projects/linux·blob f24767ca · refs

64 lines · 1.8 KiB

1// SPDX-License-Identifier: GPL-2.0
2
3//! Allocator support.
4
5use core::alloc::{GlobalAlloc, Layout};
6use core::ptr;
7
8use crate::bindings;
9
10struct KernelAllocator;
11
12unsafe impl GlobalAlloc for KernelAllocator {
13 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
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]
27static 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]
35fn __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]
40fn __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]
45fn __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]
56fn __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}