contrib/compiler-rt/lib/asan/asan_rtl.cc

   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
  15 #include "asan_activation.h"
  16 #include "asan_allocator.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 "sanitizer_common/sanitizer_atomic.h"
  28 #include "sanitizer_common/sanitizer_flags.h"
  29 #include "sanitizer_common/sanitizer_libc.h"
  30 #include "sanitizer_common/sanitizer_symbolizer.h"
  31 #include "lsan/lsan_common.h"
  32 #include "ubsan/ubsan_init.h"
  33 #include "ubsan/ubsan_platform.h"
  34
  35 uptr __asan_shadow_memory_dynamic_address;  // Global interface symbol.
  36 int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
  37 uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
  38
  39 namespace __asan {
  40
  41 uptr AsanMappingProfile[kAsanMappingProfileSize];
  42
  43 static void AsanDie() {
  44   static atomic_uint32_t num_calls;
  45   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
  46     // Don't die twice - run a busy loop.
  47     while (1) { }
  48   }
  49   if (common_flags()->print_module_map >= 1) PrintModuleMap();
  50   if (flags()->sleep_before_dying) {
  51     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
  52     SleepForSeconds(flags()->sleep_before_dying);
  53   }
  54   if (flags()->unmap_shadow_on_exit) {
  55     if (kMidMemBeg) {
  56       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
  57       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
  58     } else {
  59       UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
  60     }
  61   }
  62 }
  63
  64 static void AsanCheckFailed(const char *file, int line, const char *cond,
  65                             u64 v1, u64 v2) {
  66   Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
  67          line, cond, (uptr)v1, (uptr)v2);
  68   // FIXME: check for infinite recursion without a thread-local counter here.
  69   PRINT_CURRENT_STACK_CHECK();
  70   Die();
  71 }
  72
  73 // -------------------------- Globals --------------------- {{{1
  74 int asan_inited;
  75 bool asan_init_is_running;
  76
  77 #if !ASAN_FIXED_MAPPING
  78 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
  79 #endif
  80
  81 // -------------------------- Misc ---------------- {{{1
  82 void ShowStatsAndAbort() {
  83   __asan_print_accumulated_stats();
  84   Die();
  85 }
  86
  87 // --------------- LowLevelAllocateCallbac ---------- {{{1
  88 static void OnLowLevelAllocate(uptr ptr, uptr size) {
  89   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
  90 }
  91
  92 // -------------------------- Run-time entry ------------------- {{{1
  93 // exported functions
  94 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
  95 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
  96 void __asan_report_ ## type ## size(uptr addr) {                    \
  97   GET_CALLER_PC_BP_SP;                                              \
  98   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);    \
  99 }                                                                   \
 100 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 101 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) {       \
 102   GET_CALLER_PC_BP_SP;                                              \
 103   ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);  \
 104 }                                                                   \
 105 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 106 void __asan_report_ ## type ## size ## _noabort(uptr addr) {        \
 107   GET_CALLER_PC_BP_SP;                                              \
 108   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);   \
 109 }                                                                   \
 110
 111 ASAN_REPORT_ERROR(load, false, 1)
 112 ASAN_REPORT_ERROR(load, false, 2)
 113 ASAN_REPORT_ERROR(load, false, 4)
 114 ASAN_REPORT_ERROR(load, false, 8)
 115 ASAN_REPORT_ERROR(load, false, 16)
 116 ASAN_REPORT_ERROR(store, true, 1)
 117 ASAN_REPORT_ERROR(store, true, 2)
 118 ASAN_REPORT_ERROR(store, true, 4)
 119 ASAN_REPORT_ERROR(store, true, 8)
 120 ASAN_REPORT_ERROR(store, true, 16)
 121
 122 #define ASAN_REPORT_ERROR_N(type, is_write)                                 \
 123 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 124 void __asan_report_ ## type ## _n(uptr addr, uptr size) {                   \
 125   GET_CALLER_PC_BP_SP;                                                      \
 126   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);            \
 127 }                                                                           \
 128 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 129 void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) {      \
 130   GET_CALLER_PC_BP_SP;                                                      \
 131   ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);          \
 132 }                                                                           \
 133 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 134 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) {           \
 135   GET_CALLER_PC_BP_SP;                                                      \
 136   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);           \
 137 }                                                                           \
