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 StaticSpinMutex asan_inited_mutex; 75 static atomic_uint8_t asan_inited = {0}; 76 77 static void SetAsanInited() { 78 atomic_store(&asan_inited, 1, memory_order_release); 79 } 80 81 bool AsanInited() { 82 return atomic_load(&asan_inited, memory_order_acquire) == 1; 83 } 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 bool AsanInitInternal() { 394 if (LIKELY(AsanInited())) 395 return true; 396 SanitizerToolName = "AddressSanitizer"; 397 398 CacheBinaryName(); 399 400 // Initialize flags. This must be done early, because most of the 401 // initialization steps look at flags(). 402 InitializeFlags(); 403 404 WaitForDebugger(flags()->sleep_before_init, "before init"); 405 406 // Stop performing init at this point if we are being loaded via 407 // dlopen() and the platform supports it. 408 if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) { 409 VReport(1, "AddressSanitizer init is being performed for dlopen().\n"); 410 return false; 411 } 412 413 AsanCheckIncompatibleRT(); 414 AsanCheckDynamicRTPrereqs(); 415 AvoidCVE_2016_2143(); 416 417 SetCanPoisonMemory(flags()->poison_heap); 418 SetMallocContextSize(common_flags()->malloc_context_size); 419 420 InitializePlatformExceptionHandlers(); 421 422 InitializeHighMemEnd(); 423 424 // Make sure we are not statically linked. 425 AsanDoesNotSupportStaticLinkage(); 426 427 // Install tool-specific callbacks in sanitizer_common. 428 AddDieCallback(AsanDie); 429 SetCheckUnwindCallback(CheckUnwind); 430 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 431 432 __sanitizer_set_report_path(common_flags()->log_path); 433 434 __asan_option_detect_stack_use_after_return = 435 flags()->detect_stack_use_after_return; 436 437 __sanitizer::InitializePlatformEarly(); 438 439 // Setup internal allocator callback. 440 SetLowLevelAllocateMinAlignment(ASAN_SHADOW_GRANULARITY); 441 SetLowLevelAllocateCallback(OnLowLevelAllocate); 442 443 InitializeAsanInterceptors(); 444 CheckASLR(); 445 446 // Enable system log ("adb logcat") on Android. 447 // Doing this before interceptors are initialized crashes in: 448 // AsanInitInternal -> android_log_write -> __interceptor_strcmp 449 AndroidLogInit(); 450 451 ReplaceSystemMalloc(); 452 453 DisableCoreDumperIfNecessary(); 454 455 InitializeShadowMemory(); 456 457 AsanTSDInit(PlatformTSDDtor); 458 InstallDeadlySignalHandlers(AsanOnDeadlySignal); 459 460 AllocatorOptions allocator_options; 461 allocator_options.SetFrom(flags(), common_flags()); 462 InitializeAllocator(allocator_options); 463 464 if (SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL) 465 MaybeStartBackgroudThread(); 466 467 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 468 // should be set to 1 prior to initializing the threads. 469 replace_intrin_cached = flags()->replace_intrin; 470 SetAsanInited(); 471 472 if (flags()->atexit) 473 Atexit(asan_atexit); 474 475 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir); 476 477 // Now that ASan runtime is (mostly) initialized, deactivate it if 478 // necessary, so that it can be re-activated when requested. 479 if (flags()->start_deactivated) 480 AsanDeactivate(); 481 482 // interceptors 483 InitTlsSize(); 484 485 // Create main thread. 486 AsanThread *main_thread = CreateMainThread(); 487 CHECK_EQ(0, main_thread->tid()); 488 force_interface_symbols(); // no-op. 489 SanitizerInitializeUnwinder(); 490 491 if (CAN_SANITIZE_LEAKS) { 492 __lsan::InitCommonLsan(); 493 InstallAtExitCheckLeaks(); 494 } 495 496 InstallAtForkHandler(); 497 498 #if CAN_SANITIZE_UB 499 __ubsan::InitAsPlugin(); 500 #endif 501 502 InitializeSuppressions(); 503 504 if (CAN_SANITIZE_LEAKS) { 505 // LateInitialize() calls dlsym, which can allocate an error string buffer 506 // in the TLS. Let's ignore the allocation to avoid reporting a leak. 507 __lsan::ScopedInterceptorDisabler disabler; 508 Symbolizer::LateInitialize(); 509 } else { 510 Symbolizer::LateInitialize(); 511 } 512 513 VReport(1, "AddressSanitizer Init done\n"); 514 515 WaitForDebugger(flags()->sleep_after_init, "after init"); 516 517 return true; 518 } 519 520 // Initialize as requested from some part of ASan runtime library (interceptors, 521 // allocator, etc). 