1//===-- msan.cc -----------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of MemorySanitizer.
11//
12// MemorySanitizer runtime.
13//===----------------------------------------------------------------------===//
14
15#include "msan.h"
16#include "msan_chained_origin_depot.h"
17#include "msan_origin.h"
18#include "msan_report.h"
19#include "msan_thread.h"
20#include "msan_poisoning.h"
21#include "sanitizer_common/sanitizer_atomic.h"
22#include "sanitizer_common/sanitizer_common.h"
23#include "sanitizer_common/sanitizer_flags.h"
24#include "sanitizer_common/sanitizer_flag_parser.h"
25#include "sanitizer_common/sanitizer_libc.h"
26#include "sanitizer_common/sanitizer_procmaps.h"
27#include "sanitizer_common/sanitizer_stacktrace.h"
28#include "sanitizer_common/sanitizer_symbolizer.h"
29#include "sanitizer_common/sanitizer_stackdepot.h"
30#include "ubsan/ubsan_flags.h"
31#include "ubsan/ubsan_init.h"
32
33// ACHTUNG! No system header includes in this file.
34
35using namespace __sanitizer;
36
37// Globals.
38static THREADLOCAL int msan_expect_umr = 0;
39static THREADLOCAL int msan_expected_umr_found = 0;
40
41// Function argument shadow. Each argument starts at the next available 8-byte
42// aligned address.
43SANITIZER_INTERFACE_ATTRIBUTE
44THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSize / sizeof(u64)];
45
46// Function argument origin. Each argument starts at the same offset as the
47// corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
48// would break compatibility with older prebuilt binaries.
49SANITIZER_INTERFACE_ATTRIBUTE
50THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSize / sizeof(u32)];
51
52SANITIZER_INTERFACE_ATTRIBUTE
53THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSize / sizeof(u64)];
54
55SANITIZER_INTERFACE_ATTRIBUTE
56THREADLOCAL u32 __msan_retval_origin_tls;
57
58SANITIZER_INTERFACE_ATTRIBUTE
59ALIGNED(16) THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSize / sizeof(u64)];
60
61SANITIZER_INTERFACE_ATTRIBUTE
62ALIGNED(16)
63THREADLOCAL u32 __msan_va_arg_origin_tls[kMsanParamTlsSize / sizeof(u32)];
64
65SANITIZER_INTERFACE_ATTRIBUTE
66THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
67
68SANITIZER_INTERFACE_ATTRIBUTE
69THREADLOCAL u32 __msan_origin_tls;
70
71static THREADLOCAL int is_in_symbolizer;
72
73extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_track_origins;
74
75int __msan_get_track_origins() {
76  return &__msan_track_origins ? __msan_track_origins : 0;
77}
78
79extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
80
81namespace __msan {
82
83void EnterSymbolizer() { ++is_in_symbolizer; }
84void ExitSymbolizer()  { --is_in_symbolizer; }
85bool IsInSymbolizer() { return is_in_symbolizer; }
86
87static Flags msan_flags;
88
89Flags *flags() {
90  return &msan_flags;
91}
92
93int msan_inited = 0;
94bool msan_init_is_running;
95
96int msan_report_count = 0;
97
98// Array of stack origins.
99// FIXME: make it resizable.
100static const uptr kNumStackOriginDescrs = 1024 * 1024;
101static const char *StackOriginDescr[kNumStackOriginDescrs];
102static uptr StackOriginPC[kNumStackOriginDescrs];
103static atomic_uint32_t NumStackOriginDescrs;
104
105void Flags::SetDefaults() {
106#define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
107#include "msan_flags.inc"
108#undef MSAN_FLAG
109}
110
111// keep_going is an old name for halt_on_error,
112// and it has inverse meaning.
