_back(MapPtrIdx);
+
+                 } else {
+
+         */
+        IRB.CreateAtomicRMW(llvm::AtomicRMWInst::BinOp::Add, MapPtrIdx, One,
+#if LLVM_VERSION_MAJOR >= 13
+                            llvm::MaybeAlign(1),
+#endif
+                            llvm::AtomicOrdering::Monotonic);
+        /*
+
+                }
+
+        */
+
+      } else {
+
+        LoadInst *Counter = IRB.CreateLoad(MapPtrIdx);
+        Counter->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+
+        Value *Incr = IRB.CreateAdd(Counter, One);
+
+#if LLVM_VERSION_MAJOR < 9
+        if (neverZero_counters_str !=
+            NULL) {  // with llvm 9 we make this the default as the bug in llvm
+                     // is then fixed
+#else
+        if (NotZero) {
+
+#endif
+          /* hexcoder: Realize a counter that skips zero during overflow.
+           * Once this counter reaches its maximum value, it next increments to
+           * 1
+           *
+           * Instead of
+           * Counter + 1 -> Counter
+           * we inject now this
+           * Counter + 1 -> {Counter, OverflowFlag}
+           * Counter + OverflowFlag -> Counter
+           */
+
+          ConstantInt *Zero = ConstantInt::get(Int8Ty, 0);
+          auto         cf = IRB.CreateICmpEQ(Incr, Zero);
+          auto         carry = IRB.CreateZExt(cf, Int8Ty);
+          Incr = IRB.CreateAdd(Incr, carry);
+
+        }
+
+        IRB.CreateStore(Incr, MapPtrIdx)
+            ->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+
+      }                                                  /* non atomic case */
+
+      /* Update prev_loc history vector (by placing cur_loc at the head of the
+         vector and shuffle the other elements back by one) */
+
+      StoreInst *Store;
+
+#ifdef HAVE_VECTOR_INTRINSICS
+      if (Ngram) {
+
+        Value *ShuffledPrevLoc = IRB.CreateShuffleVector(
+            PrevLoc, UndefValue::get(PrevLocTy), PrevLocShuffleMask);
+        Value *UpdatedPrevLoc = IRB.CreateInsertElement(
+            ShuffledPrevLoc, IRB.CreateLShr(CurLoc, (uint64_t)1), (uint64_t)0);
+
+        Store = IRB.CreateStore(UpdatedPrevLoc, AFLPrevLoc);
+        Store->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+
+      } else
+
+#endif
+      {
+
+        Store = IRB.CreateStore(ConstantInt::get(Int32Ty, cur_loc >> 1),
+                                AFLPrevLoc);
+        Store->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
+
+      }
+
+      // in CTX mode we have to restore the original context for the caller -
+      // she might be calling other functions which need the correct CTX.
+      // Currently this is only needed for the Ubuntu clang-6.0 bug
+      if (instrument_ctx && has_calls) {
+
+        Instruction *Inst = BB.getTerminator();
+        if (isa<ReturnInst>(Inst) || isa<ResumeInst>(Inst)) {
+
+          IRBuilder<> Post_IRB(Inst);
+
+          StoreInst *RestoreCtx;
+#ifdef HAVE_VECTOR_INTRINSICS
+          if (CtxK)
+            RestoreCtx = IRB.CreateStore(PrevCaller, AFLPrevCaller);
+          else
+#endif
+            RestoreCtx = Post_IRB.CreateStore(PrevCtx, AFLContext);
+          RestoreCtx->setMetadata(M.getMDKindID("nosanitize"),
+                                  MDNode::get(C, None));
+
+        }
+
+      }
+
+      inst_blocks++;
+
+    }
+
+  }
+
+  /* Say something nice. */
+
+  /*if (!be_quiet) {
+
+    if (!inst_blocks)
+      WARNF("No instrumentation targets found.");
+    else {
+
+      char modeline[100];
+      snprintf(modeline, sizeof(modeline), "%s%s%s%s%s",
+               getenv("AFL_HARDEN") ? "hardened" : "non-hardened",
+               getenv("AFL_USE_ASAN") ? ", ASAN" : "",
+               getenv("AFL_USE_MSAN") ? ", MSAN" : "",
+               getenv("AFL_USE_CFISAN") ? ", CFISAN" : "",
+               getenv("AFL_USE_UBSAN") ? ", UBSAN" : "");
+      OKF("Instrumented %d locations (%s mode, ratio %u%%).", inst_blocks,
+          modeline, InstRatio);
+
+    }
+
+  }*/
+  
+  if (Debug) {
+
+    if (!inst_blocks)
+      fprintf(stderr, "No instrumentation targets found.\n");
+    else
+      fprintf(stderr, "Instrumented %d locations (ratio %u%%).\n", inst_blocks, (unsigned)InstRatio);
+
+  }
+
+#ifdef USE_NEW_PM
+  return PA;
+#else
+  return true;
+#endif
+
+}
+
+#ifndef USE_NEW_PM
+static void registerAFLPass(const PassManagerBuilder &,
+                            legacy::PassManagerBase &PM) {
+
+  PM.add(new AFLCoverage());
+
+}
+
+static RegisterStandardPasses RegisterAFLPass(
+    PassManagerBuilder::EP_OptimizerLast, registerAFLPass);
+
+static RegisterStandardPasses RegisterAFLPass0(
+    PassManagerBuilder::EP_EnabledOnOptLevel0, registerAFLPass);
+#endif

