src/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 int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
  36 uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
  37
  38 namespace __asan {
  39
  40 uptr AsanMappingProfile[kAsanMappingProfileSize];
  41
  42 static void AsanDie() {
  43   static atomic_uint32_t num_calls;
  44   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
  45     // Don't die twice - run a busy loop.
  46     while (1) { }
  47   }
  48   if (flags()->sleep_before_dying) {
  49     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
  50     SleepForSeconds(flags()->sleep_before_dying);
  51   }
  52   if (flags()->unmap_shadow_on_exit) {
  53     if (kMidMemBeg) {
  54       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
  55       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
  56     } else {
  57       UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
  58     }
  59   }
  60 }
  61
  62 static void AsanCheckFailed(const char *file, int line, const char *cond,
  63                             u64 v1, u64 v2) {
  64   Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
  65          line, cond, (uptr)v1, (uptr)v2);
  66   // FIXME: check for infinite recursion without a thread-local counter here.
  67   PRINT_CURRENT_STACK_CHECK();
  68   Die();
  69 }
  70
  71 // -------------------------- Globals --------------------- {{{1
  72 int asan_inited;
  73 bool asan_init_is_running;
  74
  75 #if !ASAN_FIXED_MAPPING
  76 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
  77 #endif
  78
  79 // -------------------------- Misc ---------------- {{{1
  80 void ShowStatsAndAbort() {
  81   __asan_print_accumulated_stats();
  82   Die();
  83 }
  84
  85 // ---------------------- mmap -------------------- {{{1
  86 // Reserve memory range [beg, end].
  87 // We need to use inclusive range because end+1 may not be representable.
  88 void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
  89   CHECK_EQ((beg % GetMmapGranularity()), 0);
  90   CHECK_EQ(((end + 1) % GetMmapGranularity()), 0);
  91   uptr size = end - beg + 1;
  92   DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
  93   void *res = MmapFixedNoReserve(beg, size, name);
  94   if (res != (void*)beg) {
  95     Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
  96            "Perhaps you're using ulimit -v\n", size);
  97     Abort();
  98   }
  99   if (common_flags()->no_huge_pages_for_shadow)
 100     NoHugePagesInRegion(beg, size);
 101   if (common_flags()->use_madv_dontdump)
 102     DontDumpShadowMemory(beg, size);
 103 }
 104
 105 // --------------- LowLevelAllocateCallbac ---------- {{{1
 106 static void OnLowLevelAllocate(uptr ptr, uptr size) {
 107   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
 108 }
 109
 110 // -------------------------- Run-time entry ------------------- {{{1
 111 // exported functions
 112 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
 113 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 114 void __asan_report_ ## type ## size(uptr addr) {                    \
 115   GET_CALLER_PC_BP_SP;                                              \
 116   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);    \
 117 }                                                                   \
 118 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 119 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) {       \
 120   GET_CALLER_PC_BP_SP;                                              \
 121   ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);  \
 122 }                                                                   \
 123 extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
 124 void __asan_report_ ## type ## size ## _noabort(uptr addr) {        \
 125   GET_CALLER_PC_BP_SP;                                              \
 126   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);   \
 127 }                                                                   \
 128
 129 ASAN_REPORT_ERROR(load, false, 1)
 130 ASAN_REPORT_ERROR(load, false, 2)
 131 ASAN_REPORT_ERROR(load, false, 4)
 132 ASAN_REPORT_ERROR(load, false, 8)
 133 ASAN_REPORT_ERROR(load, false, 16)
 134 ASAN_REPORT_ERROR(store, true, 1)
 135 ASAN_REPORT_ERROR(store, true, 2)
 136 ASAN_REPORT_ERROR(store, true, 4)
 137 ASAN_REPORT_ERROR(store, true, 8)
 138 ASAN_REPORT_ERROR(store, true, 16)
 139
 140 #define ASAN_REPORT_ERROR_N(type, is_write)                                 \
 141 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 142 void __asan_report_ ## type ## _n(uptr addr, uptr size) {                   \
 143   GET_CALLER_PC_BP_SP;                                                      \
 144   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);            \
 145 }                                                                           \
 146 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 147 void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) {      \
 148   GET_CALLER_PC_BP_SP;                                                      \
 149   ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);          \
 150 }                                                                           \
 151 extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
