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//===-- hwasan.h ------------------------------------------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file is a part of HWAddressSanitizer.
// Private Hwasan header.
#ifndef HWASAN_H
#define HWASAN_H
#include "hwasan_flags.h"
#include "hwasan_interface_internal.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_internal_defs.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "ubsan/ubsan_platform.h"
typedef u8 tag_t;
# if !defined(__x86_64__)
# error Aliasing mode is only supported on x86_64
# endif
// Tags are done in middle bits using userspace aliasing.
constexpr unsigned kAddressTagShift = 39;
constexpr unsigned kTagBits = 3;
// The alias region is placed next to the shadow so the upper bits of all
// taggable addresses matches the upper bits of the shadow base. This shift
// value determines which upper bits must match. It has a floor of 44 since the
// shadow is always 8TB.
// TODO(morehouse): In alias mode we can shrink the shadow and use a
// simpler/faster shadow calculation.
constexpr unsigned kTaggableRegionCheckShift =
__sanitizer::Max(kAddressTagShift + kTagBits + 1U, 44U);
#elif defined(__x86_64__)
// Tags are done in upper bits using Intel LAM.
constexpr unsigned kAddressTagShift = 57;
constexpr unsigned kTagBits = 6;
// TBI (Top Byte Ignore) feature of AArch64: bits [63:56] are ignored in address
// translation and can be used to store a tag.
constexpr unsigned kAddressTagShift = 56;
constexpr unsigned kTagBits = 8;
#endif // defined(HWASAN_ALIASING_MODE)
// Mask for extracting tag bits from the lower 8 bits.
constexpr uptr kTagMask = (1UL << kTagBits) - 1;
// Mask for extracting tag bits from full pointers.
constexpr uptr kAddressTagMask = kTagMask << kAddressTagShift;
// Minimal alignment of the shadow base address. Determines the space available
// for threads and stack histories. This is an ABI constant.
const unsigned kShadowBaseAlignment = 32;
const unsigned kRecordAddrBaseTagShift = 3;
const unsigned kRecordFPShift = 48;
const unsigned kRecordFPLShift = 4;
const unsigned kRecordFPModulus = 1 << (64 - kRecordFPShift + kRecordFPLShift);
static inline tag_t GetTagFromPointer(uptr p) {
return (p >> kAddressTagShift) & kTagMask;
static inline uptr UntagAddr(uptr tagged_addr) {
return tagged_addr & ~kAddressTagMask;
static inline void *UntagPtr(const void *tagged_ptr) {
return reinterpret_cast<void *>(
static inline uptr AddTagToPointer(uptr p, tag_t tag) {
return (p & ~kAddressTagMask) | ((uptr)tag << kAddressTagShift);
namespace __hwasan {
extern int hwasan_inited;
extern bool hwasan_init_is_running;
extern int hwasan_report_count;
bool InitShadow();
void InitializeOsSupport();
void InitThreads();
void InitializeInterceptors();
void HwasanAllocatorInit();
void HwasanAllocatorLock();
void HwasanAllocatorUnlock();
void *hwasan_malloc(uptr size, StackTrace *stack);
void *hwasan_calloc(uptr nmemb, uptr size, StackTrace *stack);
void *hwasan_realloc(void *ptr, uptr size, StackTrace *stack);
void *hwasan_reallocarray(void *ptr, uptr nmemb, uptr size, StackTrace *stack);
void *hwasan_valloc(uptr size, StackTrace *stack);
void *hwasan_pvalloc(uptr size, StackTrace *stack);
void *hwasan_aligned_alloc(uptr alignment, uptr size, StackTrace *stack);
void *hwasan_memalign(uptr alignment, uptr size, StackTrace *stack);
int hwasan_posix_memalign(void **memptr, uptr alignment, uptr size,
StackTrace *stack);
void hwasan_free(void *ptr, StackTrace *stack);
void InstallAtExitHandler();
BufferedStackTrace stack; \
if (hwasan_inited) \
stack.Unwind(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(), \
nullptr, common_flags()->fast_unwind_on_malloc, \
#define GET_FATAL_STACK_TRACE_PC_BP(pc, bp) \
BufferedStackTrace stack; \
if (hwasan_inited) \
stack.Unwind(pc, bp, nullptr, common_flags()->fast_unwind_on_fatal)
void HwasanTSDInit();
void HwasanTSDThreadInit();
void HwasanAtExit();
void HwasanOnDeadlySignal(int signo, void *info, void *context);
void HwasanInstallAtForkHandler();
void UpdateMemoryUsage();
void AppendToErrorMessageBuffer(const char *buffer);
void AndroidTestTlsSlot();
// This is a compiler-generated struct that can be shared between hwasan
// implementations.
struct AccessInfo {
uptr addr;
uptr size;
bool is_store;
bool is_load;
bool recover;
// Given access info and frame information, unwind the stack and report the tag
// mismatch.
void HandleTagMismatch(AccessInfo ai, uptr pc, uptr frame, void *uc,
uptr *registers_frame = nullptr);
// This dispatches to HandleTagMismatch but sets up the AccessInfo, program
// counter, and frame pointer.
void HwasanTagMismatch(uptr addr, uptr access_info, uptr *registers_frame,
size_t outsize);
} // namespace __hwasan
#define HWASAN_MALLOC_HOOK(ptr, size) \
do { \
if (&__sanitizer_malloc_hook) { \
__sanitizer_malloc_hook(ptr, size); \
} \
RunMallocHooks(ptr, size); \
} while (false)
#define HWASAN_FREE_HOOK(ptr) \
do { \
if (&__sanitizer_free_hook) { \
__sanitizer_free_hook(ptr); \
} \
RunFreeHooks(ptr); \
} while (false)
// For both bionic and glibc __sigset_t is an unsigned long.
typedef unsigned long __hw_sigset_t;
// Setjmp and longjmp implementations are platform specific, and hence the
// interception code is platform specific too.
# if defined(__aarch64__)
constexpr size_t kHwRegisterBufSize = 22;
# elif defined(__x86_64__)
constexpr size_t kHwRegisterBufSize = 8;
# endif
typedef unsigned long long __hw_register_buf[kHwRegisterBufSize];
struct __hw_jmp_buf_struct {
// NOTE: The machine-dependent definition of `__sigsetjmp'
// assume that a `__hw_jmp_buf' begins with a `__hw_register_buf' and that
// `__mask_was_saved' follows it. Do not move these members or add others
// before it.
// We add a __magic field to our struct to catch cases where libc's setjmp
// populated the jmp_buf instead of our interceptor.
__hw_register_buf __jmpbuf; // Calling environment.
unsigned __mask_was_saved : 1; // Saved the signal mask?
unsigned __magic : 31; // Used to distinguish __hw_jmp_buf from jmp_buf.
__hw_sigset_t __saved_mask; // Saved signal mask.
typedef struct __hw_jmp_buf_struct __hw_jmp_buf[1];
typedef struct __hw_jmp_buf_struct __hw_sigjmp_buf[1];
constexpr unsigned kHwJmpBufMagic = 0x248ACE77;
do { \
CHECK(!hwasan_init_is_running); \
if (!hwasan_inited) { \
__hwasan_init(); \
} \
} while (0)
#endif // HWASAN_H