libafl_qemu: allow synchronous snapshotting

Add a flag to take snapshots synchronosly.
This should be used to take or load snapshots while the emulator is not
running.

fuzzers/qemu_fret/.gitignore

@@ -0,0 +1,2 @@
+libpng-*
+libpng_harness

fuzzers/qemu_fret/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "qemu_launcher"
+version = "0.8.2"
+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
+
+[dependencies]
+libafl = { path = "../../libafl/" }
+libafl_qemu = { path = "../../libafl_qemu/", features = ["x86_64", "usermode"] }

fuzzers/qemu_fret/Makefile.toml

@@ -0,0 +1,98 @@
+# Variables
+[env]
+FUZZER_NAME='libpng_harness'
+PROJECT_DIR = { script = ["pwd"] }
+
+[tasks.unsupported]
+script_runner="@shell"
+script='''
+echo "Qemu fuzzer not supported on windows"
+'''
+
+# libpng
+[tasks.libpng]
+linux_alias = "libpng_unix"
+mac_alias = "libpng_unix"
+windows_alias = "unsupported"
+
+[tasks.libpng_unix]
+condition = { files_not_exist = [ "./libpng-1.6.37" ] }
+script_runner="@shell"
+script='''
+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
+'''
+
+# fuzzer
+[tasks.fuzzer]
+linux_alias = "fuzzer_unix"
+mac_alias = "fuzzer_unix"
+windows_alias = "unsupported"
+
+[tasks.fuzzer_unix]
+command = "cargo"
+args = ["build", "--release"]
+
+# Harness
+[tasks.harness]
+linux_alias = "harness_unix"
+mac_alias = "harness_unix"
+windows_alias = "unsupported"
+
+[tasks.harness_unix]
+script_runner="@shell"
+script='''
+cd libpng-1.6.37 && ./configure --enable-shared=no --with-pic=yes --enable-hardware-optimizations=yes
+cd "${PROJECT_DIR}"
+make -C libpng-1.6.37
+# Build the libpng harness    
+c++ \
+    ./harness.cc \
+    ./libpng-1.6.37/.libs/libpng16.a \
+    -I./libpng-1.6.37/ \
+    -o ${FUZZER_NAME} \
+    -lm -lz
+'''
+dependencies = [ "libpng" ]
+
+# Run the fuzzer
+[tasks.run]
+linux_alias = "run_unix"
+mac_alias = "run_unix"
+windows_alias = "unsupported"
+
+[tasks.run_unix]
+command = "cargo"
+args = ["run", "--release", "./${FUZZER_NAME}"]
+dependencies = [ "harness", "fuzzer" ]
+
+# Run the fuzzer
+[tasks.test]
+linux_alias = "test_unix"
+mac_alias = "test_unix"
+windows_alias = "unsupported"
+
+# Short test
+[tasks.test_unix]
+script_runner = "@shell"
+script='''
+rm -rf libafl_unix_shmem_server || true
+timeout 11s cargo run --release ./${FUZZER_NAME} 2>/dev/null &
+'''
+dependencies = [ "harness", "fuzzer" ]
+
+# Clean up
+[tasks.clean]
+linux_alias = "clean_unix"
+mac_alias = "clean_unix"
+windows_alias = "unsupported"
+
+[tasks.clean_unix]
+# Disable default `clean` definition
+clear = true
+script_runner="@shell"
+script='''
+rm -f ./${FUZZER_NAME}
+make -C libpng-1.6.37 clean
+cargo clean
+'''

fuzzers/qemu_fret/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/qemu_fret/harness.cc

@@ -0,0 +1,193 @@
+// 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;
+}
+
+int main() {
+  uint8_t buf[10] = {0};
+  LLVMFuzzerTestOneInput(buf, 10);
+}

