1 // SPDX-License-Identifier: GPL-2.0
2
3 //! Allocator support.
4
5 use core::alloc::{GlobalAlloc, Layout};
6 use core::ptr;
7
8 use crate::bindings;
9
10 struct KernelAllocator;
11
12 unsafe impl GlobalAlloc for KernelAllocator {
alloc(&self, layout: Layout) -> *mut u813 unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
14 // `krealloc()` is used instead of `kmalloc()` because the latter is
15 // an inline function and cannot be bound to as a result.
16 unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
17 }
18
dealloc(&self, ptr: *mut u8, _layout: Layout)19 unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
20 unsafe {
21 bindings::kfree(ptr as *const core::ffi::c_void);
22 }
23 }
24 }
25
26 #[global_allocator]
27 static ALLOCATOR: KernelAllocator = KernelAllocator;
28
29 // `rustc` only generates these for some crate types. Even then, we would need
30 // to extract the object file that has them from the archive. For the moment,
31 // let's generate them ourselves instead.
32 //
33 // Note that `#[no_mangle]` implies exported too, nowadays.
34 #[no_mangle]
__rust_alloc(size: usize, _align: usize) -> *mut u835 fn __rust_alloc(size: usize, _align: usize) -> *mut u8 {
36 unsafe { bindings::krealloc(core::ptr::null(), size, bindings::GFP_KERNEL) as *mut u8 }
37 }
38
39 #[no_mangle]
__rust_dealloc(ptr: *mut u8, _size: usize, _align: usize)40 fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) {
41 unsafe { bindings::kfree(ptr as *const core::ffi::c_void) };
42 }
43
44 #[no_mangle]
__rust_realloc(ptr: *mut u8, _old_size: usize, _align: usize, new_size: usize) -> *mut u845 fn __rust_realloc(ptr: *mut u8, _old_size: usize, _align: usize, new_size: usize) -> *mut u8 {
46 unsafe {
47 bindings::krealloc(
48 ptr as *const core::ffi::c_void,
49 new_size,
50 bindings::GFP_KERNEL,
51 ) as *mut u8
52 }
53 }
54
55 #[no_mangle]
__rust_alloc_zeroed(size: usize, _align: usize) -> *mut u856 fn __rust_alloc_zeroed(size: usize, _align: usize) -> *mut u8 {
57 unsafe {
58 bindings::krealloc(
59 core::ptr::null(),
60 size,
61 bindings::GFP_KERNEL | bindings::__GFP_ZERO,
62 ) as *mut u8
63 }
64 }
65
