asan_rtl.cc revision 366984e3aa286f7b4fb45f5c9e703f2768c407ed
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 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 void ParseFlagsFromString(Flags *f, const char *str) { 80 ParseFlag(str, &f->quarantine_size, "quarantine_size"); 81 ParseFlag(str, &f->symbolize, "symbolize"); 82 ParseFlag(str, &f->verbosity, "verbosity"); 83 ParseFlag(str, &f->redzone, "redzone"); 84 CHECK(f->redzone >= 16); 85 CHECK(IsPowerOfTwo(f->redzone)); 86 87 ParseFlag(str, &f->debug, "debug"); 88 ParseFlag(str, &f->report_globals, "report_globals"); 89 ParseFlag(str, &f->check_initialization_order, "initialization_order"); 90 ParseFlag(str, &f->malloc_context_size, "malloc_context_size"); 91 CHECK((uptr)f->malloc_context_size <= kStackTraceMax); 92 93 ParseFlag(str, &f->replace_str, "replace_str"); 94 ParseFlag(str, &f->replace_intrin, "replace_intrin"); 95 ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free"); 96 ParseFlag(str, &f->use_fake_stack, "use_fake_stack"); 97 ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size"); 98 ParseFlag(str, &f->exitcode, "exitcode"); 99 ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning"); 100 ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying"); 101 ParseFlag(str, &f->handle_segv, "handle_segv"); 102 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack"); 103 ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size"); 104 ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit"); 105 ParseFlag(str, &f->abort_on_error, "abort_on_error"); 106 ParseFlag(str, &f->print_stats, "print_stats"); 107 ParseFlag(str, &f->print_legend, "print_legend"); 108 ParseFlag(str, &f->atexit, "atexit"); 109 ParseFlag(str, &f->disable_core, "disable_core"); 110 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix"); 111 ParseFlag(str, &f->allow_reexec, "allow_reexec"); 112 ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history"); 113 ParseFlag(str, &f->log_path, "log_path"); 114 ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal"); 115 ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc"); 116 ParseFlag(str, &f->poison_heap, "poison_heap"); 117 ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch"); 118 ParseFlag(str, &f->use_stack_depot, "use_stack_depot"); 119} 120 121void InitializeFlags(Flags *f, const char *env) { 122 internal_memset(f, 0, sizeof(*f)); 123 124 f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28; 125 f->symbolize = false; 126 f->verbosity = 0; 127 f->redzone = ASAN_ALLOCATOR_VERSION == 2 ? 16 : (ASAN_LOW_MEMORY) ? 64 : 128; 128 f->debug = false; 129 f->report_globals = 1; 130 f->check_initialization_order = true; 131 f->malloc_context_size = kDeafultMallocContextSize; 132 f->replace_str = true; 133 f->replace_intrin = true; 134 f->mac_ignore_invalid_free = false; 135 f->use_fake_stack = true; 136 f->max_malloc_fill_size = 0; 137 f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE; 138 f->allow_user_poisoning = true; 139 f->sleep_before_dying = 0; 140 f->handle_segv = ASAN_NEEDS_SEGV; 141 f->use_sigaltstack = false; 142 f->check_malloc_usable_size = true; 143 f->unmap_shadow_on_exit = false; 144 f->abort_on_error = false; 145 f->print_stats = false; 146 f->print_legend = true; 147 f->atexit = false; 148 f->disable_core = (SANITIZER_WORDSIZE == 64); 149 f->strip_path_prefix = ""; 150 f->allow_reexec = true; 151 f->print_full_thread_history = true; 152 f->log_path = 0; 153 f->fast_unwind_on_fatal = false; 154 f->fast_unwind_on_malloc = true; 155 f->poison_heap = true; 156 f->alloc_dealloc_mismatch = true; 157 f->use_stack_depot = true; // Only affects allocator2. 158 159 // Override from user-specified string. 160 ParseFlagsFromString(f, MaybeCallAsanDefaultOptions()); 161 if (flags()->verbosity) { 162 Report("Using the defaults from __asan_default_options: %s\n", 163 MaybeCallAsanDefaultOptions()); 164 } 165 166 // Override from command line. 167 ParseFlagsFromString(f, env); 168} 169 170// -------------------------- Globals --------------------- {{{1 171int asan_inited; 172bool asan_init_is_running; 173void (*death_callback)(void); 174 175#if !ASAN_FIXED_MAPPING 176uptr kHighMemEnd, kMidMemBeg, kMidMemEnd; 177#endif 178 179// -------------------------- Misc ---------------- {{{1 180void ShowStatsAndAbort() { 181 __asan_print_accumulated_stats(); 182 Die(); 183} 184 185// ---------------------- mmap -------------------- {{{1 186// Reserve memory range [beg, end]. 