asan_rtl.cc revision 39b2e6aaf20e7a3257fd0146c35cec587b3fffb0
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#include "asan_allocator.h" 15#include "asan_interceptors.h" 16#include "asan_interface.h" 17#include "asan_internal.h" 18#include "asan_lock.h" 19#include "asan_mapping.h" 20#include "asan_stack.h" 21#include "asan_stats.h" 22#include "asan_thread.h" 23#include "asan_thread_registry.h" 24#include "sanitizer_common/sanitizer_libc.h" 25 26namespace __sanitizer { 27using namespace __asan; 28 29void Die() { 30 static int num_calls = 0; 31 if (AtomicInc(&num_calls) > 1) { 32 // Don't die twice - run a busy loop. 33 while (1) { } 34 } 35 if (FLAG_sleep_before_dying) { 36 Report("Sleeping for %zd second(s)\n", FLAG_sleep_before_dying); 37 SleepForSeconds(FLAG_sleep_before_dying); 38 } 39 if (FLAG_unmap_shadow_on_exit) 40 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 41 if (death_callback) 42 death_callback(); 43 if (FLAG_abort_on_error) 44 Abort(); 45 Exit(FLAG_exitcode); 46} 47 48void CheckFailed(const char *file, int line, const char *cond, u64 v1, u64 v2) { 49 AsanReport("AddressSanitizer CHECK failed: %s:%d \"%s\" (%zx, %zx)\n", 50 file, line, cond, (uptr)v1, (uptr)v2); 51 PRINT_CURRENT_STACK(); 52 ShowStatsAndAbort(); 53} 54 55} // namespace __sanitizer 56 57namespace __asan { 58 59// -------------------------- Flags ------------------------- {{{1 60static const uptr kMallocContextSize = 30; 61 62uptr FLAG_malloc_context_size = kMallocContextSize; 63uptr FLAG_max_malloc_fill_size = 0; 64s64 FLAG_v = 0; 65uptr FLAG_redzone = (ASAN_LOW_MEMORY) ? 64 : 128; // power of two, >= 32 66uptr FLAG_quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 24 : 1UL << 28; 67static s64 FLAG_atexit = 0; 68bool FLAG_poison_shadow = 1; 69s64 FLAG_report_globals = 1; 70bool FLAG_handle_segv = ASAN_NEEDS_SEGV; 71bool FLAG_use_sigaltstack = 0; 72bool FLAG_symbolize = 0; 73s64 FLAG_demangle = 1; 74s64 FLAG_debug = 0; 75bool FLAG_replace_cfallocator = 1; // Used on Mac only. 76bool FLAG_mac_ignore_invalid_free = 0; // Used on Mac only. 77bool FLAG_replace_str = 1; 78bool FLAG_replace_intrin = 1; 79bool FLAG_use_fake_stack = 1; 80s64 FLAG_exitcode = ASAN_DEFAULT_FAILURE_EXITCODE; 81bool FLAG_allow_user_poisoning = 1; 82s64 FLAG_sleep_before_dying = 0; 83bool FLAG_abort_on_error = 0; 84bool FLAG_unmap_shadow_on_exit = 0; 85bool FLAG_disable_core = __WORDSIZE == 64; 86bool FLAG_check_malloc_usable_size = 1; 87 88// -------------------------- Globals --------------------- {{{1 89int asan_inited; 90bool asan_init_is_running; 91void (*death_callback)(void); 92static void (*error_report_callback)(const char*); 93char *error_message_buffer = 0; 94uptr error_message_buffer_pos = 0; 95uptr error_message_buffer_size = 0; 96 97// -------------------------- Misc ---------------- {{{1 98void ShowStatsAndAbort() { 99 __asan_print_accumulated_stats(); 100 Die(); 101} 102 103static void PrintBytes(const char *before, uptr *a) { 104 u8 *bytes = (u8*)a; 105 uptr byte_num = (__WORDSIZE) / 8; 106 AsanPrintf("%s%p:", before, (void*)a); 107 for (uptr i = 0; i < byte_num; i++) { 108 AsanPrintf(" %x%x", bytes[i] >> 4, bytes[i] & 15); 109 } 110 AsanPrintf("\n"); 111} 112 113void AppendToErrorMessageBuffer(const char *buffer) { 114 if (error_message_buffer) { 115 uptr length = (uptr)internal_strlen(buffer); 116 int remaining = error_message_buffer_size - error_message_buffer_pos; 117 internal_strncpy(error_message_buffer + error_message_buffer_pos, 118 buffer, remaining); 119 error_message_buffer[error_message_buffer_size - 1] = '\0'; 120 // FIXME: reallocate the buffer instead of truncating the message. 