text: //===-- msan.cpp ----------------------------------------------------------===//
  //
  // 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 is a part of MemorySanitizer.
  //
  // MemorySanitizer runtime.
  //===----------------------------------------------------------------------===//
  
  #include "msan.h"
  #include "msan_chained_origin_depot.h"
  #include "msan_origin.h"
  #include "msan_report.h"
  #include "msan_thread.h"
  #include "msan_poisoning.h"
  #include "sanitizer_common/sanitizer_atomic.h"
  #include "sanitizer_common/sanitizer_common.h"
  #include "sanitizer_common/sanitizer_flags.h"
  #include "sanitizer_common/sanitizer_flag_parser.h"
  #include "sanitizer_common/sanitizer_libc.h"
  #include "sanitizer_common/sanitizer_procmaps.h"
  #include "sanitizer_common/sanitizer_stacktrace.h"
  #include "sanitizer_common/sanitizer_symbolizer.h"
  #include "sanitizer_common/sanitizer_stackdepot.h"
  #include "ubsan/ubsan_flags.h"
  #include "ubsan/ubsan_init.h"
  
  // ACHTUNG! No system header includes in this file.
  
  using namespace __sanitizer;
  
  // Globals.
  static THREADLOCAL int msan_expect_umr = 0;
  static THREADLOCAL int msan_expected_umr_found = 0;
  
  // Function argument shadow. Each argument starts at the next available 8-byte
  // aligned address.
  SANITIZER_INTERFACE_ATTRIBUTE
  THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSize / sizeof(u64)];
  
  // Function argument origin. Each argument starts at the same offset as the
  // corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
  // would break compatibility with older prebuilt binaries.
  SANITIZER_INTERFACE_ATTRIBUTE
  THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSize / sizeof(u32)];
  
  SANITIZER_INTERFACE_ATTRIBUTE
  THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSize / sizeof(u64)];
  
  SANITIZER_INTERFACE_ATTRIBUTE
  THREADLOCAL u32 __msan_retval_origin_tls;
  
  SANITIZER_INTERFACE_ATTRIBUTE
  ALIGNED(16) THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSize / sizeof(u64)];
  
  SANITIZER_INTERFACE_ATTRIBUTE
  ALIGNED(16)
  THREADLOCAL u32 __msan_va_arg_origin_tls[kMsanParamTlsSize / sizeof(u32)];
  
  SANITIZER_INTERFACE_ATTRIBUTE
  THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
  
  SANITIZER_INTERFACE_ATTRIBUTE
  THREADLOCAL u32 __msan_origin_tls;
  
  static THREADLOCAL int is_in_symbolizer;
  
  extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_track_origins;
  
  int __msan_get_track_origins() {
    return &__msan_track_origins ? __msan_track_origins : 0;
  }
  
  extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
  
  namespace __msan {
  
  void EnterSymbolizer() { ++is_in_symbolizer; }
  void ExitSymbolizer()  { --is_in_symbolizer; }
  bool IsInSymbolizer() { return is_in_symbolizer; }
  
  static Flags msan_flags;
  
  Flags *flags() {
    return &msan_flags;
  }
  
  int msan_inited = 0;
  bool msan_init_is_running;
  
  int msan_report_count = 0;
  
  // Array of stack origins.
  // FIXME: make it resizable.
  static const uptr kNumStackOriginDescrs = 1024 * 1024;
  static const char *StackOriginDescr[kNumStackOriginDescrs];
  static uptr StackOriginPC[kNumStackOriginDescrs];
  static atomic_uint32_t NumStackOriginDescrs;
  
  void Flags::SetDefaults() {
  #define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
  #include "msan_flags.inc"
  #undef MSAN_FLAG
  }
  
