libsanitizer/asan/asan_rtl.cc

   1 //===-- asan_rtl.cc -------------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Main file of the ASan run-time library.
  11 //===----------------------------------------------------------------------===//
  12 #include "asan_activation.h"
  13 #include "asan_allocator.h"
  14 #include "asan_interceptors.h"
  15 #include "asan_interface_internal.h"
  16 #include "asan_internal.h"
  17 #include "asan_mapping.h"
  18 #include "asan_poisoning.h"
  19 #include "asan_report.h"
  20 #include "asan_stack.h"
  21 #include "asan_stats.h"
  22 #include "asan_thread.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 #include "lsan/lsan_common.h"
  28
  29 int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
  30 uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
  31
  32 namespace __asan {
  33
  34 uptr AsanMappingProfile[kAsanMappingProfileSize];
  35
  36 static void AsanDie() {
  37   static atomic_uint32_t num_calls;
  38   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
  39     // Don't die twice - run a busy loop.
  40     while (1) { }
  41   }
  42   if (flags()->sleep_before_dying) {
  43     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
  44     SleepForSeconds(flags()->sleep_before_dying);
  45   }
  46   if (flags()->unmap_shadow_on_exit) {
  47     if (kMidMemBeg) {
  48       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
  49       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
  50     } else {
  51       UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
  52     }
  53   }
  54   if (common_flags()->coverage)
  55     __sanitizer_cov_dump();
  56   if (death_callback)
  57     death_callback();
  58   if (flags()->abort_on_error)
  59     Abort();
  60   internal__exit(flags()->exitcode);
  61 }
  62
  63 static void AsanCheckFailed(const char *file, int line, const char *cond,
  64                             u64 v1, u64 v2) {
  65   Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
  66          line, cond, (uptr)v1, (uptr)v2);
  67   // FIXME: check for infinite recursion without a thread-local counter here.
  68   PRINT_CURRENT_STACK();
  69   Die();
  70 }
  71
  72 // -------------------------- Flags ------------------------- {{{1
  73 static const int kDefaultMallocContextSize = 30;
  74
  75 Flags asan_flags_dont_use_directly;  // use via flags().
  76
  77 static const char *MaybeCallAsanDefaultOptions() {
  78   return (&__asan_default_options) ? __asan_default_options() : "";
  79 }
  80
  81 static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
  82 #ifdef ASAN_DEFAULT_OPTIONS
  83 // Stringize the macro value.
  84 # define ASAN_STRINGIZE(x) #x
  85 # define ASAN_STRINGIZE_OPTIONS(options) ASAN_STRINGIZE(options)
  86   return ASAN_STRINGIZE_OPTIONS(ASAN_DEFAULT_OPTIONS);
  87 #else
  88   return "";
  89 #endif
  90 }
  91
  92 static void ParseFlagsFromString(Flags *f, const char *str) {
  93   CommonFlags *cf = common_flags();
  94   ParseCommonFlagsFromString(cf, str);
  95   CHECK((uptr)cf->malloc_context_size <= kStackTraceMax);
  96   // Please write meaningful flag descriptions when adding new flags.
