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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_thread.h"
19 #include "sanitizer_common/sanitizer_atomic.h"
20 #include "sanitizer_common/sanitizer_common.h"
21 #include "sanitizer_common/sanitizer_flags.h"
22 #include "sanitizer_common/sanitizer_libc.h"
23 #include "sanitizer_common/sanitizer_procmaps.h"
24 #include "sanitizer_common/sanitizer_stacktrace.h"
25 #include "sanitizer_common/sanitizer_symbolizer.h"
26 #include "sanitizer_common/sanitizer_stackdepot.h"
27 
28 
29 // ACHTUNG! No system header includes in this file.
30 
31 using namespace __sanitizer;
32 
33 // Globals.
34 static THREADLOCAL int msan_expect_umr = 0;
35 static THREADLOCAL int msan_expected_umr_found = 0;
36 
37 static bool msan_running_under_dr;
38 
39 // Function argument shadow. Each argument starts at the next available 8-byte
40 // aligned address.
41 SANITIZER_INTERFACE_ATTRIBUTE
42 THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSizeInWords];
43 
44 // Function argument origin. Each argument starts at the same offset as the
45 // corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
46 // would break compatibility with older prebuilt binaries.
47 SANITIZER_INTERFACE_ATTRIBUTE
48 THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSizeInWords];
49 
50 SANITIZER_INTERFACE_ATTRIBUTE
51 THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSizeInWords];
52 
53 SANITIZER_INTERFACE_ATTRIBUTE
54 THREADLOCAL u32 __msan_retval_origin_tls;
55 
56 SANITIZER_INTERFACE_ATTRIBUTE
57 THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSizeInWords];
58 
59 SANITIZER_INTERFACE_ATTRIBUTE
60 THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
61 
62 SANITIZER_INTERFACE_ATTRIBUTE
63 THREADLOCAL u32 __msan_origin_tls;
64 
65 static THREADLOCAL int is_in_symbolizer;
66 static THREADLOCAL int is_in_loader;
67 
68 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_track_origins;
69 
__msan_get_track_origins()70 int __msan_get_track_origins() {
71   return &__msan_track_origins ? __msan_track_origins : 0;
72 }
73 
74 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
75 
76 namespace __msan {
77 
EnterSymbolizer()78 void EnterSymbolizer() { ++is_in_symbolizer; }
ExitSymbolizer()79 void ExitSymbolizer()  { --is_in_symbolizer; }
IsInSymbolizer()80 bool IsInSymbolizer() { return is_in_symbolizer; }
81 
EnterLoader()82 void EnterLoader() { ++is_in_loader; }
ExitLoader()83 void ExitLoader()  { --is_in_loader; }
84 
85 extern "C" {
86 SANITIZER_INTERFACE_ATTRIBUTE
__msan_is_in_loader()87 bool __msan_is_in_loader() { return is_in_loader; }
88 }
89 
90 static Flags msan_flags;
91 
flags()92 Flags *flags() {
93   return &msan_flags;
94 }
95 
96 int msan_inited = 0;
97 bool msan_init_is_running;
98 
99 int msan_report_count = 0;
100 
101 void (*death_callback)(void);
102 
103 // Array of stack origins.
104 // FIXME: make it resizable.
105 static const uptr kNumStackOriginDescrs = 1024 * 1024;
106 static const char *StackOriginDescr[kNumStackOriginDescrs];
107 static uptr StackOriginPC[kNumStackOriginDescrs];
108 static atomic_uint32_t NumStackOriginDescrs;
109 
ParseFlagsFromString(Flags * f,const char * str)110 static void ParseFlagsFromString(Flags *f, const char *str) {
111   CommonFlags *cf = common_flags();
112   ParseCommonFlagsFromString(cf, str);
113   ParseFlag(str, &f->poison_heap_with_zeroes, "poison_heap_with_zeroes", "");
114   ParseFlag(str, &f->poison_stack_with_zeroes, "poison_stack_with_zeroes", "");
115   ParseFlag(str, &f->poison_in_malloc, "poison_in_malloc", "");
116   ParseFlag(str, &f->poison_in_free, "poison_in_free", "");
117   ParseFlag(str, &f->exit_code, "exit_code", "");
118   if (f->exit_code < 0 || f->exit_code > 127) {
119     Printf("Exit code not in [0, 128) range: %d\n", f->exit_code);
120     Die();
121   }
122   ParseFlag(str, &f->origin_history_size, "origin_history_size", "");
123   if (f->origin_history_size < 0 ||
124       f->origin_history_size > Origin::kMaxDepth) {
125     Printf(
126         "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
127         "range.\n",
128         f->origin_history_size, Origin::kMaxDepth);
129     Die();
130   }
131   ParseFlag(str, &f->origin_history_per_stack_limit,
132             "origin_history_per_stack_limit", "");
133   // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
134   // StackDepotHandle::inc_use_count_unsafe.