113class FlagHandlerKeepGoing : public FlagHandlerBase {
114  bool *halt_on_error_;
115
116 public:
117  explicit FlagHandlerKeepGoing(bool *halt_on_error)
118      : halt_on_error_(halt_on_error) {}
119  bool Parse(const char *value) final {
120    bool tmp;
121    FlagHandler<bool> h(&tmp);
122    if (!h.Parse(value)) return false;
123    *halt_on_error_ = !tmp;
124    return true;
125  }
126};
127
128static void RegisterMsanFlags(FlagParser *parser, Flags *f) {
129#define MSAN_FLAG(Type, Name, DefaultValue, Description) \
130  RegisterFlag(parser, #Name, Description, &f->Name);
131#include "msan_flags.inc"
132#undef MSAN_FLAG
133
134  FlagHandlerKeepGoing *fh_keep_going = new (FlagParser::Alloc)  // NOLINT
135      FlagHandlerKeepGoing(&f->halt_on_error);
136  parser->RegisterHandler("keep_going", fh_keep_going,
137                          "deprecated, use halt_on_error");
138}
139
140static void InitializeFlags() {
141  SetCommonFlagsDefaults();
142  {
143    CommonFlags cf;
144    cf.CopyFrom(*common_flags());
145    cf.external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
146    cf.malloc_context_size = 20;
147    cf.handle_ioctl = true;
148    // FIXME: test and enable.
149    cf.check_printf = false;
150    cf.intercept_tls_get_addr = true;
151    cf.exitcode = 77;
152    OverrideCommonFlags(cf);
153  }
154
155  Flags *f = flags();
156  f->SetDefaults();
157
158  FlagParser parser;
159  RegisterMsanFlags(&parser, f);
160  RegisterCommonFlags(&parser);
161
162#if MSAN_CONTAINS_UBSAN
163  __ubsan::Flags *uf = __ubsan::flags();
164  uf->SetDefaults();
165
166  FlagParser ubsan_parser;
167  __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
168  RegisterCommonFlags(&ubsan_parser);
169#endif
170
171  // Override from user-specified string.
172  if (__msan_default_options)
173    parser.ParseString(__msan_default_options());
174#if MSAN_CONTAINS_UBSAN
175  const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
176  ubsan_parser.ParseString(ubsan_default_options);
177#endif
178
179  const char *msan_options = GetEnv("MSAN_OPTIONS");
180  parser.ParseString(msan_options);
181#if MSAN_CONTAINS_UBSAN
182  ubsan_parser.ParseString(GetEnv("UBSAN_OPTIONS"));
183#endif
184  VPrintf(1, "MSAN_OPTIONS: %s\n", msan_options ? msan_options : "<empty>");
185
186  InitializeCommonFlags();
187
188  if (Verbosity()) ReportUnrecognizedFlags();
189
190  if (common_flags()->help) parser.PrintFlagDescriptions();
191
192  // Check if deprecated exit_code MSan flag is set.
193  if (f->exit_code != -1) {
194    if (Verbosity())
195      Printf("MSAN_OPTIONS=exit_code is deprecated! "
196             "Please use MSAN_OPTIONS=exitcode instead.\n");
197    CommonFlags cf;
198    cf.CopyFrom(*common_flags());
199    cf.exitcode = f->exit_code;
200    OverrideCommonFlags(cf);
201  }
202
203  // Check flag values:
204  if (f->origin_history_size < 0 ||
205      f->origin_history_size > Origin::kMaxDepth) {
206    Printf(
207        "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
208        "range.\n",
209        f->origin_history_size, Origin::kMaxDepth);
210    Die();
211  }
212  // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
213  // StackDepotHandle::inc_use_count_unsafe.
214  if (f->origin_history_per_stack_limit < 0 ||
215      f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
216    Printf(
217        "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
218        "%d] range.\n",
219        f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
220    Die();
221  }
222  if (f->store_context_size < 1) f->store_context_size = 1;
223}
224
225void GetStackTrace(BufferedStackTrace *stack, uptr max_s, uptr pc, uptr bp,
226                   void *context, bool request_fast_unwind) {
227  MsanThread *t = GetCurrentThread();
228  if (!t || !StackTrace::WillUseFastUnwind(request_fast_unwind)) {
229    // Block reports from our interceptors during _Unwind_Backtrace.
