lib/asan/asan_rtl.cc

   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_activation.h"
  15 #include "asan_allocator.h"
  16 #include "asan_interceptors.h"
  17 #include "asan_interface_internal.h"
  18 #include "asan_internal.h"
  19 #include "asan_mapping.h"
  20 #include "asan_poisoning.h"
  21 #include "asan_report.h"
  22 #include "asan_stack.h"
  23 #include "asan_stats.h"
  24 #include "asan_thread.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 #include "lsan/lsan_common.h"
  30
  31 int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
  32 uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
  33
  34 namespace __asan {
  35
  36 uptr AsanMappingProfile[kAsanMappingProfileSize];
  37
  38 static void AsanDie() {
  39   static atomic_uint32_t num_calls;
  40   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
  41     // Don't die twice - run a busy loop.
  42     while (1) { }
  43   }
  44   if (flags()->sleep_before_dying) {
  45     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
  46     SleepForSeconds(flags()->sleep_before_dying);
  47   }
  48   if (flags()->unmap_shadow_on_exit) {
  49     if (kMidMemBeg) {
  50       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
  51       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
  52     } else {
  53       UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
  54     }
  55   }
  56   if (common_flags()->coverage)
  57     __sanitizer_cov_dump();
  58   if (death_callback)
  59     death_callback();
  60   if (flags()->abort_on_error)
  61     Abort();
  62   internal__exit(flags()->exitcode);
  63 }
  64
  65 static void AsanCheckFailed(const char *file, int line, const char *cond,
  66                             u64 v1, u64 v2) {
  67   Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
  68          line, cond, (uptr)v1, (uptr)v2);
  69   // FIXME: check for infinite recursion without a thread-local counter here.
  70   PRINT_CURRENT_STACK();
  71   Die();
  72 }
  73
  74 // -------------------------- Flags ------------------------- {{{1
  75 static const int kDefaultMallocContextSize = 30;
  76
  77 Flags asan_flags_dont_use_directly;  // use via flags().
  78
  79 static const char *MaybeCallAsanDefaultOptions() {
  80   return (&__asan_default_options) ? __asan_default_options() : "";
  81 }
  82
  83 static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
  84 #ifdef ASAN_DEFAULT_OPTIONS
  85 // Stringize the macro value.
  86 # define ASAN_STRINGIZE(x) #x
  87 # define ASAN_STRINGIZE_OPTIONS(options) ASAN_STRINGIZE(options)
  88   return ASAN_STRINGIZE_OPTIONS(ASAN_DEFAULT_OPTIONS);
  89 #else
  90   return "";
  91 #endif
  92 }
  93
  94 static void ParseFlagsFromString(Flags *f, const char *str) {
  95   CommonFlags *cf = common_flags();
  96   ParseCommonFlagsFromString(cf, str);
  97   CHECK((uptr)cf->malloc_context_size <= kStackTraceMax);
  98   // Please write meaningful flag descriptions when adding new flags.
