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UserspaceEmulator: Implement a proper VM allocator

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This patch brings Kernel::RangeAllocator to UserspaceEmulator in a
slightly simplified form.

It supports the basic three allocation types needed by virt$mmap():
allocate_anywhere, allocate_specific, and allocate_randomized.

Porting virt$mmap() and virt$munmap() to use the allocator makes
UE work correctly once again. :^)
This commit is contained in:
Andreas Kling 2021-02-06 23:08:51 +01:00
parent 9dacd7c0ec
commit 89483a9408
10 changed files with 438 additions and 36 deletions
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57
Userland/DevTools/UserspaceEmulator/RangeAllocator.h Normal file
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/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "Range.h"
#include <AK/Vector.h>
namespace UserspaceEmulator {
class RangeAllocator {
public:
RangeAllocator();
~RangeAllocator();
void initialize_with_range(VirtualAddress, size_t);
Optional<Range> allocate_anywhere(size_t, size_t alignment = PAGE_SIZE);
Optional<Range> allocate_specific(VirtualAddress, size_t);
Optional<Range> allocate_randomized(size_t, size_t alignment);
void deallocate(const Range&);
void dump() const;
bool contains(const Range& range) const { return m_total_range.contains(range); }
private:
void carve_at_index(int, const Range&);
Vector<Range> m_available_ranges;
Range m_total_range;
};
}