121 error_message_buffer_pos += remaining > length ? length : remaining; 122 } 123} 124 125// ---------------------- mmap -------------------- {{{1 126// Reserve memory range [beg, end]. 127static void ReserveShadowMemoryRange(uptr beg, uptr end) { 128 CHECK((beg % kPageSize) == 0); 129 CHECK(((end + 1) % kPageSize) == 0); 130 uptr size = end - beg + 1; 131 void *res = MmapFixedNoReserve(beg, size); 132 CHECK(res == (void*)beg && "ReserveShadowMemoryRange failed"); 133} 134 135// ---------------------- LowLevelAllocator ------------- {{{1 136void *LowLevelAllocator::Allocate(uptr size) { 137 CHECK((size & (size - 1)) == 0 && "size must be a power of two"); 138 if (allocated_end_ - allocated_current_ < size) { 139 uptr size_to_allocate = Max(size, kPageSize); 140 allocated_current_ = 141 (char*)MmapOrDie(size_to_allocate, __FUNCTION__); 142 allocated_end_ = allocated_current_ + size_to_allocate; 143 PoisonShadow((uptr)allocated_current_, size_to_allocate, 144 kAsanInternalHeapMagic); 145 } 146 CHECK(allocated_end_ - allocated_current_ >= size); 147 void *res = allocated_current_; 148 allocated_current_ += size; 149 return res; 150} 151 152// ---------------------- DescribeAddress -------------------- {{{1 153static bool DescribeStackAddress(uptr addr, uptr access_size) { 154 AsanThread *t = asanThreadRegistry().FindThreadByStackAddress(addr); 155 if (!t) return false; 156 const sptr kBufSize = 4095; 157 char buf[kBufSize]; 158 uptr offset = 0; 159 const char *frame_descr = t->GetFrameNameByAddr(addr, &offset); 160 // This string is created by the compiler and has the following form: 161 // "FunctioName n alloc_1 alloc_2 ... alloc_n" 162 // where alloc_i looks like "offset size len ObjectName ". 163 CHECK(frame_descr); 164 // Report the function name and the offset. 165 const char *name_end = internal_strchr(frame_descr, ' '); 166 CHECK(name_end); 167 buf[0] = 0; 168 internal_strncat(buf, frame_descr, 169 Min(kBufSize, 170 static_cast<sptr>(name_end - frame_descr))); 171 AsanPrintf("Address %p is located at offset %zu " 172 "in frame <%s> of T%d's stack:\n", 173 (void*)addr, offset, buf, t->tid()); 174 // Report the number of stack objects. 175 char *p; 176 uptr n_objects = internal_simple_strtoll(name_end, &p, 10); 177 CHECK(n_objects > 0); 178 AsanPrintf(" This frame has %zu object(s):\n", n_objects); 179 // Report all objects in this frame. 180 for (uptr i = 0; i < n_objects; i++) { 181 uptr beg, size; 182 sptr len; 183 beg = internal_simple_strtoll(p, &p, 10); 184 size = internal_simple_strtoll(p, &p, 10); 185 len = internal_simple_strtoll(p, &p, 10); 186 if (beg <= 0 || size <= 0 || len < 0 || *p != ' ') { 187 AsanPrintf("AddressSanitizer can't parse the stack frame " 188 "descriptor: |%s|\n", frame_descr); 189 break; 190 } 191 p++; 192 buf[0] = 0; 193 internal_strncat(buf, p, Min(kBufSize, len)); 194 p += len; 195 AsanPrintf(" [%zu, %zu) '%s'\n", beg, beg + size, buf); 196 } 197 AsanPrintf("HINT: this may be a false positive if your program uses " 198 "some custom stack unwind mechanism\n" 199 " (longjmp and C++ exceptions *are* supported)\n"); 200 t->summary()->Announce(); 201 return true; 202} 203 204static NOINLINE void DescribeAddress(uptr addr, uptr access_size) { 205 // Check if this is a global. 