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_interceptors.h" 17 #include "asan_interface_internal.h" 18 #include "asan_internal.h" 19 #include "asan_mapping.h" 20 #include "asan_poisoning.h" 21 #include "asan_report.h" 22 #include "asan_stack.h" 23 #include "asan_stats.h" 24 #include "asan_suppressions.h" 25 #include "asan_thread.h" 26 #include "sanitizer_common/sanitizer_atomic.h" 27 #include "sanitizer_common/sanitizer_flags.h" 28 #include "sanitizer_common/sanitizer_libc.h" 29 #include "sanitizer_common/sanitizer_symbolizer.h" 30 #include "lsan/lsan_common.h" 31 #include "ubsan/ubsan_init.h" 32 #include "ubsan/ubsan_platform.h" 33 34 uptr __asan_shadow_memory_dynamic_address; // Global interface symbol. 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 (common_flags()->print_module_map >= 1) 49 DumpProcessMap(); 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 if (kHighShadowEnd) 60 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 61 } 62 } 63 } 64 65 static void AsanCheckFailed(const char *file, int line, const char *cond, 66 u64 v1, u64 v2) { 67 Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file, 68 line, cond, (uptr)v1, (uptr)v2); 69 70 // Print a stack trace the first time we come here. Otherwise, we probably 71 // failed a CHECK during symbolization. 72 static atomic_uint32_t num_calls; 73 if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) == 0) { 74 PRINT_CURRENT_STACK_CHECK(); 75 } 76 77 Die(); 78 } 79 80 // -------------------------- Globals --------------------- {{{1 81 int asan_inited; 82 bool asan_init_is_running; 83 84 #if !ASAN_FIXED_MAPPING 85 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; 86 #endif 87 88 // -------------------------- Misc ---------------- {{{1 89 void ShowStatsAndAbort() { 90 __asan_print_accumulated_stats(); 91 Die(); 92 } 93 94 // --------------- LowLevelAllocateCallbac ---------- {{{1 95 static void OnLowLevelAllocate(uptr ptr, uptr size) { 96 PoisonShadow(ptr, size, kAsanInternalHeapMagic); 97 } 98 99 // -------------------------- Run-time entry ------------------- {{{1 100 // exported functions 101 #define ASAN_REPORT_ERROR(type, is_write, size) \ 102 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 103 void __asan_report_ ## type ## size(uptr addr) { \ 104 GET_CALLER_PC_BP_SP; \ 105 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \ 106 } \ 107 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 108 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) { \ 109 GET_CALLER_PC_BP_SP; \ 110 ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \ 111 } \ 112 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 113 void __asan_report_ ## type ## size ## _noabort(uptr addr) { \ 114 GET_CALLER_PC_BP_SP; \ 115 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \ 116 } \ 117 118 ASAN_REPORT_ERROR(load, false, 1) 119 ASAN_REPORT_ERROR(load, false, 2) 120 ASAN_REPORT_ERROR(load, false, 4) 121 ASAN_REPORT_ERROR(load, false, 8) 122 ASAN_REPORT_ERROR(load, false, 16) 123 ASAN_REPORT_ERROR(store, true, 1) 124 ASAN_REPORT_ERROR(store, true, 2) 125 ASAN_REPORT_ERROR(store, true, 4) 126 ASAN_REPORT_ERROR(store, true, 8) 127 ASAN_REPORT_ERROR(store, true, 16) 128 129 #define ASAN_REPORT_ERROR_N(type, is_write) \ 130 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 131 void __asan_report_ ## type ## _n(uptr addr, uptr size) { \ 132 GET_CALLER_PC_BP_SP; \ 133 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \ 134 } \ 135 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 136 void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) { \ 137 GET_CALLER_PC_BP_SP; \ 138 ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \ 139 } \ 140 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 141 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) { \ 142 GET_CALLER_PC_BP_SP; \ 143 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \ 144 } \ 145 146 ASAN_REPORT_ERROR_N(load, false) 147 ASAN_REPORT_ERROR_N(store, true) 148 149 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \ 150 if (SANITIZER_MYRIAD2 && !AddrIsInMem(addr) && !AddrIsInShadow(addr)) \ 151 return; \ 152 uptr sp = MEM_TO_SHADOW(addr); \ 153 uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp) \ 154 : *reinterpret_cast<u16 *>(sp); \ 155 if (UNLIKELY(s)) { \ 156 if (UNLIKELY(size >= SHADOW_GRANULARITY || \ 157 ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >= \ 158 (s8)s)) { \ 159 if (__asan_test_only_reported_buggy_pointer) { \ 160 *__asan_test_only_reported_buggy_pointer = addr; \ 161 } else { \ 162 GET_CALLER_PC_BP_SP; \ 163 ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg, \ 164 fatal); \ 165 } \ 166 } \ 167 } 168 169 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size) \ 170 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 171 void __asan_##type##size(uptr addr) { \ 172 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true) \ 173 } \ 174 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 175 void __asan_exp_##type##size(uptr addr, u32 exp) { \ 176 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true) \ 177 } \ 178 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 179 void __asan_##type##size ## _noabort(uptr addr) { \ 180 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false) \ 181 } \ 182 183 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1) 184 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2) 185 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4) 186 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8) 187 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16) 188 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1) 189 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2) 190 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4) 191 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8) 192 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16) 193 194 extern "C" 195 NOINLINE INTERFACE_ATTRIBUTE 196 void __asan_loadN(uptr addr, uptr size) { 197 if (__asan_region_is_poisoned(addr, size)) { 198 GET_CALLER_PC_BP_SP; 199 ReportGenericError(pc, bp, sp, addr, false, size, 0, true); 200 } 201 } 202 203 extern "C" 204 NOINLINE INTERFACE_ATTRIBUTE 205 void __asan_exp_loadN(uptr addr, uptr size, u32 exp) { 206 if (__asan_region_is_poisoned(addr, size)) { 207 GET_CALLER_PC_BP_SP; 208 ReportGenericError(pc, bp, sp, addr, false, size, exp, true); 209 } 210 } 211 212 extern "C" 213 NOINLINE INTERFACE_ATTRIBUTE 214 void __asan_loadN_noabort(uptr addr, uptr size) { 215 if (__asan_region_is_poisoned(addr, size)) { 216 GET_CALLER_PC_BP_SP; 217 ReportGenericError(pc, bp, sp, addr, false, size, 0, false); 218 } 219 } 220 221 extern "C" 222 NOINLINE INTERFACE_ATTRIBUTE 223 void __asan_storeN(uptr addr, uptr size) { 224 if (__asan_region_is_poisoned(addr, size)) { 225 GET_CALLER_PC_BP_SP; 226 ReportGenericError(pc, bp, sp, addr, true, size, 0, true); 227 } 228 } 229 230 extern "C" 231 NOINLINE INTERFACE_ATTRIBUTE 232 void __asan_exp_storeN(uptr addr, uptr size, u32 exp) { 233 if (__asan_region_is_poisoned(addr, size)) { 234 GET_CALLER_PC_BP_SP; 235 ReportGenericError(pc, bp, sp, addr, true, size, exp, true); 236 } 237 } 238 239 extern "C" 240 NOINLINE INTERFACE_ATTRIBUTE 241 void __asan_storeN_noabort(uptr addr, uptr size) { 242 if (__asan_region_is_poisoned(addr, size)) { 243 GET_CALLER_PC_BP_SP; 244 ReportGenericError(pc, bp, sp, addr, true, size, 0, false); 245 } 246 } 247 248 // Force the linker to keep the symbols for various ASan interface functions. 249 // We want to keep those in the executable in order to let the instrumented 250 // dynamic libraries access the symbol even if it is not used by the executable 251 // itself. This should help if the build system is removing dead code at link 252 // time. 253 static NOINLINE void force_interface_symbols() { 254 volatile int fake_condition = 0; // prevent dead condition elimination. 