llvm/compiler-rt/lib/gwp_asan/common.h

//===-- common.h ------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// This file contains code that is common between the crash handler and the
// GuardedPoolAllocator.

#ifndef GWP_ASAN_COMMON_H_
#define GWP_ASAN_COMMON_H_

#include "gwp_asan/definitions.h"
#include "gwp_asan/options.h"

#include <stddef.h>
#include <stdint.h>

namespace gwp_asan {

// Magic header that resides in the AllocatorState so that GWP-ASan bugreports
// can be understood by tools at different versions. Out-of-process crash
// handlers, like crashpad on Fuchsia, take the raw contents of the
// AllocationMetatada array and the AllocatorState, and shove them into the
// minidump. Online unpacking of these structs needs to know from which version
// of GWP-ASan it's extracting the information, as the structures are not
// stable.
struct AllocatorVersionMagic { … };

enum class Error : uint8_t { … };

const char *ErrorToString(const Error &E);

static constexpr uint64_t kInvalidThreadID = …;
// Get the current thread ID, or kInvalidThreadID if failure. Note: This
// implementation is platform-specific.
uint64_t getThreadID();

// This struct contains all the metadata recorded about a single allocation made
// by GWP-ASan. If `AllocationMetadata.Addr` is zero, the metadata is non-valid.
struct AllocationMetadata { … };

// This holds the state that's shared between the GWP-ASan allocator and the
// crash handler. This, in conjunction with the Metadata array, forms the entire
// set of information required for understanding a GWP-ASan crash.
struct AllocatorState { … };

// Below are various compile-time checks that the layout of the internal
// GWP-ASan structures are undisturbed. If they are disturbed, the version magic
// number needs to be increased by one, and the asserts need to be updated.
// Out-of-process crash handlers, like breakpad/crashpad, may copy the internal
// GWP-ASan structures into a minidump for offline reconstruction of the crash.
// In order to accomplish this, the offline reconstructor needs to know the
// version of GWP-ASan internal structures that it's unpacking (along with the
// architecture-specific layout info, which is left as an exercise to the crash
// handler).
static_assert …;
static_assert …;
#if defined(__x86_64__)
static_assert …;
static_assert …;
static_assert …;
static_assert …;
#elif defined(__aarch64__)
static_assert(sizeof(AllocatorState) == 56, "");
static_assert(offsetof(AllocatorState, FailureAddress) == 48, "");
static_assert(sizeof(AllocationMetadata) == 568, "");
static_assert(offsetof(AllocationMetadata, IsDeallocated) == 560, "");
#elif defined(__i386__)
static_assert(sizeof(AllocatorState) == 32, "");
static_assert(offsetof(AllocatorState, FailureAddress) == 28, "");
static_assert(sizeof(AllocationMetadata) == 548, "");
static_assert(offsetof(AllocationMetadata, IsDeallocated) == 544, "");
#elif defined(__arm__)
static_assert(sizeof(AllocatorState) == 32, "");
static_assert(offsetof(AllocatorState, FailureAddress) == 28, "");
static_assert(sizeof(AllocationMetadata) == 560, "");
static_assert(offsetof(AllocationMetadata, IsDeallocated) == 552, "");
#endif // defined($ARCHITECTURE)

} // namespace gwp_asan
#endif // GWP_ASAN_COMMON_H_