206 if (DescribeAddrIfGlobal(addr)) 207 return; 208 209 if (DescribeStackAddress(addr, access_size)) 210 return; 211 212 // finally, check if this is a heap. 213 DescribeHeapAddress(addr, access_size); 214} 215 216// -------------------------- Run-time entry ------------------- {{{1 217// exported functions 218#define ASAN_REPORT_ERROR(type, is_write, size) \ 219extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 220void __asan_report_ ## type ## size(uptr addr); \ 221void __asan_report_ ## type ## size(uptr addr) { \ 222 GET_CALLER_PC_BP_SP; \ 223 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 224} 225 226ASAN_REPORT_ERROR(load, false, 1) 227ASAN_REPORT_ERROR(load, false, 2) 228ASAN_REPORT_ERROR(load, false, 4) 229ASAN_REPORT_ERROR(load, false, 8) 230ASAN_REPORT_ERROR(load, false, 16) 231ASAN_REPORT_ERROR(store, true, 1) 232ASAN_REPORT_ERROR(store, true, 2) 233ASAN_REPORT_ERROR(store, true, 4) 234ASAN_REPORT_ERROR(store, true, 8) 235ASAN_REPORT_ERROR(store, true, 16) 236 237// Force the linker to keep the symbols for various ASan interface functions. 238// We want to keep those in the executable in order to let the instrumented 239// dynamic libraries access the symbol even if it is not used by the executable 240// itself. This should help if the build system is removing dead code at link 241// time. 242static NOINLINE void force_interface_symbols() { 243 volatile int fake_condition = 0; // prevent dead condition elimination. 244 if (fake_condition) { 245 __asan_report_load1(0); 246 __asan_report_load2(0); 247 __asan_report_load4(0); 248 __asan_report_load8(0); 249 __asan_report_load16(0); 250 __asan_report_store1(0); 251 __asan_report_store2(0); 252 __asan_report_store4(0); 253 __asan_report_store8(0); 254 __asan_report_store16(0); 255 __asan_register_global(0, 0, 0); 256 __asan_register_globals(0, 0); 257 __asan_unregister_globals(0, 0); 258 __asan_set_death_callback(0); 259 __asan_set_error_report_callback(0); 260 __asan_handle_no_return(); 261 } 262} 263 264// -------------------------- Init ------------------- {{{1 265static void IntFlagValue(const char *flags, const char *flag, 266 s64 *out_val) { 267 if (!flags) return; 268 const char *str = internal_strstr(flags, flag); 269 if (!str) return; 270 *out_val = internal_atoll(str + internal_strlen(flag)); 271} 272 273static void BoolFlagValue(const char *flags, const char *flag, 274 bool *out_val) { 275 if (!flags) return; 276 const char *str = internal_strstr(flags, flag); 277 if (!str) return; 278 const char *suffix = str + internal_strlen(flag); 279 if (!internal_atoll(str + internal_strlen(flag))) { 280 if (suffix[0] == '0') { 281 *out_val = false; 282 return; 283 } 284 } else { 285 *out_val = true; 286 return; 287 } 288 switch (suffix[0]) { 289 case 'y': 290 case 't': { 291 *out_val = true; 292 break; 293 } 294 case 'n': 295 case 'f': { 296 *out_val = false; 297 break; 298 } 299 default: return; 300 } 301} 302 303static void asan_atexit() { 304 AsanPrintf("AddressSanitizer exit stats:\n"); 305 __asan_print_accumulated_stats(); 306} 307 308} // namespace __asan 309 310// ---------------------- Interface ---------------- {{{1 311using namespace __asan; // NOLINT 312 313int __asan_set_error_exit_code(int exit_code) { 314 int old = FLAG_exitcode; 