 138
 139 ASAN_REPORT_ERROR_N(load, false)
 140 ASAN_REPORT_ERROR_N(store, true)
 141
 142 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \
 143     uptr sp = MEM_TO_SHADOW(addr);                                             \
 144     uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)          \
 145                                         : *reinterpret_cast<u16 *>(sp);        \
 146     if (UNLIKELY(s)) {                                                         \
 147       if (UNLIKELY(size >= SHADOW_GRANULARITY ||                               \
 148                    ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >=     \
 149                        (s8)s)) {                                               \
 150         if (__asan_test_only_reported_buggy_pointer) {                         \
 151           *__asan_test_only_reported_buggy_pointer = addr;                     \
 152         } else {                                                               \
 153           GET_CALLER_PC_BP_SP;                                                 \
 154           ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg,        \
 155                               fatal);                                          \
 156         }                                                                      \
 157       }                                                                        \
 158     }
 159
 160 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
 161   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 162   void __asan_##type##size(uptr addr) {                                        \
 163     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true)            \
 164   }                                                                            \
 165   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 166   void __asan_exp_##type##size(uptr addr, u32 exp) {                           \
 167     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true)          \
 168   }                                                                            \
 169   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 170   void __asan_##type##size ## _noabort(uptr addr) {                            \
 171     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false)           \
 172   }                                                                            \
 173
 174 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
 175 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
 176 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
 177 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
 178 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
 179 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
 180 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
 181 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
 182 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
 183 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
 184
 185 extern "C"
 186 NOINLINE INTERFACE_ATTRIBUTE
 187 void __asan_loadN(uptr addr, uptr size) {
 188   if (__asan_region_is_poisoned(addr, size)) {
 189     GET_CALLER_PC_BP_SP;
 190     ReportGenericError(pc, bp, sp, addr, false, size, 0, true);
 191   }
 192 }
 193
 194 extern "C"
 195 NOINLINE INTERFACE_ATTRIBUTE
 196 void __asan_exp_loadN(uptr addr, uptr size, u32 exp) {
 197   if (__asan_region_is_poisoned(addr, size)) {
 198     GET_CALLER_PC_BP_SP;
 199     ReportGenericError(pc, bp, sp, addr, false, size, exp, true);
 200   }
 201 }
 202
 203 extern "C"
 204 NOINLINE INTERFACE_ATTRIBUTE
 205 void __asan_loadN_noabort(uptr addr, uptr size) {
 206   if (__asan_region_is_poisoned(addr, size)) {
 207     GET_CALLER_PC_BP_SP;
 208     ReportGenericError(pc, bp, sp, addr, false, size, 0, false);
 209   }
 210 }
 211
 212 extern "C"
 213 NOINLINE INTERFACE_ATTRIBUTE
 214 void __asan_storeN(uptr addr, uptr size) {
 215   if (__asan_region_is_poisoned(addr, size)) {
 216     GET_CALLER_PC_BP_SP;
 217     ReportGenericError(pc, bp, sp, addr, true, size, 0, true);
 218   }
 219 }
 220
 221 extern "C"
 222 NOINLINE INTERFACE_ATTRIBUTE
 223 void __asan_exp_storeN(uptr addr, uptr size, u32 exp) {
 224   if (__asan_region_is_poisoned(addr, size)) {
 225     GET_CALLER_PC_BP_SP;
 226     ReportGenericError(pc, bp, sp, addr, true, size, exp, true);
 227   }
 228 }
 229
 230 extern "C"
 231 NOINLINE INTERFACE_ATTRIBUTE
 232 void __asan_storeN_noabort(uptr addr, uptr size) {
 233   if (__asan_region_is_poisoned(addr, size)) {
 234     GET_CALLER_PC_BP_SP;
 235     ReportGenericError(pc, bp, sp, addr, true, size, 0, false);
 236   }
 237 }
 238
 239 // Force the linker to keep the symbols for various ASan interface functions.
 240 // We want to keep those in the executable in order to let the instrumented
 241 // dynamic libraries access the symbol even if it is not used by the executable
 242 // itself. This should help if the build system is removing dead code at link
 243 // time.
 244 static NOINLINE void force_interface_symbols() {
 245   volatile int fake_condition = 0;  // prevent dead condition elimination.
 246   // __asan_report_* functions are noreturn, so we need a switch to prevent
 247   // the compiler from removing any of them.
