1//===-- asan_rtl.cpp ------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is a part of AddressSanitizer, an address sanity checker.
10//
11// Main file of the ASan run-time library.
12//===----------------------------------------------------------------------===//
13
14#include "asan_activation.h"
15#include "asan_allocator.h"
16#include "asan_fake_stack.h"
17#include "asan_interceptors.h"
18#include "asan_interface_internal.h"
19#include "asan_internal.h"
20#include "asan_mapping.h"
21#include "asan_poisoning.h"
22#include "asan_report.h"
23#include "asan_stack.h"
24#include "asan_stats.h"
25#include "asan_suppressions.h"
26#include "asan_thread.h"
27#include "lsan/lsan_common.h"
28#include "sanitizer_common/sanitizer_atomic.h"
29#include "sanitizer_common/sanitizer_flags.h"
30#include "sanitizer_common/sanitizer_interface_internal.h"
31#include "sanitizer_common/sanitizer_libc.h"
32#include "sanitizer_common/sanitizer_symbolizer.h"
33#include "ubsan/ubsan_init.h"
34#include "ubsan/ubsan_platform.h"
35
36uptr __asan_shadow_memory_dynamic_address;  // Global interface symbol.
37int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
38uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
39
40namespace __asan {
41
42uptr AsanMappingProfile[kAsanMappingProfileSize];
43
44static void AsanDie() {
45  static atomic_uint32_t num_calls;
46  if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
47    // Don't die twice - run a busy loop.
48    while (1) {
49      internal_sched_yield();
50    }
51  }
52  if (common_flags()->print_module_map >= 1)
53    DumpProcessMap();
54
55  WaitForDebugger(flags()->sleep_before_dying, "before dying");
56
57  if (flags()->unmap_shadow_on_exit) {
58    if (kMidMemBeg) {
59      UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
60      UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
61    } else {
62      if (kHighShadowEnd)
63        UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
64    }
65  }
66}
67
68static void CheckUnwind() {
69  GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check);
70  stack.Print();
71}
72
73// -------------------------- Globals --------------------- {{{1
74static StaticSpinMutex asan_inited_mutex;
75static atomic_uint8_t asan_inited = {0};
76
77static void SetAsanInited() {
78  atomic_store(&asan_inited, 1, memory_order_release);
79}
80
81bool AsanInited() {
82  return atomic_load(&asan_inited, memory_order_acquire) == 1;
83}
84
85bool replace_intrin_cached;
86
87#if !ASAN_FIXED_MAPPING
88uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
89#endif
90
91// -------------------------- Misc ---------------- {{{1
92void ShowStatsAndAbort() {
93  __asan_print_accumulated_stats();
94  Die();
95}
96
97NOINLINE
98static void ReportGenericErrorWrapper(uptr addr, bool is_write, int size,
99                                      int exp_arg, bool fatal) {
100  GET_CALLER_PC_BP_SP;
101  ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg, fatal);
102}
103
104// --------------- LowLevelAllocateCallbac ---------- {{{1
105static void OnLowLevelAllocate(uptr ptr, uptr size) {
106  PoisonShadow(ptr, size, kAsanInternalHeapMagic);
107}
108
109// -------------------------- Run-time entry ------------------- {{{1
110// exported functions
111#define ASAN_REPORT_ERROR(type, is_write, size)                     \
112extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
113void __asan_report_ ## type ## size(uptr addr) {                    \
114  GET_CALLER_PC_BP_SP;                                              \
115  ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);    \
116}                                                                   \
117extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
118void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) {       \
119  GET_CALLER_PC_BP_SP;                                              \
120  ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);  \
121}                                                                   \
122extern "C" NOINLINE INTERFACE_ATTRIBUTE                             \
123void __asan_report_ ## type ## size ## _noabort(uptr addr) {        \
124  GET_CALLER_PC_BP_SP;                                              \
125  ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);   \
126}                                                                   \
127
128ASAN_REPORT_ERROR(load, false, 1)
129ASAN_REPORT_ERROR(load, false, 2)
130ASAN_REPORT_ERROR(load, false, 4)
131ASAN_REPORT_ERROR(load, false, 8)
132ASAN_REPORT_ERROR(load, false, 16)
133ASAN_REPORT_ERROR(store, true, 1)
134ASAN_REPORT_ERROR(store, true, 2)
135ASAN_REPORT_ERROR(store, true, 4)
136ASAN_REPORT_ERROR(store, true, 8)
137ASAN_REPORT_ERROR(store, true, 16)
138
139#define ASAN_REPORT_ERROR_N(type, is_write)                                 \
140extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
141void __asan_report_ ## type ## _n(uptr addr, uptr size) {                   \
142  GET_CALLER_PC_BP_SP;                                                      \
