asan_rtl.cc revision 719cf0e5d7dafdf2758bb1e6324181dcb60bfd3c
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 30static void AsanDie() { 31 static atomic_uint32_t num_calls; 32 if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) { 33 // Don't die twice - run a busy loop. 34 while (1) { } 35 } 36 if (flags()->sleep_before_dying) { 37 Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying); 38 SleepForSeconds(flags()->sleep_before_dying); 39 } 40 if (flags()->unmap_shadow_on_exit) 41 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 42 if (death_callback) 43 death_callback(); 44 if (flags()->abort_on_error) 45 Abort(); 46 Exit(flags()->exitcode); 47} 48 49static void AsanCheckFailed(const char *file, int line, const char *cond, 50 u64 v1, u64 v2) { 51 Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", 52 file, line, cond, (uptr)v1, (uptr)v2); 53 // FIXME: check for infinite recursion without a thread-local counter here. 54 PRINT_CURRENT_STACK(); 55 Die(); 56} 57 58// -------------------------- Flags ------------------------- {{{1 59static const int kDeafultMallocContextSize = 30; 60 61static Flags asan_flags; 62 63Flags *flags() { 64 return &asan_flags; 65} 66 67static const char *MaybeCallAsanDefaultOptions() { 68 return (&__asan_default_options) ? __asan_default_options() : ""; 69} 70 71static void ParseFlagsFromString(Flags *f, const char *str) { 72 ParseFlag(str, &f->quarantine_size, "quarantine_size"); 73 ParseFlag(str, &f->symbolize, "symbolize"); 74 ParseFlag(str, &f->verbosity, "verbosity"); 75 ParseFlag(str, &f->redzone, "redzone"); 76 CHECK(f->redzone >= 16); 77 CHECK(IsPowerOfTwo(f->redzone)); 78 79 ParseFlag(str, &f->debug, "debug"); 80 ParseFlag(str, &f->report_globals, "report_globals"); 81 ParseFlag(str, &f->check_initialization_order, "initialization_order"); 82 ParseFlag(str, &f->malloc_context_size, "malloc_context_size"); 83 CHECK((uptr)f->malloc_context_size <= kStackTraceMax); 84 85 ParseFlag(str, &f->replace_str, "replace_str"); 86 ParseFlag(str, &f->replace_intrin, "replace_intrin"); 87 ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free"); 88 ParseFlag(str, &f->use_fake_stack, "use_fake_stack"); 89 ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size"); 90 ParseFlag(str, &f->exitcode, "exitcode"); 91 ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning"); 92 ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying"); 93 ParseFlag(str, &f->handle_segv, "handle_segv"); 94 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack"); 95 ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size"); 96 ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit"); 97 ParseFlag(str, &f->abort_on_error, "abort_on_error"); 98 ParseFlag(str, &f->print_stats, "print_stats"); 99 ParseFlag(str, &f->print_legend, "print_legend"); 100 ParseFlag(str, &f->atexit, "atexit"); 101 ParseFlag(str, &f->disable_core, "disable_core"); 102 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix"); 103 ParseFlag(str, &f->allow_reexec, "allow_reexec"); 104 ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history"); 105 ParseFlag(str, &f->log_path, "log_path"); 106 ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal"); 107 ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc"); 108 ParseFlag(str, &f->poison_heap, "poison_heap"); 109 ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch"); 110 ParseFlag(str, &f->use_stack_depot, "use_stack_depot"); 111} 112 113void InitializeFlags(Flags *f, const char *env) { 114 internal_memset(f, 0, sizeof(*f)); 115 116 f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28; 117 f->symbolize = false; 118 f->verbosity = 0; 119 f->redzone = ASAN_ALLOCATOR_VERSION == 2 ? 16 : (ASAN_LOW_MEMORY) ? 