  99   ParseFlag(str, &f->quarantine_size, "quarantine_size",
 100             "Size (in bytes) of quarantine used to detect use-after-free "
 101             "errors. Lower value may reduce memory usage but increase the "
 102             "chance of false negatives.");
 103   ParseFlag(str, &f->redzone, "redzone",
 104             "Minimal size (in bytes) of redzones around heap objects. "
 105             "Requirement: redzone >= 16, is a power of two.");
 106   ParseFlag(str, &f->max_redzone, "max_redzone",
 107             "Maximal size (in bytes) of redzones around heap objects.");
 108   CHECK_GE(f->redzone, 16);
 109   CHECK_GE(f->max_redzone, f->redzone);
 110   CHECK_LE(f->max_redzone, 2048);
 111   CHECK(IsPowerOfTwo(f->redzone));
 112   CHECK(IsPowerOfTwo(f->max_redzone));
 113
 114   ParseFlag(str, &f->debug, "debug",
 115       "If set, prints some debugging information and does additional checks.");
 116   ParseFlag(str, &f->report_globals, "report_globals",
 117       "Controls the way to handle globals (0 - don't detect buffer overflow on "
 118       "globals, 1 - detect buffer overflow, 2 - print data about registered "
 119       "globals).");
 120
 121   ParseFlag(str, &f->check_initialization_order,
 122       "check_initialization_order",
 123       "If set, attempts to catch initialization order issues.");
 124
 125   ParseFlag(str, &f->replace_str, "replace_str",
 126       "If set, uses custom wrappers and replacements for libc string functions "
 127       "to find more errors.");
 128
 129   ParseFlag(str, &f->replace_intrin, "replace_intrin",
 130       "If set, uses custom wrappers for memset/memcpy/memmove intinsics.");
 131   ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free",
 132       "Ignore invalid free() calls to work around some bugs. Used on OS X "
 133       "only.");
 134   ParseFlag(str, &f->detect_stack_use_after_return,
 135       "detect_stack_use_after_return",
 136       "Enables stack-use-after-return checking at run-time.");
 137   ParseFlag(str, &f->min_uar_stack_size_log, "min_uar_stack_size_log",
 138       "Minimum fake stack size log.");
 139   ParseFlag(str, &f->max_uar_stack_size_log, "max_uar_stack_size_log",
 140       "Maximum fake stack size log.");
 141   ParseFlag(str, &f->uar_noreserve, "uar_noreserve",
 142       "Use mmap with 'norserve' flag to allocate fake stack.");
 143   ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size",
 144       "ASan allocator flag. max_malloc_fill_size is the maximal amount of "
 145       "bytes that will be filled with malloc_fill_byte on malloc.");
 146   ParseFlag(str, &f->malloc_fill_byte, "malloc_fill_byte",
 147       "Value used to fill the newly allocated memory.");
 148   ParseFlag(str, &f->exitcode, "exitcode",
 149       "Override the program exit status if the tool found an error.");
 150   ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning",
 151       "If set, user may manually mark memory regions as poisoned or "
 152       "unpoisoned.");
 153   ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying",
 154       "Number of seconds to sleep between printing an error report and "
 155       "terminating the program. Useful for debugging purposes (e.g. when one "
 156       "needs to attach gdb).");
 157
 158   ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size",
 159       "Allows the users to work around the bug in Nvidia drivers prior to "
 160       "295.*.");
 161
 162   ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit",
 163       "If set, explicitly unmaps the (huge) shadow at exit.");
 164   ParseFlag(str, &f->abort_on_error, "abort_on_error",
 165       "If set, the tool calls abort() instead of _exit() after printing the "
 166       "error report.");
 167   ParseFlag(str, &f->print_stats, "print_stats",
 168       "Print various statistics after printing an error message or if "
 169       "atexit=1.");
 170   ParseFlag(str, &f->print_legend, "print_legend",
 171       "Print the legend for the shadow bytes.");
 172   ParseFlag(str, &f->atexit, "atexit",
 173       "If set, prints ASan exit stats even after program terminates "
 174       "successfully.");
 175
 176   ParseFlag(str, &f->disable_core, "disable_core",
 177       "Disable core dumping. By default, disable_core=1 on 64-bit to avoid "
 178       "dumping a 16T+ core file. "
 179       "Ignored on OSes that don't dump core by default.");
 180
 181   ParseFlag(str, &f->allow_reexec, "allow_reexec",
 182       "Allow the tool to re-exec the program. This may interfere badly with "
