asan_rtl.cc revision 8bd5e74fa9d37a182088114918380e255e22e493
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_internal.h" 17#include "asan_mapping.h" 18#include "asan_report.h" 19#include "asan_stack.h" 20#include "asan_stats.h" 21#include "asan_thread.h" 22#include "asan_thread_registry.h" 23#include "sanitizer_common/sanitizer_atomic.h" 24#include "sanitizer_common/sanitizer_flags.h" 25#include "sanitizer_common/sanitizer_libc.h" 26#include "sanitizer_common/sanitizer_symbolizer.h" 27 28namespace __asan { 29 30uptr AsanMappingProfile[kAsanMappingProfileSize]; 31 32static void AsanDie() { 33 static atomic_uint32_t num_calls; 34 if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) { 35 // Don't die twice - run a busy loop. 36 while (1) { } 37 } 38 if (flags()->sleep_before_dying) { 39 Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying); 40 SleepForSeconds(flags()->sleep_before_dying); 41 } 42 if (flags()->unmap_shadow_on_exit) { 43 if (kMidMemBeg) { 44 UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg); 45 UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd); 46 } else { 47 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 48 } 49 } 50 if (death_callback) 51 death_callback(); 52 if (flags()->abort_on_error) 53 Abort(); 54 internal__exit(flags()->exitcode); 55} 56 57static void AsanCheckFailed(const char *file, int line, const char *cond, 58 u64 v1, u64 v2) { 59 Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", 60 file, line, cond, (uptr)v1, (uptr)v2); 61 // FIXME: check for infinite recursion without a thread-local counter here. 62 PRINT_CURRENT_STACK(); 63 Die(); 64} 65 66// -------------------------- Flags ------------------------- {{{1 67static const int kDeafultMallocContextSize = 30; 68 69static Flags asan_flags; 70 71Flags *flags() { 72 return &asan_flags; 73} 74 75static const char *MaybeCallAsanDefaultOptions() { 76 return (&__asan_default_options) ? __asan_default_options() : ""; 77} 78 79static const char *MaybeUseAsanDefaultOptionsCompileDefiniton() { 80#ifdef ASAN_DEFAULT_OPTIONS 81// Stringize the macro value. 82# define ASAN_STRINGIZE(x) #x 83# define ASAN_STRINGIZE_OPTIONS(options) ASAN_STRINGIZE(options) 84 return ASAN_STRINGIZE_OPTIONS(ASAN_DEFAULT_OPTIONS); 85#else 86 return ""; 87#endif 88} 89 90static void ParseFlagsFromString(Flags *f, const char *str) { 91 ParseFlag(str, &f->quarantine_size, "quarantine_size"); 92 ParseFlag(str, &f->symbolize, "symbolize"); 93 ParseFlag(str, &f->verbosity, "verbosity"); 94 ParseFlag(str, &f->redzone, "redzone"); 95 CHECK(f->redzone >= 16); 96 CHECK(IsPowerOfTwo(f->redzone)); 97 98 ParseFlag(str, &f->debug, "debug"); 99 ParseFlag(str, &f->report_globals, "report_globals"); 100 ParseFlag(str, &f->check_initialization_order, "initialization_order"); 101 ParseFlag(str, &f->malloc_context_size, "malloc_context_size"); 102 CHECK((uptr)f->malloc_context_size <= kStackTraceMax); 103 104 ParseFlag(str, &f->replace_str, "replace_str"); 105 ParseFlag(str, &f->replace_intrin, "replace_intrin"); 106 ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free"); 107 ParseFlag(str, &f->use_fake_stack, "use_fake_stack"); 108 ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size"); 109 ParseFlag(str, &f->exitcode, "exitcode"); 110 ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning"); 111 ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying"); 112 ParseFlag(str, &f->handle_segv, "handle_segv"); 113 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack"); 114 ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size"); 115 ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit"); 116 ParseFlag(str, &f->abort_on_error, "abort_on_error"); 117 