  // keep_going is an old name for halt_on_error,
  // and it has inverse meaning.
  class FlagHandlerKeepGoing : public FlagHandlerBase {
    bool *halt_on_error_;
  
   public:
    explicit FlagHandlerKeepGoing(bool *halt_on_error)
        : halt_on_error_(halt_on_error) {}
    bool Parse(const char *value) final {
      bool tmp;
      FlagHandler<bool> h(&tmp);
      if (!h.Parse(value)) return false;
      *halt_on_error_ = !tmp;
      return true;
    }
    bool Format(char *buffer, uptr size) final {
      const char *keep_going_str = (*halt_on_error_) ? "false" : "true";
      return FormatString(buffer, size, keep_going_str);
    }
  };
  
  static void RegisterMsanFlags(FlagParser *parser, Flags *f) {
  #define MSAN_FLAG(Type, Name, DefaultValue, Description) \
    RegisterFlag(parser, #Name, Description, &f->Name);
  #include "msan_flags.inc"
  #undef MSAN_FLAG
  
    FlagHandlerKeepGoing *fh_keep_going =
        new (FlagParser::Alloc) FlagHandlerKeepGoing(&f->halt_on_error);
    parser->RegisterHandler("keep_going", fh_keep_going,
                            "deprecated, use halt_on_error");
  }
  
  static void InitializeFlags() {
    SetCommonFlagsDefaults();
    {
      CommonFlags cf;
      cf.CopyFrom(*common_flags());
      cf.external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
      cf.malloc_context_size = 20;
      cf.handle_ioctl = true;
      // FIXME: test and enable.
      cf.check_printf = false;
      cf.intercept_tls_get_addr = true;
      cf.exitcode = 77;
      OverrideCommonFlags(cf);
    }
  
    Flags *f = flags();
    f->SetDefaults();
  
    FlagParser parser;
    RegisterMsanFlags(&parser, f);
    RegisterCommonFlags(&parser);
  
  #if MSAN_CONTAINS_UBSAN
    __ubsan::Flags *uf = __ubsan::flags();
    uf->SetDefaults();
  
    FlagParser ubsan_parser;
    __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
    RegisterCommonFlags(&ubsan_parser);
  #endif
  
    // Override from user-specified string.
    if (__msan_default_options)
      parser.ParseString(__msan_default_options());
  #if MSAN_CONTAINS_UBSAN
    const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
    ubsan_parser.ParseString(ubsan_default_options);
  #endif
  
    parser.ParseStringFromEnv("MSAN_OPTIONS");
  #if MSAN_CONTAINS_UBSAN
    ubsan_parser.ParseStringFromEnv("UBSAN_OPTIONS");
  #endif
  
    InitializeCommonFlags();
  
    if (Verbosity()) ReportUnrecognizedFlags();
  
    if (common_flags()->help) parser.PrintFlagDescriptions();
  
    // Check if deprecated exit_code MSan flag is set.
    if (f->exit_code != -1) {
      if (Verbosity())
        Printf("MSAN_OPTIONS=exit_code is deprecated! "
               "Please use MSAN_OPTIONS=exitcode instead.\n");
      CommonFlags cf;
      cf.CopyFrom(*common_flags());
      cf.exitcode = f->exit_code;
      OverrideCommonFlags(cf);
    }
  
    // Check flag values:
    if (f->origin_history_size < 0 ||
        f->origin_history_size > Origin::kMaxDepth) {
      Printf(
          "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
          "range.\n",
          f->origin_history_size, Origin::kMaxDepth);
      Die();
    }
    // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
    // StackDepotHandle::inc_use_count_unsafe.
    if (f->origin_history_per_stack_limit < 0 ||
        f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
      Printf(
          "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
          "%d] range.\n",
          f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
      Die();
    }
    if (f->store_context_size < 1) f->store_context_size = 1;
  }
  
  void PrintWarning(uptr pc, uptr bp) {
    PrintWarningWithOrigin(pc, bp, __msan_origin_tls);
  }
  
  void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
    if (msan_expect_umr) {
      // Printf("Expected UMR\n");
      __msan_origin_tls = origin;
      msan_expected_umr_found = 1;
      return;
    }
  