  97   ParseFlag(str, &f->quarantine_size, "quarantine_size",
  98             "Size (in bytes) of quarantine used to detect use-after-free "
  99             "errors. Lower value may reduce memory usage but increase the "
 100             "chance of false negatives.");
 101   ParseFlag(str, &f->redzone, "redzone",
 102             "Minimal size (in bytes) of redzones around heap objects. "
 103             "Requirement: redzone >= 16, is a power of two.");
 104   ParseFlag(str, &f->max_redzone, "max_redzone",
 105             "Maximal size (in bytes) of redzones around heap objects.");
 106   CHECK_GE(f->redzone, 16);
 107   CHECK_GE(f->max_redzone, f->redzone);
 108   CHECK_LE(f->max_redzone, 2048);
 109   CHECK(IsPowerOfTwo(f->redzone));
 110   CHECK(IsPowerOfTwo(f->max_redzone));
 111
 112   ParseFlag(str, &f->debug, "debug",
 113       "If set, prints some debugging information and does additional checks.");
 114   ParseFlag(str, &f->report_globals, "report_globals",
 115       "Controls the way to handle globals (0 - don't detect buffer overflow on "
 116       "globals, 1 - detect buffer overflow, 2 - print data about registered "
 117       "globals).");
 118
 119   ParseFlag(str, &f->check_initialization_order,
 120       "check_initialization_order",
 121       "If set, attempts to catch initialization order issues.");
 122
 123   ParseFlag(str, &f->replace_str, "replace_str",
 124       "If set, uses custom wrappers and replacements for libc string functions "
 125       "to find more errors.");
 126
 127   ParseFlag(str, &f->replace_intrin, "replace_intrin",
 128       "If set, uses custom wrappers for memset/memcpy/memmove intinsics.");
 129   ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free",
 130       "Ignore invalid free() calls to work around some bugs. Used on OS X "
 131       "only.");
 132   ParseFlag(str, &f->detect_stack_use_after_return,
 133       "detect_stack_use_after_return",
 134       "Enables stack-use-after-return checking at run-time.");
 135   ParseFlag(str, &f->min_uar_stack_size_log, "min_uar_stack_size_log",
 136       "Minimum fake stack size log.");
 137   ParseFlag(str, &f->max_uar_stack_size_log, "max_uar_stack_size_log",
 138       "Maximum fake stack size log.");
 139   ParseFlag(str, &f->uar_noreserve, "uar_noreserve",
 140       "Use mmap with 'norserve' flag to allocate fake stack.");
 141   ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size",
 142       "ASan allocator flag. max_malloc_fill_size is the maximal amount of "
 143       "bytes that will be filled with malloc_fill_byte on malloc.");
 144   ParseFlag(str, &f->malloc_fill_byte, "malloc_fill_byte",
 145       "Value used to fill the newly allocated memory.");
 146   ParseFlag(str, &f->exitcode, "exitcode",
 147       "Override the program exit status if the tool found an error.");
 148   ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning",
 149       "If set, user may manually mark memory regions as poisoned or "
 150       "unpoisoned.");
 151   ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying",
 152       "Number of seconds to sleep between printing an error report and "
 153       "terminating the program. Useful for debugging purposes (e.g. when one "
 154       "needs to attach gdb).");
 155
 156   ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size",
 157       "Allows the users to work around the bug in Nvidia drivers prior to "
 158       "295.*.");
 159
 160   ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit",
 161       "If set, explicitly unmaps the (huge) shadow at exit.");
 162   ParseFlag(str, &f->abort_on_error, "abort_on_error",
 163       "If set, the tool calls abort() instead of _exit() after printing the "
 164       "error report.");
 165   ParseFlag(str, &f->print_stats, "print_stats",
 166       "Print various statistics after printing an error message or if "
 167       "atexit=1.");
 168   ParseFlag(str, &f->print_legend, "print_legend",
 169       "Print the legend for the shadow bytes.");
 170   ParseFlag(str, &f->atexit, "atexit",
 171       "If set, prints ASan exit stats even after program terminates "
 172       "successfully.");
 173
 174   ParseFlag(str, &f->disable_core, "disable_core",
 175       "Disable core dumping. By default, disable_core=1 on 64-bit to avoid "
 176       "dumping a 16T+ core file. "
 177       "Ignored on OSes that don't dump core by default.");
 178
 179   ParseFlag(str, &f->allow_reexec, "allow_reexec",
 180       "Allow the tool to re-exec the program. This may interfere badly with "
