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1 //===-- asan_rtl.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 AddressSanitizer, an address sanity checker.
11 //
12 // Main file of the ASan run-time library.
13 //===----------------------------------------------------------------------===//
14 #include "asan_allocator.h"
15 #include "asan_interceptors.h"
16 #include "asan_internal.h"
17 #include "asan_mapping.h"
18 #include "asan_poisoning.h"
19 #include "asan_report.h"
20 #include "asan_stack.h"
21 #include "asan_stats.h"
22 #include "asan_thread.h"
23 #include "sanitizer_common/sanitizer_atomic.h"
24 #include "sanitizer_common/sanitizer_flags.h"
25 #include "sanitizer_common/sanitizer_libc.h"
26 #include "sanitizer_common/sanitizer_symbolizer.h"
27 #include "lsan/lsan_common.h"
28 
29 namespace __asan {
30 
31 uptr AsanMappingProfile[kAsanMappingProfileSize];
32 
AsanDie()33 static void AsanDie() {
34   static atomic_uint32_t num_calls;
35   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
36     // Don't die twice - run a busy loop.
37     while (1) { }
38   }
39   if (flags()->sleep_before_dying) {
40     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
41     SleepForSeconds(flags()->sleep_before_dying);
42   }
43   if (flags()->unmap_shadow_on_exit) {
44     if (kMidMemBeg) {
45       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
46       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
47     } else {
48       UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
49     }
50   }
51   if (death_callback)
52     death_callback();
53   if (flags()->abort_on_error)
54     Abort();
55   internal__exit(flags()->exitcode);
56 }
57 
AsanCheckFailed(const char * file,int line,const char * cond,u64 v1,u64 v2)58 static void AsanCheckFailed(const char *file, int line, const char *cond,
59                             u64 v1, u64 v2) {
60   Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n",
61              file, line, cond, (uptr)v1, (uptr)v2);
62   // FIXME: check for infinite recursion without a thread-local counter here.
63   PRINT_CURRENT_STACK();
64   Die();
65 }
66 
67 // -------------------------- Flags ------------------------- {{{1
68 static const int kDefaultMallocContextSize = 30;
69 
70 Flags asan_flags_dont_use_directly;  // use via flags().
71 
MaybeCallAsanDefaultOptions()72 static const char *MaybeCallAsanDefaultOptions() {
73   return (&__asan_default_options) ? __asan_default_options() : "";
74 }
75 
MaybeUseAsanDefaultOptionsCompileDefiniton()76 static const char *MaybeUseAsanDefaultOptionsCompileDefiniton() {
77 #ifdef ASAN_DEFAULT_OPTIONS
78 // Stringize the macro value.
79 # define ASAN_STRINGIZE(x) #x
80 # define ASAN_STRINGIZE_OPTIONS(options) ASAN_STRINGIZE(options)
81   return ASAN_STRINGIZE_OPTIONS(ASAN_DEFAULT_OPTIONS);
82 #else
83   return "";
84 #endif
85 }
86 
ParseFlagsFromString(Flags * f,const char * str)87 static void ParseFlagsFromString(Flags *f, const char *str) {
88   ParseCommonFlagsFromString(str);
89   CHECK((uptr)common_flags()->malloc_context_size <= kStackTraceMax);
90 
91   ParseFlag(str, &f->quarantine_size, "quarantine_size");
92   ParseFlag(str, &f->verbosity, "verbosity");
93   ParseFlag(str, &f->redzone, "redzone");
94   CHECK_GE(f->redzone, 16);
95   CHECK(IsPowerOfTwo(f->redzone));
96 
97   ParseFlag(str, &f->debug, "debug");
98   ParseFlag(str, &f->report_globals, "report_globals");
99   ParseFlag(str, &f->check_initialization_order, "check_initialization_order");
100 
101   ParseFlag(str, &f->replace_str, "replace_str");
102   ParseFlag(str, &f->replace_intrin, "replace_intrin");
103   ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free");
104   ParseFlag(str, &f->use_fake_stack, "use_fake_stack");