187static void ReserveShadowMemoryRange(uptr beg, uptr end) { 188 CHECK((beg % GetPageSizeCached()) == 0); 189 CHECK(((end + 1) % GetPageSizeCached()) == 0); 190 uptr size = end - beg + 1; 191 void *res = MmapFixedNoReserve(beg, size); 192 if (res != (void*)beg) { 193 Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. " 194 "Perhaps you're using ulimit -v\n", size); 195 Abort(); 196 } 197} 198 199// --------------- LowLevelAllocateCallbac ---------- {{{1 200static void OnLowLevelAllocate(uptr ptr, uptr size) { 201 PoisonShadow(ptr, size, kAsanInternalHeapMagic); 202} 203 204// -------------------------- Run-time entry ------------------- {{{1 205// exported functions 206#define ASAN_REPORT_ERROR(type, is_write, size) \ 207extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 208void __asan_report_ ## type ## size(uptr addr); \ 209void __asan_report_ ## type ## size(uptr addr) { \ 210 GET_CALLER_PC_BP_SP; \ 211 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 212} 213 214ASAN_REPORT_ERROR(load, false, 1) 215ASAN_REPORT_ERROR(load, false, 2) 216ASAN_REPORT_ERROR(load, false, 4) 217ASAN_REPORT_ERROR(load, false, 8) 218ASAN_REPORT_ERROR(load, false, 16) 219ASAN_REPORT_ERROR(store, true, 1) 220ASAN_REPORT_ERROR(store, true, 2) 221ASAN_REPORT_ERROR(store, true, 4) 222ASAN_REPORT_ERROR(store, true, 8) 223ASAN_REPORT_ERROR(store, true, 16) 224 225#define ASAN_REPORT_ERROR_N(type, is_write) \ 226extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 227void __asan_report_ ## type ## _n(uptr addr, uptr size); \ 228void __asan_report_ ## type ## _n(uptr addr, uptr size) { \ 229 GET_CALLER_PC_BP_SP; \ 230 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 231} 232 233ASAN_REPORT_ERROR_N(load, false) 234ASAN_REPORT_ERROR_N(store, true) 235 236// Force the linker to keep the symbols for various ASan interface functions. 237// We want to keep those in the executable in order to let the instrumented 238// dynamic libraries access the symbol even if it is not used by the executable 239// itself. This should help if the build system is removing dead code at link 240// time. 241static NOINLINE void force_interface_symbols() { 242 volatile int fake_condition = 0; // prevent dead condition elimination. 243 // __asan_report_* functions are noreturn, so we need a switch to prevent 244 // the compiler from removing any of them. 245 switch (fake_condition) { 246 case 1: __asan_report_load1(0); break; 247 case 2: __asan_report_load2(0); break; 248 case 3: __asan_report_load4(0); break; 249 case 4: __asan_report_load8(0); break; 250 case 5: __asan_report_load16(0); break; 251 case 6: __asan_report_store1(0); break; 252 case 7: __asan_report_store2(0); break; 253 case 8: __asan_report_store4(0); break; 254 case 9: __asan_report_store8(0); break; 255 case 10: __asan_report_store16(0); break; 256 case 12: __asan_register_globals(0, 0); break; 257 case 13: __asan_unregister_globals(0, 0); break; 258 case 14: __asan_set_death_callback(0); break; 259 case 15: __asan_set_error_report_callback(0); break; 260 case 16: __asan_handle_no_return(); break; 261 case 17: __asan_address_is_poisoned(0); break; 262 case 18: __asan_get_allocated_size(0); break; 263 case 19: __asan_get_current_allocated_bytes(); break; 264 case 20: __asan_get_estimated_allocated_size(0); break; 265 case 21: __asan_get_free_bytes(); break; 266 case 22: __asan_get_heap_size(); break; 267 case 23: __asan_get_ownership(0); break; 268 case 24: __asan_get_unmapped_bytes(); break; 269 case 25: __asan_poison_memory_region(0, 0); break; 270 case 26: __asan_unpoison_memory_region(0, 0); break; 271 case 27: __asan_set_error_exit_code(0); break; 272 case 28: __asan_stack_free(0, 0, 0); break; 273 case 29: __asan_stack_malloc(0, 0); break; 274 case 30: __asan_before_dynamic_init(0, 0); break; 275 case 31: __asan_after_dynamic_init(); break; 276 case 32: __asan_poison_stack_memory(0, 0); break; 277 case 33: __asan_unpoison_stack_memory(0, 0); break; 278 case 34: __asan_region_is_poisoned(0, 0); break; 279 case 35: __asan_describe_address(0); break; 280 } 281} 282 283static void asan_atexit() { 284 Printf("AddressSanitizer exit stats:\n"); 285 __asan_print_accumulated_stats(); 286 // Print AsanMappingProfile. 