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247b365d WAF |
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 { | |
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] | |
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] | |
35 | 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] | |
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] | |
45 | 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] | |
56 | 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 | } |