105   ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size");
106   ParseFlag(str, &f->malloc_fill_byte, "malloc_fill_byte");
107   ParseFlag(str, &f->exitcode, "exitcode");
108   ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning");
109   ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying");
110   ParseFlag(str, &f->handle_segv, "handle_segv");
111   ParseFlag(str, &f->allow_user_segv_handler, "allow_user_segv_handler");
112   ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack");
113   ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size");
114   ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit");
115   ParseFlag(str, &f->abort_on_error, "abort_on_error");
116   ParseFlag(str, &f->print_stats, "print_stats");
117   ParseFlag(str, &f->print_legend, "print_legend");
118   ParseFlag(str, &f->atexit, "atexit");
119   ParseFlag(str, &f->disable_core, "disable_core");
120   ParseFlag(str, &f->allow_reexec, "allow_reexec");
121   ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history");
122   ParseFlag(str, &f->poison_heap, "poison_heap");
123   ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch");
124   ParseFlag(str, &f->use_stack_depot, "use_stack_depot");
125   ParseFlag(str, &f->strict_memcmp, "strict_memcmp");
126   ParseFlag(str, &f->strict_init_order, "strict_init_order");
127 }
128 
InitializeFlags(Flags * f,const char * env)129 void InitializeFlags(Flags *f, const char *env) {
130   CommonFlags *cf = common_flags();
131   cf->external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
132   cf->symbolize = true;
133   cf->malloc_context_size = kDefaultMallocContextSize;
134   cf->fast_unwind_on_fatal = false;
135   cf->fast_unwind_on_malloc = true;
136   cf->strip_path_prefix = "";
137   cf->handle_ioctl = false;
138   cf->log_path = 0;
139   cf->detect_leaks = false;
140   cf->leak_check_at_exit = true;
141 
142   internal_memset(f, 0, sizeof(*f));
143   f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28;
144   f->verbosity = 0;
145   f->redzone = 16;
146   f->debug = false;
147   f->report_globals = 1;
148   f->check_initialization_order = false;
149   f->replace_str = true;
150   f->replace_intrin = true;
151   f->mac_ignore_invalid_free = false;
152   f->use_fake_stack = true;
153   f->max_malloc_fill_size = 0x1000;  // By default, fill only the first 4K.
154   f->malloc_fill_byte = 0xbe;
155   f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
156   f->allow_user_poisoning = true;
157   f->sleep_before_dying = 0;
158   f->handle_segv = ASAN_NEEDS_SEGV;
159   f->allow_user_segv_handler = false;
160   f->use_sigaltstack = false;
161   f->check_malloc_usable_size = true;
162   f->unmap_shadow_on_exit = false;
163   f->abort_on_error = false;
164   f->print_stats = false;
165   f->print_legend = true;
166   f->atexit = false;
167   f->disable_core = (SANITIZER_WORDSIZE == 64);
168   f->allow_reexec = true;
169   f->print_full_thread_history = true;
170   f->poison_heap = true;
171   // Turn off alloc/dealloc mismatch checker on Mac for now.
172   // TODO(glider): Fix known issues and enable this back.
173   f->alloc_dealloc_mismatch = (SANITIZER_MAC == 0);;
174   f->use_stack_depot = true;
175   f->strict_memcmp = true;
176   f->strict_init_order = false;
177 
178   // Override from compile definition.
179   ParseFlagsFromString(f, MaybeUseAsanDefaultOptionsCompileDefiniton());
180 
181   // Override from user-specified string.
182   ParseFlagsFromString(f, MaybeCallAsanDefaultOptions());
183   if (flags()->verbosity) {
184     Report("Using the defaults from __asan_default_options: %s\n",
185            MaybeCallAsanDefaultOptions());
186   }
187 
188   // Override from command line.