 183       "the debugger.");
 184
 185   ParseFlag(str, &f->print_full_thread_history,
 186       "print_full_thread_history",
 187       "If set, prints thread creation stacks for the threads involved in the "
 188       "report and their ancestors up to the main thread.");
 189
 190   ParseFlag(str, &f->poison_heap, "poison_heap",
 191       "Poison (or not) the heap memory on [de]allocation. Zero value is useful "
 192       "for benchmarking the allocator or instrumentator.");
 193
 194   ParseFlag(str, &f->poison_partial, "poison_partial",
 195       "If true, poison partially addressable 8-byte aligned words "
 196       "(default=true). This flag affects heap and global buffers, but not "
 197       "stack buffers.");
 198
 199   ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch",
 200       "Report errors on malloc/delete, new/free, new/delete[], etc.");
 201   ParseFlag(str, &f->strict_memcmp, "strict_memcmp",
 202       "If true, assume that memcmp(p1, p2, n) always reads n bytes before "
 203       "comparing p1 and p2.");
 204
 205   ParseFlag(str, &f->strict_init_order, "strict_init_order",
 206       "If true, assume that dynamic initializers can never access globals from "
 207       "other modules, even if the latter are already initialized.");
 208
 209   ParseFlag(str, &f->start_deactivated, "start_deactivated",
 210       "If true, ASan tweaks a bunch of other flags (quarantine, redzone, heap "
 211       "poisoning) to reduce memory consumption as much as possible, and "
 212       "restores them to original values when the first instrumented module is "
 213       "loaded into the process. This is mainly intended to be used on "
 214       "Android. ");
 215
 216   ParseFlag(str, &f->detect_invalid_pointer_pairs,
 217       "detect_invalid_pointer_pairs",
 218       "If non-zero, try to detect operations like <, <=, >, >= and - on "
 219       "invalid pointer pairs (e.g. when pointers belong to different objects). "
 220       "The bigger the value the harder we try.");
 221
 222   ParseFlag(str, &f->detect_container_overflow,
 223       "detect_container_overflow",
 224       "If true, honor the container overflow  annotations. "
 225       "See https://code.google.com/p/address-sanitizer/wiki/ContainerOverflow");
 226
 227   ParseFlag(str, &f->detect_odr_violation, "detect_odr_violation",
 228             "If >=2, detect violation of One-Definition-Rule (ODR); "
 229             "If ==1, detect ODR-violation only if the two variables "
 230             "have different sizes");
 231 }
 232
 233 void InitializeFlags(Flags *f, const char *env) {
 234   CommonFlags *cf = common_flags();
 235   SetCommonFlagsDefaults(cf);
 236   cf->detect_leaks = CAN_SANITIZE_LEAKS;
 237   cf->external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
 238   cf->malloc_context_size = kDefaultMallocContextSize;
 239   cf->intercept_tls_get_addr = true;
 240   cf->coverage = false;
 241
 242   internal_memset(f, 0, sizeof(*f));
 243   f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28;
 244   f->redzone = 16;
 245   f->max_redzone = 2048;
 246   f->debug = false;
 247   f->report_globals = 1;
 248   f->check_initialization_order = false;
 249   f->replace_str = true;
 250   f->replace_intrin = true;
 251   f->mac_ignore_invalid_free = false;
 252   f->detect_stack_use_after_return = false;  // Also needs the compiler flag.
 253   f->min_uar_stack_size_log = 16;  // We can't do smaller anyway.
 254   f->max_uar_stack_size_log = 20;  // 1Mb per size class, i.e. ~11Mb per thread.
 255   f->uar_noreserve = false;
 256   f->max_malloc_fill_size = 0x1000;  // By default, fill only the first 4K.
 257   f->malloc_fill_byte = 0xbe;
 258   f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
 259   f->allow_user_poisoning = true;
 260   f->sleep_before_dying = 0;
 261   f->check_malloc_usable_size = true;
 262   f->unmap_shadow_on_exit = false;
 263   f->abort_on_error = false;
 264   f->print_stats = false;
 265   f->print_legend = true;
 266   f->atexit = false;
 267   f->disable_core = (SANITIZER_WORDSIZE == 64);
 268   f->allow_reexec = true;
 269   f->print_full_thread_history = true;
 270   f->poison_heap = true;
 271   f->poison_partial = true;
 272   // Turn off alloc/dealloc mismatch checker on Mac and Windows for now.
 273   // https://code.google.com/p/address-sanitizer/issues/detail?id=131
 274   // https://code.google.com/p/address-sanitizer/issues/detail?id=309
 275   // TODO(glider,timurrrr): Fix known issues and enable this back.
