Compile-time edge module compilation check, native support for ConstM…

…apObserver (#2592)

* compile-time edge module compilation trick

* clippy

* possible since rust 1.79

* split edge module in submodules

* Update frida to 0.14.0 (#2596)

* update frida crate to the latest version

* adapt libafl_frida to the latest version of frida

* tracers and generators private modules

* do not use star export.

* same for drcov

* forgot a file...

* first draft of generic-based edge module for ConstantLengthMapObserver.

* integration of OwnedSizedSlice.

replaced OwnedSlice in ConstMapObserver by the new OwnedSizedSlice.

* fix serde stuff

* no std

* import

* fixed qemu_cmin with new constant map abstraction.

* fix const map

* fix clippy from another pr...

* fix non-null usage

* fix ci?

* new feature stuff

* fixes

* minor fixes

* fmt

* non null

* im stupid

* fmt

* fix fuzzer

* fix fuzzers

* sized slice

* fuzzer fixes

* ptr::NonNull -> NonNull

* shorter trait length

* fmt

.github/workflows/qemu-fuzzer-tester-prepare/action.yml

@@ -5,7 +5,7 @@ runs:
   steps:
     - name: Install QEMU deps
       shell: bash
-      run: apt-get update && apt-get install -y qemu-utils sudo python3-msgpack python3-jinja2 curl
+      run: apt-get update && apt-get install -y qemu-utils sudo python3-msgpack python3-jinja2 curl python3-dev
     - uses: dtolnay/rust-toolchain@stable
     - name: enable mult-thread for `make`
       shell: bash

fuzzers/baby/backtrace_baby_fuzzers/c_code_with_fork_executor/src/main.rs

@@ -1,4 +1,4 @@
-use std::{path::PathBuf, time::Duration};
+use std::{path::PathBuf, ptr::NonNull, time::Duration};
 
 use libafl::{
     corpus::{InMemoryCorpus, OnDiskCorpus},
@@ -46,7 +46,12 @@ pub fn main() {
         libafl::executors::ExitKind::Ok
     };
     // Create an observation channel using the signals map
-    let observer = unsafe { ConstMapObserver::<u8, 3>::from_mut_ptr("signals", map_ptr) };
+    let observer = unsafe {
+        ConstMapObserver::<u8, 3>::from_mut_ptr(
+            "signals",
+            NonNull::new(map_ptr).expect("map ptr is null."),
+        )
+    };
     // Create a stacktrace observer
     let mut bt = shmem_provider.new_on_shmem::<Option<u64>>(None).unwrap();
     let bt_observer = BacktraceObserver::new(

fuzzers/baby/backtrace_baby_fuzzers/c_code_with_inprocess_executor/src/main.rs

@@ -1,4 +1,4 @@
-use std::path::PathBuf;
+use std::{path::PathBuf, ptr::NonNull};
 
 use libafl::{
     corpus::{InMemoryCorpus, OnDiskCorpus},
@@ -35,7 +35,12 @@ pub fn main() {
         libafl::executors::ExitKind::Ok
     };
     // Create an observation channel using the signals map
-    let observer = unsafe { ConstMapObserver::<u8, 3>::from_mut_ptr("signals", array_ptr) };
+    let observer = unsafe {
+        ConstMapObserver::<u8, 3>::from_mut_ptr(
+            "signals",
+            NonNull::new(array_ptr).expect("map ptr is null"),
+        )
+    };
     // Create a stacktrace observer
     let bt_observer = BacktraceObserver::owned(
         "BacktraceObserver",

fuzzers/baby/backtrace_baby_fuzzers/forkserver_executor/src/main.rs

@@ -42,7 +42,10 @@ pub fn main() {
     let mut shmem = shmem_provider.new_shmem(MAP_SIZE).unwrap();
     //let the forkserver know the shmid
     shmem.write_to_env("__AFL_SHM_ID").unwrap();
-    let shmem_map = shmem.as_slice_mut();
+    let shmem_map: &mut [u8; MAP_SIZE] = shmem
+        .as_slice_mut()
+        .try_into()
+        .expect("could not convert slice to sized slice.");
 
