libsanitizer/asan/asan_rtl.cpp

   1 //===-- asan_rtl.cpp ------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of AddressSanitizer, an address sanity checker.
  10 //
  11 // Main file of the ASan run-time library.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "asan_activation.h"
  15 #include "asan_allocator.h"
  16 #include "asan_fake_stack.h"
  17 #include "asan_interceptors.h"
  18 #include "asan_interface_internal.h"
  19 #include "asan_internal.h"
  20 #include "asan_mapping.h"
  21 #include "asan_poisoning.h"
  22 #include "asan_report.h"
  23 #include "asan_stack.h"
  24 #include "asan_stats.h"
  25 #include "asan_suppressions.h"
  26 #include "asan_thread.h"
  27 #include "lsan/lsan_common.h"
  28 #include "sanitizer_common/sanitizer_atomic.h"
  29 #include "sanitizer_common/sanitizer_flags.h"
  30 #include "sanitizer_common/sanitizer_interface_internal.h"
  31 #include "sanitizer_common/sanitizer_libc.h"
  32 #include "sanitizer_common/sanitizer_symbolizer.h"
  33 #include "ubsan/ubsan_init.h"
  34 #include "ubsan/ubsan_platform.h"
  35
  36 uptr __asan_shadow_memory_dynamic_address;  // Global interface symbol.
  37 int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
  38 uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
  39
  40 namespace __asan {
  41
  42 uptr AsanMappingProfile[kAsanMappingProfileSize];
  43
  44 static void AsanDie() {
  45   static atomic_uint32_t num_calls;
  46   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
  47     // Don't die twice - run a busy loop.
  48     while (1) {
  49       internal_sched_yield();
  50     }
  51   }
  52   if (common_flags()->print_module_map >= 1)
  53     DumpProcessMap();
  54
  55   WaitForDebugger(flags()->sleep_before_dying, "before dying");
  56
  57   if (flags()->unmap_shadow_on_exit) {
  58     if (kMidMemBeg) {
  59       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
  60       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
  61     } else {
  62       if (kHighShadowEnd)
  63         UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
  64     }
  65   }
  66 }
  67
  68 static void CheckUnwind() {
  69   GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check);
  70   stack.Print();
  71 }
  72
  73 // -------------------------- Globals --------------------- {{{1
  74 static int asan_inited = 0;
  75 static int asan_init_is_running = 0;
  76
  77 void SetAsanInited(u32 val) { asan_inited = val; }
  78
  79 void SetAsanInitIsRunning(u32 val) { asan_init_is_running = val; }
  80
  81 bool AsanInited() { return asan_inited == 1; }
  82
  83 bool AsanInitIsRunning() { return asan_init_is_running == 1; }
  84
  85 bool replace_intrin_cached;
  86
  87 #if !ASAN_FIXED_MAPPING
  88 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
  89 #endif
  90
  91 // -------------------------- Misc ---------------- {{{1
  92 void ShowStatsAndAbort() {
  93   __asan_print_accumulated_stats();
  94   Die();
  95 }
  96
  97 NOINLINE
  98 static void ReportGenericErrorWrapper(uptr addr, bool is_write, int size,
  99                                       int exp_arg, bool fatal) {
 100   GET_CALLER_PC_BP_SP;
 101   ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg, fatal);
 102 }
 103
 104 // --------------- LowLevelAllocateCallbac ---------- {{{1
 105 static void OnLowLevelAllocate(uptr ptr, uptr size) {
 106   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
 107 }
 108
 109 // -------------------------- Run-time entry ------------------- {{{1
 110 // exported functions
 111 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
 112 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 113 void __asan_report_ ## type ## size(uptr addr) {                    \
 114   GET_CALLER_PC_BP_SP;                                              \
 115   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);    \
 116 }                                                                   \
 117 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 118 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) {       \
 119   GET_CALLER_PC_BP_SP;                                              \
 120   ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);  \
 121 }                                                                   \
 122 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 123 void __asan_report_ ## type ## size ## _noabort(uptr addr) {        \
 124   GET_CALLER_PC_BP_SP;                                              \
 125   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);   \
 126 }                                                                   \
 127
 128 ASAN_REPORT_ERROR(load, false, 1)
 129 ASAN_REPORT_ERROR(load, false, 2)
 130 ASAN_REPORT_ERROR(load, false, 4)
 131 ASAN_REPORT_ERROR(load, false, 8)
 132 ASAN_REPORT_ERROR(load, false, 16)
 133 ASAN_REPORT_ERROR(store, true, 1)
 134 ASAN_REPORT_ERROR(store, true, 2)
 135 ASAN_REPORT_ERROR(store, true, 4)
 136 ASAN_REPORT_ERROR(store, true, 8)
 137 ASAN_REPORT_ERROR(store, true, 16)
 138
 139 #define ASAN_REPORT_ERROR_N(type, is_write)                                 \
 140 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 141 void __asan_report_ ## type ## _n(uptr addr, uptr size) {                   \