    ++msan_report_count;
  
    GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
  
    u32 report_origin =
      (__msan_get_track_origins() && Origin::isValidId(origin)) ? origin : 0;
    ReportUMR(&stack, report_origin);
  
    if (__msan_get_track_origins() && !Origin::isValidId(origin)) {
      Printf(
          "  ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
          "tracking.\n    This could still be a bug in your code, too!\n",
          origin);
    }
  }
  
  void UnpoisonParam(uptr n) {
    internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
  }
  
  // Backup MSan runtime TLS state.
  // Implementation must be async-signal-safe.
  // Instances of this class may live on the signal handler stack, and data size
  // may be an issue.
  void ScopedThreadLocalStateBackup::Backup() {
    va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
  }
  
  void ScopedThreadLocalStateBackup::Restore() {
    // A lame implementation that only keeps essential state and resets the rest.
    __msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
  
    internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
    internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
    internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
    internal_memset(__msan_va_arg_origin_tls, 0,
                    sizeof(__msan_va_arg_origin_tls));
  
    if (__msan_get_track_origins()) {
      internal_memset(&__msan_retval_origin_tls, 0,
                      sizeof(__msan_retval_origin_tls));
      internal_memset(__msan_param_origin_tls, 0,
                      sizeof(__msan_param_origin_tls));
    }
  }
  
  void UnpoisonThreadLocalState() {
  }
  
  const char *GetStackOriginDescr(u32 id, uptr *pc) {
    CHECK_LT(id, kNumStackOriginDescrs);
    if (pc) *pc = StackOriginPC[id];
    return StackOriginDescr[id];
  }
  
  u32 ChainOrigin(u32 id, StackTrace *stack) {
    MsanThread *t = GetCurrentThread();
    if (t && t->InSignalHandler())
      return id;
  
    Origin o = Origin::FromRawId(id);
    stack->tag = StackTrace::TAG_UNKNOWN;
    Origin chained = Origin::CreateChainedOrigin(o, stack);
    return chained.raw_id();
  }
  
  } // namespace __msan
  
  void __sanitizer::BufferedStackTrace::UnwindImpl(
      uptr pc, uptr bp, void *context, bool request_fast, u32 max_depth) {
    using namespace __msan;
    MsanThread *t = GetCurrentThread();
    if (!t || !StackTrace::WillUseFastUnwind(request_fast)) {
      // Block reports from our interceptors during _Unwind_Backtrace.
      SymbolizerScope sym_scope;
      return Unwind(max_depth, pc, bp, context, 0, 0, false);
    }
    if (StackTrace::WillUseFastUnwind(request_fast))
      Unwind(max_depth, pc, bp, nullptr, t->stack_top(), t->stack_bottom(), true);
    else
      Unwind(max_depth, pc, 0, context, 0, 0, false);
  }
  
  // Interface.
  
  using namespace __msan;
  
  #define MSAN_MAYBE_WARNING(type, size)              \
    void __msan_maybe_warning_##size(type s, u32 o) { \
      GET_CALLER_PC_BP_SP;                            \
      (void) sp;                                      \
      if (UNLIKELY(s)) {                              \
        PrintWarningWithOrigin(pc, bp, o);            \
        if (__msan::flags()->halt_on_error) {         \
          Printf("Exiting\n");                        \
          Die();                                      \
        }                                             \
      }                                               \
    }
  
  MSAN_MAYBE_WARNING(u8, 1)
  MSAN_MAYBE_WARNING(u16, 2)
  MSAN_MAYBE_WARNING(u32, 4)
  MSAN_MAYBE_WARNING(u64, 8)
  