64 : 128; 120 f->debug = false; 121 f->report_globals = 1; 122 f->check_initialization_order = true; 123 f->malloc_context_size = kDeafultMallocContextSize; 124 f->replace_str = true; 125 f->replace_intrin = true; 126 f->mac_ignore_invalid_free = false; 127 f->use_fake_stack = true; 128 f->max_malloc_fill_size = 0; 129 f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE; 130 f->allow_user_poisoning = true; 131 f->sleep_before_dying = 0; 132 f->handle_segv = ASAN_NEEDS_SEGV; 133 f->use_sigaltstack = false; 134 f->check_malloc_usable_size = true; 135 f->unmap_shadow_on_exit = false; 136 f->abort_on_error = false; 137 f->print_stats = false; 138 f->print_legend = true; 139 f->atexit = false; 140 f->disable_core = (SANITIZER_WORDSIZE == 64); 141 f->strip_path_prefix = ""; 142 f->allow_reexec = true; 143 f->print_full_thread_history = true; 144 f->log_path = 0; 145 f->fast_unwind_on_fatal = false; 146 f->fast_unwind_on_malloc = true; 147 f->poison_heap = true; 148 f->alloc_dealloc_mismatch = true; 149 f->use_stack_depot = true; // Only affects allocator2. 150 151 // Override from user-specified string. 152 ParseFlagsFromString(f, MaybeCallAsanDefaultOptions()); 153 if (flags()->verbosity) { 154 Report("Using the defaults from __asan_default_options: %s\n", 155 MaybeCallAsanDefaultOptions()); 156 } 157 158 // Override from command line. 159 ParseFlagsFromString(f, env); 160} 161 162// -------------------------- Globals --------------------- {{{1 163int asan_inited; 164bool asan_init_is_running; 165void (*death_callback)(void); 166uptr kHighMemEnd; 167 168// -------------------------- Misc ---------------- {{{1 169void ShowStatsAndAbort() { 170 __asan_print_accumulated_stats(); 171 Die(); 172} 173 174// ---------------------- mmap -------------------- {{{1 175// Reserve memory range [beg, end]. 176static void ReserveShadowMemoryRange(uptr beg, uptr end) { 177 CHECK((beg % GetPageSizeCached()) == 0); 178 CHECK(((end + 1) % GetPageSizeCached()) == 0); 179 uptr size = end - beg + 1; 180 void *res = MmapFixedNoReserve(beg, size); 181 if (res != (void*)beg) { 182 Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. " 183 "Perhaps you're using ulimit -v\n", size); 184 Abort(); 185 } 186} 187 188// --------------- LowLevelAllocateCallbac ---------- {{{1 189static void OnLowLevelAllocate(uptr ptr, uptr size) { 190 PoisonShadow(ptr, size, kAsanInternalHeapMagic); 191} 192 193// -------------------------- Run-time entry ------------------- {{{1 194// exported functions 195#define ASAN_REPORT_ERROR(type, is_write, size) \ 196extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 197void __asan_report_ ## type ## size(uptr addr); \ 198void __asan_report_ ## type ## size(uptr addr) { \ 199 GET_CALLER_PC_BP_SP; \ 200 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 201} 202 203ASAN_REPORT_ERROR(load, false, 1) 204ASAN_REPORT_ERROR(load, false, 2) 205ASAN_REPORT_ERROR(load, false, 4) 206ASAN_REPORT_ERROR(load, false, 8) 207ASAN_REPORT_ERROR(load, false, 16) 208ASAN_REPORT_ERROR(store, true, 1) 209ASAN_REPORT_ERROR(store, true, 2) 210ASAN_REPORT_ERROR(store, true, 4) 211ASAN_REPORT_ERROR(store, true, 8) 212ASAN_REPORT_ERROR(store, true, 16) 213 214// Force the linker to keep the symbols for various ASan interface functions. 215// We want to keep those in the executable in order to let the instrumented 216// dynamic libraries access the symbol even if it is not used by the executable 217// itself. This should help if the build system is removing dead code at link 218// time. 219static NOINLINE void force_interface_symbols() { 220 volatile int fake_condition = 0; // prevent dead condition elimination. 