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(a: &num_calls, v: 1, mo: 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(seconds: flags()->sleep_before_dying, label: "before dying");
56
57 if (flags()->unmap_shadow_on_exit) {
58 if (kMidMemBeg) {
59 UnmapOrDie(addr: (void*)kLowShadowBeg, size: kMidMemBeg - kLowShadowBeg);
60 UnmapOrDie(addr: (void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
61 } else {
62 if (kHighShadowEnd)
63 UnmapOrDie(addr: (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 = {.val_dont_use: 0};
76
77static void SetAsanInited() {
78 atomic_store(a: &asan_inited, v: 1, mo: memory_order_release);
79}
80
81bool AsanInited() {
82 return atomic_load(a: &asan_inited, mo: 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, access_size: size, exp: exp_arg, fatal);
102}
103
104// --------------- LowLevelAllocateCallbac ---------- {{{1
105static void OnLowLevelAllocate(uptr ptr, uptr size) {
106 PoisonShadow(addr: ptr, size, value: 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(beg: addr, size))) {
200 GET_CALLER_PC_BP_SP;
201 ReportGenericError(pc, bp, sp, addr, is_write: false, access_size: size, exp: 0, fatal: 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(beg: addr, size))) {
209 GET_CALLER_PC_BP_SP;
210 ReportGenericError(pc, bp, sp, addr, is_write: false, access_size: size, exp, fatal: true);
211 }
212}
213
214extern "C"
215NOINLINE INTERFACE_ATTRIBUTE
216void __asan_loadN_noabort(uptr addr, uptr size) {
217 if ((addr = __asan_region_is_poisoned(beg: addr, size))) {
218 GET_CALLER_PC_BP_SP;
219 ReportGenericError(pc, bp, sp, addr, is_write: false, access_size: size, exp: 0, fatal: false);
220 }
221}
222
223extern "C"
224NOINLINE INTERFACE_ATTRIBUTE
225void __asan_storeN(uptr addr, uptr size) {
226 if ((addr = __asan_region_is_poisoned(beg: addr, size))) {
227 GET_CALLER_PC_BP_SP;
228 ReportGenericError(pc, bp, sp, addr, is_write: true, access_size: size, exp: 0, fatal: 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(beg: addr, size))) {
236 GET_CALLER_PC_BP_SP;
237 ReportGenericError(pc, bp, sp, addr, is_write: true, access_size: size, exp, fatal: true);
238 }
239}
240
241extern "C"
242NOINLINE INTERFACE_ATTRIBUTE
243void __asan_storeN_noabort(uptr addr, uptr size) {
244 if ((addr = __asan_region_is_poisoned(beg: addr, size))) {
245 GET_CALLER_PC_BP_SP;
246 ReportGenericError(pc, bp, sp, addr, is_write: true, access_size: size, exp: 0, fatal: 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(addr: 0); break;
262 case 2: __asan_report_load2(addr: 0); break;
263 case 3: __asan_report_load4(addr: 0); break;
264 case 4: __asan_report_load8(addr: 0); break;
265 case 5: __asan_report_load16(addr: 0); break;
266 case 6: __asan_report_load_n(addr: 0, size: 0); break;
267 case 7: __asan_report_store1(addr: 0); break;
268 case 8: __asan_report_store2(addr: 0); break;
269 case 9: __asan_report_store4(addr: 0); break;
270 case 10: __asan_report_store8(addr: 0); break;
271 case 11: __asan_report_store16(addr: 0); break;
272 case 12: __asan_report_store_n(addr: 0, size: 0); break;
273 case 13: __asan_report_exp_load1(addr: 0, exp: 0); break;
274 case 14: __asan_report_exp_load2(addr: 0, exp: 0); break;
275 case 15: __asan_report_exp_load4(addr: 0, exp: 0); break;
276 case 16: __asan_report_exp_load8(addr: 0, exp: 0); break;
