// Copyright 2023 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.

#ifndef V8_SANDBOX_CODE_POINTER_INL_H_

#define V8_SANDBOX_CODE_POINTER_INL_H_

#include "src/sandbox/code-pointer.h"

// Include the non-inl header before the rest of the headers.

#include "include/v8-internal.h"

#include "src/base/atomic-utils.h"

#include "src/execution/isolate.h"

#include "src/sandbox/code-pointer-table-inl.h"

namespace v8 {

namespace internal {

V8_INLINE Address ReadCodeEntrypointViaCodePointerField(Address field_address,

CodeEntrypointTag tag) {

#ifdef V8_ENABLE_SANDBOX

// Handles may be written to objects from other threads so the handle needs

// to be loaded atomically. We assume that the load from the table cannot

// be reordered before the load of the handle due to the data dependency

// between the two loads and therefore use relaxed memory ordering, but

// technically we should use memory_order_consume here.

auto location = reinterpret_cast<CodePointerHandle*>(field_address);

CodePointerHandle handle = base::AsAtomic32::Relaxed_Load(location);

return IsolateGroup::current()->code_pointer_table()->GetEntrypoint(handle,

tag);

#else

UNREACHABLE();

#endif // V8_ENABLE_SANDBOX

}

V8_INLINE void WriteCodeEntrypointViaCodePointerField(Address field_address,

Address value,

CodeEntrypointTag tag) {

#ifdef V8_ENABLE_SANDBOX

// See comment above for why this is a Relaxed_Load.

auto location = reinterpret_cast<CodePointerHandle*>(field_address);

CodePointerHandle handle = base::AsAtomic32::Relaxed_Load(location);

IsolateGroup::current()->code_pointer_table()->SetEntrypoint(handle, value,

tag);

#else

UNREACHABLE();

#endif // V8_ENABLE_SANDBOX

}

} // namespace internal

} // namespace v8

#endif // V8_SANDBOX_CODE_POINTER_INL_H_