135   if (f->origin_history_per_stack_limit < 0 ||
136       f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
137     Printf(
138         "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
139         "%d] range.\n",
140         f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
141     Die();
142   }
143 
144   ParseFlag(str, &f->report_umrs, "report_umrs", "");
145   ParseFlag(str, &f->wrap_signals, "wrap_signals", "");
146   ParseFlag(str, &f->print_stats, "print_stats", "");
147   ParseFlag(str, &f->atexit, "atexit", "");
148   ParseFlag(str, &f->store_context_size, "store_context_size", "");
149   if (f->store_context_size < 1) f->store_context_size = 1;
150 
151   // keep_going is an old name for halt_on_error,
152   // and it has inverse meaning.
153   f->halt_on_error = !f->halt_on_error;
154   ParseFlag(str, &f->halt_on_error, "keep_going", "");
155   f->halt_on_error = !f->halt_on_error;
156   ParseFlag(str, &f->halt_on_error, "halt_on_error", "");
157 }
158 
InitializeFlags(Flags * f,const char * options)159 static void InitializeFlags(Flags *f, const char *options) {
160   CommonFlags *cf = common_flags();
161   SetCommonFlagsDefaults(cf);
162   cf->external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
163   cf->malloc_context_size = 20;
164   cf->handle_ioctl = true;
165   // FIXME: test and enable.
166   cf->check_printf = false;
167   cf->intercept_tls_get_addr = true;
168 
169   internal_memset(f, 0, sizeof(*f));
170   f->poison_heap_with_zeroes = false;
171   f->poison_stack_with_zeroes = false;
172   f->poison_in_malloc = true;
173   f->poison_in_free = true;
174   f->exit_code = 77;
175   f->origin_history_size = Origin::kMaxDepth;
176   f->origin_history_per_stack_limit = 20000;
177   f->report_umrs = true;
178   f->wrap_signals = true;
179   f->print_stats = false;
180   f->atexit = false;
181   f->halt_on_error = !&__msan_keep_going;
182   f->store_context_size = 20;
183 
184   // Override from user-specified string.
185   if (__msan_default_options)
186     ParseFlagsFromString(f, __msan_default_options());
187   ParseFlagsFromString(f, options);
188 }
189 
GetStackTrace(StackTrace * stack,uptr max_s,uptr pc,uptr bp,bool request_fast_unwind)190 void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
191                    bool request_fast_unwind) {
192   MsanThread *t = GetCurrentThread();
193   if (!t || !StackTrace::WillUseFastUnwind(request_fast_unwind)) {
194     // Block reports from our interceptors during _Unwind_Backtrace.
195     SymbolizerScope sym_scope;
196     return stack->Unwind(max_s, pc, bp, 0, 0, 0, request_fast_unwind);
197   }
198   stack->Unwind(max_s, pc, bp, 0, t->stack_top(), t->stack_bottom(),
199                 request_fast_unwind);
200 }
201 
PrintWarning(uptr pc,uptr bp)202 void PrintWarning(uptr pc, uptr bp) {
203   PrintWarningWithOrigin(pc, bp, __msan_origin_tls);
204 }
205 
PrintWarningWithOrigin(uptr pc,uptr bp,u32 origin)206 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
207   if (msan_expect_umr) {
208     // Printf("Expected UMR\n");
209     __msan_origin_tls = origin;
210     msan_expected_umr_found = 1;
211     return;
212   }
213 
214   ++msan_report_count;
215 
216   GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
217 
218   u32 report_origin =
219     (__msan_get_track_origins() && Origin(origin).isValid()) ? origin : 0;
220   ReportUMR(&stack, report_origin);
221 
222   if (__msan_get_track_origins() && !Origin(origin).isValid()) {
223     Printf(
224         "  ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
225         "tracking.\n    This could still be a bug in your code, too!\n",
226         origin);
227   }
228 }
229 
UnpoisonParam(uptr n)230 void UnpoisonParam(uptr n) {
231   internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
232 }
233 
234 // Backup MSan runtime TLS state.
235 // Implementation must be async-signal-safe.
236 // Instances of this class may live on the signal handler stack, and data size
237 // may be an issue.