     // Create an observation channel using the signals map
     let edges_observer = HitcountsMapObserver::new(ConstMapObserver::<_, MAP_SIZE>::new(

fuzzers/binary_only/fuzzbench_fork_qemu/src/fuzzer.rs

@@ -9,6 +9,7 @@ use std::{
     io::{self, Write},
     path::PathBuf,
     process,
+    ptr::NonNull,
     time::Duration,
 };
 
@@ -160,14 +161,14 @@ fn fuzz(
     let mut edges_observer = unsafe {
         HitcountsMapObserver::new(ConstMapObserver::<_, EDGES_MAP_DEFAULT_SIZE>::from_mut_ptr(
             "edges",
-            edges.as_mut_ptr(),
+            NonNull::new(edges.as_mut_ptr()).expect("map ptr is null."),
         ))
         .track_indices()
     };
 
     let emulator_modules = tuple_list!(
         StdEdgeCoverageChildModule::builder()
-            .map_observer(edges_observer.as_mut())
+            .const_map_observer(edges_observer.as_mut())
             .build()?,
         CmpLogChildModule::default(),
     );
@@ -199,7 +200,8 @@ fn fuzz(
 
     let stack_ptr: u64 = qemu.read_reg(Regs::Sp).unwrap();
     let mut ret_addr = [0; 8];
-    unsafe { qemu.read_mem(stack_ptr, &mut ret_addr) };
+    qemu.read_mem(stack_ptr, &mut ret_addr)
+        .expect("qemu read failed");
     let ret_addr = u64::from_le_bytes(ret_addr);
 
     println!("Stack pointer = {stack_ptr:#x}");
@@ -323,7 +325,7 @@ fn fuzz(
     let mut fuzzer = StdFuzzer::new(scheduler, feedback, objective);
 
     // The wrapped harness function, calling out to the LLVM-style harness
-    let mut harness = |emulator: &mut Emulator<_, _, _, _, _>, input: &BytesInput| {
+    let mut harness = |_emulator: &mut Emulator<_, _, _, _, _>, input: &BytesInput| {
         let target = input.target_bytes();
         let mut buf = target.as_slice();
         let mut len = buf.len();
@@ -333,7 +335,7 @@ fn fuzz(
         }
 
         unsafe {
-            qemu.write_mem(input_addr, buf);
+            qemu.write_mem_unchecked(input_addr, buf);
 
             qemu.write_reg(Regs::Rdi, input_addr).unwrap();
             qemu.write_reg(Regs::Rsi, len as GuestReg).unwrap();
@@ -394,8 +396,8 @@ fn fuzz(
     #[cfg(unix)]
     {
         let null_fd = file_null.as_raw_fd();
-        // dup2(null_fd, io::stdout().as_raw_fd())?;
-        // dup2(null_fd, io::stderr().as_raw_fd())?;
+        dup2(null_fd, io::stdout().as_raw_fd())?;
+        dup2(null_fd, io::stderr().as_raw_fd())?;
     }
     // reopen file to make sure we're at the end
     log.replace(

fuzzers/binary_only/qemu_cmin/src/fuzzer.rs

@@ -2,7 +2,7 @@
 //!
 #[cfg(feature = "i386")]
 use core::mem::size_of;
-use std::{env, io, path::PathBuf, process};
+use std::{env, io, path::PathBuf, process, ptr::NonNull};
 
 use clap::{builder::Str, Parser};
 use libafl::{
@@ -162,7 +162,7 @@ pub fn fuzz() -> Result<(), Error> {
     let mut edges_observer = unsafe {
         HitcountsMapObserver::new(ConstMapObserver::<_, EDGES_MAP_DEFAULT_SIZE>::from_mut_ptr(
             "edges",
-            edges.as_mut_ptr(),
+            NonNull::new(edges.as_mut_ptr()).expect("The edge map pointer is null."),
         ))
     };
 