 152 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) {           \
 153   GET_CALLER_PC_BP_SP;                                                      \
 154   ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);           \
 155 }                                                                           \
 156
 157 ASAN_REPORT_ERROR_N(load, false)
 158 ASAN_REPORT_ERROR_N(store, true)
 159
 160 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \
 161     uptr sp = MEM_TO_SHADOW(addr);                                             \
 162     uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)          \
 163                                         : *reinterpret_cast<u16 *>(sp);        \
 164     if (UNLIKELY(s)) {                                                         \
 165       if (UNLIKELY(size >= SHADOW_GRANULARITY ||                               \
 166                    ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >=     \
 167                        (s8)s)) {                                               \
 168         if (__asan_test_only_reported_buggy_pointer) {                         \
 169           *__asan_test_only_reported_buggy_pointer = addr;                     \
 170         } else {                                                               \
 171           GET_CALLER_PC_BP_SP;                                                 \
 172           ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg,        \
 173                               fatal);                                          \
 174         }                                                                      \
 175       }                                                                        \
 176     }
 177
 178 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
 179   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 180   void __asan_##type##size(uptr addr) {                                        \
 181     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true)            \
 182   }                                                                            \
 183   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 184   void __asan_exp_##type##size(uptr addr, u32 exp) {                           \
 185     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true)          \
 186   }                                                                            \
 187   extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
 188   void __asan_##type##size ## _noabort(uptr addr) {                            \
 189     ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false)           \
 190   }                                                                            \
 191
 192 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
 193 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
 194 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
 195 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
 196 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
 197 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
 198 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
 199 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
 200 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
 201 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
 202
 203 extern "C"
 204 NOINLINE INTERFACE_ATTRIBUTE
 205 void __asan_loadN(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, true);
 209   }
 210 }
 211
 212 extern "C"
 213 NOINLINE INTERFACE_ATTRIBUTE
 214 void __asan_exp_loadN(uptr addr, uptr size, u32 exp) {
 215   if (__asan_region_is_poisoned(addr, size)) {
 216     GET_CALLER_PC_BP_SP;
 217     ReportGenericError(pc, bp, sp, addr, false, size, exp, true);
 218   }
 219 }
 220
 221 extern "C"
 222 NOINLINE INTERFACE_ATTRIBUTE
 223 void __asan_loadN_noabort(uptr addr, uptr size) {
 224   if (__asan_region_is_poisoned(addr, size)) {
 225     GET_CALLER_PC_BP_SP;
 226     ReportGenericError(pc, bp, sp, addr, false, size, 0, false);
 227   }
 228 }
 229
 230 extern "C"
 231 NOINLINE INTERFACE_ATTRIBUTE
 232 void __asan_storeN(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, true);
 236   }
 237 }
 238
 239 extern "C"
 240 NOINLINE INTERFACE_ATTRIBUTE
 241 void __asan_exp_storeN(uptr addr, uptr size, u32 exp) {
 242   if (__asan_region_is_poisoned(addr, size)) {
 243     GET_CALLER_PC_BP_SP;
 244     ReportGenericError(pc, bp, sp, addr, true, size, exp, true);
 245   }
 246 }
 247
 248 extern "C"
 249 NOINLINE INTERFACE_ATTRIBUTE
 250 void __asan_storeN_noabort(uptr addr, uptr size) {
 251   if (__asan_region_is_poisoned(addr, size)) {
 252     GET_CALLER_PC_BP_SP;
 253     ReportGenericError(pc, bp, sp, addr, true, size, 0, false);
 254   }
 255 }
 256
 257 // Force the linker to keep the symbols for various ASan interface functions.
 258 // We want to keep those in the executable in order to let the instrumented
 259 // dynamic libraries access the symbol even if it is not used by the executable
 260 // itself. This should help if the build system is removing dead code at link
 261 // time.
 262 static NOINLINE void force_interface_symbols() {
 263   volatile int fake_condition = 0;  // prevent dead condition elimination.
 264   // __asan_report_* functions are noreturn, so we need a switch to prevent
 265   // the compiler from removing any of them.