Backup()238 void ScopedThreadLocalStateBackup::Backup() {
239   va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
240 }
241 
Restore()242 void ScopedThreadLocalStateBackup::Restore() {
243   // A lame implementation that only keeps essential state and resets the rest.
244   __msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
245 
246   internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
247   internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
248   internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
249 
250   if (__msan_get_track_origins()) {
251     internal_memset(&__msan_retval_origin_tls, 0,
252                     sizeof(__msan_retval_origin_tls));
253     internal_memset(__msan_param_origin_tls, 0,
254                     sizeof(__msan_param_origin_tls));
255   }
256 }
257 
UnpoisonThreadLocalState()258 void UnpoisonThreadLocalState() {
259 }
260 
GetStackOriginDescr(u32 id,uptr * pc)261 const char *GetStackOriginDescr(u32 id, uptr *pc) {
262   CHECK_LT(id, kNumStackOriginDescrs);
263   if (pc) *pc = StackOriginPC[id];
264   return StackOriginDescr[id];
265 }
266 
ChainOrigin(u32 id,StackTrace * stack)267 u32 ChainOrigin(u32 id, StackTrace *stack) {
268   MsanThread *t = GetCurrentThread();
269   if (t && t->InSignalHandler())
270     return id;
271 
272   Origin o(id);
273   int depth = o.depth();
274   // 0 means unlimited depth.
275   if (flags()->origin_history_size > 0 && depth > 0) {
276     if (depth >= flags()->origin_history_size) {
277       return id;
278     } else {
279       ++depth;
280     }
281   }
282 
283   StackDepotHandle h = StackDepotPut_WithHandle(stack->trace, stack->size);
284   if (!h.valid()) return id;
285   int use_count = h.use_count();
286   if (use_count > flags()->origin_history_per_stack_limit)
287     return id;
288 
289   u32 chained_id;
290   bool inserted = ChainedOriginDepotPut(h.id(), o.id(), &chained_id);
291 
292   if (inserted) h.inc_use_count_unsafe();
293 
294   return Origin(chained_id, depth).raw_id();
295 }
296 
297 }  // namespace __msan
298 
299 // Interface.
300 
301 using namespace __msan;
302 
303 #define MSAN_MAYBE_WARNING(type, size)              \
304   void __msan_maybe_warning_##size(type s, u32 o) { \
305     GET_CALLER_PC_BP_SP;                            \
306     (void) sp;                                      \
307     if (UNLIKELY(s)) {                              \
308       PrintWarningWithOrigin(pc, bp, o);            \
309       if (__msan::flags()->halt_on_error) {         \
310         Printf("Exiting\n");                        \
311         Die();                                      \
312       }                                             \
313     }                                               \
314   }
315 
316 MSAN_MAYBE_WARNING(u8, 1)
317 MSAN_MAYBE_WARNING(u16, 2)
318 MSAN_MAYBE_WARNING(u32, 4)
319 MSAN_MAYBE_WARNING(u64, 8)
320 
321 #define MSAN_MAYBE_STORE_ORIGIN(type, size)                       \
322   void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
323     if (UNLIKELY(s)) {                                            \
324       if (__msan_get_track_origins() > 1) {                       \
325         GET_CALLER_PC_BP_SP;                                      \
326         (void) sp;                                                \
327         GET_STORE_STACK_TRACE_PC_BP(pc, bp);                      \
328         o = ChainOrigin(o, &stack);                               \
329       }                                                           \
330       *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o;                  \
331     }                                                             \
332   }
333 
334 MSAN_MAYBE_STORE_ORIGIN(u8, 1)
335 MSAN_MAYBE_STORE_ORIGIN(u16, 2)
336 MSAN_MAYBE_STORE_ORIGIN(u32, 4)
337 MSAN_MAYBE_STORE_ORIGIN(u64, 8)
338 
__msan_warning()339 void __msan_warning() {
340   GET_CALLER_PC_BP_SP;
341   (void)sp;
342   PrintWarning(pc, bp);
343   if (__msan::flags()->halt_on_error) {
344     if (__msan::flags()->print_stats)
345       ReportStats();
346     Printf("Exiting\n");
347     Die();
348   }
349 }
350 
__msan_warning_noreturn()351 void __msan_warning_noreturn() {
352   GET_CALLER_PC_BP_SP;
353   (void)sp;
354   PrintWarning(pc, bp);
355   if (__msan::flags()->print_stats)
356     ReportStats();
357   Printf("Exiting\n");
358   Die();
359 }
360 
__msan_init()361 void __msan_init() {
362   CHECK(!msan_init_is_running);
363   if (msan_inited) return;
364   msan_init_is_running = 1;
365   SanitizerToolName = "MemorySanitizer";
366 
367   SetDieCallback(MsanDie);
368   InitTlsSize();
369 
370   const char *msan_options = GetEnv("MSAN_OPTIONS");
371   InitializeFlags(&msan_flags, msan_options);
372   if (common_flags()->help) PrintFlagDescriptions();
373   __sanitizer_set_report_path(common_flags()->log_path);
374 
375   InitializeInterceptors();
376   InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
377 
378   if (MSAN_REPLACE_OPERATORS_NEW_AND_DELETE)
379     ReplaceOperatorsNewAndDelete();
380   if (StackSizeIsUnlimited()) {
381     VPrintf(1, "Unlimited stack, doing reexec\n");
382     // A reasonably large stack size. It is bigger than the usual 8Mb, because,
383     // well, the program could have been run with unlimited stack for a reason.