@@ -196,7 +196,7 @@ pub fn fuzz() -> Result<(), Error> {
         let len = len as GuestReg;
 
         unsafe {
-            qemu.write_mem(input_addr, buf);
+            qemu.write_mem(input_addr, buf).expect("qemu write failed.");
             qemu.write_reg(Regs::Pc, test_one_input_ptr).unwrap();
             qemu.write_reg(Regs::Sp, stack_ptr).unwrap();
             qemu.write_return_address(ret_addr).unwrap();
@@ -219,7 +219,7 @@ pub fn fuzz() -> Result<(), Error> {
     };
 
     let modules = tuple_list!(StdEdgeCoverageChildModule::builder()
-        .map_observer(edges_observer.as_mut())
+        .const_map_observer(edges_observer.as_mut())
         .build()?);
 
     let emulator = Emulator::empty().qemu(qemu).modules(modules).build()?;

libafl/src/executors/forkserver.rs

@@ -1635,7 +1635,7 @@ mod tests {
 
         let mut shmem = shmem_provider.new_shmem(MAP_SIZE).unwrap();
         shmem.write_to_env("__AFL_SHM_ID").unwrap();
-        let shmem_buf = shmem.as_slice_mut();
+        let shmem_buf: &mut [u8; MAP_SIZE] = shmem.as_slice_mut().try_into().unwrap();
 
         let edges_observer = HitcountsMapObserver::new(ConstMapObserver::<_, MAP_SIZE>::new(
             "shared_mem",

libafl/src/observers/map/const_map.rs

@@ -5,28 +5,26 @@ use core::{
     fmt::Debug,
     hash::{Hash, Hasher},
     ops::{Deref, DerefMut},
+    ptr::NonNull,
 };
 
 use ahash::RandomState;
-use libafl_bolts::{ownedref::OwnedMutSlice, AsSlice, AsSliceMut, HasLen, Named};
+use libafl_bolts::{ownedref::OwnedMutSizedSlice, HasLen, Named};
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 
 use crate::{
-    observers::{map::MapObserver, Observer, VariableLengthMapObserver},
+    observers::{map::MapObserver, ConstLenMapObserver, Observer},
     Error,
 };
 
-// TODO: remove the size field and implement ConstantLengthMapObserver
-
 /// Use a const size to speedup `Feedback::is_interesting` when the user can
 /// know the size of the map at compile time.
 #[derive(Serialize, Deserialize, Debug)]
 #[allow(clippy::unsafe_derive_deserialize)]
 pub struct ConstMapObserver<'a, T, const N: usize> {
-    map: OwnedMutSlice<'a, T>,
+    map: OwnedMutSizedSlice<'a, T, N>,
     initial: T,
     name: Cow<'static, str>,
-    size: usize,
 }
 
 impl<I, S, T, const N: usize> Observer<I, S> for ConstMapObserver<'_, T, N>
@@ -87,19 +85,19 @@ where
 
     #[inline]
     fn get(&self, idx: usize) -> T {
-        self.as_slice()[idx]
+        self[idx]
     }
 
     #[inline]
     fn set(&mut self, idx: usize, val: T) {
-        self.map.as_slice_mut()[idx] = val;
+        (*self)[idx] = val;
     }
 
     /// Count the set bytes in the map
     fn count_bytes(&self) -> u64 {
         let initial = self.initial();
         let cnt = self.usable_count();
-        let map = self.as_slice();
+        let map = self.map.as_slice();
         let mut res = 0;
         for x in &map[0..cnt] {
             if *x != initial {
@@ -110,7 +108,7 @@ where
     }
 
     fn usable_count(&self) -> usize {
-        self.as_slice().len()
+        self.len()
     }
 
