asan_rtl.cc revision 6a08d29b2020004b801ca69d8aea5872a7e67d72
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_lock.h" 18#include "asan_mapping.h" 19#include "asan_report.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/asan_interface.h" 25#include "sanitizer_common/sanitizer_atomic.h" 26#include "sanitizer_common/sanitizer_flags.h" 27#include "sanitizer_common/sanitizer_libc.h" 28#include "sanitizer_common/sanitizer_symbolizer.h" 29 30namespace __asan { 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 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg); 44 if (death_callback) 45 death_callback(); 46 if (flags()->abort_on_error) 47 Abort(); 48 Exit(flags()->exitcode); 49} 50 51static void AsanCheckFailed(const char *file, int line, const char *cond, 52 u64 v1, u64 v2) { 53 Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", 54 file, line, cond, (uptr)v1, (uptr)v2); 55 // FIXME: check for infinite recursion without a thread-local counter here. 56 PRINT_CURRENT_STACK(); 57 ShowStatsAndAbort(); 58} 59 60// -------------------------- Flags ------------------------- {{{1 61static const int kDeafultMallocContextSize = 30; 62 63static Flags asan_flags; 64 65Flags *flags() { 66 return &asan_flags; 67} 68 69static const char *MaybeCallAsanDefaultOptions() { 70 return (&__asan_default_options) ? __asan_default_options() : ""; 71} 72 73static void ParseFlagsFromString(Flags *f, const char *str) { 74 ParseFlag(str, &f->quarantine_size, "quarantine_size"); 75 ParseFlag(str, &f->symbolize, "symbolize"); 76 ParseFlag(str, &f->verbosity, "verbosity"); 77 ParseFlag(str, &f->redzone, "redzone"); 78 CHECK(f->redzone >= 16); 79 CHECK(IsPowerOfTwo(f->redzone)); 80 81 ParseFlag(str, &f->debug, "debug"); 82 ParseFlag(str, &f->report_globals, "report_globals"); 83 ParseFlag(str, &f->check_initialization_order, "initialization_order"); 84 ParseFlag(str, &f->malloc_context_size, "malloc_context_size"); 85 CHECK((uptr)f->malloc_context_size <= kStackTraceMax); 86 87 ParseFlag(str, &f->replace_str, "replace_str"); 88 ParseFlag(str, &f->replace_intrin, "replace_intrin"); 89 ParseFlag(str, &f->replace_cfallocator, "replace_cfallocator"); 90 ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free"); 91 ParseFlag(str, &f->use_fake_stack, "use_fake_stack"); 92 ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size"); 93 ParseFlag(str, &f->exitcode, "exitcode"); 94 ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning"); 95 ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying"); 96 ParseFlag(str, &f->handle_segv, "handle_segv"); 97 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack"); 98 ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size"); 99 ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit"); 100 ParseFlag(str, &f->abort_on_error, "abort_on_error"); 101 ParseFlag(str, &f->atexit, "atexit"); 102 ParseFlag(str, &f->disable_core, "disable_core"); 103 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix"); 104 ParseFlag(str, &f->allow_reexec, "allow_reexec"); 105 ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history"); 106 ParseFlag(str, &f->log_path, "log_path"); 107} 108 109void InitializeFlags(Flags *f, const char *env) { 110 internal_memset(f, 0, sizeof(*f)); 111 112 f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28; 113 f->symbolize = false; 114 f->verbosity = 0; 115 f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128; 116 f->debug = false; 117 f->report_globals = 1; 118 f->check_initialization_order = true; 119 f->malloc_context_size = kDeafultMallocContextSize; 120 f->replace_str = true; 121 f->replace_intrin = true; 122 f->replace_cfallocator = true; 123 f->mac_ignore_invalid_free = false; 124 f->use_fake_stack = true; 125 f->max_malloc_fill_size = 0; 126 f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE; 127 f->allow_user_poisoning = true; 128 f->sleep_before_dying = 0; 129 f->handle_segv = ASAN_NEEDS_SEGV; 130 f->use_sigaltstack = false; 131 f->check_malloc_usable_size = true; 132 f->unmap_shadow_on_exit = false; 133 f->abort_on_error = false; 134 f->atexit = false; 135 f->disable_core = (SANITIZER_WORDSIZE == 64); 136 f->strip_path_prefix = ""; 137 f->allow_reexec = true; 138 f->print_full_thread_history = true; 139 f->log_path = 0; 140 141 // Override from user-specified string. 142 ParseFlagsFromString(f, MaybeCallAsanDefaultOptions()); 143 if (flags()->verbosity) { 144 Report("Using the defaults from __asan_default_options: %s\n", 145 MaybeCallAsanDefaultOptions()); 146 } 147 148 // Override from command line. 149 ParseFlagsFromString(f, env); 150} 151 152// -------------------------- Globals --------------------- {{{1 153int asan_inited; 154bool asan_init_is_running; 155void (*death_callback)(void); 156 157// -------------------------- Misc ---------------- {{{1 158void ShowStatsAndAbort() { 159 __asan_print_accumulated_stats(); 160 Die(); 161} 162 163// ---------------------- mmap -------------------- {{{1 164// Reserve memory range [beg, end]. 165static void ReserveShadowMemoryRange(uptr beg, uptr end) { 166 CHECK((beg % GetPageSizeCached()) == 0); 167 CHECK(((end + 1) % GetPageSizeCached()) == 0); 168 uptr size = end - beg + 1; 169 void *res = MmapFixedNoReserve(beg, size); 170 if (res != (void*)beg) { 171 Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. " 172 "Perhaps you're using ulimit -v\n", size); 173 Abort(); 174 } 175} 176 177// --------------- LowLevelAllocateCallbac ---------- {{{1 178static void OnLowLevelAllocate(uptr ptr, uptr size) { 179 PoisonShadow(ptr, size, kAsanInternalHeapMagic); 180} 181 182// -------------------------- Run-time entry ------------------- {{{1 183// exported functions 184#define ASAN_REPORT_ERROR(type, is_write, size) \ 185extern "C" NOINLINE INTERFACE_ATTRIBUTE \ 186void __asan_report_ ## type ## size(uptr addr); \ 187void __asan_report_ ## type ## size(uptr addr) { \ 188 GET_CALLER_PC_BP_SP; \ 189 __asan_report_error(pc, bp, sp, addr, is_write, size); \ 190} 191 192ASAN_REPORT_ERROR(load, false, 1) 193ASAN_REPORT_ERROR(load, false, 2) 194ASAN_REPORT_ERROR(load, false, 4) 195ASAN_REPORT_ERROR(load, false, 8) 196ASAN_REPORT_ERROR(load, false, 16) 197ASAN_REPORT_ERROR(store, true, 1) 198ASAN_REPORT_ERROR(store, true, 2) 199ASAN_REPORT_ERROR(store, true, 4) 200ASAN_REPORT_ERROR(store, true, 8) 201ASAN_REPORT_ERROR(store, true, 16) 202 203// Force the linker to keep the symbols for various ASan interface functions. 204// We want to keep those in the executable in order to let the instrumented 205// dynamic libraries access the symbol even if it is not used by the executable 206// itself. This should help if the build system is removing dead code at link 207// time. 208static NOINLINE void force_interface_symbols() { 209 volatile int fake_condition = 0; // prevent dead condition elimination. 