277 case 17: __asan_report_exp_load16(addr: 0, exp: 0); break;
278 case 18: __asan_report_exp_load_n(addr: 0, size: 0, exp: 0); break;
279 case 19: __asan_report_exp_store1(addr: 0, exp: 0); break;
280 case 20: __asan_report_exp_store2(addr: 0, exp: 0); break;
281 case 21: __asan_report_exp_store4(addr: 0, exp: 0); break;
282 case 22: __asan_report_exp_store8(addr: 0, exp: 0); break;
283 case 23: __asan_report_exp_store16(addr: 0, exp: 0); break;
284 case 24: __asan_report_exp_store_n(addr: 0, size: 0, exp: 0); break;
285 case 25: __asan_register_globals(globals: nullptr, n: 0); break;
286 case 26: __asan_unregister_globals(globals: nullptr, n: 0); break;
287 case 27: __asan_set_death_callback(callback: nullptr); break;
288 case 28: __asan_set_error_report_callback(callback: nullptr); break;
289 case 29: __asan_handle_no_return(); break;
290 case 30: __asan_address_is_poisoned(addr: nullptr); break;
291 case 31: __asan_poison_memory_region(addr: nullptr, size: 0); break;
292 case 32: __asan_unpoison_memory_region(addr: nullptr, size: 0); break;
293 case 34: __asan_before_dynamic_init(module_name: nullptr); break;
294 case 35: __asan_after_dynamic_init(); break;
295 case 36: __asan_poison_stack_memory(addr: 0, size: 0); break;
296 case 37: __asan_unpoison_stack_memory(addr: 0, size: 0); break;
297 case 38: __asan_region_is_poisoned(beg: 0, size: 0); break;
298 case 39: __asan_describe_address(addr: 0); break;
299 case 40: __asan_set_shadow_00(addr: 0, size: 0); break;
300 case 41: __asan_set_shadow_01(addr: 0, size: 0); break;
301 case 42: __asan_set_shadow_02(addr: 0, size: 0); break;
302 case 43: __asan_set_shadow_03(addr: 0, size: 0); break;
303 case 44: __asan_set_shadow_04(addr: 0, size: 0); break;
304 case 45: __asan_set_shadow_05(addr: 0, size: 0); break;
305 case 46: __asan_set_shadow_06(addr: 0, size: 0); break;
306 case 47: __asan_set_shadow_07(addr: 0, size: 0); break;
307 case 48: __asan_set_shadow_f1(addr: 0, size: 0); break;
308 case 49: __asan_set_shadow_f2(addr: 0, size: 0); break;
309 case 50: __asan_set_shadow_f3(addr: 0, size: 0); break;
310 case 51: __asan_set_shadow_f5(addr: 0, size: 0); break;
311 case 52: __asan_set_shadow_f8(addr: 0, size: 0); break;
312 }
313 // clang-format on
314}
315
316static void asan_atexit() {
317 Printf(format: "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(format: "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(format: "|| `[%p, %p]` || HighMem ||\n",
339 (void*)kHighMemBeg, (void*)kHighMemEnd);
340 Printf(format: "|| `[%p, %p]` || HighShadow ||\n",
341 (void*)kHighShadowBeg, (void*)kHighShadowEnd);
342 }
343 if (kMidMemBeg) {
344 Printf(format: "|| `[%p, %p]` || ShadowGap3 ||\n",
345 (void*)kShadowGap3Beg, (void*)kShadowGap3End);
346 Printf(format: "|| `[%p, %p]` || MidMem ||\n",
347 (void*)kMidMemBeg, (void*)kMidMemEnd);
348 Printf(format: "|| `[%p, %p]` || ShadowGap2 ||\n",
349 (void*)kShadowGap2Beg, (void*)kShadowGap2End);
350 Printf(format: "|| `[%p, %p]` || MidShadow ||\n",
351 (void*)kMidShadowBeg, (void*)kMidShadowEnd);
352 }
353 Printf(format: "|| `[%p, %p]` || ShadowGap ||\n",
354 (void*)kShadowGapBeg, (void*)kShadowGapEnd);
355 if (kLowShadowBeg) {
356 Printf(format: "|| `[%p, %p]` || LowShadow ||\n",
357 (void*)kLowShadowBeg, (void*)kLowShadowEnd);
358 Printf(format: "|| `[%p, %p]` || LowMem ||\n",
359 (void*)kLowMemBeg, (void*)kLowMemEnd);
360 }
