Added heap feature (#3074)

* Added heap feature

* Rename feature and add some more docs

* Use document-features crate

* Expose the patching API for more flexibility

---------

Co-authored-by: Your Name <you@example.com>

libafl_qemu/librasan/asan/Cargo.toml

@@ -8,8 +8,11 @@ rust-version.workspace = true
 crate-type = ["rlib"]
 
 [features]
+#! # Features
 default = [
   "dlmalloc",
+  "document-features",
+  "global_allocator",
   "guest",
   "hooks",
   "host",
@@ -19,14 +22,27 @@ default = [
   "test",
   "tracking",
 ]
+## Enable support for the `dlmalloc` allocator backend
 dlmalloc = ["dep:dlmalloc"]
+## Enable documentation of features
+document-features = ["dep:document-features"]
+## Configure a global allocator (using dlmalloc or mimalloc as configured)
+global_allocator = []
+## Enable support for shadow memory and tracking in the guest
 guest = []
+## Enable support for hooking functions in the guest
 hooks = []
+## Enable support for shadow memory and tracking in the host
 host = ["dep:syscalls"]
+## Enable use of the `libc` library to support creation of mappings, read/write, logging etc (more OS agnostic)
 libc = ["dep:libc"]
+## Enable the use of direct syscalls (supported by `rustix`) to interact with the operating system (Linux specific).
 linux = ["dep:rustix"]
+## Enable the `baby_mimalloc` allocator
 mimalloc = ["dep:baby-mimalloc"]
+##  Disable the magic used to support `no_std` environments for running unit and integration tests
 test = []
+## Enable support for memory tracking
 tracking = []
 
 [dependencies]
@@ -34,6 +50,7 @@ baby-mimalloc = { version = "0.2.1", default-features = false, features = [
   "spin_mutex",
 ], optional = true }
 bitflags = { version = "2.8.0", default-features = false }
+document-features = { version = "0.2.11", optional = true }
 dlmalloc = { version = "0.2.7", default-features = false, optional = true }
 itertools = { version = "0.14.0", default-features = false }
 log = { version = "0.4.22", default-features = false, features = [

libafl_qemu/librasan/asan/src/hooks/mod.rs

@@ -73,7 +73,7 @@ pub struct PatchedHook {
 }
 
 impl PatchedHook {
-    const fn new<F: Copy>(name: &'static CStr, func: F) -> Self {
+    pub const fn new<F: Copy>(name: &'static CStr, func: F) -> Self {
         let pf = (&func) as *const F as *const GuestAddr;
         let destination = unsafe { *pf };
         Self { name, destination }

libafl_qemu/librasan/asan/src/lib.rs

@@ -29,21 +29,9 @@
 //! The componentized nature of the design is intended to permit the user to
 //! adapt `asan` to their needs with minimal modification by selecting and
 //! combining alternative implementations of the various key components.
-//!
-//! ## Features
-//! - `dlmalloc` - Enable support for the dlmalloc allocator backend.
-//! - `guest` - Enable support for shadow memory and tracking in the guest
-//! - `hooks` - Enable support for hooking functions in the guest
-//! - `host` - Enable support for shadow memory and tracking in the host
-//! - `libc` - Enable use of the `libc` library to support creation of mappings,
-//!   read/write, logging etc (more OS agnostic)
-//! - `linux` - Enable the use of direct syscalls (supported by `rustix`) to
-//!   interact with the operating system (Linux specific).
-//! - `test` - Disable the magic used to support `no_std` environments for
-//!   running unit and integration tests
-//! - `tracking` - Enable support for memory tracking.
 #![cfg_attr(not(feature = "test"), no_std)]
 #![cfg_attr(target_arch = "powerpc", feature(asm_experimental_arch))]
+#![cfg_attr(feature = "document-features", doc = document_features::document_features!())]
 
 pub mod allocator;
 

libafl_qemu/librasan/asan/src/mem.rs

@@ -3,10 +3,10 @@ use core::{
     slice::{from_raw_parts, from_raw_parts_mut},
 };
 
-#[cfg(feature = "dlmalloc")]
+#[cfg(all(feature = "global_allocator", feature = "dlmalloc"))]
 use crate::allocator::backend::dlmalloc::DlmallocBackend;
 
-#[cfg(all(feature = "linux", not(feature = "libc")))]
+#[cfg(all(feature = "global_allocator", feature = "linux", not(feature = "libc")))]
 type Mmap = crate::mmap::linux::LinuxMmap;
 
 #[cfg(feature = "libc")]
@@ -14,14 +14,23 @@ type Mmap = crate::mmap::libc::LibcMmap<
     crate::symbols::dlsym::DlSymSymbols<crate::symbols::dlsym::LookupTypeNext>,
 >;
 
+#[cfg(all(feature = "global_allocator"))]
 const PAGE_SIZE: usize = 4096;
 
