hardened_malloc_sys/
lib.rs

1//
2// hardened-malloc-sys: Rust bindings for GrapheneOS allocator
3// src/lib.rs: Extern definitions for allocator functions
4//
5// Copyright (c) 2025 Ali Polatel <alip@chesswob.org>
6// Based in part upon hardened_malloc-rs/src/bindings.rs which is
7//   Copyright (c) strawberry <strawberry@puppygock.gay>
8//   SPDX-License-Identifier: Apache-2.0 OR MIT
9//
10// SPDX-License-Identifier: MIT
11
12#![no_std]
13
14use core::ffi::{c_int, c_void};
15
16// ideally we would use c_size_t but it's unstable
17
18#[allow(dead_code)]
19extern "C" {
20    /* C standard */
21    pub fn malloc(size: usize) -> *mut c_void;
22    pub fn calloc(nmemb: usize, size: usize) -> *mut c_void;
23    pub fn realloc(ptr: *mut c_void, size: usize) -> *mut c_void;
24    pub fn aligned_alloc(alignment: usize, size: usize) -> *mut c_void;
25    pub fn free(ptr: *mut c_void);
26
27    /* POSIX */
28    pub fn posix_memalign(memptr: *mut *mut c_void, alignment: usize, size: usize) -> c_int;
29
30    /* hardened_malloc extensions */
31    /// return an upper bound on object size for any pointer based on malloc
32    /// metadata
33    pub fn malloc_object_size(ptr: *const c_void) -> usize;
34
35    /// similar to malloc_object_size, but avoiding locking so the results are
36    /// much more limited
37    pub fn malloc_object_size_fast(ptr: *const c_void) -> usize;
38
39    /// The free function with an extra parameter for passing the size requested
40    /// at allocation time.
41    ///
42    /// This offers the same functionality as C++14 sized deallocation and can
43    /// be used to implement it.
44    ///
45    /// A performance-oriented allocator would use this as a performance
46    /// enhancement with undefined behavior on a mismatch. Instead, this
47    /// hardened allocator implementation uses it to improve security by
48    /// checking that the passed size matches the allocated size.
49    pub fn free_sized(ptr: *mut c_void, expected_size: usize) -> c_void;
50}
hardened_malloc_sys/lib.rs

hardened_malloc_sys/
lib.rs