361 Printf(format: "MemToShadow(shadow): %p %p",
362 (void*)MEM_TO_SHADOW(kLowShadowBeg),
363 (void*)MEM_TO_SHADOW(kLowShadowEnd));
364 if (kHighMemBeg) {
365 Printf(format: " %p %p",
366 (void*)MEM_TO_SHADOW(kHighShadowBeg),
367 (void*)MEM_TO_SHADOW(kHighShadowEnd));
368 }
369 if (kMidMemBeg) {
370 Printf(format: " %p %p",
371 (void*)MEM_TO_SHADOW(kMidShadowBeg),
372 (void*)MEM_TO_SHADOW(kMidShadowEnd));
373 }
374 Printf(format: "\n");
375 Printf(format: "redzone=%zu\n", (uptr)flags()->redzone);
376 Printf(format: "max_redzone=%zu\n", (uptr)flags()->max_redzone);
377 Printf(format: "quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
378 Printf(format: "thread_local_quarantine_size_kb=%zuK\n",
379 (uptr)flags()->thread_local_quarantine_size_kb);
380 Printf(format: "malloc_context_size=%zu\n",
381 (uptr)common_flags()->malloc_context_size);
382
383 Printf(format: "SHADOW_SCALE: %d\n", (int)ASAN_SHADOW_SCALE);
384 Printf(format: "SHADOW_GRANULARITY: %d\n", (int)ASAN_SHADOW_GRANULARITY);
385 Printf(format: "SHADOW_OFFSET: %p\n", (void *)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
393// Apply most options specified either through the ASAN_OPTIONS
394// environment variable, or through the `__asan_default_options` user function.
395//
396// This function may be called multiple times, once per weak reference callback
397// on Windows, so it needs to be idempotent.
398//
399// Context:
400// For maximum compatibility on Windows, it is necessary for ASan options to be
401// configured/registered/applied inside this method (instead of in
402// ASanInitInternal, for example). That's because, on Windows, the user-provided
403// definition for `__asan_default_opts` may not be bound when `ASanInitInternal`
404// is invoked (it is bound later).
405//
406// To work around the late binding on windows, `ApplyOptions` will be called,
407// again, after binding to the user-provided `__asan_default_opts` function.
408// Therefore, any flags not configured here are not guaranteed to be
409// configurable through `__asan_default_opts` on Windows.
410//
411//
412// For more details on this issue, see:
413// https://github.com/llvm/llvm-project/issues/117925
414void ApplyFlags() {
415 SetCanPoisonMemory(flags()->poison_heap);
416 SetMallocContextSize(common_flags()->malloc_context_size);
417
418 __asan_option_detect_stack_use_after_return =
419 flags()->detect_stack_use_after_return;
420
421 AllocatorOptions allocator_options;
422 allocator_options.SetFrom(f: flags(), cf: common_flags());
423 ApplyAllocatorOptions(options: allocator_options);
424}
425
426static bool AsanInitInternal() {
427 if (LIKELY(AsanInited()))
428 return true;
429 SanitizerToolName = "AddressSanitizer";
430
431 CacheBinaryName();
432
433 // Initialize flags. On Windows it also also register weak function callbacks.
434 // This must be done early, because most of the initialization steps look at
435 // flags().
436 InitializeFlags();
437
438 WaitForDebugger(seconds: flags()->sleep_before_init, label: "before init");
439
440 // Stop performing init at this point if we are being loaded via
441 // dlopen() and the platform supports it.
442 if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) {
443 VReport(1, "AddressSanitizer init is being performed for dlopen().\n");
444 return false;
445 }
446
447 // Make sure we are not statically linked.