  #define MSAN_MAYBE_STORE_ORIGIN(type, size)                       \
    void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
      if (UNLIKELY(s)) {                                            \
        if (__msan_get_track_origins() > 1) {                       \
          GET_CALLER_PC_BP_SP;                                      \
          (void) sp;                                                \
          GET_STORE_STACK_TRACE_PC_BP(pc, bp);                      \
          o = ChainOrigin(o, &stack);                               \
        }                                                           \
        *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o;                  \
      }                                                             \
    }
  
  MSAN_MAYBE_STORE_ORIGIN(u8, 1)
  MSAN_MAYBE_STORE_ORIGIN(u16, 2)
  MSAN_MAYBE_STORE_ORIGIN(u32, 4)
  MSAN_MAYBE_STORE_ORIGIN(u64, 8)
  
  void __msan_warning() {
    GET_CALLER_PC_BP_SP;
    (void)sp;
    PrintWarning(pc, bp);
    if (__msan::flags()->halt_on_error) {
      if (__msan::flags()->print_stats)
        ReportStats();
      Printf("Exiting\n");
      Die();
    }
  }
  
  void __msan_warning_noreturn() {
    GET_CALLER_PC_BP_SP;
    (void)sp;
    PrintWarning(pc, bp);
    if (__msan::flags()->print_stats)
      ReportStats();
    Printf("Exiting\n");
    Die();
  }
  
  void __msan_warning_with_origin(u32 origin) {
    GET_CALLER_PC_BP_SP;
    (void)sp;
    PrintWarningWithOrigin(pc, bp, origin);
    if (__msan::flags()->halt_on_error) {
      if (__msan::flags()->print_stats)
        ReportStats();
      Printf("Exiting\n");
      Die();
    }
  }
  
  void __msan_warning_with_origin_noreturn(u32 origin) {
    GET_CALLER_PC_BP_SP;
    (void)sp;
    PrintWarningWithOrigin(pc, bp, origin);
    if (__msan::flags()->print_stats)
      ReportStats();
    Printf("Exiting\n");
    Die();
  }
  
  static void OnStackUnwind(const SignalContext &sig, const void *,
                            BufferedStackTrace *stack) {
    stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
                  common_flags()->fast_unwind_on_fatal);
  }
  
  static void MsanOnDeadlySignal(int signo, void *siginfo, void *context) {
    HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
  }
  
  static void MsanCheckFailed(const char *file, int line, const char *cond,
                              u64 v1, u64 v2) {
    Report("MemorySanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
           line, cond, (uptr)v1, (uptr)v2);
    PRINT_CURRENT_STACK_CHECK();
    Die();
  }
  
  void __msan_init() {
    CHECK(!msan_init_is_running);
    if (msan_inited) return;
    msan_init_is_running = 1;
    SanitizerToolName = "MemorySanitizer";
  
    AvoidCVE_2016_2143();
  
    CacheBinaryName();
    InitializeFlags();
  
    // Install tool-specific callbacks in sanitizer_common.
    SetCheckFailedCallback(MsanCheckFailed);
  
    __sanitizer_set_report_path(common_flags()->log_path);
  
    InitializeInterceptors();
    CheckASLR();
    InitTlsSize();
    InstallDeadlySignalHandlers(MsanOnDeadlySignal);
    InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
  
    DisableCoreDumperIfNecessary();
    if (StackSizeIsUnlimited()) {
      VPrintf(1, "Unlimited stack, doing reexec\n");
      // A reasonably large stack size. It is bigger than the usual 8Mb, because,
      // well, the program could have been run with unlimited stack for a reason.
      SetStackSizeLimitInBytes(32 * 1024 * 1024);
      ReExec();
    }
  
    __msan_clear_on_return();
    if (__msan_get_track_origins())
      VPrintf(1, "msan_track_origins\n");
    if (!InitShadow(__msan_get_track_origins())) {
      Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
      Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
      Printf("FATAL: Disabling ASLR is known to cause this error.\n");
      Printf("FATAL: If running under GDB, try "
             "'set disable-randomization off'.\n");
      DumpProcessMap();
      Die();
    }
  
    Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
  
    InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
  
    MsanTSDInit(MsanTSDDtor);
  
    MsanAllocatorInit();
  
    MsanThread *main_thread = MsanThread::Create(nullptr, nullptr);
    SetCurrentThread(main_thread);
    main_thread->ThreadStart();
  
  #if MSAN_CONTAINS_UBSAN
    __ubsan::InitAsPlugin();
  #endif
  
    VPrintf(1, "MemorySanitizer init done\n");
  
    msan_init_is_running = 0;
    msan_inited = 1;
  }
  
  void __msan_set_keep_going(int keep_going) {
    flags()->halt_on_error = !keep_going;
  }
  
  void __msan_set_expect_umr(int expect_umr) {
    if (expect_umr) {
      msan_expected_umr_found = 0;
    } else if (!msan_expected_umr_found) {
      GET_CALLER_PC_BP_SP;
      (void)sp;
      GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
      ReportExpectedUMRNotFound(&stack);
      Die();
    }
    msan_expect_umr = expect_umr;
  }
  
  void __msan_print_shadow(const void *x, usize size) {
    if (!MEM_IS_APP(x)) {
      Printf("Not a valid application address: %p\n", x);
      return;
    }
  
    DescribeMemoryRange(x, size);
  }
  
  void __msan_dump_shadow(const void *x, usize size) {
    if (!MEM_IS_APP(x)) {
      Printf("Not a valid application address: %p\n", x);
      return;
    }
  
    unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
    for (uptr i = 0; i < size; i++)
      Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
    Printf("\n");
  }
  
  sptr __msan_test_shadow(const void *x, usize size) {
    if (!MEM_IS_APP(x)) return -1;
    unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
    for (uptr i = 0; i < size; ++i)
      if (s[i])
        return i;
    return -1;
  }
  
  void __msan_check_mem_is_initialized(const void *x, usize size) {
    if (!__msan::flags()->report_umrs) return;
    sptr offset = __msan_test_shadow(x, size);
    if (offset < 0)
      return;
  
    GET_CALLER_PC_BP_SP;
    (void)sp;
    ReportUMRInsideAddressRange(__func__, x, size, offset);
    __msan::PrintWarningWithOrigin(pc, bp,
                                   __msan_get_origin(((const char *)x) + offset));
    if (__msan::flags()->halt_on_error) {
      Printf("Exiting\n");
      Die();
    }
  }
  
  int __msan_set_poison_in_malloc(int do_poison) {
    int old = flags()->poison_in_malloc;
    flags()->poison_in_malloc = do_poison;
    return old;
  }
  
  int __msan_has_dynamic_component() { return false; }
  
  NOINLINE
  void __msan_clear_on_return() {
    __msan_param_tls[0] = 0;
  }
  
  void __msan_partial_poison(const void* data, void* shadow, usize size) {
    internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
  }
  
  void __msan_load_unpoisoned(const void *src, usize size, void *dst) {
    internal_memcpy(dst, src, size);
    __msan_unpoison(dst, size);
  }
  
  void __msan_set_origin(const void *a, usize size, u32 origin) {
    if (__msan_get_track_origins()) SetOrigin(a, size, origin);
  }
  
  // 'descr' is created at compile time and contains '----' in the beginning.
  // When we see descr for the first time we replace '----' with a uniq id
  // and set the origin to (id | (31-th bit)).
  void __msan_set_alloca_origin(void *a, usize size, char *descr) {
    __msan_set_alloca_origin4(a, size, descr, 0);
  }
  