 276   f->alloc_dealloc_mismatch = (SANITIZER_MAC == 0) && (SANITIZER_WINDOWS == 0);
 277   f->strict_memcmp = true;
 278   f->strict_init_order = false;
 279   f->start_deactivated = false;
 280   f->detect_invalid_pointer_pairs = 0;
 281   f->detect_container_overflow = true;
 282   f->detect_odr_violation = 2;
 283
 284   // Override from compile definition.
 285   ParseFlagsFromString(f, MaybeUseAsanDefaultOptionsCompileDefinition());
 286
 287   // Override from user-specified string.
 288   ParseFlagsFromString(f, MaybeCallAsanDefaultOptions());
 289   VReport(1, "Using the defaults from __asan_default_options: %s\n",
 290           MaybeCallAsanDefaultOptions());
 291
 292   // Override from command line.
 293   ParseFlagsFromString(f, env);
 294   if (common_flags()->help) {
 295     PrintFlagDescriptions();
 296   }
 297
 298   if (!CAN_SANITIZE_LEAKS && cf->detect_leaks) {
 299     Report("%s: detect_leaks is not supported on this platform.\n",
 300            SanitizerToolName);
 301     cf->detect_leaks = false;
 302   }
 303
 304   // Make "strict_init_order" imply "check_initialization_order".
 305   // TODO(samsonov): Use a single runtime flag for an init-order checker.
 306   if (f->strict_init_order) {
 307     f->check_initialization_order = true;
 308   }
 309 }
 310
 311 // Parse flags that may change between startup and activation.
 312 // On Android they come from a system property.
 313 // On other platforms this is no-op.
 314 void ParseExtraActivationFlags() {
 315   char buf[100];
 316   GetExtraActivationFlags(buf, sizeof(buf));
 317   ParseFlagsFromString(flags(), buf);
 318   if (buf[0] != '\0')
 319     VReport(1, "Extra activation flags: %s\n", buf);
 320 }
 321
 322 // -------------------------- Globals --------------------- {{{1
 323 int asan_inited;
 324 bool asan_init_is_running;
 325 void (*death_callback)(void);
 326
 327 #if !ASAN_FIXED_MAPPING
 328 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
 329 #endif
 330
 331 // -------------------------- Misc ---------------- {{{1
 332 void ShowStatsAndAbort() {
 333   __asan_print_accumulated_stats();
 334   Die();
 335 }
 336
 337 // ---------------------- mmap -------------------- {{{1
 338 // Reserve memory range [beg, end].
 339 static void ReserveShadowMemoryRange(uptr beg, uptr end) {
 340   CHECK_EQ((beg % GetPageSizeCached()), 0);
 341   CHECK_EQ(((end + 1) % GetPageSizeCached()), 0);
 342   uptr size = end - beg + 1;
 343   DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
 344   void *res = MmapFixedNoReserve(beg, size);
 345   if (res != (void*)beg) {
 346     Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
 347            "Perhaps you're using ulimit -v\n", size);
 348     Abort();
 349   }
 350 }
 351
 352 // --------------- LowLevelAllocateCallbac ---------- {{{1
 353 static void OnLowLevelAllocate(uptr ptr, uptr size) {
 354   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
 355 }
 356
 357 // -------------------------- Run-time entry ------------------- {{{1
 358 // exported functions
 359 #define ASAN_REPORT_ERROR(type, is_write, size)                     \
 360 extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
 361 void __asan_report_ ## type ## size(uptr addr);                \
 362 void __asan_report_ ## type ## size(uptr addr) {               \
 363   GET_CALLER_PC_BP_SP;                                              \
 364   __asan_report_error(pc, bp, sp, addr, is_write, size);            \
 365 }
 366
 367 ASAN_REPORT_ERROR(load, false, 1)
 368 ASAN_REPORT_ERROR(load, false, 2)
 369 ASAN_REPORT_ERROR(load, false, 4)
 370 ASAN_REPORT_ERROR(load, false, 8)
 371 ASAN_REPORT_ERROR(load, false, 16)
 372 ASAN_REPORT_ERROR(store, true, 1)
 373 ASAN_REPORT_ERROR(store, true, 2)
 374 ASAN_REPORT_ERROR(store, true, 4)