143  ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true);            \
144}                                                                           \
145extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
146void __asan_report_exp_ ## type ## _n(uptr addr, uptr size, u32 exp) {      \
147  GET_CALLER_PC_BP_SP;                                                      \
148  ReportGenericError(pc, bp, sp, addr, is_write, size, exp, true);          \
149}                                                                           \
150extern "C" NOINLINE INTERFACE_ATTRIBUTE                                     \
151void __asan_report_ ## type ## _n_noabort(uptr addr, uptr size) {           \
152  GET_CALLER_PC_BP_SP;                                                      \
153  ReportGenericError(pc, bp, sp, addr, is_write, size, 0, false);           \
154}                                                                           \
155
156ASAN_REPORT_ERROR_N(load, false)
157ASAN_REPORT_ERROR_N(store, true)
158
159#define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg, fatal) \
160  uptr sp = MEM_TO_SHADOW(addr);                                               \
161  uptr s = size <= ASAN_SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)       \
162                                           : *reinterpret_cast<u16 *>(sp);     \
163  if (UNLIKELY(s)) {                                                           \
164    if (UNLIKELY(size >= ASAN_SHADOW_GRANULARITY ||                            \
165                 ((s8)((addr & (ASAN_SHADOW_GRANULARITY - 1)) + size - 1)) >=  \
166                     (s8)s)) {                                                 \
167      ReportGenericErrorWrapper(addr, is_write, size, exp_arg, fatal);         \
168    }                                                                          \
169  }
170
171#define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
172  extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
173  void __asan_##type##size(uptr addr) {                                        \
174    ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true)            \
175  }                                                                            \
176  extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
177  void __asan_exp_##type##size(uptr addr, u32 exp) {                           \
178    ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true)          \
179  }                                                                            \
180  extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
181  void __asan_##type##size ## _noabort(uptr addr) {                            \
182    ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false)           \
183  }                                                                            \
184
185ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
186ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
187ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
188ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
189ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
190ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
191ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
192ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
193ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
194ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
195
196extern "C"
197NOINLINE INTERFACE_ATTRIBUTE
198void __asan_loadN(uptr addr, uptr size) {
199  if ((addr = __asan_region_is_poisoned(addr, size))) {
200    GET_CALLER_PC_BP_SP;
201    ReportGenericError(pc, bp, sp, addr, false, size, 0, true);
202  }
203}
204
205extern "C"
206NOINLINE INTERFACE_ATTRIBUTE
207void __asan_exp_loadN(uptr addr, uptr size, u32 exp) {
208  if ((addr = __asan_region_is_poisoned(addr, size))) {
209    GET_CALLER_PC_BP_SP;
210    ReportGenericError(pc, bp, sp, addr, false, size, exp, true);
211  }
212}
213
214extern "C"
215NOINLINE INTERFACE_ATTRIBUTE
216void __asan_loadN_noabort(uptr addr, uptr size) {
217  if ((addr = __asan_region_is_poisoned(addr, size))) {
218    GET_CALLER_PC_BP_SP;
219    ReportGenericError(pc, bp, sp, addr, false, size, 0, false);
220  }
221}
222
223extern "C"
224NOINLINE INTERFACE_ATTRIBUTE
225void __asan_storeN(uptr addr, uptr size) {
226  if ((addr = __asan_region_is_poisoned(addr, size))) {
227    GET_CALLER_PC_BP_SP;
228    ReportGenericError(pc, bp, sp, addr, true, size, 0, true);
229  }
230}
231
232extern "C"
233NOINLINE INTERFACE_ATTRIBUTE
234void __asan_exp_storeN(uptr addr, uptr size, u32 exp) {
235  if ((addr = __asan_region_is_poisoned(addr, size))) {
236    GET_CALLER_PC_BP_SP;
237    ReportGenericError(pc, bp, sp, addr, true, size, exp, true);
238  }
239}
240
241extern "C"
242NOINLINE INTERFACE_ATTRIBUTE
243void __asan_storeN_noabort(uptr addr, uptr size) {
244  if ((addr = __asan_region_is_poisoned(addr, size))) {
245    GET_CALLER_PC_BP_SP;
246    ReportGenericError(pc, bp, sp, addr, true, size, 0, false);
247  }
248}
249
250// Force the linker to keep the symbols for various ASan interface functions.