 181       "the debugger.");
 182
 183   ParseFlag(str, &f->print_full_thread_history,
 184       "print_full_thread_history",
 185       "If set, prints thread creation stacks for the threads involved in the "
 186       "report and their ancestors up to the main thread.");
 187
 188   ParseFlag(str, &f->poison_heap, "poison_heap",
 189       "Poison (or not) the heap memory on [de]allocation. Zero value is useful "
 190       "for benchmarking the allocator or instrumentator.");
 191
 192   ParseFlag(str, &f->poison_partial, "poison_partial",
 193       "If true, poison partially addressable 8-byte aligned words "
 194       "(default=true). This flag affects heap and global buffers, but not "
 195       "stack buffers.");
 196
 197   ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch",
 198       "Report errors on malloc/delete, new/free, new/delete[], etc.");
 199   ParseFlag(str, &f->strict_memcmp, "strict_memcmp",
 200       "If true, assume that memcmp(p1, p2, n) always reads n bytes before "
 201       "comparing p1 and p2.");
 202
 203   ParseFlag(str, &f->strict_init_order, "strict_init_order",
 204       "If true, assume that dynamic initializers can never access globals from "
 205       "other modules, even if the latter are already initialized.");
 206
 207   ParseFlag(str, &f->start_deactivated, "start_deactivated",
 208       "If true, ASan tweaks a bunch of other flags (quarantine, redzone, heap "
 209       "poisoning) to reduce memory consumption as much as possible, and "
 210       "restores them to original values when the first instrumented module is "
 211       "loaded into the process. This is mainly intended to be used on "
 212       "Android. ");
 213
 214   ParseFlag(str, &f->detect_invalid_pointer_pairs,
 215       "detect_invalid_pointer_pairs",
 216       "If non-zero, try to detect operations like <, <=, >, >= and - on "
 217       "invalid pointer pairs (e.g. when pointers belong to different objects). "
 218       "The bigger the value the harder we try.");
 219
 220   ParseFlag(str, &f->detect_container_overflow,
 221       "detect_container_overflow",
 222       "If true, honor the container overflow  annotations. "
 223       "See https://code.google.com/p/address-sanitizer/wiki/ContainerOverflow");
 224
 225   ParseFlag(str, &f->detect_odr_violation, "detect_odr_violation",
 226             "If >=2, detect violation of One-Definition-Rule (ODR); "
 227             "If ==1, detect ODR-violation only if the two variables "
 228             "have different sizes");
 229 }
 230
 231 void InitializeFlags(Flags *f, const char *env) {
 232   CommonFlags *cf = common_flags();
 233   SetCommonFlagsDefaults(cf);
 234   cf->detect_leaks = CAN_SANITIZE_LEAKS;
 235   cf->external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
 236   cf->malloc_context_size = kDefaultMallocContextSize;
 237   cf->intercept_tls_get_addr = true;
 238   cf->coverage = false;
 239
 240   internal_memset(f, 0, sizeof(*f));
 241   f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28;
 242   f->redzone = 16;
 243   f->max_redzone = 2048;
 244   f->debug = false;
 245   f->report_globals = 1;
 246   f->check_initialization_order = false;
 247   f->replace_str = true;
 248   f->replace_intrin = true;
 249   f->mac_ignore_invalid_free = false;
 250   f->detect_stack_use_after_return = false;  // Also needs the compiler flag.
 251   f->min_uar_stack_size_log = 16;  // We can't do smaller anyway.
 252   f->max_uar_stack_size_log = 20;  // 1Mb per size class, i.e. ~11Mb per thread.
 253   f->uar_noreserve = false;
 254   f->max_malloc_fill_size = 0x1000;  // By default, fill only the first 4K.
 255   f->malloc_fill_byte = 0xbe;
 256   f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
 257   f->allow_user_poisoning = true;
 258   f->sleep_before_dying = 0;
 259   f->check_malloc_usable_size = true;
 260   f->unmap_shadow_on_exit = false;
 261   f->abort_on_error = false;
 262   f->print_stats = false;
 263   f->print_legend = true;
 264   f->atexit = false;
 265   f->disable_core = (SANITIZER_WORDSIZE == 64);
 266   f->allow_reexec = true;
 267   f->print_full_thread_history = true;
 268   f->poison_heap = true;
 269   f->poison_partial = true;
 270   // Turn off alloc/dealloc mismatch checker on Mac and Windows for now.
 271   // https://code.google.com/p/address-sanitizer/issues/detail?id=131
 272   // https://code.google.com/p/address-sanitizer/issues/detail?id=309
 273   // TODO(glider,timurrrr): Fix known issues and enable this back.