189   ParseFlagsFromString(f, env);
190 
191 #if !CAN_SANITIZE_LEAKS
192   if (cf->detect_leaks) {
193     Report("%s: detect_leaks is not supported on this platform.\n",
194            SanitizerToolName);
195     cf->detect_leaks = false;
196   }
197 #endif
198 
199   if (cf->detect_leaks && !f->use_stack_depot) {
200     Report("%s: detect_leaks is ignored (requires use_stack_depot).\n",
201            SanitizerToolName);
202     cf->detect_leaks = false;
203   }
204 }
205 
206 // -------------------------- Globals --------------------- {{{1
207 int asan_inited;
208 bool asan_init_is_running;
209 void (*death_callback)(void);
210 
211 #if !ASAN_FIXED_MAPPING
212 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
213 #endif
214 
215 // -------------------------- Misc ---------------- {{{1
ShowStatsAndAbort()216 void ShowStatsAndAbort() {
217   __asan_print_accumulated_stats();
218   Die();
219 }
220 
221 // ---------------------- mmap -------------------- {{{1
222 // Reserve memory range [beg, end].
ReserveShadowMemoryRange(uptr beg,uptr end)223 static void ReserveShadowMemoryRange(uptr beg, uptr end) {
224   CHECK_EQ((beg % GetPageSizeCached()), 0);
225   CHECK_EQ(((end + 1) % GetPageSizeCached()), 0);
226   uptr size = end - beg + 1;
227   void *res = MmapFixedNoReserve(beg, size);
228   if (res != (void*)beg) {
229     Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
230            "Perhaps you're using ulimit -v\n", size);
231     Abort();
232   }
233 }
234 
235 // --------------- LowLevelAllocateCallbac ---------- {{{1
OnLowLevelAllocate(uptr ptr,uptr size)236 static void OnLowLevelAllocate(uptr ptr, uptr size) {
237   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
238 }
239 
240 // -------------------------- Run-time entry ------------------- {{{1
241 // exported functions
242 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
243 extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
244 void __asan_report_ ## type ## size(uptr addr);                \
245 void __asan_report_ ## type ## size(uptr addr) {               \
246   GET_CALLER_PC_BP_SP;                                              \
247   __asan_report_error(pc, bp, sp, addr, is_write, size);            \
248 }
249 
250 ASAN_REPORT_ERROR(load, false, 1)
251 ASAN_REPORT_ERROR(load, false, 2)
252 ASAN_REPORT_ERROR(load, false, 4)
253 ASAN_REPORT_ERROR(load, false, 8)
254 ASAN_REPORT_ERROR(load, false, 16)
255 ASAN_REPORT_ERROR(store, true, 1)
256 ASAN_REPORT_ERROR(store, true, 2)
257 ASAN_REPORT_ERROR(store, true, 4)
258 ASAN_REPORT_ERROR(store, true, 8)
259 ASAN_REPORT_ERROR(store, true, 16)
260 
261 #define ASAN_REPORT_ERROR_N(type, is_write)                    \
262 extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
263 void __asan_report_ ## type ## _n(uptr addr, uptr size);       \
264 void __asan_report_ ## type ## _n(uptr addr, uptr size) {      \
265   GET_CALLER_PC_BP_SP;                                         \
266   __asan_report_error(pc, bp, sp, addr, is_write, size);       \
267 }
268 
ASAN_REPORT_ERROR_N(load,false)269 ASAN_REPORT_ERROR_N(load, false)
270 ASAN_REPORT_ERROR_N(store, true)
271 
272 // Force the linker to keep the symbols for various ASan interface functions.
273 // We want to keep those in the executable in order to let the instrumented
274 // dynamic libraries access the symbol even if it is not used by the executable
275 // itself. This should help if the build system is removing dead code at link
276 // time.
277 static NOINLINE void force_interface_symbols() {
278   volatile int fake_condition = 0;  // prevent dead condition elimination.