 266   switch (fake_condition) {
 267     case 1: __asan_report_load1(0); break;
 268     case 2: __asan_report_load2(0); break;
 269     case 3: __asan_report_load4(0); break;
 270     case 4: __asan_report_load8(0); break;
 271     case 5: __asan_report_load16(0); break;
 272     case 6: __asan_report_load_n(0, 0); break;
 273     case 7: __asan_report_store1(0); break;
 274     case 8: __asan_report_store2(0); break;
 275     case 9: __asan_report_store4(0); break;
 276     case 10: __asan_report_store8(0); break;
 277     case 11: __asan_report_store16(0); break;
 278     case 12: __asan_report_store_n(0, 0); break;
 279     case 13: __asan_report_exp_load1(0, 0); break;
 280     case 14: __asan_report_exp_load2(0, 0); break;
 281     case 15: __asan_report_exp_load4(0, 0); break;
 282     case 16: __asan_report_exp_load8(0, 0); break;
 283     case 17: __asan_report_exp_load16(0, 0); break;
 284     case 18: __asan_report_exp_load_n(0, 0, 0); break;
 285     case 19: __asan_report_exp_store1(0, 0); break;
 286     case 20: __asan_report_exp_store2(0, 0); break;
 287     case 21: __asan_report_exp_store4(0, 0); break;
 288     case 22: __asan_report_exp_store8(0, 0); break;
 289     case 23: __asan_report_exp_store16(0, 0); break;
 290     case 24: __asan_report_exp_store_n(0, 0, 0); break;
 291     case 25: __asan_register_globals(nullptr, 0); break;
 292     case 26: __asan_unregister_globals(nullptr, 0); break;
 293     case 27: __asan_set_death_callback(nullptr); break;
 294     case 28: __asan_set_error_report_callback(nullptr); break;
 295     case 29: __asan_handle_no_return(); break;
 296     case 30: __asan_address_is_poisoned(nullptr); break;
 297     case 31: __asan_poison_memory_region(nullptr, 0); break;
 298     case 32: __asan_unpoison_memory_region(nullptr, 0); break;
 299     case 34: __asan_before_dynamic_init(nullptr); break;
 300     case 35: __asan_after_dynamic_init(); break;
 301     case 36: __asan_poison_stack_memory(0, 0); break;
 302     case 37: __asan_unpoison_stack_memory(0, 0); break;
 303     case 38: __asan_region_is_poisoned(0, 0); break;
 304     case 39: __asan_describe_address(0); break;
 305   }
 306 }
 307
 308 static void asan_atexit() {
 309   Printf("AddressSanitizer exit stats:\n");
 310   __asan_print_accumulated_stats();
 311   // Print AsanMappingProfile.
 312   for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
 313     if (AsanMappingProfile[i] == 0) continue;
 314     Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
 315   }
 316 }
 317
 318 static void InitializeHighMemEnd() {
 319 #if !ASAN_FIXED_MAPPING
 320   kHighMemEnd = GetMaxVirtualAddress();
 321   // Increase kHighMemEnd to make sure it's properly
 322   // aligned together with kHighMemBeg:
 323   kHighMemEnd |= SHADOW_GRANULARITY * GetMmapGranularity() - 1;
 324 #endif  // !ASAN_FIXED_MAPPING
 325   CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
 326 }
 327
 328 static void ProtectGap(uptr addr, uptr size) {
 329   if (!flags()->protect_shadow_gap)
 330     return;
 331   void *res = MmapFixedNoAccess(addr, size, "shadow gap");
 332   if (addr == (uptr)res)
 333     return;
 334   // A few pages at the start of the address space can not be protected.
 335   // But we really want to protect as much as possible, to prevent this memory
 336   // being returned as a result of a non-FIXED mmap().
 337   if (addr == kZeroBaseShadowStart) {
 338     uptr step = GetMmapGranularity();
 339     while (size > step && addr < kZeroBaseMaxShadowStart) {
 340       addr += step;
 341       size -= step;
 342       void *res = MmapFixedNoAccess(addr, size, "shadow gap");
 343       if (addr == (uptr)res)
 344         return;
 345     }
 346   }
 347
 348   Report("ERROR: Failed to protect the shadow gap. "
 349          "ASan cannot proceed correctly. ABORTING.\n");
 350   DumpProcessMap();
 351   Die();
 352 }
 353
 354 static void PrintAddressSpaceLayout() {
 355   Printf("|| `[%p, %p]` || HighMem    ||\n",
 356          (void*)kHighMemBeg, (void*)kHighMemEnd);
 357   Printf("|| `[%p, %p]` || HighShadow ||\n",
 358          (void*)kHighShadowBeg, (void*)kHighShadowEnd);
 359   if (kMidMemBeg) {
 360     Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
 361            (void*)kShadowGap3Beg, (void*)kShadowGap3End);
 362     Printf("|| `[%p, %p]` || MidMem     ||\n",
 363            (void*)kMidMemBeg, (void*)kMidMemEnd);
 364     Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
 365            (void*)kShadowGap2Beg, (void*)kShadowGap2End);
 366     Printf("|| `[%p, %p]` || MidShadow  ||\n",
 367            (void*)kMidShadowBeg, (void*)kMidShadowEnd);
 368   }
 369   Printf("|| `[%p, %p]` || ShadowGap  ||\n",
 370          (void*)kShadowGapBeg, (void*)kShadowGapEnd);
 371   if (kLowShadowBeg) {
 372     Printf("|| `[%p, %p]` || LowShadow  ||\n",
 373            (void*)kLowShadowBeg, (void*)kLowShadowEnd);
 374     Printf("|| `[%p, %p]` || LowMem     ||\n",
 375            (void*)kLowMemBeg, (void*)kLowMemEnd);
 376   }
 377   Printf("MemToShadow(shadow): %p %p %p %p",