 142   GET_CALLER_PC_BP_SP;                                                      \
 143   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);            \
 144 }                                                                           \
 145 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 146 void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) {      \
 147   GET_CALLER_PC_BP_SP;                                                      \
 148   ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);          \
 149 }                                                                           \
 150 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 151 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) {           \
 152   GET_CALLER_PC_BP_SP;                                                      \
 153   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);           \
 154 }                                                                           \
 155
 156 ASAN_REPORT_ERROR_N(load, false)
 157 ASAN_REPORT_ERROR_N(store, true)
 158
 159 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \
 160   uptr sp = MEM_TO_SHADOW(addr);                                               \
 161   uptr s = size <= ASAN_SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)       \
 162                                            : *reinterpret_cast<u16 *>(sp);     \
 163   if (UNLIKELY(s)) {                                                           \
 164     if (UNLIKELY(size >= ASAN_SHADOW_GRANULARITY ||                            \
 165                  ((s8)((addr & (ASAN_SHADOW_GRANULARITY - 1)) + size - 1)) >=  \
 166                      (s8)s)) {                                                 \
 167       ReportGenericErrorWrapper(addr, is_write, size, exp_arg, fatal);         \
 168     }                                                                          \
 169   }
 170
 171 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
 172   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 173   void __asan_##type##size(uptr addr) {                                        \
 174     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true)            \
 175   }                                                                            \
 176   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 177   void __asan_exp_##type##size(uptr addr, u32 exp) {                           \
 178     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true)          \
 179   }                                                                            \
 180   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 181   void __asan_##type##size ## _noabort(uptr addr) {                            \
 182     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false)           \
 183   }                                                                            \
 184
 185 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
 186 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
 187 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
 188 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
 189 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
 190 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
 191 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
 192 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
 193 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
 194 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
 195
 196 extern "C"
 197 NOINLINE INTERFACE_ATTRIBUTE
 198 void __asan_loadN(uptr addr, uptr size) {
 199   if ((addr = __asan_region_is_poisoned(addr, size))) {
 200     GET_CALLER_PC_BP_SP;
 201     ReportGenericError(pc, bp, sp, addr, false, size, 0, true);
 202   }
 203 }
 204
 205 extern "C"
 206 NOINLINE INTERFACE_ATTRIBUTE
 207 void __asan_exp_loadN(uptr addr, uptr size, u32 exp) {
 208   if ((addr = __asan_region_is_poisoned(addr, size))) {
 209     GET_CALLER_PC_BP_SP;
 210     ReportGenericError(pc, bp, sp, addr, false, size, exp, true);
 211   }
 212 }
 213
 214 extern "C"
 215 NOINLINE INTERFACE_ATTRIBUTE
 216 void __asan_loadN_noabort(uptr addr, uptr size) {
 217   if ((addr = __asan_region_is_poisoned(addr, size))) {
 218     GET_CALLER_PC_BP_SP;
 219     ReportGenericError(pc, bp, sp, addr, false, size, 0, false);
 220   }
 221 }
 222
 223 extern "C"
 224 NOINLINE INTERFACE_ATTRIBUTE
 225 void __asan_storeN(uptr addr, uptr size) {
 226   if ((addr = __asan_region_is_poisoned(addr, size))) {
 227     GET_CALLER_PC_BP_SP;
 228     ReportGenericError(pc, bp, sp, addr, true, size, 0, true);
 229   }
 230 }
 231
 232 extern "C"
 233 NOINLINE INTERFACE_ATTRIBUTE
 234 void __asan_exp_storeN(uptr addr, uptr size, u32 exp) {
 235   if ((addr = __asan_region_is_poisoned(addr, size))) {
 236     GET_CALLER_PC_BP_SP;
 237     ReportGenericError(pc, bp, sp, addr, true, size, exp, true);
 238   }
 239 }
 240
 241 extern "C"
 242 NOINLINE INTERFACE_ATTRIBUTE
 243 void __asan_storeN_noabort(uptr addr, uptr size) {
 244   if ((addr = __asan_region_is_poisoned(addr, size))) {
 245     GET_CALLER_PC_BP_SP;
 246     ReportGenericError(pc, bp, sp, addr, true, size, 0, false);
 247   }
 248 }
 249
 250 // Force the linker to keep the symbols for various ASan interface functions.
