chromium/base/allocator/partition_allocator/src/partition_alloc/pool_offset_freelist.h

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef PARTITION_ALLOC_POOL_OFFSET_FREELIST_H_
#define PARTITION_ALLOC_POOL_OFFSET_FREELIST_H_

#include <cstddef>
#include <cstdint>

#include "partition_alloc/build_config.h"
#include "partition_alloc/buildflags.h"
#include "partition_alloc/partition_address_space.h"
#include "partition_alloc/partition_alloc-inl.h"
#include "partition_alloc/partition_alloc_base/compiler_specific.h"
#include "partition_alloc/partition_alloc_config.h"
#include "partition_alloc/partition_alloc_constants.h"
#include "partition_alloc/tagging.h"

#if !PA_BUILDFLAG(PA_ARCH_CPU_BIG_ENDIAN)
#include "partition_alloc/reverse_bytes.h"
#endif

namespace partition_alloc::internal {

namespace {
PoolInfo;
}

class PoolOffsetFreelistEntry;

class EncodedPoolOffset { … };

// Freelist entries are encoded for security reasons. See
// //base/allocator/partition_allocator/PartitionAlloc.md
// and |Transform()| for the rationale and mechanism, respectively.
//
// We'd to especially point out, that as part of encoding, we store the entries
// as pool offsets. In a scenario that an attacker has a write primitive
// anywhere within the pool, they would not be able to corrupt the freelist
// in a way that would allow them to break out of the pool.
class PoolOffsetFreelistEntry { … };

}  // namespace partition_alloc::internal

#endif  // PARTITION_ALLOC_POOL_OFFSET_FREELIST_H_