230    SymbolizerScope sym_scope;
231    return stack->Unwind(max_s, pc, bp, context, 0, 0, request_fast_unwind);
232  }
233  stack->Unwind(max_s, pc, bp, context, t->stack_top(), t->stack_bottom(),
234                request_fast_unwind);
235}
236
237void PrintWarning(uptr pc, uptr bp) {
238  PrintWarningWithOrigin(pc, bp, __msan_origin_tls);
239}
240
241void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
242  if (msan_expect_umr) {
243    // Printf("Expected UMR\n");
244    __msan_origin_tls = origin;
245    msan_expected_umr_found = 1;
246    return;
247  }
248
249  ++msan_report_count;
250
251  GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
252
253  u32 report_origin =
254    (__msan_get_track_origins() && Origin::isValidId(origin)) ? origin : 0;
255  ReportUMR(&stack, report_origin);
256
257  if (__msan_get_track_origins() && !Origin::isValidId(origin)) {
258    Printf(
259        "  ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
260        "tracking.\n    This could still be a bug in your code, too!\n",
261        origin);
262  }
263}
264
265void UnpoisonParam(uptr n) {
266  internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
267}
268
269// Backup MSan runtime TLS state.
270// Implementation must be async-signal-safe.
271// Instances of this class may live on the signal handler stack, and data size
272// may be an issue.
273void ScopedThreadLocalStateBackup::Backup() {
274  va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
275}
276
277void ScopedThreadLocalStateBackup::Restore() {
278  // A lame implementation that only keeps essential state and resets the rest.
279  __msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
280
281  internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
282  internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
283  internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
284  internal_memset(__msan_va_arg_origin_tls, 0,
285                  sizeof(__msan_va_arg_origin_tls));
286
287  if (__msan_get_track_origins()) {
288    internal_memset(&__msan_retval_origin_tls, 0,
289                    sizeof(__msan_retval_origin_tls));
290    internal_memset(__msan_param_origin_tls, 0,
291                    sizeof(__msan_param_origin_tls));
292  }
293}
294
295void UnpoisonThreadLocalState() {
296}
297
298const char *GetStackOriginDescr(u32 id, uptr *pc) {
299  CHECK_LT(id, kNumStackOriginDescrs);
300  if (pc) *pc = StackOriginPC[id];
301  return StackOriginDescr[id];
302}
303
304u32 ChainOrigin(u32 id, StackTrace *stack) {
305  MsanThread *t = GetCurrentThread();
306  if (t && t->InSignalHandler())
307    return id;
308
309  Origin o = Origin::FromRawId(id);
310  stack->tag = StackTrace::TAG_UNKNOWN;
311  Origin chained = Origin::CreateChainedOrigin(o, stack);
312  return chained.raw_id();
313}
314
315} // namespace __msan
316
317// Interface.