 274   f->alloc_dealloc_mismatch = (SANITIZER_MAC == 0) && (SANITIZER_WINDOWS == 0);
 275   f->strict_memcmp = true;
 276   f->strict_init_order = false;
 277   f->start_deactivated = false;
 278   f->detect_invalid_pointer_pairs = 0;
 279   f->detect_container_overflow = true;
 280
 281   // Override from compile definition.
 282   ParseFlagsFromString(f, MaybeUseAsanDefaultOptionsCompileDefinition());
 283
 284   // Override from user-specified string.
 285   ParseFlagsFromString(f, MaybeCallAsanDefaultOptions());
 286   VReport(1, "Using the defaults from __asan_default_options: %s\n",
 287           MaybeCallAsanDefaultOptions());
 288
 289   // Override from command line.
 290   ParseFlagsFromString(f, env);
 291   if (common_flags()->help) {
 292     PrintFlagDescriptions();
 293   }
 294
 295   if (!CAN_SANITIZE_LEAKS && cf->detect_leaks) {
 296     Report("%s: detect_leaks is not supported on this platform.\n",
 297            SanitizerToolName);
 298     cf->detect_leaks = false;
 299   }
 300
 301   // Make "strict_init_order" imply "check_initialization_order".
 302   // TODO(samsonov): Use a single runtime flag for an init-order checker.
 303   if (f->strict_init_order) {
 304     f->check_initialization_order = true;
 305   }
 306 }
 307
 308 // Parse flags that may change between startup and activation.
 309 // On Android they come from a system property.
 310 // On other platforms this is no-op.
 311 void ParseExtraActivationFlags() {
 312   char buf[100];
 313   GetExtraActivationFlags(buf, sizeof(buf));
 314   ParseFlagsFromString(flags(), buf);
 315   if (buf[0] != '\0')
 316     VReport(1, "Extra activation flags: %s\n", buf);
 317 }
 318
 319 // -------------------------- Globals --------------------- {{{1
 320 int asan_inited;
 321 bool asan_init_is_running;
 322 void (*death_callback)(void);
 323
 324 #if !ASAN_FIXED_MAPPING
 325 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
 326 #endif
 327
 328 // -------------------------- Misc ---------------- {{{1
 329 void ShowStatsAndAbort() {
 330   __asan_print_accumulated_stats();
 331   Die();
 332 }
 333
 334 // ---------------------- mmap -------------------- {{{1
 335 // Reserve memory range [beg, end].
 336 static void ReserveShadowMemoryRange(uptr beg, uptr end) {
 337   CHECK_EQ((beg % GetPageSizeCached()), 0);
 338   CHECK_EQ(((end + 1) % GetPageSizeCached()), 0);
 339   uptr size = end - beg + 1;
 340   DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
 341   void *res = MmapFixedNoReserve(beg, size);
 342   if (res != (void*)beg) {
 343     Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
 344            "Perhaps you're using ulimit -v\n", size);
 345     Abort();
 346   }
 347 }
 348
 349 // --------------- LowLevelAllocateCallbac ---------- {{{1
 350 static void OnLowLevelAllocate(uptr ptr, uptr size) {
 351   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
 352 }
 353
 354 // -------------------------- Run-time entry ------------------- {{{1
 355 // exported functions
 356 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
 357 extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
 358 void __asan_report_ ## type ## size(uptr addr);                \
 359 void __asan_report_ ## type ## size(uptr addr) {               \
 360   GET_CALLER_PC_BP_SP;                                              \
 361   __asan_report_error(pc, bp, sp, addr, is_write, size);            \
 362 }
 363
 364 ASAN_REPORT_ERROR(load, false, 1)
 365 ASAN_REPORT_ERROR(load, false, 2)
 366 ASAN_REPORT_ERROR(load, false, 4)
 367 ASAN_REPORT_ERROR(load, false, 8)
 368 ASAN_REPORT_ERROR(load, false, 16)
 369 ASAN_REPORT_ERROR(store, true, 1)
 370 ASAN_REPORT_ERROR(store, true, 2)
 371 ASAN_REPORT_ERROR(store, true, 4)
 372 ASAN_REPORT_ERROR(store, true, 8)