221 // __asan_report_* functions are noreturn, so we need a switch to prevent 222 // the compiler from removing any of them. 223 switch (fake_condition) { 224 case 1: __asan_report_load1(0); break; 225 case 2: __asan_report_load2(0); break; 226 case 3: __asan_report_load4(0); break; 227 case 4: __asan_report_load8(0); break; 228 case 5: __asan_report_load16(0); break; 229 case 6: __asan_report_store1(0); break; 230 case 7: __asan_report_store2(0); break; 231 case 8: __asan_report_store4(0); break; 232 case 9: __asan_report_store8(0); break; 233 case 10: __asan_report_store16(0); break; 234 case 12: __asan_register_globals(0, 0); break; 235 case 13: __asan_unregister_globals(0, 0); break; 236 case 14: __asan_set_death_callback(0); break; 237 case 15: __asan_set_error_report_callback(0); break; 238 case 16: __asan_handle_no_return(); break; 239 case 17: __asan_address_is_poisoned(0); break; 240 case 18: __asan_get_allocated_size(0); break; 241 case 19: __asan_get_current_allocated_bytes(); break; 242 case 20: __asan_get_estimated_allocated_size(0); break; 243 case 21: __asan_get_free_bytes(); break; 244 case 22: __asan_get_heap_size(); break; 245 case 23: __asan_get_ownership(0); break; 246 case 24: __asan_get_unmapped_bytes(); break; 247 case 25: __asan_poison_memory_region(0, 0); break; 248 case 26: __asan_unpoison_memory_region(0, 0); break; 249 case 27: __asan_set_error_exit_code(0); break; 250 case 28: __asan_stack_free(0, 0, 0); break; 251 case 29: __asan_stack_malloc(0, 0); break; 252 case 30: __asan_before_dynamic_init(0, 0); break; 253 case 31: __asan_after_dynamic_init(); break; 254 case 32: __asan_poison_stack_memory(0, 0); break; 255 case 33: __asan_unpoison_stack_memory(0, 0); break; 256 case 34: __asan_region_is_poisoned(0, 0); break; 257 case 35: __asan_describe_address(0); break; 258 } 259} 260 261static void asan_atexit() { 262 Printf("AddressSanitizer exit stats:\n"); 263 __asan_print_accumulated_stats(); 264} 265 266static void InitializeHighMemEnd() { 267#if SANITIZER_WORDSIZE == 64 268# if defined(__powerpc64__) 269 // FIXME: 270 // On PowerPC64 we have two different address space layouts: 44- and 46-bit. 271 // We somehow need to figure our which one we are using now and choose 272 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. 273 // Note that with 'ulimit -s unlimited' the stack is moved away from the top 274 // of the address space, so simply checking the stack address is not enough. 275 kHighMemEnd = (1ULL << 44) - 1; // 0x00000fffffffffffUL 276# else 277 kHighMemEnd = (1ULL << 47) - 1; // 0x00007fffffffffffUL; 278# endif 279#else // SANITIZER_WORDSIZE == 32 280 kHighMemEnd = (1ULL << 32) - 1; // 0xffffffff; 281#endif // SANITIZER_WORDSIZE 282} 283 284} // namespace __asan 285 286// ---------------------- Interface ---------------- {{{1 287using namespace __asan; // NOLINT 288 289#if !SANITIZER_SUPPORTS_WEAK_HOOKS 290extern "C" { 291SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE 292const char* __asan_default_options() { return ""; } 293} // extern "C" 294#endif 295 296int NOINLINE __asan_set_error_exit_code(int exit_code) { 297 int old = flags()->exitcode; 298 flags()->exitcode = exit_code; 299 return old; 300} 301 302void NOINLINE __asan_handle_no_return() { 303 int local_stack; 304 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 305 CHECK(curr_thread); 306 uptr PageSize = GetPageSizeCached(); 307 uptr top = curr_thread->stack_top(); 308 uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1); 309 PoisonShadow(bottom, top - bottom, 0); 310} 311 312void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 313 death_callback = callback; 314} 315 316void __asan_init() { 317 if (asan_inited) return; 318 SanitizerToolName = "AddressSanitizer"; 319 CHECK(!asan_init_is_running && "ASan init calls itself!"); 320 asan_init_is_running = true; 321 InitializeHighMemEnd(); 322 323 // Make sure we are not statically linked. 324 AsanDoesNotSupportStaticLinkage(); 325 326 // Install tool-specific callbacks in sanitizer_common. 327 SetDieCallback(AsanDie); 328 SetCheckFailedCallback(AsanCheckFailed); 329 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 330 331 // Initialize flags. This must be done early, because most of the 332 // initialization steps look at flags(). 