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_libc.h" 31 #include "sanitizer_common/sanitizer_symbolizer.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) 50 DumpProcessMap(); 51 if (flags()->sleep_before_dying) { 52 Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying); 53 SleepForSeconds(flags()->sleep_before_dying); 54 } 55 if (flags()->unmap_shadow_on_exit) { 56 if (kMidMemBeg) { 57 UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg); 58 UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd); 59 } else { 60 if (kHighShadowEnd) 61 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 62 } 63 } 64 } 65 66 static void CheckUnwind() { 67 GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check); 68 stack.Print(); 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 NOINLINE 86 static void ReportGenericErrorWrapper(uptr addr, bool is_write, int size, 87 int exp_arg, bool fatal) { 88 if (__asan_test_only_reported_buggy_pointer) { 89 *__asan_test_only_reported_buggy_pointer = addr; 90 } else { 91 GET_CALLER_PC_BP_SP; 92 ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg, fatal); 93 } 94 } 95 96 // --------------- LowLevelAllocateCallbac ---------- {{{1 97 static void OnLowLevelAllocate(uptr ptr, uptr size) { 98 PoisonShadow(ptr, size, kAsanInternalHeapMagic); 99 } 100 101 // -------------------------- Run-time entry ------------------- {{{1 102 // exported functions 103 #define ASAN_REPORT_ERROR(type, is_write, size) \ 104 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 105 void __asan_report_ ## type ## size(uptr addr) { \ 106 GET_CALLER_PC_BP_SP; \ 107 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \ 108 } \ 109 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 110 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) { \ 111 GET_CALLER_PC_BP_SP; \ 112 ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \ 113 } \ 114 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 115 void __asan_report_ ## type ## size ## _noabort(uptr addr) { \ 116 GET_CALLER_PC_BP_SP; \ 117 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \ 118 } \ 119 120 ASAN_REPORT_ERROR(load, false, 1) 121 ASAN_REPORT_ERROR(load, false, 2) 122 ASAN_REPORT_ERROR(load, false, 4) 123 ASAN_REPORT_ERROR(load, false, 8) 124 ASAN_REPORT_ERROR(load, false, 16) 125 ASAN_REPORT_ERROR(store, true, 1) 126 ASAN_REPORT_ERROR(store, true, 2) 127 ASAN_REPORT_ERROR(store, true, 4) 128 ASAN_REPORT_ERROR(store, true, 8) 129 ASAN_REPORT_ERROR(store, true, 16) 130 131 #define ASAN_REPORT_ERROR_N(type, is_write) \ 132 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 133 void __asan_report_ ## type ## _n(uptr addr, uptr size) { \ 134 GET_CALLER_PC_BP_SP; \ 135 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \ 136 } \ 137 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 138 void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) { \ 139 GET_CALLER_PC_BP_SP; \ 140 ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true); \ 141 } \ 142 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 143 void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) { \ 144 GET_CALLER_PC_BP_SP; \ 145 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false); \ 146 } \ 147 148 ASAN_REPORT_ERROR_N(load, false) 149 ASAN_REPORT_ERROR_N(store, true) 150 151 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \ 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 ReportGenericErrorWrapper(addr, is_write, size, exp_arg, fatal); \ 160 } \ 161 } 162 163 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size) \ 164 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 165 void __asan_##type##size(uptr addr) { \ 166 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true) \ 167 } \ 168 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 169 void __asan_exp_##type##size(uptr addr, u32 exp) { \ 170 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true) \ 171 } \ 172 extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 173 void __asan_##type##size ## _noabort(uptr addr) { \ 174 ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false) \ 175 } \ 176 177 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1) 178 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2) 179 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4) 180 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8) 181 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16) 182 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1) 183 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2) 184 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4) 185 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8) 186 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16) 187 188 extern "C" 189 NOINLINE INTERFACE_ATTRIBUTE 190 void __asan_loadN(uptr addr, uptr size) { 191 if (__asan_region_is_poisoned(addr, size)) { 192 GET_CALLER_PC_BP_SP; 193 ReportGenericError(pc, bp, sp, addr, false, size, 0, true); 194 } 195 } 196 197 extern "C" 198 NOINLINE INTERFACE_ATTRIBUTE 199 void __asan_exp_loadN(uptr addr, uptr size, u32 exp) { 200 if (__asan_region_is_poisoned(addr, size)) { 201 GET_CALLER_PC_BP_SP; 202 ReportGenericError(pc, bp, sp, addr, false, size, exp, true); 203 } 204 } 205 206 extern "C" 207 NOINLINE INTERFACE_ATTRIBUTE 208 void __asan_loadN_noabort(uptr addr, uptr size) { 209 if (__asan_region_is_poisoned(addr, size)) { 210 GET_CALLER_PC_BP_SP; 211 ReportGenericError(pc, bp, sp, addr, false, size, 0, false); 212 } 213 } 214 215 extern "C" 216 NOINLINE INTERFACE_ATTRIBUTE 217 void __asan_storeN(uptr addr, uptr size) { 218 if (__asan_region_is_poisoned(addr, size)) { 219 GET_CALLER_PC_BP_SP; 220 ReportGenericError(pc, bp, sp, addr, true, size, 0, true); 221 } 222 } 223 224 extern "C" 225 NOINLINE INTERFACE_ATTRIBUTE 226 void __asan_exp_storeN(uptr addr, uptr size, u32 exp) { 227 if (__asan_region_is_poisoned(addr, size)) { 228 GET_CALLER_PC_BP_SP; 229 ReportGenericError(pc, bp, sp, addr, true, size, exp, true); 230 } 231 } 232 233 extern "C" 234 NOINLINE INTERFACE_ATTRIBUTE 235 void __asan_storeN_noabort(uptr addr, uptr size) { 236 if (__asan_region_is_poisoned(addr, size)) { 237 GET_CALLER_PC_BP_SP; 238 ReportGenericError(pc, bp, sp, addr, true, size, 0, false); 239 } 240 } 241 242 // Force the linker to keep the symbols for various ASan interface functions. 243 // We want to keep those in the executable in order to let the instrumented 244 // dynamic libraries access the symbol even if it is not used by the executable 245 // itself. This should help if the build system is removing dead code at link 246 // time. 247 static NOINLINE void force_interface_symbols() { 248 volatile int fake_condition = 0; // prevent dead condition elimination. 249 // __asan_report_* functions are noreturn, so we need a switch to prevent 250 // the compiler from removing any of them. 251 // clang-format off 252 switch (fake_condition) { 253 case 1: __asan_report_load1(0); break; 254 case 2: __asan_report_load2(0); break; 255 case 3: __asan_report_load4(0); break; 256 case 4: __asan_report_load8(0); break; 257 case 5: __asan_report_load16(0); break; 258 case 6: __asan_report_load_n(0, 0); break; 259 case 7: __asan_report_store1(0); break; 260 case 8: __asan_report_store2(0); break; 261 case 9: __asan_report_store4(0); break; 262 case 10: __asan_report_store8(0); break; 263 case 11: __asan_report_store16(0); break; 264 case 12: __asan_report_store_n(0, 0); break; 265 case 13: __asan_report_exp_load1(0, 0); break; 266 case 14: __asan_report_exp_load2(0, 0); break; 267 case 15: __asan_report_exp_load4(0, 0); break; 268 case 16: __asan_report_exp_load8(0, 0); break; 269 case 17: __asan_report_exp_load16(0, 0); break; 270 case 18: __asan_report_exp_load_n(0, 0, 0); break; 271 case 19: __asan_report_exp_store1(0, 0); break; 272 case 20: __asan_report_exp_store2(0, 0); break; 273 case 21: __asan_report_exp_store4(0, 0); break; 274 