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