1 //===-- asan_rtl.cc -------------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of AddressSanitizer, an address sanity checker.
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_suppressions.h"
25 #include "asan_thread.h"
26 #include "sanitizer_common/sanitizer_atomic.h"
27 #include "sanitizer_common/sanitizer_flags.h"
28 #include "sanitizer_common/sanitizer_libc.h"
29 #include "sanitizer_common/sanitizer_symbolizer.h"
30 #include "lsan/lsan_common.h"
31 #include "ubsan/ubsan_init.h"
32 #include "ubsan/ubsan_platform.h"
34 int __asan_option_detect_stack_use_after_return; // Global interface symbol.
35 uptr *__asan_test_only_reported_buggy_pointer; // Used only for testing asan.
39 uptr AsanMappingProfile[kAsanMappingProfileSize];
41 static void AsanDie() {
42 static atomic_uint32_t num_calls;
43 if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
44 // Don't die twice - run a busy loop.
47 if (flags()->sleep_before_dying) {
48 Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
49 SleepForSeconds(flags()->sleep_before_dying);
51 if (flags()->unmap_shadow_on_exit) {
53 UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
54 UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
56 UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
59 if (common_flags()->coverage)
60 __sanitizer_cov_dump();
61 if (flags()->abort_on_error)
63 internal__exit(flags()->exitcode);
66 static void AsanCheckFailed(const char *file, int line, const char *cond,
68 Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
69 line, cond, (uptr)v1, (uptr)v2);
70 // FIXME: check for infinite recursion without a thread-local counter here.
71 PRINT_CURRENT_STACK_CHECK();
75 // -------------------------- Globals --------------------- {{{1
77 bool asan_init_is_running;
79 #if !ASAN_FIXED_MAPPING
80 uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
83 // -------------------------- Misc ---------------- {{{1
84 void ShowStatsAndAbort() {
85 __asan_print_accumulated_stats();
89 // ---------------------- mmap -------------------- {{{1
90 // Reserve memory range [beg, end].
91 // We need to use inclusive range because end+1 may not be representable.
92 void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
93 CHECK_EQ((beg % GetPageSizeCached()), 0);
94 CHECK_EQ(((end + 1) % GetPageSizeCached()), 0);
95 uptr size = end - beg + 1;
96 DecreaseTotalMmap(size); // Don't count the shadow against mmap_limit_mb.
97 void *res = MmapFixedNoReserve(beg, size, name);
98 if (res != (void*)beg) {
99 Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
100 "Perhaps you're using ulimit -v\n", size);
103 if (common_flags()->no_huge_pages_for_shadow)
104 NoHugePagesInRegion(beg, size);
105 if (common_flags()->use_madv_dontdump)
106 DontDumpShadowMemory(beg, size);
109 // --------------- LowLevelAllocateCallbac ---------- {{{1
110 static void OnLowLevelAllocate(uptr ptr, uptr size) {
111 PoisonShadow(ptr, size, kAsanInternalHeapMagic);
114 // -------------------------- Run-time entry ------------------- {{{1
115 // exported functions
116 #define ASAN_REPORT_ERROR(type, is_write, size) \
117 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
118 void __asan_report_ ## type ## size(uptr addr) { \
119 GET_CALLER_PC_BP_SP; \
120 __asan_report_error(pc, bp, sp, addr, is_write, size, 0); \
122 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
123 void __asan_report_exp_ ## type ## size(uptr addr, u32 exp) { \
124 GET_CALLER_PC_BP_SP; \
125 __asan_report_error(pc, bp, sp, addr, is_write, size, exp); \
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)
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 __asan_report_error(pc, bp, sp, addr, is_write, size, 0); \
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 __asan_report_error(pc, bp, sp, addr, is_write, size, exp); \
151 ASAN_REPORT_ERROR_N(load, false)
152 ASAN_REPORT_ERROR_N(store, true)
154 #define ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp_arg) \
155 uptr sp = MEM_TO_SHADOW(addr); \
156 uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp) \
157 : *reinterpret_cast<u16 *>(sp); \
159 if (UNLIKELY(size >= SHADOW_GRANULARITY || \
160 ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >= \
162 if (__asan_test_only_reported_buggy_pointer) { \
163 *__asan_test_only_reported_buggy_pointer = addr; \