 251 // We want to keep those in the executable in order to let the instrumented
 252 // dynamic libraries access the symbol even if it is not used by the executable
 253 // itself. This should help if the build system is removing dead code at link
 254 // time.
 255 static NOINLINE void force_interface_symbols() {
 256   volatile int fake_condition = 0;  // prevent dead condition elimination.
 257   // __asan_report_* functions are noreturn, so we need a switch to prevent
 258   // the compiler from removing any of them.
 259   // clang-format off
 260   switch (fake_condition) {
 261     case 1: __asan_report_load1(0); break;
 262     case 2: __asan_report_load2(0); break;
 263     case 3: __asan_report_load4(0); break;
 264     case 4: __asan_report_load8(0); break;
 265     case 5: __asan_report_load16(0); break;
 266     case 6: __asan_report_load_n(0, 0); break;
 267     case 7: __asan_report_store1(0); break;
 268     case 8: __asan_report_store2(0); break;
 269     case 9: __asan_report_store4(0); break;
 270     case 10: __asan_report_store8(0); break;
 271     case 11: __asan_report_store16(0); break;
 272     case 12: __asan_report_store_n(0, 0); break;
 273     case 13: __asan_report_exp_load1(0, 0); break;
 274     case 14: __asan_report_exp_load2(0, 0); break;
 275     case 15: __asan_report_exp_load4(0, 0); break;
 276     case 16: __asan_report_exp_load8(0, 0); break;
 277     case 17: __asan_report_exp_load16(0, 0); break;
 278     case 18: __asan_report_exp_load_n(0, 0, 0); break;
 279     case 19: __asan_report_exp_store1(0, 0); break;
 280     case 20: __asan_report_exp_store2(0, 0); break;
 281     case 21: __asan_report_exp_store4(0, 0); break;
 282     case 22: __asan_report_exp_store8(0, 0); break;
 283     case 23: __asan_report_exp_store16(0, 0); break;
 284     case 24: __asan_report_exp_store_n(0, 0, 0); break;
 285     case 25: __asan_register_globals(nullptr, 0); break;
 286     case 26: __asan_unregister_globals(nullptr, 0); break;
 287     case 27: __asan_set_death_callback(nullptr); break;
 288     case 28: __asan_set_error_report_callback(nullptr); break;
 289     case 29: __asan_handle_no_return(); break;
 290     case 30: __asan_address_is_poisoned(nullptr); break;
 291     case 31: __asan_poison_memory_region(nullptr, 0); break;
 292     case 32: __asan_unpoison_memory_region(nullptr, 0); break;
 293     case 34: __asan_before_dynamic_init(nullptr); break;
 294     case 35: __asan_after_dynamic_init(); break;
 295     case 36: __asan_poison_stack_memory(0, 0); break;
 296     case 37: __asan_unpoison_stack_memory(0, 0); break;
 297     case 38: __asan_region_is_poisoned(0, 0); break;
 298     case 39: __asan_describe_address(0); break;
 299     case 40: __asan_set_shadow_00(0, 0); break;
 300     case 41: __asan_set_shadow_01(0, 0); break;
 301     case 42: __asan_set_shadow_02(0, 0); break;
 302     case 43: __asan_set_shadow_03(0, 0); break;
 303     case 44: __asan_set_shadow_04(0, 0); break;
 304     case 45: __asan_set_shadow_05(0, 0); break;
 305     case 46: __asan_set_shadow_06(0, 0); break;
 306     case 47: __asan_set_shadow_07(0, 0); break;
 307     case 48: __asan_set_shadow_f1(0, 0); break;
 308     case 49: __asan_set_shadow_f2(0, 0); break;
 309     case 50: __asan_set_shadow_f3(0, 0); break;
 310     case 51: __asan_set_shadow_f5(0, 0); break;
 311     case 52: __asan_set_shadow_f8(0, 0); break;
 312   }
 313   // clang-format on
 314 }
 315
 316 static void asan_atexit() {
 317   Printf("AddressSanitizer exit stats:\n");
 318   __asan_print_accumulated_stats();
 319   // Print AsanMappingProfile.