case 22: __asan_report_exp_store8(0, 0); break; 275 case 23: __asan_report_exp_store16(0, 0); break; 276 case 24: __asan_report_exp_store_n(0, 0, 0); break; 277 case 25: __asan_register_globals(nullptr, 0); break; 278 case 26: __asan_unregister_globals(nullptr, 0); break; 279 case 27: __asan_set_death_callback(nullptr); break; 280 case 28: __asan_set_error_report_callback(nullptr); break; 281 case 29: __asan_handle_no_return(); break; 282 case 30: __asan_address_is_poisoned(nullptr); break; 283 case 31: __asan_poison_memory_region(nullptr, 0); break; 284 case 32: __asan_unpoison_memory_region(nullptr, 0); break; 285 case 34: __asan_before_dynamic_init(nullptr); break; 286 case 35: __asan_after_dynamic_init(); break; 287 case 36: __asan_poison_stack_memory(0, 0); break; 288 case 37: __asan_unpoison_stack_memory(0, 0); break; 289 case 38: __asan_region_is_poisoned(0, 0); break; 290 case 39: __asan_describe_address(0); break; 291 case 40: __asan_set_shadow_00(0, 0); break; 292 case 41: __asan_set_shadow_f1(0, 0); break; 293 case 42: __asan_set_shadow_f2(0, 0); break; 294 case 43: __asan_set_shadow_f3(0, 0); break; 295 case 44: __asan_set_shadow_f5(0, 0); break; 296 case 45: __asan_set_shadow_f8(0, 0); break; 297 } 298 // clang-format on 299 } 300 301 static void asan_atexit() { 302 Printf("AddressSanitizer exit stats:\n"); 303 __asan_print_accumulated_stats(); 304 // Print AsanMappingProfile. 305 for (uptr i = 0; i < kAsanMappingProfileSize; i++) { 306 if (AsanMappingProfile[i] == 0) continue; 307 Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]); 308 } 309 } 310 311 static void InitializeHighMemEnd() { 312 #if !ASAN_FIXED_MAPPING 313 kHighMemEnd = GetMaxUserVirtualAddress(); 314 // Increase kHighMemEnd to make sure it's properly 315 // aligned together with kHighMemBeg: 316 kHighMemEnd |= (GetMmapGranularity() << SHADOW_SCALE) - 1; 317 #endif // !ASAN_FIXED_MAPPING 318 CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0); 319 } 320 321 void PrintAddressSpaceLayout() { 322 if (kHighMemBeg) { 323 Printf("|| `[%p, %p]` || HighMem ||\n", 324 (void*)kHighMemBeg, (void*)kHighMemEnd); 325 Printf("|| `[%p, %p]` || HighShadow ||\n", 326 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 327 } 328 if (kMidMemBeg) { 329 Printf("|| `[%p, %p]` || ShadowGap3 ||\n", 330 (void*)kShadowGap3Beg, (void*)kShadowGap3End); 331 Printf("|| `[%p, %p]` || MidMem ||\n", 332 (void*)kMidMemBeg, (void*)kMidMemEnd); 333 Printf("|| `[%p, %p]` || ShadowGap2 ||\n", 334 (void*)kShadowGap2Beg, (void*)kShadowGap2End); 335 Printf("|| `[%p, %p]` || MidShadow ||\n", 336 (void*)kMidShadowBeg, (void*)kMidShadowEnd); 337 } 338 Printf("|| `[%p, %p]` || ShadowGap ||\n", 339 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 340 if (kLowShadowBeg) { 341 Printf("|| `[%p, %p]` || LowShadow ||\n", 342 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 343 Printf("|| `[%p, %p]` || LowMem ||\n", 344 (void*)kLowMemBeg, (void*)kLowMemEnd); 345 } 346 Printf("MemToShadow(shadow): %p %p", 347 (void*)MEM_TO_SHADOW(kLowShadowBeg), 348 (void*)MEM_TO_SHADOW(kLowShadowEnd)); 349 if (kHighMemBeg) { 350 Printf(" %p %p", 351 (void*)MEM_TO_SHADOW(kHighShadowBeg), 352 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 353 } 354 if (kMidMemBeg) { 355 Printf(" %p %p", 356 (void*)MEM_TO_SHADOW(kMidShadowBeg), 357 (void*)MEM_TO_SHADOW(kMidShadowEnd)); 358 } 359 Printf("\n"); 360 Printf("redzone=%zu\n", (uptr)flags()->redzone); 361 Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone); 362 Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb); 363 Printf("thread_local_quarantine_size_kb=%zuK\n", 364 (uptr)flags()->thread_local_quarantine_size_kb); 365 Printf("malloc_context_size=%zu\n", 366 (uptr)common_flags()->malloc_context_size); 367 368 Printf("SHADOW_SCALE: %d\n", (int)SHADOW_SCALE); 369 Printf("SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY); 370 Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET); 371 