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