libafl_cc/src/clang.rs

@@ -26,6 +26,7 @@ include!(concat!(env!("OUT_DIR"), "/clang_constants.rs"));
 pub enum LLVMPasses {
     //CmpLogIns,
     CmpLogRtn,
+    AFLCoverage,
 }
 
 impl LLVMPasses {
@@ -34,6 +35,8 @@ impl LLVMPasses {
         match self {
             LLVMPasses::CmpLogRtn => PathBuf::from(env!("OUT_DIR"))
                 .join(format!("cmplog-routines-pass.{}", dll_extension())),
+            LLVMPasses::AFLCoverage => PathBuf::from(env!("OUT_DIR"))
+                .join(format!("afl-coverage-pass.{}", dll_extension())),
         }
     }
 }
@@ -210,6 +213,11 @@ impl CompilerWrapper for ClangWrapper {
             }
 
             args.extend_from_slice(self.link_args.as_slice());
+
+            if cfg!(unix) {
+                args.push("-pthread".into());
+                args.push("-ldl".into());
+            }
         } else {
             args.extend_from_slice(self.cc_args.as_slice());
         }

libafl_frida/Cargo.toml

@@ -20,7 +20,7 @@ cc = { version = "1.0", features = ["parallel"] }
 
 [dependencies]
 libafl = { path = "../libafl", version = "0.6.1", features = ["std", "libafl_derive"] }
-libafl_targets = { path = "../libafl_targets", version = "0.6.1", features = ["sancov_cmplog"] }
+libafl_targets = { path = "../libafl_targets", version = "0.6.1", features = ["std", "sancov_cmplog"] }
 nix = "0.23.0"
 libc = "0.2"
 hashbrown = "0.11"

libafl_targets/Cargo.toml

@@ -11,12 +11,12 @@ keywords = ["fuzzing", "testing"]
 edition = "2021"
 
 [features]
-default = []
+default = ["std"]
+std = []
 libfuzzer = []
+pointer_maps = []
 sancov_pcguard_edges = []
 sancov_pcguard_hitcounts = []
-sancov_pcguard_edges_ptr = []
-sancov_pcguard_hitcounts_ptr = []
 sancov_value_profile = []
 sancov_8bit = []
 sancov_cmplog = []

libafl_targets/build.rs

@@ -28,14 +28,14 @@ fn main() {
         &mut constants_file,
         "// These constants are autogenerated by build.rs
 
-/// The size of the edges map
-pub const EDGES_MAP_SIZE: usize = {};
-/// The size of the cmps map
-pub const CMP_MAP_SIZE: usize = {};
-/// The width of the `CmpLog` map
-pub const CMPLOG_MAP_W: usize = {};
-/// The height of the `CmpLog` map
-pub const CMPLOG_MAP_H: usize = {};
+        /// The size of the edges map
+        pub const EDGES_MAP_SIZE: usize = {};
+        /// The size of the cmps map
+        pub const CMP_MAP_SIZE: usize = {};
+        /// The width of the `CmpLog` map
+        pub const CMPLOG_MAP_W: usize = {};
+        /// The height of the `CmpLog` map
+        pub const CMPLOG_MAP_H: usize = {};
 ",
         edges_map_size, cmp_map_size, cmplog_map_w, cmplog_map_h
     )
@@ -90,6 +90,13 @@ pub const CMPLOG_MAP_H: usize = {};
         .file(src_dir.join("common.c"))
         .compile("common");
 