448 __interception::DoesNotSupportStaticLinking();
449 AsanCheckIncompatibleRT();
450 AsanCheckDynamicRTPrereqs();
451 AvoidCVE_2016_2143();
452
453 InitializePlatformExceptionHandlers();
454
455 InitializeHighMemEnd();
456
457 // Install tool-specific callbacks in sanitizer_common.
458 AddDieCallback(callback: AsanDie);
459 SetCheckUnwindCallback(CheckUnwind);
460 SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
461
462 __sanitizer_set_report_path(path: common_flags()->log_path);
463 __sanitizer::InitializePlatformEarly();
464
465 // Setup internal allocator callback.
466 SetLowLevelAllocateMinAlignment(ASAN_SHADOW_GRANULARITY);
467 SetLowLevelAllocateCallback(OnLowLevelAllocate);
468
469 InitializeAsanInterceptors();
470 CheckASLR();
471
472 // Enable system log ("adb logcat") on Android.
473 // Doing this before interceptors are initialized crashes in:
474 // AsanInitInternal -> android_log_write -> __interceptor_strcmp
475 AndroidLogInit();
476
477 ReplaceSystemMalloc();
478
479 DisableCoreDumperIfNecessary();
480
481#if SANITIZER_POSIX
482 if (StackSizeIsUnlimited()) {
483 VPrintf(1,
484 "WARNING: Unlimited stack size detected. This may affect "
485 "compatibility with the shadow mappings.\n");
486 // MSan and TSan re-exec with a fixed size stack. We don't do that because
487 // it may break the program. InitializeShadowMemory() will, if needed,
488 // re-exec without ASLR, which solves most shadow mapping compatibility
489 // issues.
490 }
491#endif // SANITIZER_POSIX
492
493 InitializeShadowMemory();
494
495 AsanTSDInit(destructor: PlatformTSDDtor);
496 InstallDeadlySignalHandlers(handler: AsanOnDeadlySignal);
497
498 AllocatorOptions allocator_options;
499 allocator_options.SetFrom(f: flags(), cf: common_flags());
500 InitializeAllocator(options: allocator_options);
501
502 // Apply ASan flags.
503 // NOTE: In order for options specified through `__asan_default_options` to be
504 // honored on Windows, it is necessary for those options to be configured
505 // inside the `ApplyOptions` method. See the function-level comment for
506 // `ApplyFlags` for more details.
507 ApplyFlags();
508
509 if (SANITIZER_START_BACKGROUND_THREAD_IN_ASAN_INTERNAL)
510 MaybeStartBackgroudThread();
511
512 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
513 // should be set to 1 prior to initializing the threads.
514 replace_intrin_cached = flags()->replace_intrin;
515 SetAsanInited();
516
517 if (flags()->atexit)
518 Atexit(function: asan_atexit);
519
520 InitializeCoverage(enabled: common_flags()->coverage, coverage_dir: common_flags()->coverage_dir);
521
522 // Now that ASan runtime is (mostly) initialized, deactivate it if
523 // necessary, so that it can be re-activated when requested.
524 if (flags()->start_deactivated)
525 AsanDeactivate();
526
527 // Create main thread.
528 AsanThread *main_thread = CreateMainThread();
529 CHECK_EQ(0, main_thread->tid());
530 force_interface_symbols(); // no-op.
531 SanitizerInitializeUnwinder();
532
533 if (CAN_SANITIZE_LEAKS) {
534 __lsan::InitCommonLsan();
535 InstallAtExitCheckLeaks();
536 }
537
538 InstallAtForkHandler();
539
540#if CAN_SANITIZE_UB
541 __ubsan::InitAsPlugin();
542#endif
543
544 InitializeSuppressions();
545
546 if (CAN_SANITIZE_LEAKS) {
547 // LateInitialize() calls dlsym, which can allocate an error string buffer
548 // in the TLS. Let's ignore the allocation to avoid reporting a leak.
549 __lsan::ScopedInterceptorDisabler disabler;
550 Symbolizer::LateInitialize();
551 } else {
552 Symbolizer::LateInitialize();
553 }
554
555 VReport(1, "AddressSanitizer Init done\n");
556
557 WaitForDebugger(seconds: flags()->sleep_after_init, label: "after init");
558
559 return true;
560}
561
562// Initialize as requested from some part of ASan runtime library (interceptors,
563// allocator, etc).