 320   for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
 321     if (AsanMappingProfile[i] == 0) continue;
 322     Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
 323   }
 324 }
 325
 326 static void InitializeHighMemEnd() {
 327 #if !ASAN_FIXED_MAPPING
 328   kHighMemEnd = GetMaxUserVirtualAddress();
 329   // Increase kHighMemEnd to make sure it's properly
 330   // aligned together with kHighMemBeg:
 331   kHighMemEnd |= (GetMmapGranularity() << ASAN_SHADOW_SCALE) - 1;
 332 #endif  // !ASAN_FIXED_MAPPING
 333   CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
 334 }
 335
 336 void PrintAddressSpaceLayout() {
 337   if (kHighMemBeg) {
 338     Printf("|| `[%p, %p]` || HighMem    ||\n",
 339            (void*)kHighMemBeg, (void*)kHighMemEnd);
 340     Printf("|| `[%p, %p]` || HighShadow ||\n",
 341            (void*)kHighShadowBeg, (void*)kHighShadowEnd);
 342   }
 343   if (kMidMemBeg) {
 344     Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
 345            (void*)kShadowGap3Beg, (void*)kShadowGap3End);
 346     Printf("|| `[%p, %p]` || MidMem     ||\n",
 347            (void*)kMidMemBeg, (void*)kMidMemEnd);
 348     Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
 349            (void*)kShadowGap2Beg, (void*)kShadowGap2End);
 350     Printf("|| `[%p, %p]` || MidShadow  ||\n",
 351            (void*)kMidShadowBeg, (void*)kMidShadowEnd);
 352   }
 353   Printf("|| `[%p, %p]` || ShadowGap  ||\n",
 354          (void*)kShadowGapBeg, (void*)kShadowGapEnd);
 355   if (kLowShadowBeg) {
 356     Printf("|| `[%p, %p]` || LowShadow  ||\n",
 357            (void*)kLowShadowBeg, (void*)kLowShadowEnd);
 358     Printf("|| `[%p, %p]` || LowMem     ||\n",
 359            (void*)kLowMemBeg, (void*)kLowMemEnd);
 360   }
 361   Printf("MemToShadow(shadow): %p %p",
 362          (void*)MEM_TO_SHADOW(kLowShadowBeg),
 363          (void*)MEM_TO_SHADOW(kLowShadowEnd));
 364   if (kHighMemBeg) {
 365     Printf(" %p %p",
 366            (void*)MEM_TO_SHADOW(kHighShadowBeg),
 367            (void*)MEM_TO_SHADOW(kHighShadowEnd));
 368   }
 369   if (kMidMemBeg) {
 370     Printf(" %p %p",
 371            (void*)MEM_TO_SHADOW(kMidShadowBeg),
 372            (void*)MEM_TO_SHADOW(kMidShadowEnd));
 373   }
 374   Printf("\n");
 375   Printf("redzone=%zu\n", (uptr)flags()->redzone);
 376   Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
 377   Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
 378   Printf("thread_local_quarantine_size_kb=%zuK\n",
 379          (uptr)flags()->thread_local_quarantine_size_kb);
 380   Printf("malloc_context_size=%zu\n",
 381          (uptr)common_flags()->malloc_context_size);
 382
 383   Printf("SHADOW_SCALE: %d\n", (int)ASAN_SHADOW_SCALE);
 384   Printf("SHADOW_GRANULARITY: %d\n", (int)ASAN_SHADOW_GRANULARITY);
 385   Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)ASAN_SHADOW_OFFSET);
 386   CHECK(ASAN_SHADOW_SCALE >= 3 && ASAN_SHADOW_SCALE <= 7);
 387   if (kMidMemBeg)
 388     CHECK(kMidShadowBeg > kLowShadowEnd &&
 389           kMidMemBeg > kMidShadowEnd &&
 390           kHighShadowBeg > kMidMemEnd);
 391 }
 392
 393 static void AsanInitInternal() {
 394   if (LIKELY(AsanInited()))
 395     return;
 396   SanitizerToolName = "AddressSanitizer";
 397   CHECK(!AsanInitIsRunning() && "ASan init calls itself!");
 398   SetAsanInitIsRunning(1);
 399
 400   CacheBinaryName();
 401
 402   // Initialize flags. This must be done early, because most of the
 403   // initialization steps look at flags().
