src/pagealloc.rs

// SPDX-License-Identifier: GPL-2.0
// Copyright 2022-2023 Google LLC
// Author: Ard Biesheuvel <ardb@google.com>

use core::alloc::GlobalAlloc;

use crate::paging::PAGE_SIZE;
use crate::ALLOCATOR;

pub fn get_zeroed_page() -> u64 {
    let layout = core::alloc::Layout::from_size_align(PAGE_SIZE, PAGE_SIZE).unwrap();
    let page = unsafe { ALLOCATOR.alloc(layout) };
    if page.is_null() {
        panic!("Out of memory!");
    }

    unsafe { core::ptr::write_bytes(page, 0u8, PAGE_SIZE) };
    page as u64
}