 375 ASAN_REPORT_ERROR(store, true, 8)
 376 ASAN_REPORT_ERROR(store, true, 16)
 377
 378 #define ASAN_REPORT_ERROR_N(type, is_write)                    \
 379 extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
 380 void __asan_report_ ## type ## _n(uptr addr, uptr size);       \
 381 void __asan_report_ ## type ## _n(uptr addr, uptr size) {      \
 382   GET_CALLER_PC_BP_SP;                                         \
 383   __asan_report_error(pc, bp, sp, addr, is_write, size);       \
 384 }
 385
 386 ASAN_REPORT_ERROR_N(load, false)
 387 ASAN_REPORT_ERROR_N(store, true)
 388
 389 #define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
 390   extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_##type##size(uptr addr); \
 391   void __asan_##type##size(uptr addr) {                                        \
 392     uptr sp = MEM_TO_SHADOW(addr);                                             \
 393     uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)          \
 394                                         : *reinterpret_cast<u16 *>(sp);        \
 395     if (UNLIKELY(s)) {                                                         \
 396       if (UNLIKELY(size >= SHADOW_GRANULARITY ||                               \
 397                    ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >=     \
 398                        (s8)s)) {                                               \
 399         if (__asan_test_only_reported_buggy_pointer) {                         \
 400           *__asan_test_only_reported_buggy_pointer = addr;                     \
 401         } else {                                                               \
 402           GET_CALLER_PC_BP_SP;                                                 \
 403           __asan_report_error(pc, bp, sp, addr, is_write, size);               \
 404         }                                                                      \
 405       }                                                                        \
 406     }                                                                          \
 407   }
 408
 409 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
 410 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
 411 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
 412 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
 413 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
 414 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
 415 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
 416 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
 417 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
 418 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
 419
 420 extern "C"
 421 NOINLINE INTERFACE_ATTRIBUTE void __asan_loadN(uptr addr, uptr size) {
 422   if (__asan_region_is_poisoned(addr, size)) {
 423     GET_CALLER_PC_BP_SP;
 424     __asan_report_error(pc, bp, sp, addr, false, size);
 425   }
 426 }
 427
 428 extern "C"
 429 NOINLINE INTERFACE_ATTRIBUTE void __asan_storeN(uptr addr, uptr size) {
 430   if (__asan_region_is_poisoned(addr, size)) {
 431     GET_CALLER_PC_BP_SP;
 432     __asan_report_error(pc, bp, sp, addr, true, size);
 433   }
 434 }
 435
 436 // Force the linker to keep the symbols for various ASan interface functions.
 437 // We want to keep those in the executable in order to let the instrumented
 438 // dynamic libraries access the symbol even if it is not used by the executable
 439 // itself. This should help if the build system is removing dead code at link
 440 // time.
 441 static NOINLINE void force_interface_symbols() {
 442   volatile int fake_condition = 0;  // prevent dead condition elimination.
 443   // __asan_report_* functions are noreturn, so we need a switch to prevent
 444   // the compiler from removing any of them.