210 // __asan_report_* functions are noreturn, so we need a switch to prevent 211 // the compiler from removing any of them. 212 switch (fake_condition) { 213 case 1: __asan_report_load1(0); break; 214 case 2: __asan_report_load2(0); break; 215 case 3: __asan_report_load4(0); break; 216 case 4: __asan_report_load8(0); break; 217 case 5: __asan_report_load16(0); break; 218 case 6: __asan_report_store1(0); break; 219 case 7: __asan_report_store2(0); break; 220 case 8: __asan_report_store4(0); break; 221 case 9: __asan_report_store8(0); break; 222 case 10: __asan_report_store16(0); break; 223 case 11: __asan_register_global(0, 0, 0); break; 224 case 12: __asan_register_globals(0, 0); break; 225 case 13: __asan_unregister_globals(0, 0); break; 226 case 14: __asan_set_death_callback(0); break; 227 case 15: __asan_set_error_report_callback(0); break; 228 case 16: __asan_handle_no_return(); break; 229 case 17: __asan_address_is_poisoned(0); break; 230 case 18: __asan_get_allocated_size(0); break; 231 case 19: __asan_get_current_allocated_bytes(); break; 232 case 20: __asan_get_estimated_allocated_size(0); break; 233 case 21: __asan_get_free_bytes(); break; 234 case 22: __asan_get_heap_size(); break; 235 case 23: __asan_get_ownership(0); break; 236 case 24: __asan_get_unmapped_bytes(); break; 237 case 25: __asan_poison_memory_region(0, 0); break; 238 case 26: __asan_unpoison_memory_region(0, 0); break; 239 case 27: __asan_set_error_exit_code(0); break; 240 case 28: __asan_stack_free(0, 0, 0); break; 241 case 29: __asan_stack_malloc(0, 0); break; 242 case 30: __asan_before_dynamic_init(0, 0); break; 243 case 31: __asan_after_dynamic_init(); break; 244 case 32: __asan_poison_stack_memory(0, 0); break; 245 case 33: __asan_unpoison_stack_memory(0, 0); break; 246 } 247} 248 249static void asan_atexit() { 250 Printf("AddressSanitizer exit stats:\n"); 251 __asan_print_accumulated_stats(); 252} 253 254} // namespace __asan 255 256// ---------------------- Interface ---------------- {{{1 257using namespace __asan; // NOLINT 258 259#if !SANITIZER_SUPPORTS_WEAK_HOOKS 260extern "C" { 261SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE 262const char* __asan_default_options() { return ""; } 263} // extern "C" 264#endif 265 266int NOINLINE __asan_set_error_exit_code(int exit_code) { 267 int old = flags()->exitcode; 268 flags()->exitcode = exit_code; 269 return old; 270} 271 272void NOINLINE __asan_handle_no_return() { 273 int local_stack; 274 AsanThread *curr_thread = asanThreadRegistry().GetCurrent(); 275 CHECK(curr_thread); 276 uptr PageSize = GetPageSizeCached(); 277 uptr top = curr_thread->stack_top(); 278 uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1); 279 PoisonShadow(bottom, top - bottom, 0); 280} 281 282void NOINLINE __asan_set_death_callback(void (*callback)(void)) { 283 death_callback = callback; 284} 285 286void __asan_init() { 287 if (asan_inited) return; 288 CHECK(!asan_init_is_running && "ASan init calls itself!"); 289 asan_init_is_running = true; 290 291 // Make sure we are not statically linked. 292 AsanDoesNotSupportStaticLinkage(); 293 294 // Install tool-specific callbacks in sanitizer_common. 295 SetDieCallback(AsanDie); 296 SetCheckFailedCallback(AsanCheckFailed); 297 SetPrintfAndReportCallback(AppendToErrorMessageBuffer); 298 299 // Initialize flags. This must be done early, because most of the 300 // initialization steps look at flags(). 301 const char *options = GetEnv("ASAN_OPTIONS"); 302 InitializeFlags(flags(), options); 303 __sanitizer_set_report_path(flags()->log_path); 304 305 if (flags()->verbosity && options) { 306 Report("Parsed ASAN_OPTIONS: %s\n", options); 307 } 308 309 // Re-exec ourselves if we need to set additional env or command line args. 310 MaybeReexec(); 311 312 // Setup internal allocator callback. 