318
319using namespace __msan;
320
321#define MSAN_MAYBE_WARNING(type, size)              \
322  void __msan_maybe_warning_##size(type s, u32 o) { \
323    GET_CALLER_PC_BP_SP;                            \
324    (void) sp;                                      \
325    if (UNLIKELY(s)) {                              \
326      PrintWarningWithOrigin(pc, bp, o);            \
327      if (__msan::flags()->halt_on_error) {         \
328        Printf("Exiting\n");                        \
329        Die();                                      \
330      }                                             \
331    }                                               \
332  }
333
334MSAN_MAYBE_WARNING(u8, 1)
335MSAN_MAYBE_WARNING(u16, 2)
336MSAN_MAYBE_WARNING(u32, 4)
337MSAN_MAYBE_WARNING(u64, 8)
338
339#define MSAN_MAYBE_STORE_ORIGIN(type, size)                       \
340  void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
341    if (UNLIKELY(s)) {                                            \
342      if (__msan_get_track_origins() > 1) {                       \
343        GET_CALLER_PC_BP_SP;                                      \
344        (void) sp;                                                \
345        GET_STORE_STACK_TRACE_PC_BP(pc, bp);                      \
346        o = ChainOrigin(o, &stack);                               \
347      }                                                           \
348      *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o;                  \
349    }                                                             \
350  }
351
352MSAN_MAYBE_STORE_ORIGIN(u8, 1)
353MSAN_MAYBE_STORE_ORIGIN(u16, 2)
354MSAN_MAYBE_STORE_ORIGIN(u32, 4)
355MSAN_MAYBE_STORE_ORIGIN(u64, 8)
356
357void __msan_warning() {
358  GET_CALLER_PC_BP_SP;
359  (void)sp;
360  PrintWarning(pc, bp);
361  if (__msan::flags()->halt_on_error) {
362    if (__msan::flags()->print_stats)
363      ReportStats();
364    Printf("Exiting\n");
365    Die();
366  }
367}
368
369void __msan_warning_noreturn() {
370  GET_CALLER_PC_BP_SP;
371  (void)sp;
372  PrintWarning(pc, bp);
373  if (__msan::flags()->print_stats)
374    ReportStats();
375  Printf("Exiting\n");
376  Die();
377}
378
379static void OnStackUnwind(const SignalContext &sig, const void *,
380                          BufferedStackTrace *stack) {
381  GetStackTrace(stack, kStackTraceMax, sig.pc, sig.bp, sig.context,
382                common_flags()->fast_unwind_on_fatal);
383}
384
385static void MsanOnDeadlySignal(int signo, void *siginfo, void *context) {
386  HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
387}
388
389static void MsanCheckFailed(const char *file, int line, const char *cond,
390                            u64 v1, u64 v2) {
391  Report("MemorySanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
392         line, cond, (uptr)v1, (uptr)v2);
393  PRINT_CURRENT_STACK_CHECK();
394  Die();
395}
396
397void __msan_init() {
398  CHECK(!msan_init_is_running);
399  if (msan_inited) return;
400  msan_init_is_running = 1;
401  SanitizerToolName = "MemorySanitizer";
402
403  AvoidCVE_2016_2143();
404
405  CacheBinaryName();
406  CheckASLR();
407  InitializeFlags();
408
409  // Install tool-specific callbacks in sanitizer_common.
410  SetCheckFailedCallback(MsanCheckFailed);
411
412  __sanitizer_set_report_path(common_flags()->log_path);
413
414  InitializeInterceptors();
415  InitTlsSize();
416  InstallDeadlySignalHandlers(MsanOnDeadlySignal);
417  InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
418
419  DisableCoreDumperIfNecessary();
420  if (StackSizeIsUnlimited()) {
421    VPrintf(1, "Unlimited stack, doing reexec\n");
422    // A reasonably large stack size. It is bigger than the usual 8Mb, because,
423    // well, the program could have been run with unlimited stack for a reason.