 445   switch (fake_condition) {
 446     case 1: __asan_report_load1(0); break;
 447     case 2: __asan_report_load2(0); break;
 448     case 3: __asan_report_load4(0); break;
 449     case 4: __asan_report_load8(0); break;
 450     case 5: __asan_report_load16(0); break;
 451     case 6: __asan_report_store1(0); break;
 452     case 7: __asan_report_store2(0); break;
 453     case 8: __asan_report_store4(0); break;
 454     case 9: __asan_report_store8(0); break;
 455     case 10: __asan_report_store16(0); break;
 456     case 12: __asan_register_globals(0, 0); break;
 457     case 13: __asan_unregister_globals(0, 0); break;
 458     case 14: __asan_set_death_callback(0); break;
 459     case 15: __asan_set_error_report_callback(0); break;
 460     case 16: __asan_handle_no_return(); break;
 461     case 17: __asan_address_is_poisoned(0); break;
 462     case 18: __asan_get_allocated_size(0); break;
 463     case 19: __asan_get_current_allocated_bytes(); break;
 464     case 20: __asan_get_estimated_allocated_size(0); break;
 465     case 21: __asan_get_free_bytes(); break;
 466     case 22: __asan_get_heap_size(); break;
 467     case 23: __asan_get_ownership(0); break;
 468     case 24: __asan_get_unmapped_bytes(); break;
 469     case 25: __asan_poison_memory_region(0, 0); break;
 470     case 26: __asan_unpoison_memory_region(0, 0); break;
 471     case 27: __asan_set_error_exit_code(0); break;
 472     case 30: __asan_before_dynamic_init(0); break;
 473     case 31: __asan_after_dynamic_init(); break;
 474     case 32: __asan_poison_stack_memory(0, 0); break;
 475     case 33: __asan_unpoison_stack_memory(0, 0); break;
 476     case 34: __asan_region_is_poisoned(0, 0); break;
 477     case 35: __asan_describe_address(0); break;
 478   }
 479 }
 480
 481 static void asan_atexit() {
 482   Printf("AddressSanitizer exit stats:\n");
 483   __asan_print_accumulated_stats();
 484   // Print AsanMappingProfile.
 485   for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
 486     if (AsanMappingProfile[i] == 0) continue;
 487     Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
 488   }
 489 }
 490
 491 static void InitializeHighMemEnd() {
 492 #if !ASAN_FIXED_MAPPING
 493   kHighMemEnd = GetMaxVirtualAddress();
 494   // Increase kHighMemEnd to make sure it's properly
 495   // aligned together with kHighMemBeg:
 496   kHighMemEnd |= SHADOW_GRANULARITY * GetPageSizeCached() - 1;
 497 #endif  // !ASAN_FIXED_MAPPING
 498   CHECK_EQ((kHighMemBeg % GetPageSizeCached()), 0);
 499 }
 500
 501 static void ProtectGap(uptr a, uptr size) {
 502   CHECK_EQ(a, (uptr)Mprotect(a, size));
 503 }
 504
 505 static void PrintAddressSpaceLayout() {
 506   Printf("|| `[%p, %p]` || HighMem    ||\n",
 507          (void*)kHighMemBeg, (void*)kHighMemEnd);
 508   Printf("|| `[%p, %p]` || HighShadow ||\n",
 509          (void*)kHighShadowBeg, (void*)kHighShadowEnd);
 510   if (kMidMemBeg) {
 511     Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
 512            (void*)kShadowGap3Beg, (void*)kShadowGap3End);
 513     Printf("|| `[%p, %p]` || MidMem     ||\n",
 514            (void*)kMidMemBeg, (void*)kMidMemEnd);
 515     Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
 516            (void*)kShadowGap2Beg, (void*)kShadowGap2End);
 517     Printf("|| `[%p, %p]` || MidShadow  ||\n",
 518            (void*)kMidShadowBeg, (void*)kMidShadowEnd);
 519   }
 520   Printf("|| `[%p, %p]` || ShadowGap  ||\n",
 521          (void*)kShadowGapBeg, (void*)kShadowGapEnd);
 522   if (kLowShadowBeg) {
 523     Printf("|| `[%p, %p]` || LowShadow  ||\n",
 524            (void*)kLowShadowBeg, (void*)kLowShadowEnd);
 525     Printf("|| `[%p, %p]` || LowMem     ||\n",
 526            (void*)kLowMemBeg, (void*)kLowMemEnd);
 527   }
 528   Printf("MemToShadow(shadow): %p %p %p %p",
 529          (void*)MEM_TO_SHADOW(kLowShadowBeg),
 530          (void*)MEM_TO_SHADOW(kLowShadowEnd),
 531          (void*)MEM_TO_SHADOW(kHighShadowBeg),
 532          (void*)MEM_TO_SHADOW(kHighShadowEnd));
 533   if (kMidMemBeg) {
 534     Printf(" %p %p",
 535            (void*)MEM_TO_SHADOW(kMidShadowBeg),
 536            (void*)MEM_TO_SHADOW(kMidShadowEnd));
 537   }
 538   Printf("\n");
 539   Printf("redzone=%zu\n", (uptr)flags()->redzone);
 540   Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
 541   Printf("quarantine_size=%zuM\n", (uptr)flags()->quarantine_size >> 20);
 542   Printf("malloc_context_size=%zu\n",
 543          (uptr)common_flags()->malloc_context_size);
 544
 545   Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
 546   Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
 547   Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
 548   CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
 549   if (kMidMemBeg)
 550     CHECK(kMidShadowBeg > kLowShadowEnd &&
 551           kMidMemBeg > kMidShadowEnd &&
 552           kHighShadowBeg > kMidMemEnd);
 553 }
 554
 555 static void AsanInitInternal() {
 556   if (LIKELY(asan_inited)) return;
 557   SanitizerToolName = "AddressSanitizer";
 558   CHECK(!asan_init_is_running && "ASan init calls itself!");
 559   asan_init_is_running = true;
 560
 561   // Initialize flags. This must be done early, because most of the
 562   // initialization steps look at flags().