384     SetStackSizeLimitInBytes(32 * 1024 * 1024);
385     ReExec();
386   }
387 
388   VPrintf(1, "MSAN_OPTIONS: %s\n", msan_options ? msan_options : "<empty>");
389 
390   __msan_clear_on_return();
391   if (__msan_get_track_origins())
392     VPrintf(1, "msan_track_origins\n");
393   if (!InitShadow(/* prot1 */ !msan_running_under_dr, /* prot2 */ true,
394                   /* map_shadow */ true, __msan_get_track_origins())) {
395     Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
396     Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
397     Printf("FATAL: Disabling ASLR is known to cause this error.\n");
398     Printf("FATAL: If running under GDB, try "
399            "'set disable-randomization off'.\n");
400     DumpProcessMap();
401     Die();
402   }
403 
404   Symbolizer::Init(common_flags()->external_symbolizer_path);
405   Symbolizer::Get()->AddHooks(EnterSymbolizer, ExitSymbolizer);
406 
407   MsanTSDInit(MsanTSDDtor);
408 
409   MsanThread *main_thread = MsanThread::Create(0, 0);
410   SetCurrentThread(main_thread);
411   main_thread->ThreadStart();
412 
413   VPrintf(1, "MemorySanitizer init done\n");
414 
415   msan_init_is_running = 0;
416   msan_inited = 1;
417 }
418 
__msan_set_exit_code(int exit_code)419 void __msan_set_exit_code(int exit_code) {
420   flags()->exit_code = exit_code;
421 }
422 
__msan_set_keep_going(int keep_going)423 void __msan_set_keep_going(int keep_going) {
424   flags()->halt_on_error = !keep_going;
425 }
426 
__msan_set_expect_umr(int expect_umr)427 void __msan_set_expect_umr(int expect_umr) {
428   if (expect_umr) {
429     msan_expected_umr_found = 0;
430   } else if (!msan_expected_umr_found) {
431     GET_CALLER_PC_BP_SP;
432     (void)sp;
433     GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
434     ReportExpectedUMRNotFound(&stack);
435     Die();
436   }
437   msan_expect_umr = expect_umr;
438 }
439 
__msan_print_shadow(const void * x,uptr size)440 void __msan_print_shadow(const void *x, uptr size) {
441   if (!MEM_IS_APP(x)) {
442     Printf("Not a valid application address: %p\n", x);
443     return;
444   }
445 
446   DescribeMemoryRange(x, size);
447 }
448 
__msan_dump_shadow(const void * x,uptr size)449 void __msan_dump_shadow(const void *x, uptr size) {
450   if (!MEM_IS_APP(x)) {
451     Printf("Not a valid application address: %p\n", x);
452     return;
453   }
454 
455   unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
456   for (uptr i = 0; i < size; i++) {
457 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
458     Printf("%x%x ", s[i] & 0xf, s[i] >> 4);
459 #else
460     Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
461 #endif
462   }
463   Printf("\n");
464 }
465 
__msan_test_shadow(const void * x,uptr size)466 sptr __msan_test_shadow(const void *x, uptr size) {
467   if (!MEM_IS_APP(x)) return -1;
468   unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
469   for (uptr i = 0; i < size; ++i)
470     if (s[i])
471       return i;
472   return -1;
473 }
474 
__msan_check_mem_is_initialized(const void * x,uptr size)475 void __msan_check_mem_is_initialized(const void *x, uptr size) {
476   if (!__msan::flags()->report_umrs) return;
477   sptr offset = __msan_test_shadow(x, size);
478   if (offset < 0)
479     return;
480 