424    SetStackSizeLimitInBytes(32 * 1024 * 1024);
425    ReExec();
426  }
427
428  __msan_clear_on_return();
429  if (__msan_get_track_origins())
430    VPrintf(1, "msan_track_origins\n");
431  if (!InitShadow(__msan_get_track_origins())) {
432    Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
433    Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
434    Printf("FATAL: Disabling ASLR is known to cause this error.\n");
435    Printf("FATAL: If running under GDB, try "
436           "'set disable-randomization off'.\n");
437    DumpProcessMap();
438    Die();
439  }
440
441  Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
442
443  InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
444
445  MsanTSDInit(MsanTSDDtor);
446
447  MsanAllocatorInit();
448
449  MsanThread *main_thread = MsanThread::Create(nullptr, nullptr);
450  SetCurrentThread(main_thread);
451  main_thread->ThreadStart();
452
453#if MSAN_CONTAINS_UBSAN
454  __ubsan::InitAsPlugin();
455#endif
456
457  VPrintf(1, "MemorySanitizer init done\n");
458
459  msan_init_is_running = 0;
460  msan_inited = 1;
461}
462
463void __msan_set_keep_going(int keep_going) {
464  flags()->halt_on_error = !keep_going;
465}
466
467void __msan_set_expect_umr(int expect_umr) {
468  if (expect_umr) {
469    msan_expected_umr_found = 0;
470  } else if (!msan_expected_umr_found) {
471    GET_CALLER_PC_BP_SP;
472    (void)sp;
473    GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
474    ReportExpectedUMRNotFound(&stack);
475    Die();
476  }
477  msan_expect_umr = expect_umr;
478}
479
480void __msan_print_shadow(const void *x, uptr size) {
481  if (!MEM_IS_APP(x)) {
482    Printf("Not a valid application address: %p\n", x);
483    return;
484  }
485
486  DescribeMemoryRange(x, size);
487}
488
489void __msan_dump_shadow(const void *x, uptr size) {
490  if (!MEM_IS_APP(x)) {
491    Printf("Not a valid application address: %p\n", x);
492    return;
493  }
494
495  unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
496  for (uptr i = 0; i < size; i++)
497    Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
498  Printf("\n");
499}
500
501sptr __msan_test_shadow(const void *x, uptr size) {
502  if (!MEM_IS_APP(x)) return -1;
503  unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
504  for (uptr i = 0; i < size; ++i)
505    if (s[i])
506      return i;
507  return -1;
508}
509
510void __msan_check_mem_is_initialized(const void *x, uptr size) {
511  if (!__msan::flags()->report_umrs) return;
512  sptr offset = __msan_test_shadow(x, size);
513  if (offset < 0)
514    return;
515
516  GET_CALLER_PC_BP_SP;
517  (void)sp;
518  ReportUMRInsideAddressRange(__func__, x, size, offset);
519  __msan::PrintWarningWithOrigin(pc, bp,
520                                 __msan_get_origin(((const char *)x) + offset));
521  if (__msan::flags()->halt_on_error) {
522    Printf("Exiting\n");
523    Die();
524  }
525}
526
527int __msan_set_poison_in_malloc(int do_poison) {
528  int old = flags()->poison_in_malloc;
529  flags()->poison_in_malloc = do_poison;
530  return old;
531}
532
533int __msan_has_dynamic_component() { return false; }
534
535NOINLINE
536void __msan_clear_on_return() {
537  __msan_param_tls[0] = 0;
538}
539
540void __msan_partial_poison(const void* data, void* shadow, uptr size) {
541  internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
542}
543
544void __msan_load_unpoisoned(const void *src, uptr size, void *dst) {
545  internal_memcpy(dst, src, size);
546  __msan_unpoison(dst, size);
547}
548
549void __msan_set_origin(const void *a, uptr size, u32 origin) {
550  if (__msan_get_track_origins()) SetOrigin(a, size, origin);
551}
552
553// 'descr' is created at compile time and contains '----' in the beginning.
554// When we see descr for the first time we replace '----' with a uniq id
555// and set the origin to (id | (31-th bit)).
556void __msan_set_alloca_origin(void *a, uptr size, char *descr) {
557  __msan_set_alloca_origin4(a, size, descr, 0);
558}
559
560void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc) {
561  static const u32 dash = '-';
562  static const u32 first_timer =
563      dash + (dash << 8) + (dash << 16) + (dash << 24);
564  u32 *id_ptr = (u32*)descr;
565  bool print = false;  // internal_strstr(descr + 4, "AllocaTOTest") != 0;
566  u32 id = *id_ptr;
567  if (id == first_timer) {
568    u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
569    CHECK_LT(idx, kNumStackOriginDescrs);
570    StackOriginDescr[idx] = descr + 4;
571#if SANITIZER_PPC64V1
572    // On PowerPC64 ELFv1, the address of a function actually points to a
573    // three-doubleword data structure with the first field containing
574    // the address of the function's code.
