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
36 uptr __asan_shadow_memory_dynamic_address; // Global interface symbol.
37 int __asan_option_detect_stack_use_after_return; // Global interface symbol.
38 uptr *__asan_test_only_reported_buggy_pointer; // Used only for testing asan.
39
40 namespace __asan {
41
42 uptr AsanMappingProfile[kAsanMappingProfileSize];
43
AsanDie()44 static 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
CheckUnwind()68 static void CheckUnwind() {
69 GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_check);
70 stack.Print();
71 }
72
73 // -------------------------- Globals --------------------- {{{1
74 static StaticSpinMutex asan_inited_mutex;
75 static atomic_uint8_t asan_inited = {0};
76
SetAsanInited()77 static void SetAsanInited() {
78 atomic_store(&asan_inited, 1, memory_order_release);
79 }
80
AsanInited()81 bool AsanInited() {
82 return atomic_load(&asan_inited, memory_order_acquire) == 1;
83 }
84
85 bool replace_intrin_cached;
86
87 #if !ASAN_FIXED_MAPPING
88 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
89 #endif
90
91 // -------------------------- Misc ---------------- {{{1
ShowStatsAndAbort()92 void ShowStatsAndAbort() {
93 __asan_print_accumulated_stats();
94 Die();
95 }
96
97 NOINLINE
ReportGenericErrorWrapper(uptr addr,bool is_write,int size,int exp_arg,bool fatal)98 static 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
OnLowLevelAllocate(uptr ptr,uptr size)105 static 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) \
112 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
113 void __asan_report_ ## type ## size(uptr addr) { \
114 GET_CALLER_PC_BP_SP; \
115 ReportGenericError(pc, bp, sp, addr, is_write, size, 0, true); \
116 } \
117 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
118 void __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 } \
122 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
123 void __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
128 ASAN_REPORT_ERROR(load, false, 1)
129 ASAN_REPORT_ERROR(load, false, 2)
130 ASAN_REPORT_ERROR(load, false, 4)
131 ASAN_REPORT_ERROR(load, false, 8)
132 ASAN_REPORT_ERROR(load, false, 16)
133 ASAN_REPORT_ERROR(store, true, 1)
134 ASAN_REPORT_ERROR(store, true, 2)
135 ASAN_REPORT_ERROR(store, true, 4)
136 ASAN_REPORT_ERROR(store, true, 8)
137 ASAN_REPORT_ERROR(store, true, 16)
138
139 #define ASAN_REPORT_ERROR_N(type, is_write) \
140 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
141 void __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 } \
145 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
146 void __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 } \
150 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
151 void __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
ASAN_REPORT_ERROR_N(load,false)156 ASAN_REPORT_ERROR_N(load, false)
157 ASAN_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
185 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
186 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
187 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
188 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
189 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
190 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
191 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
192 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
193 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
194 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
195
196 extern "C"
197 NOINLINE INTERFACE_ATTRIBUTE
198 void __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
205 extern "C"
206 NOINLINE INTERFACE_ATTRIBUTE
__asan_exp_loadN(uptr addr,uptr size,u32 exp)207 void __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
214 extern "C"
215 NOINLINE INTERFACE_ATTRIBUTE
__asan_loadN_noabort(uptr addr,uptr size)216 void __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
223 extern "C"
224 NOINLINE INTERFACE_ATTRIBUTE
__asan_storeN(uptr addr,uptr size)225 void __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
232 extern "C"
233 NOINLINE INTERFACE_ATTRIBUTE
__asan_exp_storeN(uptr addr,uptr size,u32 exp)234 void __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
241 extern "C"
242 NOINLINE INTERFACE_ATTRIBUTE
__asan_storeN_noabort(uptr addr,uptr size)243 void __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.
force_interface_symbols()255 static 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
asan_atexit()316 static 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
InitializeHighMemEnd()326 static 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
PrintAddressSpaceLayout()336 void 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
AsanInitInternal()393 static 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).
AsanInitFromRtl()522 void AsanInitFromRtl() {
523 if (LIKELY(AsanInited()))
524 return;
525 SpinMutexLock lock(&asan_inited_mutex);
526 AsanInitInternal();
527 }
528
TryAsanInitFromRtl()529 bool 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
543 class AsanInitializer {
544 public:
AsanInitializer()545 AsanInitializer() {
546 AsanInitFromRtl();
547 }
548 };
549
550 static AsanInitializer asan_initializer;
551 #endif // ASAN_DYNAMIC
552
UnpoisonStack(uptr bottom,uptr top,const char * type)553 void 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
UnpoisonDefaultStack()573 static 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
UnpoisonFakeStack()593 static 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
606 using namespace __asan;
607
__asan_handle_no_return()608 void NOINLINE __asan_handle_no_return() {
609 if (UNLIKELY(!AsanInited()))
610 return;
611
612 if (!PlatformUnpoisonStacks())
613 UnpoisonDefaultStack();
614
615 UnpoisonFakeStack();
616 }
617
__asan_extra_spill_area()618 extern "C" void *__asan_extra_spill_area() {
619 AsanThread *t = GetCurrentThread();
620 CHECK(t);
621 return t->extra_spill_area();
622 }
623
__asan_handle_vfork(void * sp)624 void __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
__asan_set_death_callback(void (* callback)(void))631 void 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.
__asan_init()637 void __asan_init() {
638 AsanActivate();
639 AsanInitFromRtl();
640 }
641
__asan_version_mismatch_check()642 void __asan_version_mismatch_check() {
643 // Do nothing.
644 }
645