ParseFlag(str, &f->print_stats, "print_stats"); 118 ParseFlag(str, &f->print_legend, "print_legend"); 119 ParseFlag(str, &f->atexit, "atexit"); 120 ParseFlag(str, &f->disable_core, "disable_core"); 121 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix"); 122 ParseFlag(str, &f->allow_reexec, "allow_reexec"); 123 ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history"); 124 ParseFlag(str, &f->log_path, "log_path"); 125 ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal"); 126 ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc"); 127 ParseFlag(str, &f->poison_heap, "poison_heap"); 128 ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch"); 129 ParseFlag(str, &f->use_stack_depot, "use_stack_depot"); 130 ParseFlag(str, &f->strict_memcmp, "strict_memcmp"); 131} 132 133void InitializeFlags(Flags *f, const char *env) { 134 internal_memset(f, 0, sizeof(*f)); 135 136 f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28; 137 f->symbolize = false; 138 f->verbosity = 0; 139 f->redzone = ASAN_ALLOCATOR_VERSION == 2 ? 16 : (ASAN_LOW_MEMORY) ? 64 : 128; 140 f->debug = false; 141 f->report_globals = 1; 142 f->check_initialization_order = true; 143 f->malloc_context_size = kDeafultMallocContextSize; 144 f->replace_str = true; 145 f->replace_intrin = true; 146 f->mac_ignore_invalid_free = false; 147 f->use_fake_stack = true; 148 f->max_malloc_fill_size = 0; 149 f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE; 150 f->allow_user_poisoning = true; 151 f->sleep_before_dying = 0; 152 f->handle_segv = ASAN_NEEDS_SEGV; 153 f->use_sigaltstack = false; 154 f->check_malloc_usable_size = true; 155 f->unmap_shadow_on_exit = false; 156 f->abort_on_error = false; 157 f->print_stats = false; 158 f->print_legend = true; 159 f->atexit = false; 160 f->disable_core = (SANITIZER_WORDSIZE == 64); 161 f->strip_path_prefix = ""; 162 f->allow_reexec = true; 163 f->print_full_thread_history = true; 164 f->log_path = 0; 165 f->fast_unwind_on_fatal = false; 166 f->fast_unwind_on_malloc = true; 167 f->poison_heap = true; 168 // Turn off alloc/dealloc mismatch checker on Mac for now. 169 // TODO(glider): Fix known issues and enable this back. 170 f->alloc_dealloc_mismatch = (ASAN_MAC == 0);; 171 f->use_stack_depot = true; // Only affects allocator2. 172 f->strict_memcmp = true; 173 174 // Override from compile definition. 175 ParseFlagsFromString(f, MaybeUseAsanDefaultOptionsCompileDefiniton()); 176 177 // Override from user-specified string. 178 ParseFlagsFromString(f, MaybeCallAsanDefaultOptions()); 179 if (flags()->verbosity) { 180 Report("Using the defaults from __asan_default_options: %s\n", 181 MaybeCallAsanDefaultOptions()); 182 } 183 184 // Override from command line. 185 ParseFlagsFromString(f, env); 186} 187 188// -------------------------- Globals --------------------- {{{1 189int asan_inited; 190bool asan_init_is_running; 191void (*death_callback)(void); 192 193#if !ASAN_FIXED_MAPPING 194uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; 195#endif 196 197// -------------------------- Misc ---------------- {{{1 198void ShowStatsAndAbort() { 199 __asan_print_accumulated_stats(); 200 Die(); 201} 202 203// ---------------------- mmap -------------------- {{{1 204// Reserve memory range [beg, end]. 