279   // __asan_report_* functions are noreturn, so we need a switch to prevent
280   // the compiler from removing any of them.
281   switch (fake_condition) {
282     case 1: __asan_report_load1(0); break;
283     case 2: __asan_report_load2(0); break;
284     case 3: __asan_report_load4(0); break;
285     case 4: __asan_report_load8(0); break;
286     case 5: __asan_report_load16(0); break;
287     case 6: __asan_report_store1(0); break;
288     case 7: __asan_report_store2(0); break;
289     case 8: __asan_report_store4(0); break;
290     case 9: __asan_report_store8(0); break;
291     case 10: __asan_report_store16(0); break;
292     case 12: __asan_register_globals(0, 0); break;
293     case 13: __asan_unregister_globals(0, 0); break;
294     case 14: __asan_set_death_callback(0); break;
295     case 15: __asan_set_error_report_callback(0); break;
296     case 16: __asan_handle_no_return(); break;
297     case 17: __asan_address_is_poisoned(0); break;
298     case 18: __asan_get_allocated_size(0); break;
299     case 19: __asan_get_current_allocated_bytes(); break;
300     case 20: __asan_get_estimated_allocated_size(0); break;
301     case 21: __asan_get_free_bytes(); break;
302     case 22: __asan_get_heap_size(); break;
303     case 23: __asan_get_ownership(0); break;
304     case 24: __asan_get_unmapped_bytes(); break;
305     case 25: __asan_poison_memory_region(0, 0); break;
306     case 26: __asan_unpoison_memory_region(0, 0); break;
307     case 27: __asan_set_error_exit_code(0); break;
308     case 28: __asan_stack_free(0, 0, 0); break;
309     case 29: __asan_stack_malloc(0, 0); break;
310     case 30: __asan_before_dynamic_init(0); break;
311     case 31: __asan_after_dynamic_init(); break;
312     case 32: __asan_poison_stack_memory(0, 0); break;
313     case 33: __asan_unpoison_stack_memory(0, 0); break;
314     case 34: __asan_region_is_poisoned(0, 0); break;
315     case 35: __asan_describe_address(0); break;
316   }
317 }
318 
asan_atexit()319 static void asan_atexit() {
320   Printf("AddressSanitizer exit stats:\n");
321   __asan_print_accumulated_stats();
322   // Print AsanMappingProfile.
323   for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
324     if (AsanMappingProfile[i] == 0) continue;
325     Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
326   }
327 }
328 
InitializeHighMemEnd()329 static void InitializeHighMemEnd() {
330 #if !ASAN_FIXED_MAPPING
331   kHighMemEnd = GetMaxVirtualAddress();
332   // Increase kHighMemEnd to make sure it's properly
333   // aligned together with kHighMemBeg:
334   kHighMemEnd |= SHADOW_GRANULARITY * GetPageSizeCached() - 1;
335 #endif  // !ASAN_FIXED_MAPPING
336   CHECK_EQ((kHighMemBeg % GetPageSizeCached()), 0);
337 }
338 
ProtectGap(uptr a,uptr size)339 static void ProtectGap(uptr a, uptr size) {
340   CHECK_EQ(a, (uptr)Mprotect(a, size));
341 }
342 
PrintAddressSpaceLayout()343 static void PrintAddressSpaceLayout() {
344   Printf("|| `[%p, %p]` || HighMem    ||\n",
345          (void*)kHighMemBeg, (void*)kHighMemEnd);
346   Printf("|| `[%p, %p]` || HighShadow ||\n",
347          (void*)kHighShadowBeg, (void*)kHighShadowEnd);
348   if (kMidMemBeg) {
349     Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
350            (void*)kShadowGap3Beg, (void*)kShadowGap3End);
351     Printf("|| `[%p, %p]` || MidMem     ||\n",
352            (void*)kMidMemBeg, (void*)kMidMemEnd);
353     Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
354            (void*)kShadowGap2Beg, (void*)kShadowGap2End);
355     Printf("|| `[%p, %p]` || MidShadow  ||\n",