481   GET_CALLER_PC_BP_SP;
482   (void)sp;
483   ReportUMRInsideAddressRange(__func__, x, size, offset);
484   __msan::PrintWarningWithOrigin(pc, bp,
485                                  __msan_get_origin(((char *)x) + offset));
486   if (__msan::flags()->halt_on_error) {
487     Printf("Exiting\n");
488     Die();
489   }
490 }
491 
__msan_set_poison_in_malloc(int do_poison)492 int __msan_set_poison_in_malloc(int do_poison) {
493   int old = flags()->poison_in_malloc;
494   flags()->poison_in_malloc = do_poison;
495   return old;
496 }
497 
__msan_has_dynamic_component()498 int  __msan_has_dynamic_component() {
499   return msan_running_under_dr;
500 }
501 
502 NOINLINE
__msan_clear_on_return()503 void __msan_clear_on_return() {
504   __msan_param_tls[0] = 0;
505 }
506 
get_tls_base()507 static void* get_tls_base() {
508   u64 p;
509   asm("mov %%fs:0, %0"
510       : "=r"(p) ::);
511   return (void*)p;
512 }
513 
__msan_get_retval_tls_offset()514 int __msan_get_retval_tls_offset() {
515   // volatile here is needed to avoid UB, because the compiler thinks that we
516   // are doing address arithmetics on unrelated pointers, and takes some
517   // shortcuts
518   volatile sptr retval_tls_p = (sptr)&__msan_retval_tls;
519   volatile sptr tls_base_p = (sptr)get_tls_base();
520   return retval_tls_p - tls_base_p;
521 }
522 
__msan_get_param_tls_offset()523 int __msan_get_param_tls_offset() {
524   // volatile here is needed to avoid UB, because the compiler thinks that we
525   // are doing address arithmetics on unrelated pointers, and takes some
526   // shortcuts
527   volatile sptr param_tls_p = (sptr)&__msan_param_tls;
528   volatile sptr tls_base_p = (sptr)get_tls_base();
529   return param_tls_p - tls_base_p;
530 }
531 
__msan_partial_poison(const void * data,void * shadow,uptr size)532 void __msan_partial_poison(const void* data, void* shadow, uptr size) {
533   internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
534 }
535 
__msan_load_unpoisoned(void * src,uptr size,void * dst)536 void __msan_load_unpoisoned(void *src, uptr size, void *dst) {
537   internal_memcpy(dst, src, size);
538   __msan_unpoison(dst, size);
539 }
540 
__msan_set_origin(const void * a,uptr size,u32 origin)541 void __msan_set_origin(const void *a, uptr size, u32 origin) {
542   // Origin mapping is 4 bytes per 4 bytes of application memory.
543   // Here we extend the range such that its left and right bounds are both
544   // 4 byte aligned.
545   if (!__msan_get_track_origins()) return;
546   uptr x = MEM_TO_ORIGIN((uptr)a);
547   uptr beg = x & ~3UL;  // align down.
548   uptr end = (x + size + 3) & ~3UL;  // align up.
549   u64 origin64 = ((u64)origin << 32) | origin;
550   // This is like memset, but the value is 32-bit. We unroll by 2 to write
551   // 64 bits at once. May want to unroll further to get 128-bit stores.
552   if (beg & 7ULL) {
553     *(u32*)beg = origin;
554     beg += 4;
555   }
556   for (uptr addr = beg; addr < (end & ~7UL); addr += 8)
557     *(u64*)addr = origin64;
558   if (end & 7ULL)
559     *(u32*)(end - 4) = origin;
560 }
561 
562 // 'descr' is created at compile time and contains '----' in the beginning.
563 // When we see descr for the first time we replace '----' with a uniq id
564 // and set the origin to (id | (31-th bit)).