 373 ASAN_REPORT_ERROR(store, true, 16)
 374
 375 #define ASAN_REPORT_ERROR_N(type, is_write)                    \
 376 extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
 377 void __asan_report_ ## type ## _n(uptr addr, uptr size);       \
 378 void __asan_report_ ## type ## _n(uptr addr, uptr size) {      \
 379   GET_CALLER_PC_BP_SP;                                         \
 380   __asan_report_error(pc, bp, sp, addr, is_write, size);       \
 381 }
 382
 383 ASAN_REPORT_ERROR_N(load, false)
 384 ASAN_REPORT_ERROR_N(store, true)
 385
 386 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
 387   extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_##type##size(uptr addr); \
 388   void __asan_##type##size(uptr addr) {                                        \
 389     uptr sp = MEM_TO_SHADOW(addr);                                             \
 390     uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)          \
 391                                         : *reinterpret_cast<u16 *>(sp);        \
 392     if (UNLIKELY(s)) {                                                         \
 393       if (UNLIKELY(size >= SHADOW_GRANULARITY ||                               \
 394                    ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >=     \
 395                        (s8)s)) {                                               \
 396         if (__asan_test_only_reported_buggy_pointer) {                         \
 397           *__asan_test_only_reported_buggy_pointer = addr;                     \
 398         } else {                                                               \
 399           GET_CALLER_PC_BP_SP;                                                 \
 400           __asan_report_error(pc, bp, sp, addr, is_write, size);               \
 401         }                                                                      \
 402       }                                                                        \
 403     }                                                                          \
 404   }
 405
 406 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
 407 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
 408 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
 409 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
 410 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
 411 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
 412 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
 413 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
 414 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
 415 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
 416
 417 extern "C"
 418 NOINLINE INTERFACE_ATTRIBUTE void __asan_loadN(uptr addr, uptr size) {
 419   if (__asan_region_is_poisoned(addr, size)) {
 420     GET_CALLER_PC_BP_SP;
 421     __asan_report_error(pc, bp, sp, addr, false, size);
 422   }
 423 }
 424
 425 extern "C"
 426 NOINLINE INTERFACE_ATTRIBUTE void __asan_storeN(uptr addr, uptr size) {
 427   if (__asan_region_is_poisoned(addr, size)) {
 428     GET_CALLER_PC_BP_SP;
 429     __asan_report_error(pc, bp, sp, addr, true, size);
 430   }
 431 }
 432
 433 // Force the linker to keep the symbols for various ASan interface functions.
 434 // We want to keep those in the executable in order to let the instrumented
 435 // dynamic libraries access the symbol even if it is not used by the executable
 436 // itself. This should help if the build system is removing dead code at link
 437 // time.
 438 static NOINLINE void force_interface_symbols() {
 439   volatile int fake_condition = 0;  // prevent dead condition elimination.
 440   // __asan_report_* functions are noreturn, so we need a switch to prevent
 441   // the compiler from removing any of them.