 248   // clang-format off
 249   switch (fake_condition) {
 250     case 1: __asan_report_load1(0); break;
 251     case 2: __asan_report_load2(0); break;
 252     case 3: __asan_report_load4(0); break;
 253     case 4: __asan_report_load8(0); break;
 254     case 5: __asan_report_load16(0); break;
 255     case 6: __asan_report_load_n(0, 0); break;
 256     case 7: __asan_report_store1(0); break;
 257     case 8: __asan_report_store2(0); break;
 258     case 9: __asan_report_store4(0); break;
 259     case 10: __asan_report_store8(0); break;
 260     case 11: __asan_report_store16(0); break;
 261     case 12: __asan_report_store_n(0, 0); break;
 262     case 13: __asan_report_exp_load1(0, 0); break;
 263     case 14: __asan_report_exp_load2(0, 0); break;
 264     case 15: __asan_report_exp_load4(0, 0); break;
 265     case 16: __asan_report_exp_load8(0, 0); break;
 266     case 17: __asan_report_exp_load16(0, 0); break;
 267     case 18: __asan_report_exp_load_n(0, 0, 0); break;
 268     case 19: __asan_report_exp_store1(0, 0); break;
 269     case 20: __asan_report_exp_store2(0, 0); break;
 270     case 21: __asan_report_exp_store4(0, 0); break;
 271     case 22: __asan_report_exp_store8(0, 0); break;
 272     case 23: __asan_report_exp_store16(0, 0); break;
 273     case 24: __asan_report_exp_store_n(0, 0, 0); break;
 274     case 25: __asan_register_globals(nullptr, 0); break;
 275     case 26: __asan_unregister_globals(nullptr, 0); break;
 276     case 27: __asan_set_death_callback(nullptr); break;
 277     case 28: __asan_set_error_report_callback(nullptr); break;
 278     case 29: __asan_handle_no_return(); break;
 279     case 30: __asan_address_is_poisoned(nullptr); break;
 280     case 31: __asan_poison_memory_region(nullptr, 0); break;
 281     case 32: __asan_unpoison_memory_region(nullptr, 0); break;
 282     case 34: __asan_before_dynamic_init(nullptr); break;
 283     case 35: __asan_after_dynamic_init(); break;
 284     case 36: __asan_poison_stack_memory(0, 0); break;
 285     case 37: __asan_unpoison_stack_memory(0, 0); break;
 286     case 38: __asan_region_is_poisoned(0, 0); break;
 287     case 39: __asan_describe_address(0); break;
 288     case 40: __asan_set_shadow_00(0, 0); break;
 289     case 41: __asan_set_shadow_f1(0, 0); break;
 290     case 42: __asan_set_shadow_f2(0, 0); break;
 291     case 43: __asan_set_shadow_f3(0, 0); break;
 292     case 44: __asan_set_shadow_f5(0, 0); break;
 293     case 45: __asan_set_shadow_f8(0, 0); break;
 294   }
 295   // clang-format on
 296 }
 297
 298 static void asan_atexit() {
 299   Printf("AddressSanitizer exit stats:\n");
 300   __asan_print_accumulated_stats();
 301   // Print AsanMappingProfile.
 302   for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
 303     if (AsanMappingProfile[i] == 0) continue;
 304     Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
 305   }
 306 }
 307
 308 static void InitializeHighMemEnd() {
 309 #if !ASAN_FIXED_MAPPING
 310   kHighMemEnd = GetMaxUserVirtualAddress();
 311   // Increase kHighMemEnd to make sure it's properly
 312   // aligned together with kHighMemBeg:
 313   kHighMemEnd |= SHADOW_GRANULARITY * GetMmapGranularity() - 1;
 314 #endif  // !ASAN_FIXED_MAPPING
 315   CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
 316 }
 317
 318 void PrintAddressSpaceLayout() {
 319   Printf("|| `[%p, %p]` || HighMem    ||\n",
 320          (void*)kHighMemBeg, (void*)kHighMemEnd);
 321   Printf("|| `[%p, %p]` || HighShadow ||\n",
 322          (void*)kHighShadowBeg, (void*)kHighShadowEnd);
 323   if (kMidMemBeg) {
 324     Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
 325            (void*)kShadowGap3Beg, (void*)kShadowGap3End);
 326     Printf("|| `[%p, %p]` || MidMem     ||\n",
 327            (void*)kMidMemBeg, (void*)kMidMemEnd);
 328     Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
 329            (void*)kShadowGap2Beg, (void*)kShadowGap2End);
 330     Printf("|| `[%p, %p]` || MidShadow  ||\n",
 331            (void*)kMidShadowBeg, (void*)kMidShadowEnd);