255 // __asan_report_* functions are noreturn, so we need a switch to prevent 256 // the compiler from removing any of them. 257 // clang-format off 258 switch (fake_condition) { 259 case 1: __asan_report_load1(0); break; 260 case 2: __asan_report_load2(0); break; 261 case 3: __asan_report_load4(0); break; 262 case 4: __asan_report_load8(0); break; 263 case 5: __asan_report_load16(0); break; 264 case 6: __asan_report_load_n(0, 0); break; 265 case 7: __asan_report_store1(0); break; 266 case 8: __asan_report_store2(0); break; 267 case 9: __asan_report_store4(0); break; 268 case 10: __asan_report_store8(0); break; 269 case 11: __asan_report_store16(0); break; 270 case 12: __asan_report_store_n(0, 0); break; 271 case 13: __asan_report_exp_load1(0, 0); break; 272 case 14: __asan_report_exp_load2(0, 0); break; 273 case 15: __asan_report_exp_load4(0, 0); break; 274 case 16: __asan_report_exp_load8(0, 0); break; 275 case 17: __asan_report_exp_load16(0, 0); break; 276 case 18: __asan_report_exp_load_n(0, 0, 0); break; 277 case 19: __asan_report_exp_store1(0, 0); break; 278 case 20: __asan_report_exp_store2(0, 0); break; 279 case 21: __asan_report_exp_store4(0, 0); break; 280 case 22: __asan_report_exp_store8(0, 0); break; 281 case 23: __asan_report_exp_store16(0, 0); break; 282 case 24: __asan_report_exp_store_n(0, 0, 0); break; 283 case 25: __asan_register_globals(nullptr, 0); break; 284 case 26: __asan_unregister_globals(nullptr, 0); break; 285 case 27: __asan_set_death_callback(nullptr); break; 286 case 28: __asan_set_error_report_callback(nullptr); break; 287 case 29: __asan_handle_no_return(); break; 288 case 30: __asan_address_is_poisoned(nullptr); break; 289 case 31: __asan_poison_memory_region(nullptr, 0); break; 290 case 32: __asan_unpoison_memory_region(nullptr, 0); break; 291 case 34: __asan_before_dynamic_init(nullptr); break; 292 case 35: __asan_after_dynamic_init(); break; 293 case 36: __asan_poison_stack_memory(0, 0); break; 294 case 37: __asan_unpoison_stack_memory(0, 0); break; 295 case 38: __asan_region_is_poisoned(0, 0); break; 296 case 39: __asan_describe_address(0); break; 297 case 40: __asan_set_shadow_00(0, 0); break; 298 case 41: __asan_set_shadow_f1(0, 0); break; 299 case 42: __asan_set_shadow_f2(0, 0); break; 300 case 43: __asan_set_shadow_f3(0, 0); break; 301 case 44: __asan_set_shadow_f5(0, 0); break; 302 case 45: __asan_set_shadow_f8(0, 0); break; 303 } 304 // clang-format on 305 } 306 307 static void asan_atexit() { 308 Printf("AddressSanitizer exit stats:\n"); 309 __asan_print_accumulated_stats(); 310 // Print AsanMappingProfile. 311 for (uptr i = 0; i < kAsanMappingProfileSize; i++) { 312 if (AsanMappingProfile[i] == 0) continue; 313 Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]); 314 } 315 } 316 317 static void InitializeHighMemEnd() { 318 #if !SANITIZER_MYRIAD2 319 #if !ASAN_FIXED_MAPPING 320 kHighMemEnd = GetMaxUserVirtualAddress(); 321 // Increase kHighMemEnd to make sure it's properly 322 // aligned together with kHighMemBeg: 323 kHighMemEnd |= (GetMmapGranularity() << SHADOW_SCALE) - 1; 324 #endif // !ASAN_FIXED_MAPPING 325 CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0); 326 #endif // !SANITIZER_MYRIAD2 327 } 328 329 void PrintAddressSpaceLayout() { 330 if (kHighMemBeg) { 331 Printf("|| `[%p, %p]` || HighMem ||\n", 332 (void*)kHighMemBeg, (void*)kHighMemEnd); 333 Printf("|| `[%p, %p]` || HighShadow ||\n", 334 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 335 } 336 if (kMidMemBeg) { 337 Printf("|| `[%p, %p]` || ShadowGap3 ||\n", 338 (void*)kShadowGap3Beg, (void*)kShadowGap3End); 339 Printf("|| `[%p, %p]` || MidMem ||\n", 340 (void*)kMidMemBeg, (void*)kMidMemEnd); 341 Printf("|| `[%p, %p]` || ShadowGap2 ||\n", 342 (void*)kShadowGap2Beg, (void*)kShadowGap2End); 343 Printf("|| `[%p, %p]` || MidShadow ||\n", 344 (void*)kMidShadowBeg, (void*)kMidShadowEnd); 345 } 346 Printf("|| `[%p, %p]` || ShadowGap ||\n", 347 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 348 if (kLowShadowBeg) { 349 Printf("|| `[%p, %p]` || LowShadow ||\n", 350 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 351 Printf("|| `[%p, %p]` || LowMem ||\n", 352 (void*)kLowMemBeg, (void*)kLowMemEnd); 353 } 354 Printf("MemToShadow(shadow): %p %p", 355 (void*)MEM_TO_SHADOW(kLowShadowBeg), 356 (void*)MEM_TO_SHADOW(kLowShadowEnd)); 357 if (kHighMemBeg) { 358 Printf(" %p %p", 359 (void*)MEM_TO_SHADOW(kHighShadowBeg), 360 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 361 } 362 if (kMidMemBeg) { 363 Printf(" %p %p", 364 (void*)MEM_TO_SHADOW(kMidShadowBeg), 365 (void*)MEM_TO_SHADOW(kMidShadowEnd)); 366 } 367 Printf("\n"); 368 Printf("redzone=%zu\n", (uptr)flags()->redzone); 369 Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone); 370 Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb); 371 Printf("thread_local_quarantine_size_kb=%zuK\n", 372 (uptr)flags()->thread_local_quarantine_size_kb); 373 Printf("malloc_context_size=%zu\n", 374 (uptr)common_flags()->malloc_context_size); 375 376 Printf("SHADOW_SCALE: %d\n", (int)SHADOW_SCALE); 377 Printf("SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY); 378 Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET); 379 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 380 if (kMidMemBeg) 381 CHECK(kMidShadowBeg > kLowShadowEnd && 382 kMidMemBeg > kMidShadowEnd && 383 kHighShadowBeg > kMidMemEnd); 384 } 385 386 #if defined(__thumb__) && defined(__linux__) 387 #define START_BACKGROUND_THREAD_IN_ASAN_INTERNAL 388 #endif 389 390 #ifndef START_BACKGROUND_THREAD_IN_ASAN_INTERNAL 391 static bool UNUSED __local_asan_dyninit = [] { 392 MaybeStartBackgroudThread(); 393 SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback); 394 395 return false; 396 }(); 397 #endif 398 399 static void AsanInitInternal() { 400 if (LIKELY(asan_inited)) return; 401 SanitizerToolName = "AddressSanitizer"; 402 CHECK(!asan_init_is_running && "ASan init calls itself!"); 403 asan_init_is_running = true; 404 405 CacheBinaryName(); 406 407 // Initialize flags. This must be done early, because most of the 408 // initialization steps look at flags(). 409 InitializeFlags(); 410 411 // Stop performing init at this point if we are being loaded via 412 // dlopen() and the platform supports it. 413 if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) { 414 asan_init_is_running = false; 415 VReport(1, "AddressSanitizer init is being performed for dlopen().\n"); 416 return; 417 } 418 419 AsanCheckIncompatibleRT(); 420 AsanCheckDynamicRTPrereqs(); 421 AvoidCVE_2016_2143(); 422 423 SetCanPoisonMemory(flags()->poison_heap); 424 SetMallocContextSize(common_flags()->malloc_context_size); 425 426 InitializePlatformExceptionHandlers(); 427 428 InitializeHighMemEnd(); 429 430 // Make sure we are not statically linked. 431 AsanDoesNotSupportStaticLinkage(); 432 433 // Install tool-specific callbacks in sanitizer_common. 434 AddDieCallback(AsanDie); 435 SetCheckFailedCallback(AsanCheckFailed); 436 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 437 438 __sanitizer_set_report_path(common_flags()->log_path); 439 440 __asan_option_detect_stack_use_after_return = 441 flags()->detect_stack_use_after_return; 442 443 __sanitizer::InitializePlatformEarly(); 444 445 // Re-exec ourselves if we need to set additional env or command line args. 446 MaybeReexec(); 447 448 // Setup internal allocator callback. 449 SetLowLevelAllocateMinAlignment(SHADOW_GRANULARITY); 450 SetLowLevelAllocateCallback(OnLowLevelAllocate); 451 452 InitializeAsanInterceptors(); 453 CheckASLR(); 454 455 // Enable system log ("adb logcat") on Android. 456 // Doing this before interceptors are initialized crashes in: 457 // AsanInitInternal -> android_log_write -> __interceptor_strcmp 458 AndroidLogInit(); 459 460 ReplaceSystemMalloc(); 461 462 DisableCoreDumperIfNecessary(); 463 464 InitializeShadowMemory(); 465 466 AsanTSDInit(PlatformTSDDtor); 467 InstallDeadlySignalHandlers(AsanOnDeadlySignal); 468 469 AllocatorOptions allocator_options; 470 allocator_options.SetFrom(flags(), common_flags()); 471 InitializeAllocator(allocator_options); 472 473 #ifdef START_BACKGROUND_THREAD_IN_ASAN_INTERNAL 474 MaybeStartBackgroudThread(); 475 SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback); 476 #endif 477 478 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 479 // should be set to 1 prior to initializing the threads. 