 442   switch (fake_condition) {
 443     case 1: __asan_report_load1(0); break;
 444     case 2: __asan_report_load2(0); break;
 445     case 3: __asan_report_load4(0); break;
 446     case 4: __asan_report_load8(0); break;
 447     case 5: __asan_report_load16(0); break;
 448     case 6: __asan_report_store1(0); break;
 449     case 7: __asan_report_store2(0); break;
 450     case 8: __asan_report_store4(0); break;
 451     case 9: __asan_report_store8(0); break;
 452     case 10: __asan_report_store16(0); break;
 453     case 12: __asan_register_globals(0, 0); break;
 454     case 13: __asan_unregister_globals(0, 0); break;
 455     case 14: __asan_set_death_callback(0); break;
 456     case 15: __asan_set_error_report_callback(0); break;
 457     case 16: __asan_handle_no_return(); break;
 458     case 17: __asan_address_is_poisoned(0); break;
 459     case 18: __asan_get_allocated_size(0); break;
 460     case 19: __asan_get_current_allocated_bytes(); break;
 461     case 20: __asan_get_estimated_allocated_size(0); break;
 462     case 21: __asan_get_free_bytes(); break;
 463     case 22: __asan_get_heap_size(); break;
 464     case 23: __asan_get_ownership(0); break;
 465     case 24: __asan_get_unmapped_bytes(); break;
 466     case 25: __asan_poison_memory_region(0, 0); break;
 467     case 26: __asan_unpoison_memory_region(0, 0); break;
 468     case 27: __asan_set_error_exit_code(0); break;
 469     case 30: __asan_before_dynamic_init(0); break;
 470     case 31: __asan_after_dynamic_init(); break;
 471     case 32: __asan_poison_stack_memory(0, 0); break;
 472     case 33: __asan_unpoison_stack_memory(0, 0); break;
 473     case 34: __asan_region_is_poisoned(0, 0); break;
 474     case 35: __asan_describe_address(0); break;
 475   }
 476 }
 477
 478 static void asan_atexit() {
 479   Printf("AddressSanitizer exit stats:\n");
 480   __asan_print_accumulated_stats();
 481   // Print AsanMappingProfile.
 482   for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
 483     if (AsanMappingProfile[i] == 0) continue;
 484     Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
 485   }
 486 }
 487
 488 static void InitializeHighMemEnd() {
 489 #if !ASAN_FIXED_MAPPING
 490   kHighMemEnd = GetMaxVirtualAddress();
 491   // Increase kHighMemEnd to make sure it's properly
 492   // aligned together with kHighMemBeg:
 493   kHighMemEnd |= SHADOW_GRANULARITY * GetPageSizeCached() - 1;
 494 #endif  // !ASAN_FIXED_MAPPING
 495   CHECK_EQ((kHighMemBeg % GetPageSizeCached()), 0);
 496 }
 497
 498 static void ProtectGap(uptr a, uptr size) {
 499   CHECK_EQ(a, (uptr)Mprotect(a, size));
 500 }
 501
 502 static void PrintAddressSpaceLayout() {
 503   Printf("|| `[%p, %p]` || HighMem    ||\n",
 504          (void*)kHighMemBeg, (void*)kHighMemEnd);
 505   Printf("|| `[%p, %p]` || HighShadow ||\n",
 506          (void*)kHighShadowBeg, (void*)kHighShadowEnd);
 507   if (kMidMemBeg) {
 508     Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
 509            (void*)kShadowGap3Beg, (void*)kShadowGap3End);
 510     Printf("|| `[%p, %p]` || MidMem     ||\n",
 511            (void*)kMidMemBeg, (void*)kMidMemEnd);
 512     Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
 513            (void*)kShadowGap2Beg, (void*)kShadowGap2End);
 514     Printf("|| `[%p, %p]` || MidShadow  ||\n",
 515            (void*)kMidShadowBeg, (void*)kMidShadowEnd);
 516   }
 517   Printf("|| `[%p, %p]` || ShadowGap  ||\n",
 518          (void*)kShadowGapBeg, (void*)kShadowGapEnd);
 519   if (kLowShadowBeg) {
 520     Printf("|| `[%p, %p]` || LowShadow  ||\n",
 521            (void*)kLowShadowBeg, (void*)kLowShadowEnd);
 522     Printf("|| `[%p, %p]` || LowMem     ||\n",
 523            (void*)kLowMemBeg, (void*)kLowMemEnd);
 524   }
 525   Printf("MemToShadow(shadow): %p %p %p %p",
 526          (void*)MEM_TO_SHADOW(kLowShadowBeg),
 527          (void*)MEM_TO_SHADOW(kLowShadowEnd),
 528          (void*)MEM_TO_SHADOW(kHighShadowBeg),
 529          (void*)MEM_TO_SHADOW(kHighShadowEnd));
 530   if (kMidMemBeg) {
 531     Printf(" %p %p",
 532            (void*)MEM_TO_SHADOW(kMidShadowBeg),
 533            (void*)MEM_TO_SHADOW(kMidShadowEnd));
 534   }
 535   Printf("\n");
 536   Printf("redzone=%zu\n", (uptr)flags()->redzone);
 537   Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
 538   Printf("quarantine_size=%zuM\n", (uptr)flags()->quarantine_size >> 20);
 539   Printf("malloc_context_size=%zu\n",
 540          (uptr)common_flags()->malloc_context_size);
 541
 542   Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
 543   Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
 544   Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
 545   CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
 546   if (kMidMemBeg)
 547     CHECK(kMidShadowBeg > kLowShadowEnd &&
 548           kMidMemBeg > kMidShadowEnd &&
 549           kHighShadowBeg > kMidMemEnd);
 550 }
 551
 552 static void AsanInitInternal() {
 553   if (LIKELY(asan_inited)) return;
 554   SanitizerToolName = "AddressSanitizer";
 555   CHECK(!asan_init_is_running && "ASan init calls itself!");
 556   asan_init_is_running = true;
 557
 558   // Initialize flags. This must be done early, because most of the
 559   // initialization steps look at flags().