287 for (uptr i = 0; i < kAsanMappingProfileSize; i++) { 288 if (AsanMappingProfile[i] == 0) continue; 289 Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]); 290 } 291} 292 293static void InitializeHighMemEnd() { 294#if !ASAN_FIXED_MAPPING 295#if SANITIZER_WORDSIZE == 64 296# if defined(__powerpc64__) 297 // FIXME: 298 // On PowerPC64 we have two different address space layouts: 44- and 46-bit. 299 // We somehow need to figure our which one we are using now and choose 300 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. 301 // Note that with 'ulimit -s unlimited' the stack is moved away from the top 302 // of the address space, so simply checking the stack address is not enough. 303 kHighMemEnd = (1ULL << 44) - 1; // 0x00000fffffffffffUL 304# else 305 kHighMemEnd = (1ULL << 47) - 1; // 0x00007fffffffffffUL; 306# endif 307#else // SANITIZER_WORDSIZE == 32 308 kHighMemEnd = (1ULL << 32) - 1; // 0xffffffff; 309#endif // SANITIZER_WORDSIZE 310#endif // !ASAN_FIXED_MAPPING 311} 312 313static void ProtectGap(uptr a, uptr size) { 314 CHECK_EQ(a, (uptr)Mprotect(a, size)); 315} 316 317static void PrintAddressSpaceLayout() { 318 Printf("|| `[%p, %p]` || HighMem ||\n", 319 (void*)kHighMemBeg, (void*)kHighMemEnd); 320 Printf("|| `[%p, %p]` || HighShadow ||\n", 321 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 322 if (kMidMemBeg) { 323 Printf("|| `[%p, %p]` || ShadowGap3 ||\n", 324 (void*)kShadowGap3Beg, (void*)kShadowGap3End); 325 Printf("|| `[%p, %p]` || MidMem ||\n", 326 (void*)kMidMemBeg, (void*)kMidMemEnd); 327 Printf("|| `[%p, %p]` || ShadowGap2 ||\n", 328 (void*)kShadowGap2Beg, (void*)kShadowGap2End); 329 Printf("|| `[%p, %p]` || MidShadow ||\n", 330 (void*)kMidShadowBeg, (void*)kMidShadowEnd); 331 } 332 Printf("|| `[%p, %p]` || ShadowGap ||\n", 333 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 334 if (kLowShadowBeg) { 335 Printf("|| `[%p, %p]` || LowShadow ||\n", 336 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 337 Printf("|| `[%p, %p]` || LowMem ||\n", 338 (void*)kLowMemBeg, (void*)kLowMemEnd); 339 } 340 Printf("MemToShadow(shadow): %p %p %p %p", 341 (void*)MEM_TO_SHADOW(kLowShadowBeg), 342 (void*)MEM_TO_SHADOW(kLowShadowEnd), 343 (void*)MEM_TO_SHADOW(kHighShadowBeg), 344 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 345 if (kMidMemBeg) { 346 Printf(" %p %p", 347 (void*)MEM_TO_SHADOW(kMidShadowBeg), 348 (void*)MEM_TO_SHADOW(kMidShadowEnd)); 349 } 350 Printf("\n"); 351 Printf("red_zone=%zu\n", (uptr)flags()->redzone); 352 Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size); 353 354 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE); 355 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY); 356 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET); 357 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 358 if (kMidMemBeg) 359 CHECK(kMidShadowBeg > kLowShadowEnd && 360 kMidMemBeg > kMidShadowEnd && 361 kHighShadowBeg > kMidMemEnd); 362} 363 364} // namespace __asan 365 366// ---------------------- Interface ---------------- {{{1 367using namespace __asan; // NOLINT 368 369#if !SANITIZER_SUPPORTS_WEAK_HOOKS 370extern "C" { 371SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE 372const char* __asan_default_options() { return ""; } 373} // extern "C" 374#endif 375 376int NOINLINE __asan_set_error_exit_code(int exit_code) { 377 int old = flags()->exitcode; 378 flags()->exitcode = exit_code; 379 return old; 380} 381 382void NOINLINE __asan_handle_no_return() { 383 int local_stack; 384 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 385 CHECK(curr_thread); 386 uptr PageSize = GetPageSizeCached(); 387 uptr top = curr_thread->stack_top(); 388 uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1); 389 PoisonShadow(bottom, top - bottom, 0); 390} 391 392void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 393 death_callback = callback; 394} 395 396void __asan_init() { 397 if (asan_inited) return; 398 SanitizerToolName = "AddressSanitizer"; 399 CHECK(!asan_init_is_running && "ASan init calls itself!"); 400 asan_init_is_running = true; 401 InitializeHighMemEnd(); 402 403 // Make sure we are not statically linked. 