356            (void*)kMidShadowBeg, (void*)kMidShadowEnd);
357   }
358   Printf("|| `[%p, %p]` || ShadowGap  ||\n",
359          (void*)kShadowGapBeg, (void*)kShadowGapEnd);
360   if (kLowShadowBeg) {
361     Printf("|| `[%p, %p]` || LowShadow  ||\n",
362            (void*)kLowShadowBeg, (void*)kLowShadowEnd);
363     Printf("|| `[%p, %p]` || LowMem     ||\n",
364            (void*)kLowMemBeg, (void*)kLowMemEnd);
365   }
366   Printf("MemToShadow(shadow): %p %p %p %p",
367          (void*)MEM_TO_SHADOW(kLowShadowBeg),
368          (void*)MEM_TO_SHADOW(kLowShadowEnd),
369          (void*)MEM_TO_SHADOW(kHighShadowBeg),
370          (void*)MEM_TO_SHADOW(kHighShadowEnd));
371   if (kMidMemBeg) {
372     Printf(" %p %p",
373            (void*)MEM_TO_SHADOW(kMidShadowBeg),
374            (void*)MEM_TO_SHADOW(kMidShadowEnd));
375   }
376   Printf("\n");
377   Printf("red_zone=%zu\n", (uptr)flags()->redzone);
378   Printf("malloc_context_size=%zu\n",
379          (uptr)common_flags()->malloc_context_size);
380 
381   Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
382   Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
383   Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
384   CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
385   if (kMidMemBeg)
386     CHECK(kMidShadowBeg > kLowShadowEnd &&
387           kMidMemBeg > kMidShadowEnd &&
388           kHighShadowBeg > kMidMemEnd);
389 }
390 
391 }  // namespace __asan
392 
393 // ---------------------- Interface ---------------- {{{1
394 using namespace __asan;  // NOLINT
395 
396 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
397 extern "C" {
398 SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE
__asan_default_options()399 const char* __asan_default_options() { return ""; }
400 }  // extern "C"
401 #endif
402 
__asan_set_error_exit_code(int exit_code)403 int NOINLINE __asan_set_error_exit_code(int exit_code) {
404   int old = flags()->exitcode;
405   flags()->exitcode = exit_code;
406   return old;
407 }
408 
__asan_handle_no_return()409 void NOINLINE __asan_handle_no_return() {
410   int local_stack;
411   AsanThread *curr_thread = GetCurrentThread();
412   CHECK(curr_thread);
413   uptr PageSize = GetPageSizeCached();
414   uptr top = curr_thread->stack_top();
415   uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1);
416   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
417   if (top - bottom > kMaxExpectedCleanupSize) {
418     static bool reported_warning = false;
419     if (reported_warning)
420       return;
421     reported_warning = true;
422     Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
423            "stack top: %p; bottom %p; size: %p (%zd)\n"
424            "False positive error reports may follow\n"
425            "For details see "
426            "http://code.google.com/p/address-sanitizer/issues/detail?id=189\n",
427            top, bottom, top - bottom, top - bottom);
428     return;
429   }
430   PoisonShadow(bottom, top - bottom, 0);
431 }
432 
__asan_set_death_callback(void (* callback)(void))433 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
434   death_callback = callback;
435 }
436 
__asan_init()437 void __asan_init() {
438   if (asan_inited) return;
439   SanitizerToolName = "AddressSanitizer";
440   CHECK(!asan_init_is_running && "ASan init calls itself!");
441   asan_init_is_running = true;
442   InitializeHighMemEnd();
443 
444   // Make sure we are not statically linked.
445   AsanDoesNotSupportStaticLinkage();
446 
447   // Install tool-specific callbacks in sanitizer_common.