 404   InitializeFlags();
 405
 406   WaitForDebugger(flags()->sleep_before_init, "before init");
 407
 408   // Stop performing init at this point if we are being loaded via
 409   // dlopen() and the platform supports it.
 410   if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) {
 411     SetAsanInitIsRunning(0);
 412     VReport(1, "AddressSanitizer init is being performed for dlopen().\n");
 413     return;
 414   }
 415
 416   AsanCheckIncompatibleRT();
 417   AsanCheckDynamicRTPrereqs();
 418   AvoidCVE_2016_2143();
 419
 420   SetCanPoisonMemory(flags()->poison_heap);
 421   SetMallocContextSize(common_flags()->malloc_context_size);
 422
 423   InitializePlatformExceptionHandlers();
 424
 425   InitializeHighMemEnd();
 426
 427   // Make sure we are not statically linked.
 428   AsanDoesNotSupportStaticLinkage();
 429
 430   // Install tool-specific callbacks in sanitizer_common.
 431   AddDieCallback(AsanDie);
 432   SetCheckUnwindCallback(CheckUnwind);
 433   SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
 434
 435   __sanitizer_set_report_path(common_flags()->log_path);
 436
 437   __asan_option_detect_stack_use_after_return =
 438       flags()->detect_stack_use_after_return;
 439
 440   __sanitizer::InitializePlatformEarly();
 441
 442   // Setup internal allocator callback.
 443   SetLowLevelAllocateMinAlignment(ASAN_SHADOW_GRANULARITY);
 444   SetLowLevelAllocateCallback(OnLowLevelAllocate);
 445
 446   InitializeAsanInterceptors();
 447   CheckASLR();
 448
 449   // Enable system log ("adb logcat") on Android.
 450   // Doing this before interceptors are initialized crashes in:
 451   // AsanInitInternal -> android_log_write -> __interceptor_strcmp
 452   AndroidLogInit();
 453
 454   ReplaceSystemMalloc();
 455
 456   DisableCoreDumperIfNecessary();
 457
 458   InitializeShadowMemory();
 459
 460   AsanTSDInit(PlatformTSDDtor);
 461   InstallDeadlySignalHandlers(AsanOnDeadlySignal);
 462
 463   AllocatorOptions allocator_options;
 464   allocator_options.SetFrom(flags(), common_flags());
 465   InitializeAllocator(allocator_options);
 466
 467   if (SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL)
 468     MaybeStartBackgroudThread();
 469
 470   // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
 471   // should be set to 1 prior to initializing the threads.
 472   replace_intrin_cached = flags()->replace_intrin;
 473   SetAsanInited(1);
 474   SetAsanInitIsRunning(0);
 475
 476   if (flags()->atexit)
 477     Atexit(asan_atexit);
 478
 479   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
 480
 481   // Now that ASan runtime is (mostly) initialized, deactivate it if
 482   // necessary, so that it can be re-activated when requested.
 483   if (flags()->start_deactivated)
 484     AsanDeactivate();
 485
 486   // interceptors
 487   InitTlsSize();
 488
 489   // Create main thread.
 490   AsanThread *main_thread = CreateMainThread();
 491   CHECK_EQ(0, main_thread->tid());
 492   force_interface_symbols();  // no-op.
 493   SanitizerInitializeUnwinder();
 494
 495   if (CAN_SANITIZE_LEAKS) {
 496     __lsan::InitCommonLsan();
 497     InstallAtExitCheckLeaks();
 498   }
 499
 500 #if CAN_SANITIZE_UB
 501   __ubsan::InitAsPlugin();
 502 #endif
 503
 504   InitializeSuppressions();
 505
 506   if (CAN_SANITIZE_LEAKS) {
 507     // LateInitialize() calls dlsym, which can allocate an error string buffer
 508     // in the TLS.  Let's ignore the allocation to avoid reporting a leak.