__msan_set_alloca_origin(void * a,uptr size,const char * descr)565 void __msan_set_alloca_origin(void *a, uptr size, const char *descr) {
566   __msan_set_alloca_origin4(a, size, descr, 0);
567 }
568 
__msan_set_alloca_origin4(void * a,uptr size,const char * descr,uptr pc)569 void __msan_set_alloca_origin4(void *a, uptr size, const char *descr, uptr pc) {
570   static const u32 dash = '-';
571   static const u32 first_timer =
572       dash + (dash << 8) + (dash << 16) + (dash << 24);
573   u32 *id_ptr = (u32*)descr;
574   bool print = false;  // internal_strstr(descr + 4, "AllocaTOTest") != 0;
575   u32 id = *id_ptr;
576   if (id == first_timer) {
577     u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
578     CHECK_LT(idx, kNumStackOriginDescrs);
579     StackOriginDescr[idx] = descr + 4;
580     StackOriginPC[idx] = pc;
581     ChainedOriginDepotPut(idx, Origin::kStackRoot, &id);
582     *id_ptr = id;
583     if (print)
584       Printf("First time: idx=%d id=%d %s %p \n", idx, id, descr + 4, pc);
585   }
586   if (print)
587     Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
588   __msan_set_origin(a, size, Origin(id, 1).raw_id());
589 }
590 
__msan_chain_origin(u32 id)591 u32 __msan_chain_origin(u32 id) {
592   GET_CALLER_PC_BP_SP;
593   (void)sp;
594   GET_STORE_STACK_TRACE_PC_BP(pc, bp);
595   return ChainOrigin(id, &stack);
596 }
597 
__msan_get_origin(const void * a)598 u32 __msan_get_origin(const void *a) {
599   if (!__msan_get_track_origins()) return 0;
600   uptr x = (uptr)a;
601   uptr aligned = x & ~3ULL;
602   uptr origin_ptr = MEM_TO_ORIGIN(aligned);
603   return *(u32*)origin_ptr;
604 }
605 
__msan_get_umr_origin()606 u32 __msan_get_umr_origin() {
607   return __msan_origin_tls;
608 }
609 
__sanitizer_unaligned_load16(const uu16 * p)610 u16 __sanitizer_unaligned_load16(const uu16 *p) {
611   __msan_retval_tls[0] = *(uu16 *)MEM_TO_SHADOW((uptr)p);
612   if (__msan_get_track_origins())
613     __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
614   return *p;
615 }
__sanitizer_unaligned_load32(const uu32 * p)616 u32 __sanitizer_unaligned_load32(const uu32 *p) {
617   __msan_retval_tls[0] = *(uu32 *)MEM_TO_SHADOW((uptr)p);
618   if (__msan_get_track_origins())
619     __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
620   return *p;
621 }
__sanitizer_unaligned_load64(const uu64 * p)622 u64 __sanitizer_unaligned_load64(const uu64 *p) {
623   __msan_retval_tls[0] = *(uu64 *)MEM_TO_SHADOW((uptr)p);
624   if (__msan_get_track_origins())
625     __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
626   return *p;
627 }
__sanitizer_unaligned_store16(uu16 * p,u16 x)628 void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
629   u16 s = __msan_param_tls[1];
630   *(uu16 *)MEM_TO_SHADOW((uptr)p) = s;
631   if (s && __msan_get_track_origins())
632     if (uu32 o = __msan_param_origin_tls[2])
633       SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
634   *p = x;
635 }
__sanitizer_unaligned_store32(uu32 * p,u32 x)636 void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
637   u32 s = __msan_param_tls[1];
638   *(uu32 *)MEM_TO_SHADOW((uptr)p) = s;
639   if (s && __msan_get_track_origins())
640     if (uu32 o = __msan_param_origin_tls[2])
641       SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
642   *p = x;
643 }
__sanitizer_unaligned_store64(uu64 * p,u64 x)644 void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
645   u64 s = __msan_param_tls[1];
646   *(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
647   if (s && __msan_get_track_origins())
648     if (uu32 o = __msan_param_origin_tls[2])
649       SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
650   *p = x;
651 }
652 
__msan_set_death_callback(void (* callback)(void))653 void __msan_set_death_callback(void (*callback)(void)) {
654   death_callback = callback;
655 }
656 
__msan_wrap_indirect_call(void * target)657 void *__msan_wrap_indirect_call(void *target) {
658   return IndirectExternCall(target);
659 }
660 
__msan_dr_is_initialized()661 void __msan_dr_is_initialized() {
662   msan_running_under_dr = true;
663 }
664 
__msan_set_indirect_call_wrapper(uptr wrapper)665 void __msan_set_indirect_call_wrapper(uptr wrapper) {
666   SetIndirectCallWrapper(wrapper);
667 }
668 
669 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
670 extern "C" {
671 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
__msan_default_options()672 const char* __msan_default_options() { return ""; }
673 }  // extern "C"
674 #endif
675 
676 extern "C" {
677 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_print_stack_trace()678 void __sanitizer_print_stack_trace() {
679   GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
680   stack.Print();
681 }
682 }  // extern "C"
683