251// We want to keep those in the executable in order to let the instrumented
252// dynamic libraries access the symbol even if it is not used by the executable
253// itself. This should help if the build system is removing dead code at link
254// time.
255static NOINLINE void force_interface_symbols() {
256  volatile int fake_condition = 0;  // prevent dead condition elimination.
257  // __asan_report_* functions are noreturn, so we need a switch to prevent
258  // the compiler from removing any of them.
259  // clang-format off
260  switch (fake_condition) {
261    case 1: __asan_report_load1(0); break;
262    case 2: __asan_report_load2(0); break;
263    case 3: __asan_report_load4(0); break;
264    case 4: __asan_report_load8(0); break;
265    case 5: __asan_report_load16(0); break;
266    case 6: __asan_report_load_n(0, 0); break;
267    case 7: __asan_report_store1(0); break;
268    case 8: __asan_report_store2(0); break;
269    case 9: __asan_report_store4(0); break;
270    case 10: __asan_report_store8(0); break;
271    case 11: __asan_report_store16(0); break;
272    case 12: __asan_report_store_n(0, 0); break;
273    case 13: __asan_report_exp_load1(0, 0); break;
274    case 14: __asan_report_exp_load2(0, 0); break;
275    case 15: __asan_report_exp_load4(0, 0); break;
276    case 16: __asan_report_exp_load8(0, 0); break;
277    case 17: __asan_report_exp_load16(0, 0); break;
278    case 18: __asan_report_exp_load_n(0, 0, 0); break;
279    case 19: __asan_report_exp_store1(0, 0); break;
280    case 20: __asan_report_exp_store2(0, 0); break;
281    case 21: __asan_report_exp_store4(0, 0); break;
282    case 22: __asan_report_exp_store8(0, 0); break;
283    case 23: __asan_report_exp_store16(0, 0); break;
284    case 24: __asan_report_exp_store_n(0, 0, 0); break;
285    case 25: __asan_register_globals(nullptr, 0); break;
286    case 26: __asan_unregister_globals(nullptr, 0); break;
287    case 27: __asan_set_death_callback(nullptr); break;
288    case 28: __asan_set_error_report_callback(nullptr); break;
289    case 29: __asan_handle_no_return(); break;
290    case 30: __asan_address_is_poisoned(nullptr); break;
291    case 31: __asan_poison_memory_region(nullptr, 0); break;
292    case 32: __asan_unpoison_memory_region(nullptr, 0); break;
293    case 34: __asan_before_dynamic_init(nullptr); break;
294    case 35: __asan_after_dynamic_init(); break;
295    case 36: __asan_poison_stack_memory(0, 0); break;
296    case 37: __asan_unpoison_stack_memory(0, 0); break;
297    case 38: __asan_region_is_poisoned(0, 0); break;
298    case 39: __asan_describe_address(0); break;
299    case 40: __asan_set_shadow_00(0, 0); break;
300    case 41: __asan_set_shadow_01(0, 0); break;
301    case 42: __asan_set_shadow_02(0, 0); break;
302    case 43: __asan_set_shadow_03(0, 0); break;
303    case 44: __asan_set_shadow_04(0, 0); break;
304    case 45: __asan_set_shadow_05(0, 0); break;
305    case 46: __asan_set_shadow_06(0, 0); break;
306    case 47: __asan_set_shadow_07(0, 0); break;
307    case 48: __asan_set_shadow_f1(0, 0); break;
308    case 49: __asan_set_shadow_f2(0, 0); break;
309    case 50: __asan_set_shadow_f3(0, 0); break;
310    case 51: __asan_set_shadow_f5(0, 0); break;
311    case 52: __asan_set_shadow_f8(0, 0); break;
312  }
313  // clang-format on
314}
315
316static void asan_atexit() {
317  Printf("AddressSanitizer exit stats:\n");
318  __asan_print_accumulated_stats();
319  // Print AsanMappingProfile.