448   SetDieCallback(AsanDie);
449   SetCheckFailedCallback(AsanCheckFailed);
450   SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
451 
452   // Initialize flags. This must be done early, because most of the
453   // initialization steps look at flags().
454   const char *options = GetEnv("ASAN_OPTIONS");
455   InitializeFlags(flags(), options);
456   __sanitizer_set_report_path(common_flags()->log_path);
457 
458   if (flags()->verbosity && options) {
459     Report("Parsed ASAN_OPTIONS: %s\n", options);
460   }
461 
462   // Re-exec ourselves if we need to set additional env or command line args.
463   MaybeReexec();
464 
465   // Setup internal allocator callback.
466   SetLowLevelAllocateCallback(OnLowLevelAllocate);
467 
468   if (flags()->atexit) {
469     Atexit(asan_atexit);
470   }
471 
472   // interceptors
473   InitializeAsanInterceptors();
474 
475   ReplaceSystemMalloc();
476   ReplaceOperatorsNewAndDelete();
477 
478   uptr shadow_start = kLowShadowBeg;
479   if (kLowShadowBeg)
480     shadow_start -= GetMmapGranularity();
481   bool full_shadow_is_available =
482       MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
483 
484 #if SANITIZER_LINUX && defined(__x86_64__) && !ASAN_FIXED_MAPPING
485   if (!full_shadow_is_available) {
486     kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
487     kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
488   }
489 #endif
490 
491   if (flags()->verbosity)
492     PrintAddressSpaceLayout();
493 
494   if (flags()->disable_core) {
495     DisableCoreDumper();
496   }
497 
498   if (full_shadow_is_available) {
499     // mmap the low shadow plus at least one page at the left.
500     if (kLowShadowBeg)
501       ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
502     // mmap the high shadow.
503     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
504     // protect the gap.
505     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
506   } else if (kMidMemBeg &&
507       MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
508       MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
509     CHECK(kLowShadowBeg != kLowShadowEnd);
510     // mmap the low shadow plus at least one page at the left.
511     ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
512     // mmap the mid shadow.
513     ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd);
514     // mmap the high shadow.
515     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
516     // protect the gaps.
517     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
518     ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
519     ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
520   } else {
521     Report("Shadow memory range interleaves with an existing memory mapping. "
522            "ASan cannot proceed correctly. ABORTING.\n");
523     DumpProcessMap();
524     Die();
525   }
526 
527   InstallSignalHandlers();
528 
529   AsanTSDInit(AsanThread::TSDDtor);
530   // Allocator should be initialized before starting external symbolizer, as
531   // fork() on Mac locks the allocator.
532   InitializeAllocator();
533 
534   // Start symbolizer process if necessary.
535   const char* external_symbolizer = common_flags()->external_symbolizer_path;
536   if (common_flags()->symbolize && external_symbolizer &&
537       external_symbolizer[0]) {
538     InitializeExternalSymbolizer(external_symbolizer);
539   }
540 
541   // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
542   // should be set to 1 prior to initializing the threads.
543   asan_inited = 1;
544   asan_init_is_running = false;
545 
546   InitTlsSize();
547 
548   // Create main thread.
549   AsanThread *main_thread = AsanThread::Create(0, 0);
550   CreateThreadContextArgs create_main_args = { main_thread, 0 };
551   u32 main_tid = asanThreadRegistry().CreateThread(
552       0, true, 0, &create_main_args);
553   CHECK_EQ(0, main_tid);
554   SetCurrentThread(main_thread);
555   main_thread->ThreadStart(internal_getpid());
556   force_interface_symbols();  // no-op.
557 
558 #if CAN_SANITIZE_LEAKS
559   __lsan::InitCommonLsan();
560   if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
561     Atexit(__lsan::DoLeakCheck);
562   }
563 #endif  // CAN_SANITIZE_LEAKS
564 
565   if (flags()->verbosity) {
566     Report("AddressSanitizer Init done\n");
567   }
568 }
569