fuzzers/qemu_fret/src/fuzzer.rs

@@ -0,0 +1,236 @@
+//! A libfuzzer-like fuzzer using qemu for binary-only coverage
+//!
+use core::time::Duration;
+use std::{env, path::PathBuf, process};
+
+use libafl::{
+    bolts::{
+        core_affinity::Cores,
+        current_nanos,
+        launcher::Launcher,
+        rands::StdRand,
+        shmem::{ShMemProvider, StdShMemProvider},
+        tuples::tuple_list,
+        AsSlice,
+    },
+    corpus::{Corpus, InMemoryCorpus, OnDiskCorpus},
+    events::EventConfig,
+    executors::{ExitKind, TimeoutExecutor},
+    feedback_or, feedback_or_fast,
+    feedbacks::{CrashFeedback, MaxMapFeedback, TimeFeedback, TimeoutFeedback},
+    fuzzer::{Fuzzer, StdFuzzer},
+    inputs::{BytesInput, HasTargetBytes},
+    monitors::MultiMonitor,
+    mutators::scheduled::{havoc_mutations, StdScheduledMutator},
+    observers::{HitcountsMapObserver, TimeObserver, VariableMapObserver},
+    schedulers::{IndexesLenTimeMinimizerScheduler, QueueScheduler},
+    stages::StdMutationalStage,
+    state::{HasCorpus, StdState},
+    Error,
+};
+use libafl_qemu::{
+    //asan::QemuAsanHelper,
+    cmplog,
+    cmplog::{CmpLogObserver, QemuCmpLogHelper},
+    edges,
+    edges::QemuEdgeCoverageHelper,
+    elf::EasyElf,
+    emu::Emulator,
+    filter_qemu_args,
+    //snapshot::QemuSnapshotHelper,
+    MmapPerms,
+    QemuExecutor,
+    QemuHooks,
+    Regs,
+};
+
+// pub const MAX_INPUT_SIZE: usize = 1048576; // 1MB
+
+pub fn fuzz() {
+    let MAX_INPUT_SIZE: usize = match env::var("FUZZ_SIZE") {
+        Ok(s) => str::parse::<usize>(&s).expect("FUZZ_SIZE was not a number"),
+        _ => 1048576,
+    }; // 1MB
+    // Hardcoded parameters
+    let timeout = Duration::from_secs(1);
+    let broker_port = 1337;
+    let cores = Cores::from_cmdline("0-11").unwrap();
+    let corpus_dirs = [PathBuf::from("./corpus")];
+    let mut objective_dir = PathBuf::from("./crashes");
+
+    // Initialize QEMU
+    env::remove_var("LD_LIBRARY_PATH");
+    let args: Vec<String> = env::args().collect();
+    let env: Vec<(String, String)> = env::vars().collect();
+    let emu = Emulator::new(&args, &env);
+
+    let mut elf_buffer = Vec::new();
+    let elf = EasyElf::from_file(emu.binary_path(), &mut elf_buffer).unwrap();
+
+    let test_one_input_ptr = match env::var("MAIN_FUNC") {
+        Ok(s) => elf
+            .resolve_symbol(&s, emu.load_addr())
+            .expect(&format!("Symbol {} not found",s)),
+        Err(e) => elf
+            .resolve_symbol("LLVMFuzzerTestOneInput", emu.load_addr())
+            .expect("Symbol LLVMFuzzerTestOneInput not found"),
+    };
+    println!("Main funtion @ {:#x}", test_one_input_ptr);
+
+    emu.set_breakpoint(test_one_input_ptr); // LLVMFuzzerTestOneInput
+    unsafe { emu.run() };
+
+    println!("Break at {:#x}", emu.read_reg::<_, u64>(Regs::Rip).unwrap());
+
+    // Get the return address
+    let stack_ptr: u64 = emu.read_reg(Regs::Rsp).unwrap();
+    let mut ret_addr = [0; 8];
+    unsafe { emu.read_mem(stack_ptr, &mut ret_addr) };
+    let ret_addr = u64::from_le_bytes(ret_addr);
+
+    println!("Stack pointer = {:#x}", stack_ptr);
+    println!("Return address = {:#x}", ret_addr);
+
+    emu.remove_breakpoint(test_one_input_ptr); // LLVMFuzzerTestOneInput
+    emu.set_breakpoint(ret_addr); // LLVMFuzzerTestOneInput ret addr
+    let input_addr = match env::var("DIRECT_WRITE") { 
+        Ok(_) => elf
+            .resolve_symbol(&env::var("FUZZ_INPUT").expect("FUZZ_INPUT not set"), emu.load_addr())
+            .expect("FUZZ_INPUT symbol not found"),
+        _ => emu
+            .map_private(0, MAX_INPUT_SIZE, MmapPerms::ReadWrite)
+            .unwrap(),
+    };
+        
+    println!("Placing input at {:#x}", input_addr);
+
+    // The wrapped harness function, calling out to the LLVM-style harness
+    let mut harness = |input: &BytesInput| {
+        let target = input.target_bytes();
+        let mut buf = target.as_slice();
+        let mut len = buf.len();