575    if (pc)
576      pc = *reinterpret_cast<uptr*>(pc);
577#endif
578    StackOriginPC[idx] = pc;
579    id = Origin::CreateStackOrigin(idx).raw_id();
580    *id_ptr = id;
581    if (print)
582      Printf("First time: idx=%d id=%d %s %p \n", idx, id, descr + 4, pc);
583  }
584  if (print)
585    Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
586  __msan_set_origin(a, size, id);
587}
588
589u32 __msan_chain_origin(u32 id) {
590  GET_CALLER_PC_BP_SP;
591  (void)sp;
592  GET_STORE_STACK_TRACE_PC_BP(pc, bp);
593  return ChainOrigin(id, &stack);
594}
595
596u32 __msan_get_origin(const void *a) {
597  if (!__msan_get_track_origins()) return 0;
598  uptr x = (uptr)a;
599  uptr aligned = x & ~3ULL;
600  uptr origin_ptr = MEM_TO_ORIGIN(aligned);
601  return *(u32*)origin_ptr;
602}
603
604int __msan_origin_is_descendant_or_same(u32 this_id, u32 prev_id) {
605  Origin o = Origin::FromRawId(this_id);
606  while (o.raw_id() != prev_id && o.isChainedOrigin())
607    o = o.getNextChainedOrigin(nullptr);
608  return o.raw_id() == prev_id;
609}
610
611u32 __msan_get_umr_origin() {
612  return __msan_origin_tls;
613}
614
615u16 __sanitizer_unaligned_load16(const uu16 *p) {
616  *(uu16 *)&__msan_retval_tls[0] = *(uu16 *)MEM_TO_SHADOW((uptr)p);
617  if (__msan_get_track_origins())
618    __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
619  return *p;
620}
621u32 __sanitizer_unaligned_load32(const uu32 *p) {
622  *(uu32 *)&__msan_retval_tls[0] = *(uu32 *)MEM_TO_SHADOW((uptr)p);
623  if (__msan_get_track_origins())
624    __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
625  return *p;
626}
627u64 __sanitizer_unaligned_load64(const uu64 *p) {
628  __msan_retval_tls[0] = *(uu64 *)MEM_TO_SHADOW((uptr)p);
629  if (__msan_get_track_origins())
630    __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
631  return *p;
632}
633void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
634  u16 s = *(uu16 *)&__msan_param_tls[1];
635  *(uu16 *)MEM_TO_SHADOW((uptr)p) = s;
636  if (s && __msan_get_track_origins())
637    if (uu32 o = __msan_param_origin_tls[2])
638      SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
639  *p = x;
640}
641void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
642  u32 s = *(uu32 *)&__msan_param_tls[1];
643  *(uu32 *)MEM_TO_SHADOW((uptr)p) = s;
644  if (s && __msan_get_track_origins())
645    if (uu32 o = __msan_param_origin_tls[2])
646      SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
647  *p = x;
648}
649void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
650  u64 s = __msan_param_tls[1];
651  *(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
652  if (s && __msan_get_track_origins())
653    if (uu32 o = __msan_param_origin_tls[2])
654      SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
655  *p = x;
656}
657
658void __msan_set_death_callback(void (*callback)(void)) {
659  SetUserDieCallback(callback);
660}
661
662#if !SANITIZER_SUPPORTS_WEAK_HOOKS
663extern "C" {
664SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
665const char* __msan_default_options() { return ""; }
666}  // extern "C"
667#endif
668
669extern "C" {
670SANITIZER_INTERFACE_ATTRIBUTE
671void __sanitizer_print_stack_trace() {
672  GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
673  stack.Print();
674}
675} // extern "C"
676