 332   }
 333   Printf("|| `[%p, %p]` || ShadowGap  ||\n",
 334          (void*)kShadowGapBeg, (void*)kShadowGapEnd);
 335   if (kLowShadowBeg) {
 336     Printf("|| `[%p, %p]` || LowShadow  ||\n",
 337            (void*)kLowShadowBeg, (void*)kLowShadowEnd);
 338     Printf("|| `[%p, %p]` || LowMem     ||\n",
 339            (void*)kLowMemBeg, (void*)kLowMemEnd);
 340   }
 341   Printf("MemToShadow(shadow): %p %p %p %p",
 342          (void*)MEM_TO_SHADOW(kLowShadowBeg),
 343          (void*)MEM_TO_SHADOW(kLowShadowEnd),
 344          (void*)MEM_TO_SHADOW(kHighShadowBeg),
 345          (void*)MEM_TO_SHADOW(kHighShadowEnd));
 346   if (kMidMemBeg) {
 347     Printf(" %p %p",
 348            (void*)MEM_TO_SHADOW(kMidShadowBeg),
 349            (void*)MEM_TO_SHADOW(kMidShadowEnd));
 350   }
 351   Printf("\n");
 352   Printf("redzone=%zu\n", (uptr)flags()->redzone);
 353   Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
 354   Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
 355   Printf("thread_local_quarantine_size_kb=%zuK\n",
 356          (uptr)flags()->thread_local_quarantine_size_kb);
 357   Printf("malloc_context_size=%zu\n",
 358          (uptr)common_flags()->malloc_context_size);
 359
 360   Printf("SHADOW_SCALE: %d\n", (int)SHADOW_SCALE);
 361   Printf("SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY);
 362   Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET);
 363   CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
 364   if (kMidMemBeg)
 365     CHECK(kMidShadowBeg > kLowShadowEnd &&
 366           kMidMemBeg > kMidShadowEnd &&
 367           kHighShadowBeg > kMidMemEnd);
 368 }
 369
 370 static void AsanInitInternal() {
 371   if (LIKELY(asan_inited)) return;
 372   SanitizerToolName = "AddressSanitizer";
 373   CHECK(!asan_init_is_running && "ASan init calls itself!");
 374   asan_init_is_running = true;
 375
 376   CacheBinaryName();
 377
 378   // Initialize flags. This must be done early, because most of the
 379   // initialization steps look at flags().
 380   InitializeFlags();
 381
 382   AsanCheckIncompatibleRT();
 383   AsanCheckDynamicRTPrereqs();
 384   AvoidCVE_2016_2143();
 385
 386   SetCanPoisonMemory(flags()->poison_heap);
 387   SetMallocContextSize(common_flags()->malloc_context_size);
 388
 389   InitializePlatformExceptionHandlers();
 390
 391   InitializeHighMemEnd();
 392
 393   // Make sure we are not statically linked.
 394   AsanDoesNotSupportStaticLinkage();
 395
 396   // Install tool-specific callbacks in sanitizer_common.
 397   AddDieCallback(AsanDie);
 398   SetCheckFailedCallback(AsanCheckFailed);
 399   SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
 400
 401   __sanitizer_set_report_path(common_flags()->log_path);
 402
 403   __asan_option_detect_stack_use_after_return =
 404       flags()->detect_stack_use_after_return;
 405
 406   // Re-exec ourselves if we need to set additional env or command line args.
 407   MaybeReexec();
 408
 409   // Setup internal allocator callback.
 410   SetLowLevelAllocateMinAlignment(SHADOW_GRANULARITY);
 411   SetLowLevelAllocateCallback(OnLowLevelAllocate);
 412
 413   InitializeAsanInterceptors();
 414
 415   // Enable system log ("adb logcat") on Android.
 416   // Doing this before interceptors are initialized crashes in:
 417   // AsanInitInternal -> android_log_write -> __interceptor_strcmp
 418   AndroidLogInit();
 419
 420   ReplaceSystemMalloc();
 421
 422   DisableCoreDumperIfNecessary();
 423
 424   InitializeShadowMemory();
 425
 426   AsanTSDInit(PlatformTSDDtor);
 427   InstallDeadlySignalHandlers(AsanOnDeadlySignal);
 428
 429   AllocatorOptions allocator_options;
 430   allocator_options.SetFrom(flags(), common_flags());
 431   InitializeAllocator(allocator_options);
 432
 433   MaybeStartBackgroudThread();
 434   SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback);
 435
 436   // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
 437   // should be set to 1 prior to initializing the threads.