480 asan_inited = 1; 481 asan_init_is_running = false; 482 483 if (flags()->atexit) 484 Atexit(asan_atexit); 485 486 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir); 487 488 // Now that ASan runtime is (mostly) initialized, deactivate it if 489 // necessary, so that it can be re-activated when requested. 490 if (flags()->start_deactivated) 491 AsanDeactivate(); 492 493 // interceptors 494 InitTlsSize(); 495 496 // Create main thread. 497 AsanThread *main_thread = CreateMainThread(); 498 CHECK_EQ(0, main_thread->tid()); 499 force_interface_symbols(); // no-op. 500 SanitizerInitializeUnwinder(); 501 502 if (CAN_SANITIZE_LEAKS) { 503 __lsan::InitCommonLsan(); 504 if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) { 505 if (flags()->halt_on_error) 506 Atexit(__lsan::DoLeakCheck); 507 else 508 Atexit(__lsan::DoRecoverableLeakCheckVoid); 509 } 510 } 511 512 #if CAN_SANITIZE_UB 513 __ubsan::InitAsPlugin(); 514 #endif 515 516 InitializeSuppressions(); 517 518 if (CAN_SANITIZE_LEAKS) { 519 // LateInitialize() calls dlsym, which can allocate an error string buffer 520 // in the TLS. Let's ignore the allocation to avoid reporting a leak. 521 __lsan::ScopedInterceptorDisabler disabler; 522 Symbolizer::LateInitialize(); 523 } else { 524 Symbolizer::LateInitialize(); 525 } 526 527 VReport(1, "AddressSanitizer Init done\n"); 528 529 if (flags()->sleep_after_init) { 530 Report("Sleeping for %d second(s)\n", flags()->sleep_after_init); 531 SleepForSeconds(flags()->sleep_after_init); 532 } 533 } 534 535 // Initialize as requested from some part of ASan runtime library (interceptors, 536 // allocator, etc). 537 void AsanInitFromRtl() { 538 AsanInitInternal(); 539 } 540 541 #if ASAN_DYNAMIC 542 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable 543 // (and thus normal initializers from .preinit_array or modules haven't run). 544 545 class AsanInitializer { 546 public: 547 AsanInitializer() { 548 AsanInitFromRtl(); 549 } 550 }; 551 552 static AsanInitializer asan_initializer; 553 #endif // ASAN_DYNAMIC 554 555 void UnpoisonStack(uptr bottom, uptr top, const char *type) { 556 static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M 557 if (top - bottom > kMaxExpectedCleanupSize) { 558 static bool reported_warning = false; 559 if (reported_warning) 560 return; 561 reported_warning = true; 562 Report( 563 "WARNING: ASan is ignoring requested __asan_handle_no_return: " 564 "stack type: %s top: %p; bottom %p; size: %p (%zd)\n" 565 "False positive error reports may follow\n" 566 "For details see " 567 "https://github.com/google/sanitizers/issues/189\n", 568 type, top, bottom, top - bottom, top - bottom); 569 return; 570 } 571 PoisonShadow(bottom, top - bottom, 0); 572 } 573 574 static void UnpoisonDefaultStack() { 575 uptr bottom, top; 576 577 if (AsanThread *curr_thread = GetCurrentThread()) { 578 int local_stack; 579 const uptr page_size = GetPageSizeCached(); 580 top = curr_thread->stack_top(); 581 bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1); 582 } else if (SANITIZER_RTEMS) { 583 // Give up On RTEMS. 584 return; 585 } else { 586 CHECK(!SANITIZER_FUCHSIA); 587 // If we haven't seen this thread, try asking the OS for stack bounds. 588 uptr tls_addr, tls_size, stack_size; 589 GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr, 590 &tls_size); 591 top = bottom + stack_size; 592 } 593 594 UnpoisonStack(bottom, top, "default"); 595 } 596 597 static void UnpoisonFakeStack() { 598 AsanThread *curr_thread = GetCurrentThread(); 599 if (curr_thread && curr_thread->has_fake_stack()) 600 curr_thread->fake_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 (asan_init_is_running) 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 AsanInitInternal(); 640 } 641 642 void __asan_version_mismatch_check() { 643 // Do nothing. 644 } 645