315 FLAG_exitcode = exit_code; 316 return old; 317} 318 319void NOINLINE __asan_handle_no_return() { 320 int local_stack; 321 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 322 CHECK(curr_thread); 323 uptr top = curr_thread->stack_top(); 324 uptr bottom = ((uptr)&local_stack - kPageSize) & ~(kPageSize-1); 325 PoisonShadow(bottom, top - bottom, 0); 326} 327 328void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 329 death_callback = callback; 330} 331 332void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) { 333 error_report_callback = callback; 334 if (callback) { 335 error_message_buffer_size = 1 << 16; 336 error_message_buffer = 337 (char*)MmapOrDie(error_message_buffer_size, __FUNCTION__); 338 error_message_buffer_pos = 0; 339 } 340} 341 342void __asan_report_error(uptr pc, uptr bp, uptr sp, 343 uptr addr, bool is_write, uptr access_size) { 344 // Do not print more than one report, otherwise they will mix up. 345 static int num_calls = 0; 346 if (AtomicInc(&num_calls) > 1) return; 347 348 AsanPrintf("====================================================" 349 "=============\n"); 350 const char *bug_descr = "unknown-crash"; 351 if (AddrIsInMem(addr)) { 352 u8 *shadow_addr = (u8*)MemToShadow(addr); 353 // If we are accessing 16 bytes, look at the second shadow byte. 354 if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY) 355 shadow_addr++; 356 // If we are in the partial right redzone, look at the next shadow byte. 357 if (*shadow_addr > 0 && *shadow_addr < 128) 358 shadow_addr++; 359 switch (*shadow_addr) { 360 case kAsanHeapLeftRedzoneMagic: 361 case kAsanHeapRightRedzoneMagic: 362 bug_descr = "heap-buffer-overflow"; 363 break; 364 case kAsanHeapFreeMagic: 365 bug_descr = "heap-use-after-free"; 366 break; 367 case kAsanStackLeftRedzoneMagic: 368 bug_descr = "stack-buffer-underflow"; 369 break; 370 case kAsanStackMidRedzoneMagic: 371 case kAsanStackRightRedzoneMagic: 372 case kAsanStackPartialRedzoneMagic: 373 bug_descr = "stack-buffer-overflow"; 374 break; 375 case kAsanStackAfterReturnMagic: 376 bug_descr = "stack-use-after-return"; 377 break; 378 case kAsanUserPoisonedMemoryMagic: 379 bug_descr = "use-after-poison"; 380 break; 381 case kAsanGlobalRedzoneMagic: 382 bug_descr = "global-buffer-overflow"; 383 break; 384 } 385 } 386 387 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 388 u32 curr_tid = asanThreadRegistry().GetCurrentTidOrInvalid(); 389 390 if (curr_thread) { 391 // We started reporting an error message. Stop using the fake stack 392 // in case we will call an instrumented function from a symbolizer. 393 curr_thread->fake_stack().StopUsingFakeStack(); 394 } 395 396 AsanReport("ERROR: AddressSanitizer %s on address " 397 "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n", 398 bug_descr, (void*)addr, pc, bp, sp); 399 400 AsanPrintf("%s of size %zu at %p thread T%d\n", 401 access_size ? (is_write ? "WRITE" : "READ") : "ACCESS", 402 access_size, (void*)addr, curr_tid); 403 404 if (FLAG_debug) { 405 PrintBytes("PC: ", (uptr*)pc); 406 } 407 408 GET_STACK_TRACE_WITH_PC_AND_BP(kStackTraceMax, pc, bp); 409 stack.PrintStack(); 410 411 CHECK(AddrIsInMem(addr)); 412 413 DescribeAddress(addr, access_size); 414 415 uptr shadow_addr = MemToShadow(addr); 416 AsanReport("ABORTING\n"); 417 __asan_print_accumulated_stats(); 418 AsanPrintf("Shadow byte and word:\n"); 419 AsanPrintf(" %p: %x\n", (void*)shadow_addr, *(unsigned char*)shadow_addr); 420 uptr aligned_shadow = shadow_addr & ~(kWordSize - 1); 421 PrintBytes(" ", (uptr*)(aligned_shadow)); 422 AsanPrintf("More shadow bytes:\n"); 423 PrintBytes(" ", (uptr*)(aligned_shadow-4*kWordSize)); 424 PrintBytes(" ", (uptr*)(aligned_shadow-3*kWordSize)); 425 PrintBytes(" ", (uptr*)(aligned_shadow-2*kWordSize)); 426 PrintBytes(" ", (uptr*)(aligned_shadow-1*kWordSize)); 427 PrintBytes("=>", (uptr*)(aligned_shadow+0*kWordSize)); 428 PrintBytes(" ", (uptr*)(aligned_shadow+1*kWordSize)); 429 PrintBytes(" ", (uptr*)(aligned_shadow+2*kWordSize)); 430 PrintBytes(" ", (uptr*)(aligned_shadow+3*kWordSize)); 431 PrintBytes(" ", (uptr*)(aligned_shadow+4*kWordSize)); 432 if (error_report_callback) { 433 error_report_callback(error_message_buffer); 434 } 435 Die(); 436} 437 438static void ParseAsanOptions(const char *options) { 439 IntFlagValue(options, "malloc_context_size=", 440 (s64*)&FLAG_malloc_context_size); 441 CHECK(FLAG_malloc_context_size <= kMallocContextSize); 442 443 IntFlagValue(options, "max_malloc_fill_size=", 444 (s64*)&FLAG_max_malloc_fill_size); 445 446 IntFlagValue(options, "verbosity=", &FLAG_v); 447 448 IntFlagValue(options, "redzone=", (s64*)&FLAG_redzone); 449 CHECK(FLAG_redzone >= 16); 450 CHECK(IsPowerOfTwo(FLAG_redzone)); 451 IntFlagValue(options, "quarantine_size=", (s64*)&FLAG_quarantine_size); 452 453 IntFlagValue(options, "atexit=", &FLAG_atexit); 454 BoolFlagValue(options, "poison_shadow=", &FLAG_poison_shadow); 455 IntFlagValue(options, "report_globals=", &FLAG_report_globals); 456 BoolFlagValue(options, "handle_segv=", &FLAG_handle_segv); 457 BoolFlagValue(options, "use_sigaltstack=", &FLAG_use_sigaltstack); 458 BoolFlagValue(options, "symbolize=", &FLAG_symbolize); 459 IntFlagValue(options, "demangle=", &FLAG_demangle); 460 IntFlagValue(options, "debug=", &FLAG_debug); 461 BoolFlagValue(options, "replace_cfallocator=", &FLAG_replace_cfallocator); 462 BoolFlagValue(options, "mac_ignore_invalid_free=", 463 &FLAG_mac_ignore_invalid_free); 464 BoolFlagValue(options, "replace_str=", &FLAG_replace_str); 465 BoolFlagValue(options, "replace_intrin=", &FLAG_replace_intrin); 466 BoolFlagValue(options, "use_fake_stack=", &FLAG_use_fake_stack); 467 IntFlagValue(options, "exitcode=", &FLAG_exitcode); 468 BoolFlagValue(options, "allow_user_poisoning=", &FLAG_allow_user_poisoning); 469 IntFlagValue(options, "sleep_before_dying=", &FLAG_sleep_before_dying); 470 BoolFlagValue(options, "abort_on_error=", &FLAG_abort_on_error); 471 BoolFlagValue(options, "unmap_shadow_on_exit=", &FLAG_unmap_shadow_on_exit); 472 // By default, disable core dumper on 64-bit -- 473 // it makes little sense to dump 16T+ core. 474 BoolFlagValue(options, "disable_core=", &FLAG_disable_core); 475 476 // Allow the users to work around the bug in Nvidia drivers prior to 295.*. 477 BoolFlagValue(options, "check_malloc_usable_size=", 478 &FLAG_check_malloc_usable_size); 479} 480 481void __asan_init() { 482 if (asan_inited) return; 483 asan_init_is_running = true; 484 485 // Make sure we are not statically linked. 