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 372 if (kMidMemBeg) 373 CHECK(kMidShadowBeg > kLowShadowEnd && 374 kMidMemBeg > kMidShadowEnd && 375 kHighShadowBeg > kMidMemEnd); 376 } 377 378 #if defined(__thumb__) && defined(__linux__) 379 #define START_BACKGROUND_THREAD_IN_ASAN_INTERNAL 380 #endif 381 382 #ifndef START_BACKGROUND_THREAD_IN_ASAN_INTERNAL 383 static bool UNUSED __local_asan_dyninit = [] { 384 MaybeStartBackgroudThread(); 385 SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback); 386 387 return false; 388 }(); 389 #endif 390 391 static void AsanInitInternal() { 392 if (LIKELY(asan_inited)) return; 393 SanitizerToolName = "AddressSanitizer"; 394 CHECK(!asan_init_is_running && "ASan init calls itself!"); 395 asan_init_is_running = true; 396 397 CacheBinaryName(); 398 399 // Initialize flags. This must be done early, because most of the 400 // initialization steps look at flags(). 401 InitializeFlags(); 402 403 // Stop performing init at this point if we are being loaded via 404 // dlopen() and the platform supports it. 405 if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) { 406 asan_init_is_running = false; 407 VReport(1, "AddressSanitizer init is being performed for dlopen().\n"); 408 return; 409 } 410 411 AsanCheckIncompatibleRT(); 412 AsanCheckDynamicRTPrereqs(); 413 AvoidCVE_2016_2143(); 414 415 SetCanPoisonMemory(flags()->poison_heap); 416 SetMallocContextSize(common_flags()->malloc_context_size); 417 418 InitializePlatformExceptionHandlers(); 419 420 InitializeHighMemEnd(); 421 422 // Make sure we are not statically linked. 423 AsanDoesNotSupportStaticLinkage(); 424 425 // Install tool-specific callbacks in sanitizer_common. 426 AddDieCallback(AsanDie); 427 SetCheckUnwindCallback(CheckUnwind); 428 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 429 430 __sanitizer_set_report_path(common_flags()->log_path); 431 432 __asan_option_detect_stack_use_after_return = 433 flags()->detect_stack_use_after_return; 434 435 __sanitizer::InitializePlatformEarly(); 436 437 // Re-exec ourselves if we need to set additional env or command line args. 438 MaybeReexec(); 439 440 // Setup internal allocator callback. 441 SetLowLevelAllocateMinAlignment(SHADOW_GRANULARITY); 442 SetLowLevelAllocateCallback(OnLowLevelAllocate); 443 444 InitializeAsanInterceptors(); 445 CheckASLR(); 446 447 // Enable system log ("adb logcat") on Android. 448 // Doing this before interceptors are initialized crashes in: 449 // AsanInitInternal -> android_log_write -> __interceptor_strcmp 450 AndroidLogInit(); 451 452 ReplaceSystemMalloc(); 453 454 DisableCoreDumperIfNecessary(); 455 456 InitializeShadowMemory(); 457 458 AsanTSDInit(PlatformTSDDtor); 459 InstallDeadlySignalHandlers(AsanOnDeadlySignal); 460 461 AllocatorOptions allocator_options; 462 allocator_options.SetFrom(flags(), common_flags()); 463 InitializeAllocator(allocator_options); 464 465 #ifdef START_BACKGROUND_THREAD_IN_ASAN_INTERNAL 466 MaybeStartBackgroudThread(); 467 SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback); 468 #endif 469 470 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 471 // should be set to 1 prior to initializing the threads. 472 asan_inited = 1; 473 asan_init_is_running = false; 474 475 if (flags()->atexit) 476 Atexit(asan_atexit); 477 478 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir); 479 480 // Now that ASan runtime is (mostly) initialized, deactivate it if 481 // necessary, so that it can be re-activated when requested. 482 if (flags()->start_deactivated) 483 AsanDeactivate(); 484 485 // interceptors 486 InitTlsSize(); 487 488 // Create main thread. 