165 GET_CALLER_PC_BP_SP; \
166 __asan_report_error(pc, bp, sp, addr, is_write, size, exp_arg); \
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) \
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) \
181 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
182 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
183 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
184 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
185 ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
186 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
187 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
188 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
189 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
190 ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
193 NOINLINE INTERFACE_ATTRIBUTE
194 void __asan_loadN(uptr addr, uptr size) {
195 if (__asan_region_is_poisoned(addr, size)) {
197 __asan_report_error(pc, bp, sp, addr, false, size, 0);
202 NOINLINE INTERFACE_ATTRIBUTE
203 void __asan_exp_loadN(uptr addr, uptr size, u32 exp) {
204 if (__asan_region_is_poisoned(addr, size)) {
206 __asan_report_error(pc, bp, sp, addr, false, size, exp);
211 NOINLINE INTERFACE_ATTRIBUTE
212 void __asan_storeN(uptr addr, uptr size) {
213 if (__asan_region_is_poisoned(addr, size)) {
215 __asan_report_error(pc, bp, sp, addr, true, size, 0);
220 NOINLINE INTERFACE_ATTRIBUTE
221 void __asan_exp_storeN(uptr addr, uptr size, u32 exp) {
222 if (__asan_region_is_poisoned(addr, size)) {
224 __asan_report_error(pc, bp, sp, addr, true, size, exp);
228 // Force the linker to keep the symbols for various ASan interface functions.
229 // We want to keep those in the executable in order to let the instrumented
230 // dynamic libraries access the symbol even if it is not used by the executable
231 // itself. This should help if the build system is removing dead code at link
233 static NOINLINE void force_interface_symbols() {
234 volatile int fake_condition = 0; // prevent dead condition elimination.
235 // __asan_report_* functions are noreturn, so we need a switch to prevent
236 // the compiler from removing any of them.
237 switch (fake_condition) {
238 case 1: __asan_report_load1(0); break;
239 case 2: __asan_report_load2(0); break;
240 case 3: __asan_report_load4(0); break;
241 case 4: __asan_report_load8(0); break;
242 case 5: __asan_report_load16(0); break;
243 case 6: __asan_report_load_n(0, 0); break;
244 case 7: __asan_report_store1(0); break;
245 case 8: __asan_report_store2(0); break;
246 case 9: __asan_report_store4(0); break;
247 case 10: __asan_report_store8(0); break;
248 case 11: __asan_report_store16(0); break;
249 case 12: __asan_report_store_n(0, 0); break;
250 case 13: __asan_report_exp_load1(0, 0); break;
251 case 14: __asan_report_exp_load2(0, 0); break;
252 case 15: __asan_report_exp_load4(0, 0); break;
253 case 16: __asan_report_exp_load8(0, 0); break;
254 case 17: __asan_report_exp_load16(0, 0); break;
255 case 18: __asan_report_exp_load_n(0, 0, 0); break;
256 case 19: __asan_report_exp_store1(0, 0); break;
257 case 20: __asan_report_exp_store2(0, 0); break;
258 case 21: __asan_report_exp_store4(0, 0); break;
259 case 22: __asan_report_exp_store8(0, 0); break;
260 case 23: __asan_report_exp_store16(0, 0); break;
261 case 24: __asan_report_exp_store_n(0, 0, 0); break;
262 case 25: __asan_register_globals(0, 0); break;
263 case 26: __asan_unregister_globals(0, 0); break;
264 case 27: __asan_set_death_callback(0); break;
265 case 28: __asan_set_error_report_callback(0); break;
266 case 29: __asan_handle_no_return(); break;
267 case 30: __asan_address_is_poisoned(0); break;
268 case 31: __asan_poison_memory_region(0, 0); break;
269 case 32: __asan_unpoison_memory_region(0, 0); break;
270 case 33: __asan_set_error_exit_code(0); break;
271 case 34: __asan_before_dynamic_init(0); break;
272 case 35: __asan_after_dynamic_init(); break;
273 case 36: __asan_poison_stack_memory(0, 0); break;
274 case 37: __asan_unpoison_stack_memory(0, 0); break;
275 case 38: __asan_region_is_poisoned(0, 0); break;
276 case 39: __asan_describe_address(0); break;
280 static void asan_atexit() {
281 Printf("AddressSanitizer exit stats:\n");
282 __asan_print_accumulated_stats();
283 // Print AsanMappingProfile.
