chromium/v8/src/base/platform/memory-protection-key.cc

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/base/platform/memory-protection-key.h"

#if V8_HAS_PKU_JIT_WRITE_PROTECT

#include <sys/mman.h>  // For {mprotect()} protection macros.
#undef MAP_TYPE  // Conflicts with MAP_TYPE in Torque-generated instance-types.h

#include "src/base/logging.h"
#include "src/base/macros.h"

// Declare all the pkey functions as weak to support older glibc versions where
// they don't exist yet.
int pkey_mprotect(void* addr, size_t len, int prot, int pkey) V8_WEAK;
int pkey_get(int key) V8_WEAK;
int pkey_set(int, unsigned) V8_WEAK;
int pkey_alloc(unsigned int, unsigned int) V8_WEAK;

namespace v8 {
namespace base {

namespace {

int GetProtectionFromMemoryPermission(PageAllocator::Permission permission) { … }

}  // namespace

bool MemoryProtectionKey::HasMemoryProtectionKeySupport() { … }

// static
int MemoryProtectionKey::AllocateKey() { … }

// static
bool MemoryProtectionKey::SetPermissionsAndKey(
    base::AddressRegion region, v8::PageAllocator::Permission page_permissions,
    int key) { … }

// static
void MemoryProtectionKey::SetPermissionsForKey(int key,
                                               Permission permissions) { … }

// static
MemoryProtectionKey::Permission MemoryProtectionKey::GetKeyPermission(int key) { … }

}  // namespace base
}  // namespace v8

#endif  // V8_HAS_PKU_JIT_WRITE_PROTECT