 560   const char *options = GetEnv("ASAN_OPTIONS");
 561   InitializeFlags(flags(), options);
 562
 563   InitializeHighMemEnd();
 564
 565   // Make sure we are not statically linked.
 566   AsanDoesNotSupportStaticLinkage();
 567
 568   // Install tool-specific callbacks in sanitizer_common.
 569   SetDieCallback(AsanDie);
 570   SetCheckFailedCallback(AsanCheckFailed);
 571   SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
 572
 573   if (!flags()->start_deactivated)
 574     ParseExtraActivationFlags();
 575
 576   __sanitizer_set_report_path(common_flags()->log_path);
 577   __asan_option_detect_stack_use_after_return =
 578       flags()->detect_stack_use_after_return;
 579   CHECK_LE(flags()->min_uar_stack_size_log, flags()->max_uar_stack_size_log);
 580
 581   if (options) {
 582     VReport(1, "Parsed ASAN_OPTIONS: %s\n", options);
 583   }
 584
 585   if (flags()->start_deactivated)
 586     AsanStartDeactivated();
 587
 588   // Re-exec ourselves if we need to set additional env or command line args.
 589   MaybeReexec();
 590
 591   // Setup internal allocator callback.
 592   SetLowLevelAllocateCallback(OnLowLevelAllocate);
 593
 594   InitializeAsanInterceptors();
 595
 596   ReplaceSystemMalloc();
 597
 598   uptr shadow_start = kLowShadowBeg;
 599   if (kLowShadowBeg)
 600     shadow_start -= GetMmapGranularity();
 601   bool full_shadow_is_available =
 602       MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
 603
 604 #if SANITIZER_LINUX && defined(__x86_64__) && !ASAN_FIXED_MAPPING
 605   if (!full_shadow_is_available) {
 606     kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
 607     kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
 608   }
 609 #endif
 610
 611   if (common_flags()->verbosity)
 612     PrintAddressSpaceLayout();
 613
 614   if (flags()->disable_core) {
 615     DisableCoreDumper();
 616   }
 617
 618   if (full_shadow_is_available) {
 619     // mmap the low shadow plus at least one page at the left.
 620     if (kLowShadowBeg)
 621       ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
 622     // mmap the high shadow.
 623     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
 624     // protect the gap.
 625     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
 626     CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
 627   } else if (kMidMemBeg &&
 628       MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
 629       MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
 630     CHECK(kLowShadowBeg != kLowShadowEnd);
 631     // mmap the low shadow plus at least one page at the left.
 632     ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
 633     // mmap the mid shadow.
 634     ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd);
 635     // mmap the high shadow.
 636     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
 637     // protect the gaps.
 638     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
 639     ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
 640     ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
 641   } else {
 642     Report("Shadow memory range interleaves with an existing memory mapping. "
 643            "ASan cannot proceed correctly. ABORTING.\n");
 644     DumpProcessMap();
 645     Die();
 646   }
 647
 648   AsanTSDInit(PlatformTSDDtor);
 649   InstallDeadlySignalHandlers(AsanOnSIGSEGV);
 650
 651   // Allocator should be initialized before starting external symbolizer, as
 652   // fork() on Mac locks the allocator.