489 AsanThread *main_thread = CreateMainThread(); 490 CHECK_EQ(0, main_thread->tid()); 491 force_interface_symbols(); // no-op. 492 SanitizerInitializeUnwinder(); 493 494 if (CAN_SANITIZE_LEAKS) { 495 __lsan::InitCommonLsan(); 496 if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) { 497 if (flags()->halt_on_error) 498 Atexit(__lsan::DoLeakCheck); 499 else 500 Atexit(__lsan::DoRecoverableLeakCheckVoid); 501 } 502 } 503 504 #if CAN_SANITIZE_UB 505 __ubsan::InitAsPlugin(); 506 #endif 507 508 InitializeSuppressions(); 509 510 if (CAN_SANITIZE_LEAKS) { 511 // LateInitialize() calls dlsym, which can allocate an error string buffer 512 // in the TLS. Let's ignore the allocation to avoid reporting a leak. 513 __lsan::ScopedInterceptorDisabler disabler; 514 Symbolizer::LateInitialize(); 515 } else { 516 Symbolizer::LateInitialize(); 517 } 518 519 VReport(1, "AddressSanitizer Init done\n"); 520 521 if (flags()->sleep_after_init) { 522 Report("Sleeping for %d second(s)\n", flags()->sleep_after_init); 523 SleepForSeconds(flags()->sleep_after_init); 524 } 525 } 526 527 // Initialize as requested from some part of ASan runtime library (interceptors, 528 // allocator, etc). 529 void AsanInitFromRtl() { 530 AsanInitInternal(); 531 } 532 533 #if ASAN_DYNAMIC 534 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable 535 // (and thus normal initializers from .preinit_array or modules haven't run). 536 537 class AsanInitializer { 538 public: 539 AsanInitializer() { 540 AsanInitFromRtl(); 541 } 542 }; 543 544 static AsanInitializer asan_initializer; 545 #endif // ASAN_DYNAMIC 546 547 void UnpoisonStack(uptr bottom, uptr top, const char *type) { 548 static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M 549 if (top - bottom > kMaxExpectedCleanupSize) { 550 static bool reported_warning = false; 551 if (reported_warning) 552 return; 553 reported_warning = true; 554 Report( 555 "WARNING: ASan is ignoring requested __asan_handle_no_return: " 556 "stack type: %s top: %p; bottom %p; size: %p (%zd)\n" 557 "False positive error reports may follow\n" 558 "For details see " 559 "https://github.com/google/sanitizers/issues/189\n", 560 type, (void *)top, (void *)bottom, (void *)(top - bottom), 561 top - bottom); 562 return; 563 } 564 PoisonShadow(bottom, RoundUpTo(top - bottom, SHADOW_GRANULARITY), 0); 565 } 566 567 static void UnpoisonDefaultStack() { 568 uptr bottom, top; 569 570 if (AsanThread *curr_thread = GetCurrentThread()) { 571 int local_stack; 572 const uptr page_size = GetPageSizeCached(); 573 top = curr_thread->stack_top(); 574 bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1); 575 } else { 576 CHECK(!SANITIZER_FUCHSIA); 577 // If we haven't seen this thread, try asking the OS for stack bounds. 578 uptr tls_addr, tls_size, stack_size; 579 GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr, 580 &tls_size); 581 top = bottom + stack_size; 582 } 583 584 UnpoisonStack(bottom, top, "default"); 585 } 586 587 static void UnpoisonFakeStack() { 588 AsanThread *curr_thread = GetCurrentThread(); 589 if (!curr_thread) 590 return; 591 FakeStack *stack = curr_thread->get_fake_stack(); 592 if (!stack) 593 return; 594 stack->HandleNoReturn(); 595 } 596 597 } // namespace __asan 598 599 // ---------------------- Interface ---------------- {{{1 600 using namespace __asan; 601 602 void NOINLINE __asan_handle_no_return() { 603 if (asan_init_is_running) 604 return; 605 606 if (!PlatformUnpoisonStacks()) 607 UnpoisonDefaultStack(); 608 609 UnpoisonFakeStack(); 610 } 611 612 extern "C" void *__asan_extra_spill_area() { 613 AsanThread *t = GetCurrentThread(); 614 CHECK(t); 615 return t->extra_spill_area(); 616 } 617 618 void __asan_handle_vfork(void *sp) { 619 AsanThread *t = GetCurrentThread(); 620 CHECK(t); 621 uptr bottom = t->stack_bottom(); 622 PoisonShadow(bottom, (uptr)sp - bottom, 0); 623 } 624 625 void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 626 SetUserDieCallback(callback); 627 } 628 629 // Initialize as requested from instrumented application code. 630 // We use this call as a trigger to wake up ASan from deactivated state. 631 void __asan_init() { 632 AsanActivate(); 633 AsanInitInternal(); 634 } 635 636 void __asan_version_mismatch_check() { 637 // Do nothing. 638 } 639
Indexes created Thu Jul 02 00:25:40 UTC 2026