chromium/components/gwp_asan/common/allocator_state.h

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// The AllocatorState class is the subset of the GuardedPageAllocator that is
// required by the crash handler to analyzer crashes and provide debug
// information. The crash handler initializes an instance of this class from
// the crashed processes memory. Because the out-of-process allocator could be
// corrupted or maliciously tampered with, this class is security sensitive and
// needs to be modified with care. It has been purposefully designed to be:
// - Minimal: This is the minimum set of methods and members required by the
//     crash handler.
// - Trivially copyable: An instance of this object is copied from another
//     processes memory. Ensuring it is trivially copyable means that the crash
//     handler will not accidentally trigger a complex destructor on objects
//     initialized from another processes memory.
// - Free of pointers: Pointers are all uintptr_t since none of these pointers
//     need to be directly dereferenced. Encourage users like the crash handler
//     to consider them addresses instead of pointers.
// - Validatable: The IsValid() method is intended to sanity check the internal
//     fields such that it's safe to call any method on a valid object. All
//     additional methods and fields need to be audited to ensure they maintain
//     this invariant!

#ifndef COMPONENTS_GWP_ASAN_COMMON_ALLOCATOR_STATE_H_
#define COMPONENTS_GWP_ASAN_COMMON_ALLOCATOR_STATE_H_

#include <atomic>
#include <limits>
#include <string>
#include <type_traits>

#include "components/gwp_asan/common/allocation_info.h"

namespace gwp_asan {
namespace internal {

class GuardedPageAllocator;

class AllocatorState { … };

// Ensure that the allocator state is a plain-old-data. That way we can safely
// initialize it by copying memory from out-of-process without worrying about
// destructors operating on the fields in an unexpected way.
static_assert …;
static_assert …;

}  // namespace internal
}  // namespace gwp_asan

#endif  // COMPONENTS_GWP_ASAN_COMMON_ALLOCATOR_STATE_H_