+    println!("cargo:rerun-if-changed=src/coverage.c");
+
+    cc::Build::new()
+        .file(src_dir.join("coverage.c"))
+        .define("EDGES_MAP_SIZE", Some(&*format!("{}", edges_map_size)))
+        .compile("coverage");
+
     println!("cargo:rerun-if-changed=src/cmplog.h");
     println!("cargo:rerun-if-changed=src/cmplog.c");
 

libafl_targets/src/common.h

@@ -8,6 +8,37 @@
 
 #define STATIC_ASSERT(pred) switch(0){case 0:case pred:;}
 
+// From https://stackoverflow.com/a/18298965
+#if __STDC_VERSION__ >= 201112 && !defined __STDC_NO_THREADS__
+  #define THREAD_LOCAL _Thread_local
+#elif defined _WIN32 && ( \
+      defined _MSC_VER || \
+      defined __ICL || \
+      defined __DMC__ || \
+      defined __BORLANDC__ )
+  #define THREAD_LOCAL __declspec(thread) 
+/* note that ICC (linux) and Clang are covered by __GNUC__ */
+#elif defined __GNUC__ || \
+      defined __SUNPRO_C || \
+      defined __xlC__
+  #define THREAD_LOCAL __thread
+#endif
+
+#if defined(__ANDROID__) || defined(__HAIKU__)
+  #undef THREAD_LOCAL
+#elif defined(__APPLE__)
+  #include <TargetConditionals.h>
+  #if TARGET_OS_IPHONE
+    #undef THREAD_LOCAL
+  #endif
+#endif
+
+#ifdef THREAD_LOCAL
+  #define MAYBE_THREAD_LOCAL THREAD_LOCAL
+#else
+  #define MAYBE_THREAD_LOCAL
+#endif
+
 #ifdef _WIN32
   #define RETADDR (uintptr_t)_ReturnAddress()
   #define EXPORT_FN __declspec(dllexport)

libafl_targets/src/coverage.c

@@ -0,0 +1,17 @@
+#include "common.h"
+
+typedef uint32_t prev_loc_t;
+
+/* Maximum ngram size */
+#define NGRAM_SIZE_MAX 16U
+
+/* Maximum K for top-K context sensitivity */
+#define CTX_MAX_K 32U
+
+extern uint8_t __afl_area_ptr_local[EDGES_MAP_SIZE];
+uint8_t* __afl_area_ptr = __afl_area_ptr_local;
+
+//#if defined(__ANDROID__) || defined(__HAIKU__)
+MAYBE_THREAD_LOCAL prev_loc_t __afl_prev_loc[NGRAM_SIZE_MAX];
+MAYBE_THREAD_LOCAL prev_loc_t __afl_prev_caller[CTX_MAX_K];
+MAYBE_THREAD_LOCAL uint32_t   __afl_prev_ctx;

libafl_targets/src/coverage.rs

@@ -1,19 +1,47 @@
 //! Coverage maps as static mut array
 
 use crate::EDGES_MAP_SIZE;
-#[cfg(any(
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
-use core::ptr;
+use core::slice::from_raw_parts_mut;
 
 /// The map for edges.
-pub static mut EDGES_MAP: [u8; EDGES_MAP_SIZE] = [0; EDGES_MAP_SIZE];
-#[cfg(any(
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
-pub static mut EDGES_MAP_PTR: *mut u8 = ptr::null_mut();
+#[no_mangle]
+pub static mut __afl_area_ptr_local: [u8; EDGES_MAP_SIZE] = [0; EDGES_MAP_SIZE];
+pub use __afl_area_ptr_local as EDGES_MAP;
 