 #[global_allocator]
-#[cfg(all(feature = "dlmalloc", not(feature = "mimalloc")))]
+#[cfg(all(
+    feature = "global_allocator",
+    feature = "dlmalloc",
+    not(feature = "mimalloc")
+))]
 static GLOBAL_ALLOCATOR: DlmallocBackend<Mmap> = DlmallocBackend::new(PAGE_SIZE);
 
 #[global_allocator]
-#[cfg(all(feature = "dlmalloc", feature = "mimalloc"))]
+#[cfg(all(
+    feature = "global_allocator",
+    feature = "dlmalloc",
+    feature = "mimalloc"
+))]
 static GLOBAL_ALLOCATOR: baby_mimalloc::MimallocMutexWrapper<DlmallocBackend<Mmap>> =
     baby_mimalloc::MimallocMutexWrapper::with_os_allocator(DlmallocBackend::new(PAGE_SIZE));
 

libafl_qemu/librasan/asan/src/patch/hooks.rs

@@ -23,26 +23,32 @@ impl PatchedHooks {
     pub fn init<S: Symbols, P: Patch, R: MapReader, M: Mmap>()
     -> Result<(), PatchesError<S, P, R, M>> {
         debug!("Installing patches");
-        let reader = R::new().map_err(|e| PatchesError::MapReaderError(e))?;
-        let mappings = MapIterator::new(reader).collect::<Vec<MapEntry>>();
+        let mappings = Self::get_mappings()?;
         mappings.iter().for_each(|m| trace!("{m:?}"));
-        let patches = PatchedHook::all()
-            .into_iter()
-            .map(|p| Self::apply_patch(p, &mappings))
-            .collect::<Result<BTreeMap<GuestAddr, PatchedHook>, PatchesError<S, P, R, M>>>()?;
-        PATCHED.lock().replace(patches);
+        for patch in PatchedHook::all() {
+            Self::patch(patch, &mappings)?;
+        }
         debug!("Patching complete");
         Ok(())
     }
 
-    fn apply_patch<S: Symbols, P: Patch, R: MapReader, M: Mmap>(
-        p: PatchedHook,
+    pub fn get_mappings<S: Symbols, P: Patch, R: MapReader, M: Mmap>()
+    -> Result<Vec<MapEntry>, PatchesError<S, P, R, M>> {
+        let reader = R::new().map_err(|e| PatchesError::MapReaderError(e))?;
+        Ok(MapIterator::new(reader).collect::<Vec<MapEntry>>())
+    }
+
+    pub fn patch<S: Symbols, P: Patch, R: MapReader, M: Mmap>(
+        patch: PatchedHook,
         mappings: &[MapEntry],
-    ) -> Result<(GuestAddr, PatchedHook), PatchesError<S, P, R, M>> {
-        trace!("patch: {:?}, destination: {:#x}", p.name, p.destination);
-        let target = S::lookup(p.name.as_ptr() as *const c_char)
+    ) -> Result<(), PatchesError<S, P, R, M>> {
+        trace!(
+            "patch: {:?}, destination: {:#x}",
+            patch.name, patch.destination
+        );
+        let target = S::lookup(patch.name.as_ptr() as *const c_char)
             .map_err(|e| PatchesError::SymbolsError(e))?;
-        trace!("patching: {:#x} -> {:#x}", target, p.destination);
+        trace!("patching: {:#x} -> {:#x}", target, patch.destination);
         let mapping = mappings
             .iter()
             .filter(|m| m.contains(target))
@@ -51,9 +57,10 @@ impl PatchedHooks {
         let prot = mapping
             .writeable::<M>()
             .map_err(|e| PatchesError::MmapError(e))?;
-        P::patch(target, p.destination).map_err(|e| PatchesError::PatchError(e))?;
+        P::patch(target, patch.destination).map_err(|e| PatchesError::PatchError(e))?;
         drop(prot);
-        Ok((target, p))
+        PATCHED.lock().get_or_insert_default().insert(target, patch);
+        Ok(())
     }
 
     pub fn check_patched(addr: GuestAddr) -> Result<(), PatchesCheckError> {

libafl_qemu/librasan/gasan/Cargo.toml

@@ -14,6 +14,7 @@ test = ["asan/test", "dummy_libc/test"]
 [dependencies]
 asan = { path = "../asan", default-features = false, features = [
   "dlmalloc",
+  "global_allocator",
   "guest",
   "hooks",
   "libc",

libafl_qemu/librasan/qasan/Cargo.toml

@@ -14,6 +14,7 @@ test = ["asan/test", "dummy_libc/test"]
 [dependencies]
 asan = { path = "../asan", default-features = false, features = [
   "dlmalloc",
+  "global_allocator",
   "hooks",
   "host",
   "libc",

libafl_qemu/librasan/zasan/Cargo.toml

@@ -14,6 +14,7 @@ test = ["asan/test"]
 [dependencies]
 asan = { path = "../asan", default-features = false, features = [
   "dlmalloc",
+  "global_allocator",
   "guest",
   "hooks",
   "host",