+        if len > MAX_INPUT_SIZE {
+            buf = &buf[0..MAX_INPUT_SIZE];
+            len = MAX_INPUT_SIZE;
+        }
+
+        unsafe {
+            emu.write_mem(input_addr, buf);
+
+            if env::var("DIRECT_WRITE").is_err() {
+                emu.write_reg(Regs::Rdi, input_addr).unwrap();
+                emu.write_reg(Regs::Rsi, len).unwrap();
+            }
+                emu.write_reg(Regs::Rip, test_one_input_ptr).unwrap();
+                emu.write_reg(Regs::Rsp, stack_ptr).unwrap();
+
+            emu.run();
+        }
+
+        ExitKind::Ok
+    };
+
+    let mut run_client = |state: Option<_>, mut mgr, _core_id| {
+        // Create an observation channel using the coverage map
+        let edges = unsafe { &mut edges::EDGES_MAP };
+        let edges_counter = unsafe { &mut edges::MAX_EDGES_NUM };
+        let edges_observer =
+            HitcountsMapObserver::new(VariableMapObserver::new("edges", edges, edges_counter));
+
+        // Create an observation channel to keep track of the execution time
+        let time_observer = TimeObserver::new("time");
+
+        // Feedback to rate the interestingness of an input
+        // This one is composed by two Feedbacks in OR
+        let mut feedback = feedback_or!(
+            // New maximization map feedback linked to the edges observer and the feedback state
+            MaxMapFeedback::new_tracking(&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 mut 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.clone()).unwrap(),
+                // States of the feedbacks.
+                // The feedbacks can report the data that should persist in the State.
+                &mut feedback,
+                // Same for objective feedbacks
+                &mut objective,
+            )
+            .unwrap()
+        });
+
+        // A minimization+queue policy to get testcasess from the corpus
+        let scheduler = IndexesLenTimeMinimizerScheduler::new(QueueScheduler::new());
+
+        // A fuzzer with feedbacks and a corpus scheduler
+        let mut fuzzer = StdFuzzer::new(scheduler, feedback, objective);
+
+        let mut hooks = QemuHooks::new(&emu, tuple_list!(QemuEdgeCoverageHelper::default()));
+
+        // Create a QEMU in-process executor
+        let executor = QemuExecutor::new(
+            &mut hooks,
+            &mut harness,
+            tuple_list!(edges_observer, time_observer),
+            &mut fuzzer,
+            &mut state,
+            &mut mgr,
+        )
+        .expect("Failed to create QemuExecutor");
+
+        // Wrap the executor to keep track of the timeout
+        let mut executor = TimeoutExecutor::new(executor, timeout);
+
+        if state.corpus().count() < 1 {
+            state
+                .load_initial_inputs(&mut fuzzer, &mut executor, &mut mgr, &corpus_dirs)
+                .unwrap_or_else(|_| {
+                    println!("Failed to load initial corpus at {:?}", &corpus_dirs);
+                    process::exit(0);
+                });
+            println!("We imported {} inputs from disk.", state.corpus().count());
+        }
+
+        // Setup an havoc mutator with a mutational stage
+        let mutator = StdScheduledMutator::new(havoc_mutations());
+        let mut stages = tuple_list!(StdMutationalStage::new(mutator));
+
+        fuzzer.fuzz_loop(&mut stages, &mut executor, &mut state, &mut mgr)?;
+        Ok(())
+    };
+
+    // The shared memory allocator
+    let shmem_provider = StdShMemProvider::new().expect("Failed to init shared memory");
+
+    // The stats reporter for the broker
+    let monitor = MultiMonitor::new(|s| println!("{}", s));
+
+    // Build and run a Launcher
+    match Launcher::builder()
+        .shmem_provider(shmem_provider)
+        .broker_port(broker_port)
+        .configuration(EventConfig::from_build_id())
+        .monitor(monitor)
+        .run_client(&mut run_client)
+        .cores(&cores)
+        .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),
+    }
+}