205static void ReserveShadowMemoryRange(uptr beg, uptr end) { 206 CHECK((beg % GetPageSizeCached()) == 0); 207 CHECK(((end + 1) % GetPageSizeCached()) == 0); 208 uptr size = end - beg + 1; 209 void *res = MmapFixedNoReserve(beg, size); 210 if (res != (void*)beg) { 211 Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. " 212 "Perhaps you're using ulimit -v\n", size); 213 Abort(); 214 } 215} 216 217// --------------- LowLevelAllocateCallbac ---------- {{{1 218static void OnLowLevelAllocate(uptr ptr, uptr size) { 219 PoisonShadow(ptr, size, kAsanInternalHeapMagic); 220} 221 222// -------------------------- Run-time entry ------------------- {{{1 223// exported functions 224#define ASAN_REPORT_ERROR(type, is_write, size) \ 225extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 226void __asan_report_ ## type ## size(uptr addr); \ 227void __asan_report_ ## type ## size(uptr addr) { \ 228 GET_CALLER_PC_BP_SP; \ 229 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 230} 231 232ASAN_REPORT_ERROR(load, false, 1) 233ASAN_REPORT_ERROR(load, false, 2) 234ASAN_REPORT_ERROR(load, false, 4) 235ASAN_REPORT_ERROR(load, false, 8) 236ASAN_REPORT_ERROR(load, false, 16) 237ASAN_REPORT_ERROR(store, true, 1) 238ASAN_REPORT_ERROR(store, true, 2) 239ASAN_REPORT_ERROR(store, true, 4) 240ASAN_REPORT_ERROR(store, true, 8) 241ASAN_REPORT_ERROR(store, true, 16) 242 243#define ASAN_REPORT_ERROR_N(type, is_write) \ 244extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 245void __asan_report_ ## type ## _n(uptr addr, uptr size); \ 246void __asan_report_ ## type ## _n(uptr addr, uptr size) { \ 247 GET_CALLER_PC_BP_SP; \ 248 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 249} 250 251ASAN_REPORT_ERROR_N(load, false) 252ASAN_REPORT_ERROR_N(store, true) 253 254// Force the linker to keep the symbols for various ASan interface functions. 255// We want to keep those in the executable in order to let the instrumented 256// dynamic libraries access the symbol even if it is not used by the executable 257// itself. This should help if the build system is removing dead code at link 258// time. 259static NOINLINE void force_interface_symbols() { 260 volatile int fake_condition = 0; // prevent dead condition elimination. 261 // __asan_report_* functions are noreturn, so we need a switch to prevent 262 // the compiler from removing any of them. 263 switch (fake_condition) { 264 case 1: __asan_report_load1(0); break; 265 case 2: __asan_report_load2(0); break; 266 case 3: __asan_report_load4(0); break; 267 case 4: __asan_report_load8(0); break; 268 case 5: __asan_report_load16(0); break; 269 case 6: __asan_report_store1(0); break; 270 case 7: __asan_report_store2(0); break; 271 case 8: __asan_report_store4(0); break; 272 case 9: __asan_report_store8(0); break; 273 case 10: __asan_report_store16(0); break; 274 case 12: __asan_register_globals(0, 0); break; 275 case 13: __asan_unregister_globals(0, 0); break; 276 case 14: __asan_set_death_callback(0); break; 277 case 15: __asan_set_error_report_callback(0); break; 278 case 16: __asan_handle_no_return(); break; 279 case 17: __asan_address_is_poisoned(0); break; 280 case 18: __asan_get_allocated_size(0); break; 281 case 19: __asan_get_current_allocated_bytes(); break; 282 case 20: __asan_get_estimated_allocated_size(0); break; 283 case 21: __asan_get_free_bytes(); break; 284 case 22: __asan_get_heap_size(); break; 285 case 23: __asan_get_ownership(0); break; 286 case 24: __asan_get_unmapped_bytes(); break; 287 case 25: __asan_poison_memory_region(0, 0); break; 288 case 26: __asan_unpoison_memory_region(0, 0); break; 289 case 27: __asan_set_error_exit_code(0); break; 290 case 28: __asan_stack_free(0, 0, 0); break; 291 case 29: __asan_stack_malloc(0, 0); break; 292 case 30: __asan_before_dynamic_init(0, 0); break; 293 case 31: __asan_after_dynamic_init(); break; 294 case 32: __asan_poison_stack_memory(0, 0); break; 295 case 33: __asan_unpoison_stack_memory(0, 0); break; 296 case 34: __asan_region_is_poisoned(0, 0); break; 297 case 35: __asan_describe_address(0); break; 298 } 299} 300 301static 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 311static void InitializeHighMemEnd() { 312#if !ASAN_FIXED_MAPPING 313#if SANITIZER_WORDSIZE == 64 314# if defined(__powerpc64__) 315 // FIXME: 316 // On PowerPC64 we have two different address space layouts: 44- and 46-bit. 317 // We somehow need to figure our which one we are using now and choose 318 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. 