 378          (void*)MEM_TO_SHADOW(kLowShadowBeg),
 379          (void*)MEM_TO_SHADOW(kLowShadowEnd),
 380          (void*)MEM_TO_SHADOW(kHighShadowBeg),
 381          (void*)MEM_TO_SHADOW(kHighShadowEnd));
 382   if (kMidMemBeg) {
 383     Printf(" %p %p",
 384            (void*)MEM_TO_SHADOW(kMidShadowBeg),
 385            (void*)MEM_TO_SHADOW(kMidShadowEnd));
 386   }
 387   Printf("\n");
 388   Printf("redzone=%zu\n", (uptr)flags()->redzone);
 389   Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
 390   Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
 391   Printf("malloc_context_size=%zu\n",
 392          (uptr)common_flags()->malloc_context_size);
 393
 394   Printf("SHADOW_SCALE: %d\n", (int)SHADOW_SCALE);
 395   Printf("SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY);
 396   Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET);
 397   CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
 398   if (kMidMemBeg)
 399     CHECK(kMidShadowBeg > kLowShadowEnd &&
 400           kMidMemBeg > kMidShadowEnd &&
 401           kHighShadowBeg > kMidMemEnd);
 402 }
 403
 404 static void AsanInitInternal() {
 405   if (LIKELY(asan_inited)) return;
 406   SanitizerToolName = "AddressSanitizer";
 407   CHECK(!asan_init_is_running && "ASan init calls itself!");
 408   asan_init_is_running = true;
 409
 410   CacheBinaryName();
 411
 412   // Initialize flags. This must be done early, because most of the
 413   // initialization steps look at flags().
 414   InitializeFlags();
 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   SetCheckFailedCallback(AsanCheckFailed);
 433   SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
 434
 435   __sanitizer_set_report_path(common_flags()->log_path);
 436
 437   // Enable UAR detection, if required.
 438   __asan_option_detect_stack_use_after_return =
 439       flags()->detect_stack_use_after_return;
 440
 441   // Re-exec ourselves if we need to set additional env or command line args.
 442   MaybeReexec();
 443
 444   // Setup internal allocator callback.
 445   SetLowLevelAllocateCallback(OnLowLevelAllocate);
 446
 447   InitializeAsanInterceptors();
 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   uptr shadow_start = kLowShadowBeg;
 457   if (kLowShadowBeg)
 458     shadow_start -= GetMmapGranularity();
 459   bool full_shadow_is_available =
 460       MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
 461
 462 #if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) &&                \
 463     !ASAN_FIXED_MAPPING
 464   if (!full_shadow_is_available) {
 465     kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
 466     kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
 467   }
 468 #elif SANITIZER_WINDOWS64
 469   // Disable the "mid mem" shadow layout.
 470   if (!full_shadow_is_available) {
 471     kMidMemBeg = 0;
 472     kMidMemEnd = 0;
 473   }
 474 #endif
 475
 476   if (Verbosity()) PrintAddressSpaceLayout();
 477
 478   DisableCoreDumperIfNecessary();
 479
 480   if (full_shadow_is_available) {
 481     // mmap the low shadow plus at least one page at the left.
 482     if (kLowShadowBeg)
 483       ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
 484     // mmap the high shadow.
 485     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
 486     // protect the gap.
 487     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
 488     CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
 489   } else if (kMidMemBeg &&
 490       MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
 491       MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
 492     CHECK(kLowShadowBeg != kLowShadowEnd);
 493     // mmap the low shadow plus at least one page at the left.
 494     ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
 495     // mmap the mid shadow.
 496     ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
 497     // mmap the high shadow.
 498     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
 499     // protect the gaps.
 500     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
 501     ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
 502     ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
 503   } else {
 504     Report("Shadow memory range interleaves with an existing memory mapping. "
 505            "ASan cannot proceed correctly. ABORTING.\n");
 506     Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
 507            shadow_start, kHighShadowEnd);
 508     DumpProcessMap();
 509     Die();
 510   }
 511
 512   AsanTSDInit(PlatformTSDDtor);
 513   InstallDeadlySignalHandlers(AsanOnDeadlySignal);
 514
 515   AllocatorOptions allocator_options;
 516   allocator_options.SetFrom(flags(), common_flags());
 517   InitializeAllocator(allocator_options);
 518
 519   MaybeStartBackgroudThread();
 520   SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback);
 521
 522   // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
 523   // should be set to 1 prior to initializing the threads.