fuzzers/qemu_fret/src/main.rs

@@ -0,0 +1,13 @@
+//! A libfuzzer-like fuzzer using qemu for binary-only coverage
+#[cfg(target_os = "linux")]
+mod fuzzer;
+
+#[cfg(target_os = "linux")]
+pub fn main() {
+    fuzzer::fuzz();
+}
+
+#[cfg(not(target_os = "linux"))]
+pub fn main() {
+    panic!("qemu-user and libafl_qemu is only supported on linux!");
+}

libafl_qemu/Cargo.toml

@@ -26,6 +26,8 @@ be = []
 usermode = []
 systemmode = []
 
+slirp = [ "systemmode" ] # build qemu with host libslirp (for user networking)
+
 clippy = [] # special feature for clippy, don't use in normal projects§
 
 [dependencies]

libafl_qemu/build_linux.rs

@@ -44,8 +44,6 @@ pub fn build() {
     println!("cargo:rustc-cfg=emulation_mode=\"{emulation_mode}\"");
 
     println!("cargo:rerun-if-changed=build.rs");
-    println!("cargo:rerun-if-changed=src/asan-giovese.c");
-    println!("cargo:rerun-if-changed=src/asan-giovese.h");
     println!("cargo:rerun-if-env-changed=CROSS_CC");
 
     // Make sure we have at most one architecutre feature set
@@ -215,7 +213,7 @@ pub fn build() {
                 //.arg("--as-static-lib")
                 .arg("--as-shared-lib")
                 .arg(&format!("--target-list={cpu_target}-{target_suffix}"))
-                .arg("--enable-slirp=internal")
+                .arg(if cfg!(feature = "slirp") {"--enable-slirp"} else {"--disable-slirp"})
                 .arg("--enable-fdt=internal")
                 .arg("--audio-drv-list=")
                 .arg("--disable-alsa")
@@ -422,7 +420,6 @@ pub fn build() {
                 build_dir.display()
             ))
             .arg(format!("{}/libfdt.a", build_dir.display()))
-            .arg(format!("{}/libslirp.a", build_dir.display()))
             .arg(format!("{}/libmigration.fa", build_dir.display()))
             .arg(format!("{}/libhwcore.fa", build_dir.display()))
             .arg(format!("{}/libqom.fa", build_dir.display()))
@@ -457,6 +454,8 @@ pub fn build() {
     println!("cargo:rustc-link-lib=glib-2.0");
     println!("cargo:rustc-link-lib=stdc++");
     println!("cargo:rustc-link-lib=z");
+    #[cfg(all(feature = "slirp", feature = "systemmode"))]
+    println!("cargo:rustc-link-lib=slirp");
 
     if emulation_mode == "systemmode" {
         println!("cargo:rustc-link-lib=pixman-1");

libafl_qemu/src/emu.rs

@@ -7,7 +7,7 @@ use core::{
 };
 #[cfg(emulation_mode = "usermode")]
 use core::{mem::MaybeUninit, ptr::copy_nonoverlapping};
-use std::{slice::from_raw_parts, str::from_utf8_unchecked};
+use std::{slice::from_raw_parts, str::from_utf8_unchecked,ffi::CString};
 
 #[cfg(emulation_mode = "usermode")]
 use libc::c_int;
@@ -226,6 +226,7 @@ extern "C" {
 extern "C" {
     fn qemu_init(argc: i32, argv: *const *const u8, envp: *const *const u8);
 
+    fn vm_start();
     fn qemu_main_loop();
     fn qemu_cleanup();
 
@@ -244,11 +245,9 @@ extern "C" {
 
     static mut libafl_start_vcpu: extern "C" fn(cpu: CPUStatePtr);
 
-    /*
-    fn libafl_save_qemu_snapshot(name: *const u8);
+    fn libafl_save_qemu_snapshot(name: *const u8, sync: bool);
     #[allow(unused)]
-    fn libafl_load_qemu_snapshot(name: *const u8);
-     */
+    fn libafl_load_qemu_snapshot(name: *const u8, sync: bool);
 }
 
 #[cfg(emulation_mode = "systemmode")]
@@ -723,7 +722,10 @@ impl Emulator {
         #[cfg(emulation_mode = "usermode")]
         libafl_qemu_run();
         #[cfg(emulation_mode = "systemmode")]
-        qemu_main_loop();
+        {
+            vm_start();
+            qemu_main_loop();
+        }
     }
 
     #[cfg(emulation_mode = "usermode")]
@@ -910,17 +912,17 @@ impl Emulator {
         }
     }
 
-    /*#[cfg(emulation_mode = "systemmode")]
-    pub fn save_snapshot(&self, name: &str) {
+    #[cfg(emulation_mode = "systemmode")]
+    pub fn save_snapshot(&self, name: &str, sync : bool) {
         let s = CString::new(name).expect("Invalid snapshot name");
-        unsafe { libafl_save_qemu_snapshot(s.as_ptr() as *const _) };
+        unsafe { libafl_save_qemu_snapshot(s.as_ptr() as *const _, sync) };
     }
 
     #[cfg(emulation_mode = "systemmode")]
-    pub fn load_snapshot(&self, name: &str) {
+    pub fn load_snapshot(&self, name: &str, sync : bool) {
         let s = CString::new(name).expect("Invalid snapshot name");
-        unsafe { libafl_load_qemu_snapshot(s.as_ptr() as *const _) };
-    }*/
+        unsafe { libafl_load_qemu_snapshot(s.as_ptr() as *const _, sync) };
+    }
 
     #[cfg(emulation_mode = "usermode")]
     pub fn set_pre_syscall_hook(