 563   const char *options = GetEnv("ASAN_OPTIONS");
 564   InitializeFlags(flags(), options);
 565
 566   InitializeHighMemEnd();
 567
 568   // Make sure we are not statically linked.
 569   AsanDoesNotSupportStaticLinkage();
 570
 571   // Install tool-specific callbacks in sanitizer_common.
 572   SetDieCallback(AsanDie);
 573   SetCheckFailedCallback(AsanCheckFailed);
 574   SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
 575
 576   if (!flags()->start_deactivated)
 577     ParseExtraActivationFlags();
 578
 579   __sanitizer_set_report_path(common_flags()->log_path);
 580   __asan_option_detect_stack_use_after_return =
 581       flags()->detect_stack_use_after_return;
 582   CHECK_LE(flags()->min_uar_stack_size_log, flags()->max_uar_stack_size_log);
 583
 584   if (options) {
 585     VReport(1, "Parsed ASAN_OPTIONS: %s\n", options);
 586   }
 587
 588   if (flags()->start_deactivated)
 589     AsanStartDeactivated();
 590
 591   // Re-exec ourselves if we need to set additional env or command line args.
 592   MaybeReexec();
 593
 594   // Setup internal allocator callback.
 595   SetLowLevelAllocateCallback(OnLowLevelAllocate);
 596
 597   InitializeAsanInterceptors();
 598
 599   ReplaceSystemMalloc();
 600
 601   uptr shadow_start = kLowShadowBeg;
 602   if (kLowShadowBeg)
 603     shadow_start -= GetMmapGranularity();
 604   bool full_shadow_is_available =
 605       MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
 606
 607 #if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) &&                \
 608     !ASAN_FIXED_MAPPING
 609   if (!full_shadow_is_available) {
 610     kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
 611     kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
 612   }
 613 #endif
 614
 615   if (common_flags()->verbosity)
 616     PrintAddressSpaceLayout();
 617
 618   if (flags()->disable_core) {
 619     DisableCoreDumper();
 620   }
 621
 622   if (full_shadow_is_available) {
 623     // mmap the low shadow plus at least one page at the left.
 624     if (kLowShadowBeg)
 625       ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
 626     // mmap the high shadow.
 627     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
 628     // protect the gap.
 629     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
 630     CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
 631   } else if (kMidMemBeg &&
 632       MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
 633       MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
 634     CHECK(kLowShadowBeg != kLowShadowEnd);
 635     // mmap the low shadow plus at least one page at the left.
 636     ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
 637     // mmap the mid shadow.
 638     ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd);
 639     // mmap the high shadow.
 640     ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
 641     // protect the gaps.
 642     ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
 643     ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
 644     ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
 645   } else {
 646     Report("Shadow memory range interleaves with an existing memory mapping. "
 647            "ASan cannot proceed correctly. ABORTING.\n");
 648     DumpProcessMap();
 649     Die();
 650   }
 651
 652   AsanTSDInit(PlatformTSDDtor);
 653   InstallDeadlySignalHandlers(AsanOnSIGSEGV);
 654
 655   // Allocator should be initialized before starting external symbolizer, as
 656   // fork() on Mac locks the allocator.