320  for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
321    if (AsanMappingProfile[i] == 0) continue;
322    Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
323  }
324}
325
326static void InitializeHighMemEnd() {
327#if !ASAN_FIXED_MAPPING
328  kHighMemEnd = GetMaxUserVirtualAddress();
329  // Increase kHighMemEnd to make sure it's properly
330  // aligned together with kHighMemBeg:
331  kHighMemEnd |= (GetMmapGranularity() << ASAN_SHADOW_SCALE) - 1;
332#endif  // !ASAN_FIXED_MAPPING
333  CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
334}
335
336void PrintAddressSpaceLayout() {
337  if (kHighMemBeg) {
338    Printf("|| `[%p, %p]` || HighMem    ||\n",
339           (void*)kHighMemBeg, (void*)kHighMemEnd);
340    Printf("|| `[%p, %p]` || HighShadow ||\n",
341           (void*)kHighShadowBeg, (void*)kHighShadowEnd);
342  }
343  if (kMidMemBeg) {
344    Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
345           (void*)kShadowGap3Beg, (void*)kShadowGap3End);
346    Printf("|| `[%p, %p]` || MidMem     ||\n",
347           (void*)kMidMemBeg, (void*)kMidMemEnd);
348    Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
349           (void*)kShadowGap2Beg, (void*)kShadowGap2End);
350    Printf("|| `[%p, %p]` || MidShadow  ||\n",
351           (void*)kMidShadowBeg, (void*)kMidShadowEnd);
352  }
353  Printf("|| `[%p, %p]` || ShadowGap  ||\n",
354         (void*)kShadowGapBeg, (void*)kShadowGapEnd);
355  if (kLowShadowBeg) {
356    Printf("|| `[%p, %p]` || LowShadow  ||\n",
357           (void*)kLowShadowBeg, (void*)kLowShadowEnd);
358    Printf("|| `[%p, %p]` || LowMem     ||\n",
359           (void*)kLowMemBeg, (void*)kLowMemEnd);
360  }
361  Printf("MemToShadow(shadow): %p %p",
362         (void*)MEM_TO_SHADOW(kLowShadowBeg),
363         (void*)MEM_TO_SHADOW(kLowShadowEnd));
364  if (kHighMemBeg) {
365    Printf(" %p %p",
366           (void*)MEM_TO_SHADOW(kHighShadowBeg),
367           (void*)MEM_TO_SHADOW(kHighShadowEnd));
368  }
369  if (kMidMemBeg) {
370    Printf(" %p %p",
371           (void*)MEM_TO_SHADOW(kMidShadowBeg),
372           (void*)MEM_TO_SHADOW(kMidShadowEnd));
373  }
374  Printf("\n");
375  Printf("redzone=%zu\n", (uptr)flags()->redzone);
376  Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
377  Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
378  Printf("thread_local_quarantine_size_kb=%zuK\n",
379         (uptr)flags()->thread_local_quarantine_size_kb);
380  Printf("malloc_context_size=%zu\n",
381         (uptr)common_flags()->malloc_context_size);
382
383  Printf("SHADOW_SCALE: %d\n", (int)ASAN_SHADOW_SCALE);
384  Printf("SHADOW_GRANULARITY: %d\n", (int)ASAN_SHADOW_GRANULARITY);
385  Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)ASAN_SHADOW_OFFSET);
386  CHECK(ASAN_SHADOW_SCALE >= 3 && ASAN_SHADOW_SCALE <= 7);
387  if (kMidMemBeg)
388    CHECK(kMidShadowBeg > kLowShadowEnd &&
389          kMidMemBeg > kMidShadowEnd &&
390          kHighShadowBeg > kMidMemEnd);
391}
392
393static bool AsanInitInternal() {
394  if (LIKELY(AsanInited()))
395    return true;
396  SanitizerToolName = "AddressSanitizer";
397
398  CacheBinaryName();
399
400  // Initialize flags. This must be done early, because most of the
401  // initialization steps look at flags().