319 // Note that with 'ulimit -s unlimited' the stack is moved away from the top 320 // of the address space, so simply checking the stack address is not enough. 321 kHighMemEnd = (1ULL << 44) - 1; // 0x00000fffffffffffUL 322# else 323 kHighMemEnd = (1ULL << 47) - 1; // 0x00007fffffffffffUL; 324# endif 325#else // SANITIZER_WORDSIZE == 32 326 kHighMemEnd = (1ULL << 32) - 1; // 0xffffffff; 327#endif // SANITIZER_WORDSIZE 328#endif // !ASAN_FIXED_MAPPING 329} 330 331static void ProtectGap(uptr a, uptr size) { 332 CHECK_EQ(a, (uptr)Mprotect(a, size)); 333} 334 335static void PrintAddressSpaceLayout() { 336 Printf("|| `[%p, %p]` || HighMem ||\n", 337 (void*)kHighMemBeg, (void*)kHighMemEnd); 338 Printf("|| `[%p, %p]` || HighShadow ||\n", 339 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 340 if (kMidMemBeg) { 341 Printf("|| `[%p, %p]` || ShadowGap3 ||\n", 342 (void*)kShadowGap3Beg, (void*)kShadowGap3End); 343 Printf("|| `[%p, %p]` || MidMem ||\n", 344 (void*)kMidMemBeg, (void*)kMidMemEnd); 345 Printf("|| `[%p, %p]` || ShadowGap2 ||\n", 346 (void*)kShadowGap2Beg, (void*)kShadowGap2End); 347 Printf("|| `[%p, %p]` || MidShadow ||\n", 348 (void*)kMidShadowBeg, (void*)kMidShadowEnd); 349 } 350 Printf("|| `[%p, %p]` || ShadowGap ||\n", 351 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 352 if (kLowShadowBeg) { 353 Printf("|| `[%p, %p]` || LowShadow ||\n", 354 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 355 Printf("|| `[%p, %p]` || LowMem ||\n", 356 (void*)kLowMemBeg, (void*)kLowMemEnd); 357 } 358 Printf("MemToShadow(shadow): %p %p %p %p", 359 (void*)MEM_TO_SHADOW(kLowShadowBeg), 360 (void*)MEM_TO_SHADOW(kLowShadowEnd), 361 (void*)MEM_TO_SHADOW(kHighShadowBeg), 362 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 363 if (kMidMemBeg) { 364 Printf(" %p %p", 365 (void*)MEM_TO_SHADOW(kMidShadowBeg), 366 (void*)MEM_TO_SHADOW(kMidShadowEnd)); 367 } 368 Printf("\n"); 369 Printf("red_zone=%zu\n", (uptr)flags()->redzone); 370 Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size); 371 372 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE); 373 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY); 374 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET); 375 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 376 if (kMidMemBeg) 377 CHECK(kMidShadowBeg > kLowShadowEnd && 378 kMidMemBeg > kMidShadowEnd && 379 kHighShadowBeg > kMidMemEnd); 380} 381 382} // namespace __asan 383 384// ---------------------- Interface ---------------- {{{1 385using namespace __asan; // NOLINT 386 387#if !SANITIZER_SUPPORTS_WEAK_HOOKS 388extern "C" { 389SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE 390const char* __asan_default_options() { return ""; } 391} // extern "C" 392#endif 393 394int NOINLINE __asan_set_error_exit_code(int exit_code) { 395 int old = flags()->exitcode; 396 flags()->exitcode = exit_code; 397 return old; 398} 399 400void NOINLINE __asan_handle_no_return() { 401 int local_stack; 402 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 403 CHECK(curr_thread); 404 uptr PageSize = GetPageSizeCached(); 405 uptr top = curr_thread->stack_top(); 406 uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1); 407 PoisonShadow(bottom, top - bottom, 0); 408} 409 410void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 411 death_callback = callback; 412} 413 414void __asan_init() { 415 if (asan_inited) return; 416 SanitizerToolName = "AddressSanitizer"; 417 CHECK(!asan_init_is_running && "ASan init calls itself!"); 418 asan_init_is_running = true; 419 InitializeHighMemEnd(); 420 421 // Make sure we are not statically linked. 