  void __msan_set_alloca_origin4(void *a, usize size, char *descr, uptr pc) {
    static const u32 dash = '-';
    static const u32 first_timer =
        dash + (dash << 8) + (dash << 16) + (dash << 24);
    u32 *id_ptr = (u32*)descr;
    bool print = false;  // internal_strstr(descr + 4, "AllocaTOTest") != 0;
    u32 id = *id_ptr;
    if (id == first_timer) {
      u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
      CHECK_LT(idx, kNumStackOriginDescrs);
      StackOriginDescr[idx] = descr + 4;
  #if SANITIZER_PPC64V1
      // On PowerPC64 ELFv1, the address of a function actually points to a
      // three-doubleword data structure with the first field containing
      // the address of the function's code.
      if (pc)
        pc = *reinterpret_cast<uptr*>(pc);
  #endif
      StackOriginPC[idx] = pc;
      id = Origin::CreateStackOrigin(idx).raw_id();
      *id_ptr = id;
      if (print)
        Printf("First time: idx=%d id=%d %s %p \n", idx, id, descr + 4, pc);
    }
    if (print)
      Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
    __msan_set_origin(a, size, id);
  }
  
  u32 __msan_chain_origin(u32 id) {
    GET_CALLER_PC_BP_SP;
    (void)sp;
    GET_STORE_STACK_TRACE_PC_BP(pc, bp);
    return ChainOrigin(id, &stack);
  }
  
  u32 __msan_get_origin(const void *a) {
    if (!__msan_get_track_origins()) return 0;
    uptr x = (uptr)a;
    uptr aligned = x & ~3ULL;
    uptr origin_ptr = MEM_TO_ORIGIN(aligned);
    return *(u32*)origin_ptr;
  }
  
  int __msan_origin_is_descendant_or_same(u32 this_id, u32 prev_id) {
    Origin o = Origin::FromRawId(this_id);
    while (o.raw_id() != prev_id && o.isChainedOrigin())
      o = o.getNextChainedOrigin(nullptr);
    return o.raw_id() == prev_id;
  }
  
  u32 __msan_get_umr_origin() {
    return __msan_origin_tls;
  }
  
  u16 __sanitizer_unaligned_load16(const uu16 *p) {
    internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
                    sizeof(uu16));
    if (__msan_get_track_origins())
      __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
    return *p;
  }
  u32 __sanitizer_unaligned_load32(const uu32 *p) {
    internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
                    sizeof(uu32));
    if (__msan_get_track_origins())
      __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
    return *p;
  }
  u64 __sanitizer_unaligned_load64(const uu64 *p) {
    internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
                    sizeof(uu64));
    if (__msan_get_track_origins())
      __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
    return *p;
  }
  void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
    static_assert(sizeof(uu16) == sizeof(u16), "incompatible types");
    u16 s;
    internal_memcpy(&s, &__msan_param_tls[1], sizeof(uu16));
    internal_memcpy((void *)MEM_TO_SHADOW((uptr)p), &s, sizeof(uu16));
    if (s && __msan_get_track_origins())
      if (uu32 o = __msan_param_origin_tls[2])
        SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
    *p = x;
  }
  void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
    static_assert(sizeof(uu32) == sizeof(u32), "incompatible types");
    u32 s;
    internal_memcpy(&s, &__msan_param_tls[1], sizeof(uu32));
    internal_memcpy((void *)MEM_TO_SHADOW((uptr)p), &s, sizeof(uu32));
    if (s && __msan_get_track_origins())
      if (uu32 o = __msan_param_origin_tls[2])
        SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
    *p = x;
  }
  void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
    u64 s = __msan_param_tls[1];
    *(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
    if (s && __msan_get_track_origins())
      if (uu32 o = __msan_param_origin_tls[2])
        SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
    *p = x;
  }
  
  void __msan_set_death_callback(void (*callback)(void)) {
    SetUserDieCallback(callback);
  }
  
  #if !SANITIZER_SUPPORTS_WEAK_HOOKS
  extern "C" {
  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
  const char* __msan_default_options() { return ""; }
  }  // extern "C"
  #endif
  
  extern "C" {
  SANITIZER_INTERFACE_ATTRIBUTE
  void __sanitizer_print_stack_trace() {
    GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
    stack.Print();
  }
  } // extern "C"
  