 653   InitializeAllocator();
 654
 655   Symbolizer::Init(common_flags()->external_symbolizer_path);
 656
 657   // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
 658   // should be set to 1 prior to initializing the threads.
 659   asan_inited = 1;
 660   asan_init_is_running = false;
 661
 662   if (flags()->atexit)
 663     Atexit(asan_atexit);
 664
 665   if (common_flags()->coverage) {
 666     __sanitizer_cov_init();
 667     Atexit(__sanitizer_cov_dump);
 668   }
 669
 670   // interceptors
 671   InitTlsSize();
 672
 673   // Create main thread.
 674   AsanThread *main_thread = AsanThread::Create(0, 0);
 675   CreateThreadContextArgs create_main_args = { main_thread, 0 };
 676   u32 main_tid = asanThreadRegistry().CreateThread(
 677       0, true, 0, &create_main_args);
 678   CHECK_EQ(0, main_tid);
 679   SetCurrentThread(main_thread);
 680   main_thread->ThreadStart(internal_getpid());
 681   force_interface_symbols();  // no-op.
 682   SanitizerInitializeUnwinder();
 683
 684 #if CAN_SANITIZE_LEAKS
 685   __lsan::InitCommonLsan();
 686   if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
 687     Atexit(__lsan::DoLeakCheck);
 688   }
 689 #endif  // CAN_SANITIZE_LEAKS
 690
 691   VReport(1, "AddressSanitizer Init done\n");
 692 }
 693
 694 // Initialize as requested from some part of ASan runtime library (interceptors,
 695 // allocator, etc).
 696 void AsanInitFromRtl() {
 697   AsanInitInternal();
 698 }
 699
 700 #if ASAN_DYNAMIC
 701 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
 702 // (and thus normal initializer from .preinit_array haven't run).
 703
 704 class AsanInitializer {
 705 public:  // NOLINT
 706   AsanInitializer() {
 707     AsanCheckIncompatibleRT();
 708     AsanCheckDynamicRTPrereqs();
 709     if (UNLIKELY(!asan_inited))
 710       __asan_init();
 711   }
 712 };
 713
 714 static AsanInitializer asan_initializer;
 715 #endif  // ASAN_DYNAMIC
 716
 717 }  // namespace __asan
 718
 719 // ---------------------- Interface ---------------- {{{1
 720 using namespace __asan;  // NOLINT
 721
 722 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 723 extern "C" {
 724 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 725 const char* __asan_default_options() { return ""; }
 726 }  // extern "C"
 727 #endif
 728
 729 int NOINLINE __asan_set_error_exit_code(int exit_code) {
 730   int old = flags()->exitcode;
 731   flags()->exitcode = exit_code;
 732   return old;
 733 }
 734
 735 void NOINLINE __asan_handle_no_return() {
 736   int local_stack;
 737   AsanThread *curr_thread = GetCurrentThread();
 738   CHECK(curr_thread);
 739   uptr PageSize = GetPageSizeCached();
 740   uptr top = curr_thread->stack_top();
 741   uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1);
 742   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
 743   if (top - bottom > kMaxExpectedCleanupSize) {
 744     static bool reported_warning = false;
 745     if (reported_warning)
 746       return;
 747     reported_warning = true;
 748     Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
 749            "stack top: %p; bottom %p; size: %p (%zd)\n"
 750            "False positive error reports may follow\n"
 751            "For details see "
 752            "http://code.google.com/p/address-sanitizer/issues/detail?id=189\n",
 753            top, bottom, top - bottom, top - bottom);
 754     return;
 755   }
 756   PoisonShadow(bottom, top - bottom, 0);
 757   if (curr_thread->has_fake_stack())
 758     curr_thread->fake_stack()->HandleNoReturn();
 759 }
 760
 761 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
 762   death_callback = callback;
 763 }
 764
 765 // Initialize as requested from instrumented application code.
 766 // We use this call as a trigger to wake up ASan from deactivated state.
 767 void __asan_init() {
 768   AsanCheckIncompatibleRT();
 769   AsanActivate();
 770   AsanInitInternal();
 771 }