402  InitializeFlags();
403
404  WaitForDebugger(flags()->sleep_before_init, "before init");
405
406  // Stop performing init at this point if we are being loaded via
407  // dlopen() and the platform supports it.
408  if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) {
409    VReport(1, "AddressSanitizer init is being performed for dlopen().\n");
410    return false;
411  }
412
413  AsanCheckIncompatibleRT();
414  AsanCheckDynamicRTPrereqs();
415  AvoidCVE_2016_2143();
416
417  SetCanPoisonMemory(flags()->poison_heap);
418  SetMallocContextSize(common_flags()->malloc_context_size);
419
420  InitializePlatformExceptionHandlers();
421
422  InitializeHighMemEnd();
423
424  // Make sure we are not statically linked.
425  AsanDoesNotSupportStaticLinkage();
426
427  // Install tool-specific callbacks in sanitizer_common.
428  AddDieCallback(AsanDie);
429  SetCheckUnwindCallback(CheckUnwind);
430  SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
431
432  __sanitizer_set_report_path(common_flags()->log_path);
433
434  __asan_option_detect_stack_use_after_return =
435      flags()->detect_stack_use_after_return;
436
437  __sanitizer::InitializePlatformEarly();
438
439  // Setup internal allocator callback.
440  SetLowLevelAllocateMinAlignment(ASAN_SHADOW_GRANULARITY);
441  SetLowLevelAllocateCallback(OnLowLevelAllocate);
442
443  InitializeAsanInterceptors();
444  CheckASLR();
445
446  // Enable system log ("adb logcat") on Android.
447  // Doing this before interceptors are initialized crashes in:
448  // AsanInitInternal -> android_log_write -> __interceptor_strcmp
449  AndroidLogInit();
450
451  ReplaceSystemMalloc();
452
453  DisableCoreDumperIfNecessary();
454
455  InitializeShadowMemory();
456
457  AsanTSDInit(PlatformTSDDtor);
458  InstallDeadlySignalHandlers(AsanOnDeadlySignal);
459
460  AllocatorOptions allocator_options;
461  allocator_options.SetFrom(flags(), common_flags());
462  InitializeAllocator(allocator_options);
463
464  if (SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL)
465    MaybeStartBackgroudThread();
466
467  // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
468  // should be set to 1 prior to initializing the threads.
469  replace_intrin_cached = flags()->replace_intrin;
470  SetAsanInited();
471
472  if (flags()->atexit)
473    Atexit(asan_atexit);
474
475  InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
476
477  // Now that ASan runtime is (mostly) initialized, deactivate it if
478  // necessary, so that it can be re-activated when requested.
479  if (flags()->start_deactivated)
480    AsanDeactivate();
481
482  // interceptors
483  InitTlsSize();
484
485  // Create main thread.
486  AsanThread *main_thread = CreateMainThread();
487  CHECK_EQ(0, main_thread->tid());
488  force_interface_symbols();  // no-op.
489  SanitizerInitializeUnwinder();
490
491  if (CAN_SANITIZE_LEAKS) {
492    __lsan::InitCommonLsan();
493    InstallAtExitCheckLeaks();
494  }
495
496  InstallAtForkHandler();
497
498#if CAN_SANITIZE_UB
499  __ubsan::InitAsPlugin();
500#endif
501
502  InitializeSuppressions();
503
504  if (CAN_SANITIZE_LEAKS) {
505    // LateInitialize() calls dlsym, which can allocate an error string buffer
506    // in the TLS.  Let's ignore the allocation to avoid reporting a leak.