422 AsanDoesNotSupportStaticLinkage(); 423 424 // Install tool-specific callbacks in sanitizer_common. 425 SetDieCallback(AsanDie); 426 SetCheckFailedCallback(AsanCheckFailed); 427 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 428 429 // Initialize flags. This must be done early, because most of the 430 // initialization steps look at flags(). 431 const char *options = GetEnv("ASAN_OPTIONS"); 432 InitializeFlags(flags(), options); 433 __sanitizer_set_report_path(flags()->log_path); 434 435 if (flags()->verbosity && options) { 436 Report("Parsed ASAN_OPTIONS: %s\n", options); 437 } 438 439 // Re-exec ourselves if we need to set additional env or command line args. 440 MaybeReexec(); 441 442 // Setup internal allocator callback. 443 SetLowLevelAllocateCallback(OnLowLevelAllocate); 444 445 if (flags()->atexit) { 446 Atexit(asan_atexit); 447 } 448 449 // interceptors 450 InitializeAsanInterceptors(); 451 452 ReplaceSystemMalloc(); 453 ReplaceOperatorsNewAndDelete(); 454 455 uptr shadow_start = kLowShadowBeg; 456 if (kLowShadowBeg) shadow_start -= GetMmapGranularity(); 457 uptr shadow_end = kHighShadowEnd; 458 bool full_shadow_is_available = 459 MemoryRangeIsAvailable(shadow_start, shadow_end); 460 461#if ASAN_LINUX && defined(__x86_64__) && !ASAN_FIXED_MAPPING 462 if (!full_shadow_is_available) { 463 kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0; 464 kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0; 465 } 466#endif 467 468 if (flags()->verbosity) 469 PrintAddressSpaceLayout(); 470 471 if (flags()->disable_core) { 472 DisableCoreDumper(); 473 } 474 475 if (full_shadow_is_available) { 476 // mmap the low shadow plus at least one page at the left. 477 if (kLowShadowBeg) 478 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd); 479 // mmap the high shadow. 480 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 481 // protect the gap. 482 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 483 } else if (kMidMemBeg && 484 MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) && 485 MemoryRangeIsAvailable(kMidMemEnd + 1, shadow_end)) { 486 CHECK(kLowShadowBeg != kLowShadowEnd); 487 // mmap the low shadow plus at least one page at the left. 488 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd); 489 // mmap the mid shadow. 490 ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd); 491 // mmap the high shadow. 492 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 493 // protect the gaps. 494 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 495 ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1); 496 ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1); 497 } else { 498 Report("Shadow memory range interleaves with an existing memory mapping. " 499 "ASan cannot proceed correctly. ABORTING.\n"); 500 DumpProcessMap(); 501 Die(); 502 } 503 504 InstallSignalHandlers(); 505 // Start symbolizer process if necessary. 506 if (flags()->symbolize) { 507 const char *external_symbolizer = GetEnv("ASAN_SYMBOLIZER_PATH"); 508 if (external_symbolizer) { 509 InitializeExternalSymbolizer(external_symbolizer); 510 } 511 } 512 513 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 514 // should be set to 1 prior to initializing the threads. 515 asan_inited = 1; 516 asan_init_is_running = false; 517 518 asanThreadRegistry().Init(); 519 asanThreadRegistry().GetMain()->ThreadStart(); 520 force_interface_symbols(); // no-op. 521 522 InitializeAllocator(); 523 524 if (flags()->verbosity) { 525 Report("AddressSanitizer Init done\n"); 526 } 527} 528