 /// The max count of edges tracked.
 pub static mut MAX_EDGES_NUM: usize = 0;
+
+extern "C" {
+    pub static mut __afl_area_ptr: *mut u8;
+}
+pub use __afl_area_ptr as EDGES_MAP_PTR;
+
+#[no_mangle]
+pub static mut __afl_map_size: usize = EDGES_MAP_SIZE;
+pub use __afl_map_size as EDGES_MAP_PTR_SIZE;
+
+#[must_use]
+pub fn edges_map_from_ptr<'a>() -> &'a mut [u8] {
+    unsafe {
+        assert!(!EDGES_MAP_PTR.is_null());
+        from_raw_parts_mut(EDGES_MAP_PTR, EDGES_MAP_PTR_SIZE)
+    }
+}
+
+#[must_use]
+pub fn edges_max_num() -> usize {
+    unsafe {
+        if MAX_EDGES_NUM > 0 {
+            MAX_EDGES_NUM
+        } else {
+            #[cfg(feature = "pointer_maps")]
+            {
+                EDGES_MAP_PTR_SIZE
+            }
+            #[cfg(not(feature = "pointer_maps"))]
+            {
+                EDGES_MAP.len()
+            }
+        }
+    }
+}

libafl_targets/src/drcov.rs

@@ -45,7 +45,7 @@ impl<'a> DrCovWriter<'a> {
     ) -> Self {
         Self {
             writer: BufWriter::new(
-                File::create(path).expect("unable to create file for coverage data"),
+                File::create(path).expect("Unable to create file for coverage data"),
             ),
             module_mapping,
             basic_blocks,

libafl_targets/src/lib.rs

@@ -5,19 +5,9 @@ extern crate alloc;
 
 include!(concat!(env!("OUT_DIR"), "/constants.rs"));
 
-#[cfg(any(
-    feature = "sancov_pcguard_edges",
-    feature = "sancov_pcguard_hitcounts",
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
+#[cfg(any(feature = "sancov_pcguard_edges", feature = "sancov_pcguard_hitcounts",))]
 pub mod sancov_pcguard;
-#[cfg(any(
-    feature = "sancov_pcguard_edges",
-    feature = "sancov_pcguard_hitcounts",
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
+#[cfg(any(feature = "sancov_pcguard_edges", feature = "sancov_pcguard_hitcounts",))]
 pub use sancov_pcguard::*;
 
 #[cfg(any(feature = "sancov_cmplog", feature = "sancov_value_profile"))]
@@ -44,4 +34,5 @@ pub use value_profile::*;
 pub mod cmplog;
 pub use cmplog::*;
 
+#[cfg(feature = "std")]
 pub mod drcov;

libafl_targets/src/sancov_pcguard.rs

@@ -1,20 +1,8 @@
 //! [`LLVM` `PcGuard`](https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-pcs-with-guards) runtime for `LibAFL`.
 
-#[cfg(any(
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
-use crate::coverage::EDGES_MAP_PTR;
 use crate::coverage::{EDGES_MAP, MAX_EDGES_NUM};
-
-#[cfg(all(
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
-#[cfg(not(any(doc, feature = "clippy")))]
-compile_error!(
-    "the libafl_targets `sancov_pcguard_edges_ptr` and `sancov_pcguard_hitcounts_ptr` features are mutually exclusive."
-);
+#[cfg(feature = "pointer_maps")]
+use crate::coverage::{EDGES_MAP_PTR, EDGES_MAP_PTR_SIZE};
 