507    __lsan::ScopedInterceptorDisabler disabler;
508    Symbolizer::LateInitialize();
509  } else {
510    Symbolizer::LateInitialize();
511  }
512
513  VReport(1, "AddressSanitizer Init done\n");
514
515  WaitForDebugger(flags()->sleep_after_init, "after init");
516
517  return true;
518}
519
520// Initialize as requested from some part of ASan runtime library (interceptors,
521// allocator, etc).
522void AsanInitFromRtl() {
523  if (LIKELY(AsanInited()))
524    return;
525  SpinMutexLock lock(&asan_inited_mutex);
526  AsanInitInternal();
527}
528
529bool TryAsanInitFromRtl() {
530  if (LIKELY(AsanInited()))
531    return true;
532  if (!asan_inited_mutex.TryLock())
533    return false;
534  bool result = AsanInitInternal();
535  asan_inited_mutex.Unlock();
536  return result;
537}
538
539#if ASAN_DYNAMIC
540// Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
541// (and thus normal initializers from .preinit_array or modules haven't run).
542
543class AsanInitializer {
544 public:
545  AsanInitializer() {
546    AsanInitFromRtl();
547  }
548};
549
550static AsanInitializer asan_initializer;
551#endif  // ASAN_DYNAMIC
552
553void UnpoisonStack(uptr bottom, uptr top, const char *type) {
554  static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
555  if (top - bottom > kMaxExpectedCleanupSize) {
556    static bool reported_warning = false;
557    if (reported_warning)
558      return;
559    reported_warning = true;
560    Report(
561        "WARNING: ASan is ignoring requested __asan_handle_no_return: "
562        "stack type: %s top: %p; bottom %p; size: %p (%zd)\n"
563        "False positive error reports may follow\n"
564        "For details see "
565        "https://github.com/google/sanitizers/issues/189\n",
566        type, (void *)top, (void *)bottom, (void *)(top - bottom),
567        top - bottom);
568    return;
569  }
570  PoisonShadow(bottom, RoundUpTo(top - bottom, ASAN_SHADOW_GRANULARITY), 0);
571}
572
573static void UnpoisonDefaultStack() {
574  uptr bottom, top;
575
576  if (AsanThread *curr_thread = GetCurrentThread()) {
577    int local_stack;
578    const uptr page_size = GetPageSizeCached();
579    top = curr_thread->stack_top();
580    bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1);
581  } else {
582    CHECK(!SANITIZER_FUCHSIA);
583    // If we haven't seen this thread, try asking the OS for stack bounds.
584    uptr tls_addr, tls_size, stack_size;
585    GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr,
586                         &tls_size);
587    top = bottom + stack_size;
588  }
589
590  UnpoisonStack(bottom, top, "default");
591}
592
593static void UnpoisonFakeStack() {
594  AsanThread *curr_thread = GetCurrentThread();
595  if (!curr_thread)
596    return;
597  FakeStack *stack = curr_thread->get_fake_stack();
598  if (!stack)
599    return;
600  stack->HandleNoReturn();
601}
602
603}  // namespace __asan
604
605// ---------------------- Interface ---------------- {{{1
606using namespace __asan;
607
608void NOINLINE __asan_handle_no_return() {
609  if (UNLIKELY(!AsanInited()))
610    return;
611
612  if (!PlatformUnpoisonStacks())
613    UnpoisonDefaultStack();
614
615  UnpoisonFakeStack();
616}
617
618extern "C" void *__asan_extra_spill_area() {
619  AsanThread *t = GetCurrentThread();
620  CHECK(t);
621  return t->extra_spill_area();
622}
623
624void __asan_handle_vfork(void *sp) {
625  AsanThread *t = GetCurrentThread();
626  CHECK(t);
627  uptr bottom = t->stack_bottom();
628  PoisonShadow(bottom, (uptr)sp - bottom, 0);
629}
630
631void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
632  SetUserDieCallback(callback);
633}
634
635// Initialize as requested from instrumented application code.
636// We use this call as a trigger to wake up ASan from deactivated state.
637void __asan_init() {
638  AsanActivate();
639  AsanInitFromRtl();
640}
641
642void __asan_version_mismatch_check() {
643  // Do nothing.
644}
645