chromium/base/allocator/partition_allocator/src/partition_alloc/thread_isolation/pkey.h

// Copyright 2022 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_THREAD_ISOLATION_PKEY_H_
#define PARTITION_ALLOC_THREAD_ISOLATION_PKEY_H_

#include "partition_alloc/buildflags.h"

#if PA_BUILDFLAG(ENABLE_PKEYS)

#include <cstddef>
#include <cstdint>

#include "partition_alloc/buildflags.h"
#include "partition_alloc/partition_alloc_base/component_export.h"
#include "partition_alloc/thread_isolation/alignment.h"

namespace partition_alloc::internal {

constexpr int kDefaultPkey = …;
constexpr int kInvalidPkey = …;

// Check if the CPU supports pkeys.
bool CPUHasPkeySupport();

// A wrapper around the pkey_mprotect syscall.
[[nodiscard]] int PkeyMprotect(void* addr, size_t len, int prot, int pkey);

void TagMemoryWithPkey(int pkey, void* address, size_t size);

int PkeyAlloc(int access_rights);

void PkeyFree(int pkey);

// Read the pkru register (the current pkey state).
uint32_t Rdpkru();

// Write the pkru register (the current pkey state).
void Wrpkru(uint32_t pkru);

#if PA_BUILDFLAG(DCHECKS_ARE_ON)

class PA_COMPONENT_EXPORT(PARTITION_ALLOC) LiftPkeyRestrictionsScope { … };

#endif  // PA_BUILDFLAG(DCHECKS_ARE_ON)

}  // namespace partition_alloc::internal

#endif  // PA_BUILDFLAG(ENABLE_PKEYS)

#endif  // PARTITION_ALLOC_THREAD_ISOLATION_PKEY_H_