 #[cfg(all(feature = "sancov_pcguard_edges", feature = "sancov_pcguard_hitcounts"))]
 #[cfg(not(any(doc, feature = "clippy")))]
@@ -27,33 +15,33 @@ compile_error!(
 /// # Safety
 /// Dereferences `guard`, reads the position from there, then dereferences the [`EDGES_MAP`] at that position.
 /// Should usually not be called directly.
-#[cfg(any(
-    feature = "sancov_pcguard_edges",
-    feature = "sancov_pcguard_hitcounts",
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
 #[no_mangle]
 pub unsafe extern "C" fn __sanitizer_cov_trace_pc_guard(guard: *mut u32) {
     let pos = *guard as usize;
-    #[cfg(feature = "sancov_pcguard_edges")]
+    #[cfg(feature = "pointer_maps")]
     {
-        *EDGES_MAP.get_unchecked_mut(pos) = 1;
+        #[cfg(feature = "sancov_pcguard_edges")]
+        {
+            (EDGES_MAP_PTR as *mut u8).add(pos).write(1);
+        }
+        #[cfg(feature = "sancov_pcguard_hitcounts")]
+        {
+            let addr = (EDGES_MAP_PTR as *mut u8).add(pos);
+            let val = addr.read().wrapping_add(1);
+            addr.write(val);
+        }
     }
-    #[cfg(feature = "sancov_pcguard_hitcounts")]
+    #[cfg(not(feature = "pointer_maps"))]
     {
-        let val = (*EDGES_MAP.get_unchecked(pos) as u8).wrapping_add(1);
-        *EDGES_MAP.get_unchecked_mut(pos) = val;
-    }
-    #[cfg(feature = "sancov_pcguard_edges_ptr")]
-    {
-        (EDGES_MAP_PTR as *mut u8).add(pos).write(1);
-    }
-    #[cfg(feature = "sancov_pcguard_hitcounts_ptr")]
-    {
-        let addr = (EDGES_MAP_PTR as *mut u8).add(pos);
-        let val = addr.read().wrapping_add(1);
-        addr.write(val);
+        #[cfg(feature = "sancov_pcguard_edges")]
+        {
+            *EDGES_MAP.get_unchecked_mut(pos) = 1;
+        }
+        #[cfg(feature = "sancov_pcguard_hitcounts")]
+        {
+            let val = (*EDGES_MAP.get_unchecked(pos) as u8).wrapping_add(1);
+            *EDGES_MAP.get_unchecked_mut(pos) = val;
+        }
     }
 }
 
@@ -61,20 +49,12 @@ pub unsafe extern "C" fn __sanitizer_cov_trace_pc_guard(guard: *mut u32) {
 ///
 /// # Safety
 /// Dereferences at `start` and writes to it.
-#[cfg(any(
-    feature = "sancov_pcguard_edges",
-    feature = "sancov_pcguard_hitcounts",
-    feature = "sancov_pcguard_edges_ptr",
-    feature = "sancov_pcguard_hitcounts_ptr"
-))]
 #[no_mangle]
 pub unsafe extern "C" fn __sanitizer_cov_trace_pc_guard_init(mut start: *mut u32, stop: *mut u32) {
-    #[cfg(any(
-        feature = "sancov_pcguard_edges_ptr",
-        feature = "sancov_pcguard_hitcounts_ptr"
-    ))]
+    #[cfg(feature = "pointer_maps")]
     if EDGES_MAP_PTR.is_null() {
         EDGES_MAP_PTR = EDGES_MAP.as_mut_ptr();
+        EDGES_MAP_PTR_SIZE = EDGES_MAP.len();
     }
 
     if start == stop || *start != 0 {
@@ -84,8 +64,15 @@ pub unsafe extern "C" fn __sanitizer_cov_trace_pc_guard_init(mut start: *mut u32
     while start < stop {
         *start = MAX_EDGES_NUM as u32;
         start = start.offset(1);
-        MAX_EDGES_NUM = MAX_EDGES_NUM.wrapping_add(1);
 
-        assert!((MAX_EDGES_NUM <= EDGES_MAP.len()), "The number of edges reported by SanitizerCoverage exceed the size of the edges map ({}). Use the LIBAFL_EDGES_MAP_SIZE env to increase it at compile time.", EDGES_MAP.len());
+        #[cfg(feature = "pointer_maps")]
+        {
+            MAX_EDGES_NUM = MAX_EDGES_NUM.wrapping_add(1) % EDGES_MAP_PTR_SIZE;
+        }
+        #[cfg(not(feature = "pointer_maps"))]
+        {
+            MAX_EDGES_NUM = MAX_EDGES_NUM.wrapping_add(1);
+            assert!((MAX_EDGES_NUM <= EDGES_MAP.len()), "The number of edges reported by SanitizerCoverage exceed the size of the edges map ({}). Use the LIBAFL_EDGES_MAP_SIZE env to increase it at compile time.", EDGES_MAP.len());
+        }
     }
 }