 657   InitializeAllocator();
 658
 659   Symbolizer::Init(common_flags()->external_symbolizer_path);
 660
 661   // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
 662   // should be set to 1 prior to initializing the threads.
 663   asan_inited = 1;
 664   asan_init_is_running = false;
 665
 666   if (flags()->atexit)
 667     Atexit(asan_atexit);
 668
 669   if (common_flags()->coverage) {
 670     __sanitizer_cov_init();
 671     Atexit(__sanitizer_cov_dump);
 672   }
 673
 674   // interceptors
 675   InitTlsSize();
 676
 677   // Create main thread.
 678   AsanThread *main_thread = AsanThread::Create(0, 0);
 679   CreateThreadContextArgs create_main_args = { main_thread, 0 };
 680   u32 main_tid = asanThreadRegistry().CreateThread(
 681       0, true, 0, &create_main_args);
 682   CHECK_EQ(0, main_tid);
 683   SetCurrentThread(main_thread);
 684   main_thread->ThreadStart(internal_getpid());
 685   force_interface_symbols();  // no-op.
 686   SanitizerInitializeUnwinder();
 687
 688 #if CAN_SANITIZE_LEAKS
 689   __lsan::InitCommonLsan();
 690   if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
 691     Atexit(__lsan::DoLeakCheck);
 692   }
 693 #endif  // CAN_SANITIZE_LEAKS
 694
 695   VReport(1, "AddressSanitizer Init done\n");
 696 }
 697
 698 // Initialize as requested from some part of ASan runtime library (interceptors,
 699 // allocator, etc).
 700 void AsanInitFromRtl() {
 701   AsanInitInternal();
 702 }
 703
 704 #if ASAN_DYNAMIC
 705 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
 706 // (and thus normal initializer from .preinit_array haven't run).
 707
 708 class AsanInitializer {
 709 public:  // NOLINT
 710   AsanInitializer() {
 711     AsanCheckIncompatibleRT();
 712     AsanCheckDynamicRTPrereqs();
 713     if (UNLIKELY(!asan_inited))
 714       __asan_init();
 715   }
 716 };
 717
 718 static AsanInitializer asan_initializer;
 719 #endif  // ASAN_DYNAMIC
 720
 721 }  // namespace __asan
 722
 723 // ---------------------- Interface ---------------- {{{1
 724 using namespace __asan;  // NOLINT
 725
 726 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 727 extern "C" {
 728 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 729 const char* __asan_default_options() { return ""; }
 730 }  // extern "C"
 731 #endif
 732
 733 int NOINLINE __asan_set_error_exit_code(int exit_code) {
 734   int old = flags()->exitcode;
 735   flags()->exitcode = exit_code;
 736   return old;
 737 }
 738
 739 void NOINLINE __asan_handle_no_return() {
 740   int local_stack;
 741   AsanThread *curr_thread = GetCurrentThread();
 742   CHECK(curr_thread);
 743   uptr PageSize = GetPageSizeCached();
 744   uptr top = curr_thread->stack_top();
 745   uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1);
 746   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
 747   if (top - bottom > kMaxExpectedCleanupSize) {
 748     static bool reported_warning = false;
 749     if (reported_warning)
 750       return;
 751     reported_warning = true;
 752     Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
 753            "stack top: %p; bottom %p; size: %p (%zd)\n"
 754            "False positive error reports may follow\n"
 755            "For details see "
 756            "http://code.google.com/p/address-sanitizer/issues/detail?id=189\n",
 757            top, bottom, top - bottom, top - bottom);
 758     return;
 759   }
 760   PoisonShadow(bottom, top - bottom, 0);
 761   if (curr_thread->has_fake_stack())
 762     curr_thread->fake_stack()->HandleNoReturn();
 763 }
 764
 765 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
 766   death_callback = callback;
 767 }
 768
 769 // Initialize as requested from instrumented application code.
 770 // We use this call as a trigger to wake up ASan from deactivated state.
 771 void __asan_init() {
 772   AsanCheckIncompatibleRT();
 773   AsanActivate();
 774   AsanInitInternal();
 775 }