333 const char *options = GetEnv("ASAN_OPTIONS"); 334 InitializeFlags(flags(), options); 335 __sanitizer_set_report_path(flags()->log_path); 336 337 if (flags()->verbosity && options) { 338 Report("Parsed ASAN_OPTIONS: %s\n", options); 339 } 340 341 // Re-exec ourselves if we need to set additional env or command line args. 342 MaybeReexec(); 343 344 // Setup internal allocator callback. 345 SetLowLevelAllocateCallback(OnLowLevelAllocate); 346 347 if (flags()->atexit) { 348 Atexit(asan_atexit); 349 } 350 351 // interceptors 352 InitializeAsanInterceptors(); 353 354 ReplaceSystemMalloc(); 355 ReplaceOperatorsNewAndDelete(); 356 357 if (flags()->verbosity) { 358 Printf("|| `[%p, %p]` || HighMem ||\n", 359 (void*)kHighMemBeg, (void*)kHighMemEnd); 360 Printf("|| `[%p, %p]` || HighShadow ||\n", 361 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 362 Printf("|| `[%p, %p]` || ShadowGap ||\n", 363 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 364 Printf("|| `[%p, %p]` || LowShadow ||\n", 365 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 366 Printf("|| `[%p, %p]` || LowMem ||\n", 367 (void*)kLowMemBeg, (void*)kLowMemEnd); 368 Printf("MemToShadow(shadow): %p %p %p %p\n", 369 (void*)MEM_TO_SHADOW(kLowShadowBeg), 370 (void*)MEM_TO_SHADOW(kLowShadowEnd), 371 (void*)MEM_TO_SHADOW(kHighShadowBeg), 372 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 373 Printf("red_zone=%zu\n", (uptr)flags()->redzone); 374 Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size); 375 376 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE); 377 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY); 378 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET); 379 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 380 } 381 382 if (flags()->disable_core) { 383 DisableCoreDumper(); 384 } 385 386 uptr shadow_start = kLowShadowBeg; 387 if (kLowShadowBeg > 0) shadow_start -= GetMmapGranularity(); 388 uptr shadow_end = kHighShadowEnd; 389 if (MemoryRangeIsAvailable(shadow_start, shadow_end)) { 390 if (kLowShadowBeg != kLowShadowEnd) { 391 // mmap the low shadow plus at least one page. 392 ReserveShadowMemoryRange(kLowShadowBeg - GetMmapGranularity(), 393 kLowShadowEnd); 394 } 395 // mmap the high shadow. 396 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 397 // protect the gap 398 void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 399 CHECK(prot == (void*)kShadowGapBeg); 400 } else { 401 Report("Shadow memory range interleaves with an existing memory mapping. " 402 "ASan cannot proceed correctly. ABORTING.\n"); 403 DumpProcessMap(); 404 Die(); 405 } 406 407 InstallSignalHandlers(); 408 // Start symbolizer process if necessary. 409 if (flags()->symbolize) { 410 const char *external_symbolizer = GetEnv("ASAN_SYMBOLIZER_PATH"); 411 if (external_symbolizer) { 412 InitializeExternalSymbolizer(external_symbolizer); 413 } 414 } 415 416 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 417 // should be set to 1 prior to initializing the threads. 418 asan_inited = 1; 419 asan_init_is_running = false; 420 421 asanThreadRegistry().Init(); 422 asanThreadRegistry().GetMain()->ThreadStart(); 423 force_interface_symbols(); // no-op. 424 425 InitializeAllocator(); 426 427 if (flags()->verbosity) { 428 Report("AddressSanitizer Init done\n"); 429 } 430} 431 432#if defined(ASAN_USE_PREINIT_ARRAY) 433 // On Linux, we force __asan_init to be called before anyone else 434 // by placing it into .preinit_array section. 435 // FIXME: do we have anything like this on Mac? 436 __attribute__((section(".preinit_array"))) 437 typeof(__asan_init) *__asan_preinit =__asan_init; 438#elif defined(_WIN32) && defined(_DLL) 439 // On Windows, when using dynamic CRT (/MD), we can put a pointer 440 // to __asan_init into the global list of C initializers. 441 // See crt0dat.c in the CRT sources for the details. 442 #pragma section(".CRT$XIB", long, read) // NOLINT 443 __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init; 444#endif 445