313 SetLowLevelAllocateCallback(OnLowLevelAllocate); 314 315 if (flags()->atexit) { 316 Atexit(asan_atexit); 317 } 318 319 // interceptors 320 InitializeAsanInterceptors(); 321 322 ReplaceSystemMalloc(); 323 ReplaceOperatorsNewAndDelete(); 324 325 if (flags()->verbosity) { 326 Printf("|| `[%p, %p]` || HighMem ||\n", 327 (void*)kHighMemBeg, (void*)kHighMemEnd); 328 Printf("|| `[%p, %p]` || HighShadow ||\n", 329 (void*)kHighShadowBeg, (void*)kHighShadowEnd); 330 Printf("|| `[%p, %p]` || ShadowGap ||\n", 331 (void*)kShadowGapBeg, (void*)kShadowGapEnd); 332 Printf("|| `[%p, %p]` || LowShadow ||\n", 333 (void*)kLowShadowBeg, (void*)kLowShadowEnd); 334 Printf("|| `[%p, %p]` || LowMem ||\n", 335 (void*)kLowMemBeg, (void*)kLowMemEnd); 336 Printf("MemToShadow(shadow): %p %p %p %p\n", 337 (void*)MEM_TO_SHADOW(kLowShadowBeg), 338 (void*)MEM_TO_SHADOW(kLowShadowEnd), 339 (void*)MEM_TO_SHADOW(kHighShadowBeg), 340 (void*)MEM_TO_SHADOW(kHighShadowEnd)); 341 Printf("red_zone=%zu\n", (uptr)flags()->redzone); 342 Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size); 343 344 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE); 345 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY); 346 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET); 347 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7); 348 } 349 350 if (flags()->disable_core) { 351 DisableCoreDumper(); 352 } 353 354 uptr shadow_start = kLowShadowBeg; 355 if (kLowShadowBeg > 0) shadow_start -= GetMmapGranularity(); 356 uptr shadow_end = kHighShadowEnd; 357 if (MemoryRangeIsAvailable(shadow_start, shadow_end)) { 358 if (kLowShadowBeg != kLowShadowEnd) { 359 // mmap the low shadow plus at least one page. 360 ReserveShadowMemoryRange(kLowShadowBeg - GetMmapGranularity(), 361 kLowShadowEnd); 362 } 363 // mmap the high shadow. 364 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd); 365 // protect the gap 366 void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1); 367 CHECK(prot == (void*)kShadowGapBeg); 368 } else { 369 Report("Shadow memory range interleaves with an existing memory mapping. " 370 "ASan cannot proceed correctly. ABORTING.\n"); 371 DumpProcessMap(); 372 Die(); 373 } 374 375 InstallSignalHandlers(); 376 // Start symbolizer process if necessary. 377 if (flags()->symbolize) { 378 const char *external_symbolizer = GetEnv("ASAN_SYMBOLIZER_PATH"); 379 if (external_symbolizer) { 380 InitializeExternalSymbolizer(external_symbolizer); 381 } 382 } 383 384 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited 385 // should be set to 1 prior to initializing the threads. 386 asan_inited = 1; 387 asan_init_is_running = false; 388 389 asanThreadRegistry().Init(); 390 asanThreadRegistry().GetMain()->ThreadStart(); 391 force_interface_symbols(); // no-op. 392 393 if (flags()->verbosity) { 394 Report("AddressSanitizer Init done\n"); 395 } 396} 397 398#if defined(ASAN_USE_PREINIT_ARRAY) 399 // On Linux, we force __asan_init to be called before anyone else 400 // by placing it into .preinit_array section. 401 // FIXME: do we have anything like this on Mac? 402 __attribute__((section(".preinit_array"))) 403 typeof(__asan_init) *__asan_preinit =__asan_init; 404#elif defined(_WIN32) && defined(_DLL) 405 // On Windows, when using dynamic CRT (/MD), we can put a pointer 406 // to __asan_init into the global list of C initializers. 407 // See crt0dat.c in the CRT sources for the details. 408 #pragma section(".CRT$XIB", long, read) // NOLINT 409 __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init; 410#endif 411