 438   asan_inited = 1;
 439   asan_init_is_running = false;
 440
 441   if (flags()->atexit)
 442     Atexit(asan_atexit);
 443
 444   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
 445
 446   // Now that ASan runtime is (mostly) initialized, deactivate it if
 447   // necessary, so that it can be re-activated when requested.
 448   if (flags()->start_deactivated)
 449     AsanDeactivate();
 450
 451   // interceptors
 452   InitTlsSize();
 453
 454   // Create main thread.
 455   AsanThread *main_thread = CreateMainThread();
 456   CHECK_EQ(0, main_thread->tid());
 457   force_interface_symbols();  // no-op.
 458   SanitizerInitializeUnwinder();
 459
 460   if (CAN_SANITIZE_LEAKS) {
 461     __lsan::InitCommonLsan();
 462     if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
 463       if (flags()->halt_on_error)
 464         Atexit(__lsan::DoLeakCheck);
 465       else
 466         Atexit(__lsan::DoRecoverableLeakCheckVoid);
 467     }
 468   }
 469
 470 #if CAN_SANITIZE_UB
 471   __ubsan::InitAsPlugin();
 472 #endif
 473
 474   InitializeSuppressions();
 475
 476   if (CAN_SANITIZE_LEAKS) {
 477     // LateInitialize() calls dlsym, which can allocate an error string buffer
 478     // in the TLS.  Let's ignore the allocation to avoid reporting a leak.
 479     __lsan::ScopedInterceptorDisabler disabler;
 480     Symbolizer::LateInitialize();
 481   } else {
 482     Symbolizer::LateInitialize();
 483   }
 484
 485   VReport(1, "AddressSanitizer Init done\n");
 486
 487   if (flags()->sleep_after_init) {
 488     Report("Sleeping for %d second(s)\n", flags()->sleep_after_init);
 489     SleepForSeconds(flags()->sleep_after_init);
 490   }
 491 }
 492
 493 // Initialize as requested from some part of ASan runtime library (interceptors,
 494 // allocator, etc).
 495 void AsanInitFromRtl() {
 496   AsanInitInternal();
 497 }
 498
 499 #if ASAN_DYNAMIC
 500 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
 501 // (and thus normal initializers from .preinit_array or modules haven't run).
 502
 503 class AsanInitializer {
 504 public:  // NOLINT
 505   AsanInitializer() {
 506     AsanInitFromRtl();
 507   }
 508 };
 509
 510 static AsanInitializer asan_initializer;
 511 #endif  // ASAN_DYNAMIC
 512
 513 } // namespace __asan
 514
 515 // ---------------------- Interface ---------------- {{{1
 516 using namespace __asan;  // NOLINT
 517
 518 void NOINLINE __asan_handle_no_return() {
 519   if (asan_init_is_running)
 520     return;
 521
 522   int local_stack;
 523   AsanThread *curr_thread = GetCurrentThread();
 524   uptr PageSize = GetPageSizeCached();
 525   uptr top, bottom;
 526   if (curr_thread) {
 527     top = curr_thread->stack_top();
 528     bottom = ((uptr)&local_stack - PageSize) & ~(PageSize - 1);
 529   } else {
 530     CHECK(!SANITIZER_FUCHSIA);
 531     // If we haven't seen this thread, try asking the OS for stack bounds.
 532     uptr tls_addr, tls_size, stack_size;
 533     GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr,
 534                          &tls_size);
 535     top = bottom + stack_size;
 536   }
 537   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
 538   if (top - bottom > kMaxExpectedCleanupSize) {
 539     static bool reported_warning = false;
 540     if (reported_warning)
 541       return;
 542     reported_warning = true;
 543     Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
 544            "stack top: %p; bottom %p; size: %p (%zd)\n"
 545            "False positive error reports may follow\n"
 546            "For details see "
 547            "https://github.com/google/sanitizers/issues/189\n",
 548            top, bottom, top - bottom, top - bottom);
 549     return;
 550   }
 551   PoisonShadow(bottom, top - bottom, 0);
 552   if (curr_thread && curr_thread->has_fake_stack())
 553     curr_thread->fake_stack()->HandleNoReturn();
 554 }
 555
 556 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
 557   SetUserDieCallback(callback);
 558 }
 559
 560 // Initialize as requested from instrumented application code.
 561 // We use this call as a trigger to wake up ASan from deactivated state.
 562 void __asan_init() {
 563   AsanActivate();
 564   AsanInitInternal();
 565 }
 566
 567 void __asan_version_mismatch_check() {
 568   // Do nothing.
 569 }