564void AsanInitFromRtl() {
565 if (LIKELY(AsanInited()))
566 return;
567 SpinMutexLock lock(&asan_inited_mutex);
568 AsanInitInternal();
569}
570
571bool TryAsanInitFromRtl() {
572 if (LIKELY(AsanInited()))
573 return true;
574 if (!asan_inited_mutex.TryLock())
575 return false;
576 bool result = AsanInitInternal();
577 asan_inited_mutex.Unlock();
578 return result;
579}
580
581#if ASAN_DYNAMIC
582// Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
583// (and thus normal initializers from .preinit_array or modules haven't run).
584
585class AsanInitializer {
586 public:
587 AsanInitializer() {
588 AsanInitFromRtl();
589 }
590};
591
592static AsanInitializer asan_initializer;
593#endif // ASAN_DYNAMIC
594
595void UnpoisonStack(uptr bottom, uptr top, const char *type) {
596 static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M
597 if (top - bottom > kMaxExpectedCleanupSize) {
598 static bool reported_warning = false;
599 if (reported_warning)
600 return;
601 reported_warning = true;
602 Report(
603 format: "WARNING: ASan is ignoring requested __asan_handle_no_return: "
604 "stack type: %s top: %p; bottom %p; size: %p (%zd)\n"
605 "False positive error reports may follow\n"
606 "For details see "
607 "https://github.com/google/sanitizers/issues/189\n",
608 type, (void *)top, (void *)bottom, (void *)(top - bottom),
609 top - bottom);
610 return;
611 }
612 PoisonShadow(addr: bottom, size: RoundUpTo(size: top - bottom, ASAN_SHADOW_GRANULARITY), value: 0);
613}
614
615static void UnpoisonDefaultStack() {
616 uptr bottom, top;
617
618 if (AsanThread *curr_thread = GetCurrentThread()) {
619 int local_stack;
620 const uptr page_size = GetPageSizeCached();
621 top = curr_thread->stack_top();
622 bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1);
623 } else {
624 CHECK(!SANITIZER_FUCHSIA);
625 // If we haven't seen this thread, try asking the OS for stack bounds.
626 uptr tls_begin, tls_end;
627 GetThreadStackAndTls(/*main=*/false, stk_begin: &bottom, stk_end: &top, tls_begin: &tls_begin, tls_end: &tls_end);
628 }
629
630 UnpoisonStack(bottom, top, type: "default");
631}
632
633static void UnpoisonFakeStack() {
634 AsanThread *curr_thread = GetCurrentThread();
635 if (!curr_thread)
636 return;
637 FakeStack *stack = curr_thread->get_fake_stack();
638 if (!stack)
639 return;
640 stack->HandleNoReturn();
641}
642
643} // namespace __asan
644
645// ---------------------- Interface ---------------- {{{1
646using namespace __asan;
647
648void NOINLINE __asan_handle_no_return() {
649 if (UNLIKELY(!AsanInited()))
650 return;
651
652 if (!PlatformUnpoisonStacks())
653 UnpoisonDefaultStack();
654
655 UnpoisonFakeStack();
656}
657
658extern "C" void *__asan_extra_spill_area() {
659 AsanThread *t = GetCurrentThread();
660 CHECK(t);
661 return t->extra_spill_area();
662}
663
664void __asan_handle_vfork(void *sp) {
665 AsanThread *t = GetCurrentThread();
666 CHECK(t);
667 uptr bottom = t->stack_bottom();
668 PoisonShadow(addr: bottom, size: (uptr)sp - bottom, value: 0);
669}
670
671void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
672 SetUserDieCallback(callback);
673}
674
675// Initialize as requested from instrumented application code.
676// We use this call as a trigger to wake up ASan from deactivated state.
677void __asan_init() {
678 AsanActivate();
679 AsanInitFromRtl();
680}
681
682void __asan_version_mismatch_check() {
683 // Do nothing.
684}
685