// SPDX-License-Identifier: GPL-2.0 //! Allocator support. use core::alloc::{GlobalAlloc, Layout};use core::ptr; use crate::bindings; struct KernelAllocator; unsafe impl GlobalAlloc for KernelAllocator {    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {        // `krealloc()` is used instead of `kmalloc()` because the latter is        // an inline function and cannot be bound to as a result.        unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }    }     unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {        unsafe {            bindings::kfree(ptr as *const core::ffi::c_void);        }    }} #[global_allocator]static ALLOCATOR: KernelAllocator = KernelAllocator; // `rustc` only generates these for some crate types. Even then, we would need// to extract the object file that has them from the archive. For the moment,// let's generate them ourselves instead.//// Note that `#[no_mangle]` implies exported too, nowadays.#[no_mangle]fn __rust_alloc(size: usize, _align: usize) -> *mut u8 {    unsafe { bindings::krealloc(core::ptr::null(), size, bindings::GFP_KERNEL) as *mut u8 }} #[no_mangle]fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) {    unsafe { bindings::kfree(ptr as *const core::ffi::c_void) };} #[no_mangle]fn __rust_realloc(ptr: *mut u8, _old_size: usize, _align: usize, new_size: usize) -> *mut u8 {    unsafe {        bindings::krealloc(            ptr as *const core::ffi::c_void,            new_size,            bindings::GFP_KERNEL,        ) as *mut u8    }} #[no_mangle]fn __rust_alloc_zeroed(size: usize, _align: usize) -> *mut u8 {    unsafe {        bindings::krealloc(            core::ptr::null(),            size,            bindings::GFP_KERNEL | bindings::__GFP_ZERO,        ) as *mut u8    }}