 524   asan_inited = 1;
 525   asan_init_is_running = false;
 526
 527   if (flags()->atexit)
 528     Atexit(asan_atexit);
 529
 530   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
 531
 532   // Now that ASan runtime is (mostly) initialized, deactivate it if
 533   // necessary, so that it can be re-activated when requested.
 534   if (flags()->start_deactivated)
 535     AsanDeactivate();
 536
 537   // interceptors
 538   InitTlsSize();
 539
 540   // Create main thread.
 541   AsanThread *main_thread = AsanThread::Create(
 542       /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ 0,
 543       /* stack */ nullptr, /* detached */ true);
 544   CHECK_EQ(0, main_thread->tid());
 545   SetCurrentThread(main_thread);
 546   main_thread->ThreadStart(internal_getpid(),
 547                            /* signal_thread_is_registered */ nullptr);
 548   force_interface_symbols();  // no-op.
 549   SanitizerInitializeUnwinder();
 550
 551   if (CAN_SANITIZE_LEAKS) {
 552     __lsan::InitCommonLsan();
 553     if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
 554       Atexit(__lsan::DoLeakCheck);
 555     }
 556   }
 557
 558 #if CAN_SANITIZE_UB
 559   __ubsan::InitAsPlugin();
 560 #endif
 561
 562   InitializeSuppressions();
 563
 564   if (CAN_SANITIZE_LEAKS) {
 565     // LateInitialize() calls dlsym, which can allocate an error string buffer
 566     // in the TLS.  Let's ignore the allocation to avoid reporting a leak.
 567     __lsan::ScopedInterceptorDisabler disabler;
 568     Symbolizer::LateInitialize();
 569   } else {
 570     Symbolizer::LateInitialize();
 571   }
 572
 573   VReport(1, "AddressSanitizer Init done\n");
 574 }
 575
 576 // Initialize as requested from some part of ASan runtime library (interceptors,
 577 // allocator, etc).
 578 void AsanInitFromRtl() {
 579   AsanInitInternal();
 580 }
 581
 582 #if ASAN_DYNAMIC
 583 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
 584 // (and thus normal initializers from .preinit_array or modules haven't run).
 585
 586 class AsanInitializer {
 587 public:  // NOLINT
 588   AsanInitializer() {
 589     AsanInitFromRtl();
 590   }
 591 };
 592
 593 static AsanInitializer asan_initializer;
 594 #endif  // ASAN_DYNAMIC
 595
 596 } // namespace __asan
 597
 598 // ---------------------- Interface ---------------- {{{1
 599 using namespace __asan;  // NOLINT
 600
 601 void NOINLINE __asan_handle_no_return() {
 602   int local_stack;
 603   AsanThread *curr_thread = GetCurrentThread();
 604   uptr PageSize = GetPageSizeCached();
 605   uptr top, bottom;
 606   if (curr_thread) {
 607     top = curr_thread->stack_top();
 608     bottom = ((uptr)&local_stack - PageSize) & ~(PageSize - 1);
 609   } else {
 610     // If we haven't seen this thread, try asking the OS for stack bounds.
 611     uptr tls_addr, tls_size, stack_size;
 612     GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr,
 613                          &tls_size);
 614     top = bottom + stack_size;
 615   }
 616   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
 617   if (top - bottom > kMaxExpectedCleanupSize) {
 618     static bool reported_warning = false;
 619     if (reported_warning)
 620       return;
 621     reported_warning = true;
 622     Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
 623            "stack top: %p; bottom %p; size: %p (%zd)\n"
 624            "False positive error reports may follow\n"
 625            "For details see "
 626            "https://github.com/google/sanitizers/issues/189\n",
 627            top, bottom, top - bottom, top - bottom);
 628     return;
 629   }
 630   PoisonShadow(bottom, top - bottom, 0);
 631   if (curr_thread && curr_thread->has_fake_stack())
 632     curr_thread->fake_stack()->HandleNoReturn();
 633 }
 634
 635 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
 636   SetUserDieCallback(callback);
 637 }
 638
 639 // Initialize as requested from instrumented application code.
 640 // We use this call as a trigger to wake up ASan from deactivated state.
 641 void __asan_init() {
 642   AsanActivate();
 643   AsanInitInternal();
 644 }
 645
 646 void __asan_version_mismatch_check() {
 647   // Do nothing.
 648 }