404 AsanDoesNotSupportStaticLinkage(); 405 406 // Install tool-specific callbacks in sanitizer_common. 407 SetDieCallback(AsanDie); 408 SetCheckFailedCallback(AsanCheckFailed); 409 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 410 411 // Initialize flags. This must be done early, because most of the 412 // initialization steps look at flags(). 413 const char *options = GetEnv("ASAN_OPTIONS"); 414 InitializeFlags(flags(), options); 415 __sanitizer_set_report_path(flags()->log_path); 416 417 if (flags()->verbosity && options) { 418 Report("Parsed ASAN_OPTIONS: %s\n", options); 419 } 420 421 // Re-exec ourselves if we need to set additional env or command line args. 422 MaybeReexec(); 423 424 // Setup internal allocator callback. 425 SetLowLevelAllocateCallback(OnLowLevelAllocate); 426 427 if (flags()->atexit) { 428 Atexit(asan_atexit); 429 } 430 431 // interceptors 432 InitializeAsanInterceptors(); 433 434 ReplaceSystemMalloc(); 435 ReplaceOperatorsNewAndDelete(); 436 437 uptr shadow_start = kLowShadowBeg; 438 if (kLowShadowBeg) shadow_start -= GetMmapGranularity(); 439 uptr shadow_end = kHighShadowEnd; 440 bool full_shadow_is_available = 441 MemoryRangeIsAvailable(shadow_start, shadow_end); 442 443#if ASAN_LINUX && defined(__x86_64__) && !ASAN_FIXED_MAPPING 444 if (!full_shadow_is_available) { 445 kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0; 446 kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x3fffffffffULL : 0; 447 } 448#endif 449 450 if (flags()->verbosity) 451 PrintAddressSpaceLayout(); 452 453 if (flags()->disable_core) { 454 DisableCoreDumper(); 455 } 456 457 if (full_shadow_is_available) { 458 // mmap the low shadow plus at least one page at the left. 459 if (kLowShadowBeg) 460 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd); 461 // mmap the high shadow. 462 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 463 // protect the gap. 464 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 465 } else if (kMidMemBeg && 466 MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) && 467 MemoryRangeIsAvailable(kMidMemEnd + 1, shadow_end)) { 468 CHECK(kLowShadowBeg != kLowShadowEnd); 469 // mmap the low shadow plus at least one page at the left. 470 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd); 471 // mmap the mid shadow. 472 ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd); 473 // mmap the high shadow. 474 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 475 // protect the gaps. 476 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 477 ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1); 478 ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1); 479 } else { 480 Report("Shadow memory range interleaves with an existing memory mapping. " 481 "ASan cannot proceed correctly. ABORTING.\n"); 482 DumpProcessMap(); 483 Die(); 484 } 485 486 InstallSignalHandlers(); 487 // Start symbolizer process if necessary. 488 if (flags()->symbolize) { 489 const char *external_symbolizer = GetEnv("ASAN_SYMBOLIZER_PATH"); 490 if (external_symbolizer) { 491 InitializeExternalSymbolizer(external_symbolizer); 492 } 493 } 494 495 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 496 // should be set to 1 prior to initializing the threads. 497 asan_inited = 1; 498 asan_init_is_running = false; 499 500 asanThreadRegistry().Init(); 501 asanThreadRegistry().GetMain()->ThreadStart(); 502 force_interface_symbols(); // no-op. 503 504 InitializeAllocator(); 505 506 if (flags()->verbosity) { 507 Report("AddressSanitizer Init done\n"); 508 } 509} 510 511#if defined(ASAN_USE_PREINIT_ARRAY) 512 // On Linux, we force __asan_init to be called before anyone else 513 // by placing it into .preinit_array section. 514 // FIXME: do we have anything like this on Mac? 515 __attribute__((section(".preinit_array"))) 516 typeof(__asan_init) *__asan_preinit =__asan_init; 517#elif defined(_WIN32) && defined(_DLL) 518 // On Windows, when using dynamic CRT (/MD), we can put a pointer 519 // to __asan_init into the global list of C initializers. 520 // See crt0dat.c in the CRT sources for the details. 521 #pragma section(".CRT$XIB", long, read) // NOLINT 522 __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init; 523#endif 524