     #[inline]
@@ -124,22 +122,22 @@ where
         // Normal memset, see https://rust.godbolt.org/z/Trs5hv
         let initial = self.initial();
         let cnt = self.usable_count();
-        let map = self.as_slice_mut();
+        let map = &mut (*self);
         for x in &mut map[0..cnt] {
             *x = initial;
         }
         Ok(())
     }
 
     fn to_vec(&self) -> Vec<T> {
-        self.as_slice().to_vec()
+        self.map.to_vec()
     }
 
     /// Get the number of set entries with the specified indexes
     fn how_many_set(&self, indexes: &[usize]) -> usize {
         let initial = self.initial();
         let cnt = self.usable_count();
-        let map = self.as_slice();
+        let map = self.map.as_slice();
         let mut res = 0;
         for i in indexes {
             if *i < cnt && map[*i] != initial {
@@ -150,37 +148,30 @@ where
     }
 }
 
-impl<T, const N: usize> VariableLengthMapObserver for ConstMapObserver<'_, T, N>
+impl<T, const N: usize> ConstLenMapObserver<N> for ConstMapObserver<'_, T, N>
 where
     T: PartialEq + Copy + Hash + Serialize + DeserializeOwned + Debug + 'static,
 {
-    fn map_slice(&mut self) -> &[Self::Entry] {
-        self.map.as_slice()
-    }
-
-    fn map_slice_mut(&mut self) -> &mut [Self::Entry] {
-        self.map.as_slice_mut()
-    }
-
-    fn size(&mut self) -> &usize {
-        &N
+    fn map_slice(&self) -> &[Self::Entry; N] {
+        &self.map
     }
 
-    fn size_mut(&mut self) -> &mut usize {
-        &mut self.size
+    fn map_slice_mut(&mut self) -> &mut [Self::Entry; N] {
+        &mut self.map
     }
 }
 
 impl<T, const N: usize> Deref for ConstMapObserver<'_, T, N> {
     type Target = [T];
+
     fn deref(&self) -> &[T] {
-        &self.map
+        self.map.as_slice()
     }
 }
 
 impl<T, const N: usize> DerefMut for ConstMapObserver<'_, T, N> {
     fn deref_mut(&mut self) -> &mut [T] {
-        &mut self.map
+        self.map.as_mut_slice()
     }
 }
 
@@ -194,48 +185,25 @@ where
     /// Will get a pointer to the map and dereference it at any point in time.
     /// The map must not move in memory!
     #[must_use]
-    pub fn new(name: &'static str, map: &'a mut [T]) -> Self {
+    pub fn new(name: &'static str, map: &'a mut [T; N]) -> Self {
         assert!(map.len() >= N);
         Self {
-            map: OwnedMutSlice::from(map),
+            map: OwnedMutSizedSlice::from(map),
             name: Cow::from(name),
             initial: T::default(),
-            size: N,
         }
     }
 
     /// Creates a new [`MapObserver`] from a raw pointer
     ///
     /// # Safety
     /// Will dereference the `map_ptr` with up to len elements.
-    pub unsafe fn from_mut_ptr(name: &'static str, map_ptr: *mut T) -> Self {
+    #[must_use]
+    pub unsafe fn from_mut_ptr(name: &'static str, map_ptr: NonNull<T>) -> Self {
         ConstMapObserver {
-            map: OwnedMutSlice::from_raw_parts_mut(map_ptr, N),
+            map: OwnedMutSizedSlice::from_raw_mut(map_ptr),
             name: Cow::from(name),
             initial: T::default(),
-            size: N,
-        }
-    }
-}
-
-impl<T, const N: usize> ConstMapObserver<'_, T, N>
-where
-    T: Default + Clone,
-{
-    /// Creates a new [`MapObserver`] with an owned map
-    #[must_use]
-    pub fn owned(name: &'static str, map: Vec<T>) -> Self {
-        assert!(map.len() >= N);
-        let initial = if map.is_empty() {
-            T::default()
-        } else {
-            map[0].clone()
-        };
-        Self {
-            map: OwnedMutSlice::from(map),
-            name: Cow::from(name),
-            initial,
-            size: N,
         }
     }
 }