522 void AsanInitFromRtl() { 523 if (LIKELY(AsanInited())) 524 return; 525 SpinMutexLock lock(&asan_inited_mutex); 526 AsanInitInternal(); 527 } 528 529 bool TryAsanInitFromRtl() { 530 if (LIKELY(AsanInited())) 531 return true; 532 if (!asan_inited_mutex.TryLock()) 533 return false; 534 bool result = AsanInitInternal(); 535 asan_inited_mutex.Unlock(); 536 return result; 537 } 538 539 #if ASAN_DYNAMIC 540 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable 541 // (and thus normal initializers from .preinit_array or modules haven't run). 542 543 class AsanInitializer { 544 public: 545 AsanInitializer() { 546 AsanInitFromRtl(); 547 } 548 }; 549 550 static AsanInitializer asan_initializer; 551 #endif // ASAN_DYNAMIC 552 553 void UnpoisonStack(uptr bottom, uptr top, const char *type) { 554 static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M 555 if (top - bottom > kMaxExpectedCleanupSize) { 556 static bool reported_warning = false; 557 if (reported_warning) 558 return; 559 reported_warning = true; 560 Report( 561 "WARNING: ASan is ignoring requested __asan_handle_no_return: " 562 "stack type: %s top: %p; bottom %p; size: %p (%zd)\n" 563 "False positive error reports may follow\n" 564 "For details see " 565 "https://github.com/google/sanitizers/issues/189\n", 566 type, (void *)top, (void *)bottom, (void *)(top - bottom), 567 top - bottom); 568 return; 569 } 570 PoisonShadow(bottom, RoundUpTo(top - bottom, ASAN_SHADOW_GRANULARITY), 0); 571 } 572 573 static void UnpoisonDefaultStack() { 574 uptr bottom, top; 575 576 if (AsanThread *curr_thread = GetCurrentThread()) { 577 int local_stack; 578 const uptr page_size = GetPageSizeCached(); 579 top = curr_thread->stack_top(); 580 bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1); 581 } else { 582 CHECK(!SANITIZER_FUCHSIA); 583 // If we haven't seen this thread, try asking the OS for stack bounds. 584 uptr tls_addr, tls_size, stack_size; 585 GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr, 586 &tls_size); 587 top = bottom + stack_size; 588 } 589 590 UnpoisonStack(bottom, top, "default"); 591 } 592 593 static void UnpoisonFakeStack() { 594 AsanThread *curr_thread = GetCurrentThread(); 595 if (!curr_thread) 596 return; 597 FakeStack *stack = curr_thread->get_fake_stack(); 598 if (!stack) 599 return; 600 stack->HandleNoReturn(); 601 } 602 603 } // namespace __asan 604 605 // ---------------------- Interface ---------------- {{{1 606 using namespace __asan; 607 608 void NOINLINE __asan_handle_no_return() { 609 if (UNLIKELY(!AsanInited())) 610 return; 611 612 if (!PlatformUnpoisonStacks()) 613 UnpoisonDefaultStack(); 614 615 UnpoisonFakeStack(); 616 } 617 618 extern "C" void *__asan_extra_spill_area() { 619 AsanThread *t = GetCurrentThread(); 620 CHECK(t); 621 return t->extra_spill_area(); 622 } 623 624 void __asan_handle_vfork(void *sp) { 625 AsanThread *t = GetCurrentThread(); 626 CHECK(t); 627 uptr bottom = t->stack_bottom(); 628 PoisonShadow(bottom, (uptr)sp - bottom, 0); 629 } 630 631 void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 632 SetUserDieCallback(callback); 633 } 634 635 // Initialize as requested from instrumented application code. 636 // We use this call as a trigger to wake up ASan from deactivated state. 637 void __asan_init() { 638 AsanActivate(); 639 AsanInitFromRtl(); 640 } 641 642 void __asan_version_mismatch_check() { 643 // Do nothing. 644 } 645