 509     __lsan::ScopedInterceptorDisabler disabler;
 510     Symbolizer::LateInitialize();
 511   } else {
 512     Symbolizer::LateInitialize();
 513   }
 514
 515   VReport(1, "AddressSanitizer Init done\n");
 516
 517   WaitForDebugger(flags()->sleep_after_init, "after init");
 518 }
 519
 520 // Initialize as requested from some part of ASan runtime library (interceptors,
 521 // allocator, etc).
 522 void AsanInitFromRtl() {
 523   AsanInitInternal();
 524 }
 525
 526 #if ASAN_DYNAMIC
 527 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
 528 // (and thus normal initializers from .preinit_array or modules haven't run).
 529
 530 class AsanInitializer {
 531  public:
 532   AsanInitializer() {
 533     AsanInitFromRtl();
 534   }
 535 };
 536
 537 static AsanInitializer asan_initializer;
 538 #endif  // ASAN_DYNAMIC
 539
 540 void UnpoisonStack(uptr bottom, uptr top, const char *type) {
 541   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
 542   if (top - bottom > kMaxExpectedCleanupSize) {
 543     static bool reported_warning = false;
 544     if (reported_warning)
 545       return;
 546     reported_warning = true;
 547     Report(
 548         "WARNING: ASan is ignoring requested __asan_handle_no_return: "
 549         "stack type: %s top: %p; bottom %p; size: %p (%zd)\n"
 550         "False positive error reports may follow\n"
 551         "For details see "
 552         "https://github.com/google/sanitizers/issues/189\n",
 553         type, (void *)top, (void *)bottom, (void *)(top - bottom),
 554         top - bottom);
 555     return;
 556   }
 557   PoisonShadow(bottom, RoundUpTo(top - bottom, ASAN_SHADOW_GRANULARITY), 0);
 558 }
 559
 560 static void UnpoisonDefaultStack() {
 561   uptr bottom, top;
 562
 563   if (AsanThread *curr_thread = GetCurrentThread()) {
 564     int local_stack;
 565     const uptr page_size = GetPageSizeCached();
 566     top = curr_thread->stack_top();
 567     bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1);
 568   } else {
 569     CHECK(!SANITIZER_FUCHSIA);
 570     // If we haven't seen this thread, try asking the OS for stack bounds.
 571     uptr tls_addr, tls_size, stack_size;
 572     GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr,
 573                          &tls_size);
 574     top = bottom + stack_size;
 575   }
 576
 577   UnpoisonStack(bottom, top, "default");
 578 }
 579
 580 static void UnpoisonFakeStack() {
 581   AsanThread *curr_thread = GetCurrentThread();
 582   if (!curr_thread)
 583     return;
 584   FakeStack *stack = curr_thread->get_fake_stack();
 585   if (!stack)
 586     return;
 587   stack->HandleNoReturn();
 588 }
 589
 590 }  // namespace __asan
 591
 592 // ---------------------- Interface ---------------- {{{1
 593 using namespace __asan;
 594
 595 void NOINLINE __asan_handle_no_return() {
 596   if (AsanInitIsRunning())
 597     return;
 598
 599   if (!PlatformUnpoisonStacks())
 600     UnpoisonDefaultStack();
 601
 602   UnpoisonFakeStack();
 603 }
 604
 605 extern "C" void *__asan_extra_spill_area() {
 606   AsanThread *t = GetCurrentThread();
 607   CHECK(t);
 608   return t->extra_spill_area();
 609 }
 610
 611 void __asan_handle_vfork(void *sp) {
 612   AsanThread *t = GetCurrentThread();
 613   CHECK(t);
 614   uptr bottom = t->stack_bottom();
 615   PoisonShadow(bottom, (uptr)sp - bottom, 0);
 616 }
 617
 618 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
 619   SetUserDieCallback(callback);
 620 }
 621
 622 // Initialize as requested from instrumented application code.
 623 // We use this call as a trigger to wake up ASan from deactivated state.
 624 void __asan_init() {
 625   AsanActivate();
 626   AsanInitInternal();
 627 }
 628
 629 void __asan_version_mismatch_check() {
 630   // Do nothing.
 631 }