486 AsanDoesNotSupportStaticLinkage(); 487 488#if !defined(_WIN32) 489 if (__asan_default_options) { 490 ParseAsanOptions(__asan_default_options); 491 if (FLAG_v) { 492 Report("Using the defaults from __asan_default_options: %s\n", 493 __asan_default_options); 494 } 495 } 496#endif 497 // flags 498 const char *options = GetEnv("ASAN_OPTIONS"); 499 ParseAsanOptions(options); 500 501 if (FLAG_v && options) { 502 Report("Parsed ASAN_OPTIONS: %s\n", options); 503 } 504 505 if (FLAG_atexit) { 506 Atexit(asan_atexit); 507 } 508 509 // interceptors 510 InitializeAsanInterceptors(); 511 512 ReplaceSystemMalloc(); 513 ReplaceOperatorsNewAndDelete(); 514 515 if (FLAG_v) { 516 Printf("|| `[%p, %p]` || HighMem ||\n", 517 (void*)kHighMemBeg, (void*)kHighMemEnd); 518 Printf("|| `[%p, %p]` || HighShadow ||\n", 519 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 520 Printf("|| `[%p, %p]` || ShadowGap ||\n", 521 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 522 Printf("|| `[%p, %p]` || LowShadow ||\n", 523 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 524 Printf("|| `[%p, %p]` || LowMem ||\n", 525 (void*)kLowMemBeg, (void*)kLowMemEnd); 526 Printf("MemToShadow(shadow): %p %p %p %p\n", 527 (void*)MEM_TO_SHADOW(kLowShadowBeg), 528 (void*)MEM_TO_SHADOW(kLowShadowEnd), 529 (void*)MEM_TO_SHADOW(kHighShadowBeg), 530 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 531 Printf("red_zone=%zu\n", (uptr)FLAG_redzone); 532 Printf("malloc_context_size=%zu\n", (uptr)FLAG_malloc_context_size); 533 534 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE); 535 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY); 536 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET); 537 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 538 } 539 540 if (FLAG_disable_core) { 541 DisableCoreDumper(); 542 } 543 544 uptr shadow_start = kLowShadowBeg; 545 if (kLowShadowBeg > 0) shadow_start -= kMmapGranularity; 546 uptr shadow_end = kHighShadowEnd; 547 if (MemoryRangeIsAvailable(shadow_start, shadow_end)) { 548 if (kLowShadowBeg != kLowShadowEnd) { 549 // mmap the low shadow plus at least one page. 550 ReserveShadowMemoryRange(kLowShadowBeg - kMmapGranularity, kLowShadowEnd); 551 } 552 // mmap the high shadow. 553 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 554 // protect the gap 555 void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 556 CHECK(prot == (void*)kShadowGapBeg); 557 } else { 558 Report("Shadow memory range interleaves with an existing memory mapping. " 559 "ASan cannot proceed correctly. ABORTING.\n"); 560 DumpProcessMap(); 561 Die(); 562 } 563 564 InstallSignalHandlers(); 565 566 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 567 // should be set to 1 prior to initializing the threads. 568 asan_inited = 1; 569 asan_init_is_running = false; 570 571 asanThreadRegistry().Init(); 572 asanThreadRegistry().GetMain()->ThreadStart(); 573 force_interface_symbols(); // no-op. 574 575 if (FLAG_v) { 576 Report("AddressSanitizer Init done\n"); 577 } 578} 579 580#if defined(ASAN_USE_PREINIT_ARRAY) 581 // On Linux, we force __asan_init to be called before anyone else 582 // by placing it into .preinit_array section. 583 // FIXME: do we have anything like this on Mac? 584 __attribute__((section(".preinit_array"))) 585 typeof(__asan_init) *__asan_preinit =__asan_init; 586#elif defined(_WIN32) && defined(_DLL) 587 // On Windows, when using dynamic CRT (/MD), we can put a pointer 588 // to __asan_init into the global list of C initializers. 589 // See crt0dat.c in the CRT sources for the details. 590 #pragma section(".CRT$XIB", long, read) // NOLINT 591 __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init; 592#endif 593