284 for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
285 if (AsanMappingProfile[i] == 0) continue;
286 Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
290 static void InitializeHighMemEnd() {
291 #if !ASAN_FIXED_MAPPING
292 kHighMemEnd = GetMaxVirtualAddress();
293 // Increase kHighMemEnd to make sure it's properly
294 // aligned together with kHighMemBeg:
295 kHighMemEnd |= SHADOW_GRANULARITY * GetPageSizeCached() - 1;
296 #endif // !ASAN_FIXED_MAPPING
297 CHECK_EQ((kHighMemBeg % GetPageSizeCached()), 0);
300 static void ProtectGap(uptr addr, uptr size) {
301 void *res = MmapNoAccess(addr, size, "shadow gap");
302 if (addr == (uptr)res)
304 Report("ERROR: Failed to protect the shadow gap. "
305 "ASan cannot proceed correctly. ABORTING.\n");
310 static void PrintAddressSpaceLayout() {
311 Printf("|| `[%p, %p]` || HighMem ||\n",
312 (void*)kHighMemBeg, (void*)kHighMemEnd);
313 Printf("|| `[%p, %p]` || HighShadow ||\n",
314 (void*)kHighShadowBeg, (void*)kHighShadowEnd);
316 Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
317 (void*)kShadowGap3Beg, (void*)kShadowGap3End);
318 Printf("|| `[%p, %p]` || MidMem ||\n",
319 (void*)kMidMemBeg, (void*)kMidMemEnd);
320 Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
321 (void*)kShadowGap2Beg, (void*)kShadowGap2End);
322 Printf("|| `[%p, %p]` || MidShadow ||\n",
323 (void*)kMidShadowBeg, (void*)kMidShadowEnd);
325 Printf("|| `[%p, %p]` || ShadowGap ||\n",
326 (void*)kShadowGapBeg, (void*)kShadowGapEnd);
328 Printf("|| `[%p, %p]` || LowShadow ||\n",
329 (void*)kLowShadowBeg, (void*)kLowShadowEnd);
330 Printf("|| `[%p, %p]` || LowMem ||\n",
331 (void*)kLowMemBeg, (void*)kLowMemEnd);
333 Printf("MemToShadow(shadow): %p %p %p %p",
334 (void*)MEM_TO_SHADOW(kLowShadowBeg),
335 (void*)MEM_TO_SHADOW(kLowShadowEnd),
336 (void*)MEM_TO_SHADOW(kHighShadowBeg),
337 (void*)MEM_TO_SHADOW(kHighShadowEnd));
340 (void*)MEM_TO_SHADOW(kMidShadowBeg),
341 (void*)MEM_TO_SHADOW(kMidShadowEnd));
344 Printf("redzone=%zu\n", (uptr)flags()->redzone);
345 Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
346 Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
347 Printf("malloc_context_size=%zu\n",
348 (uptr)common_flags()->malloc_context_size);
350 Printf("SHADOW_SCALE: %d\n", (int)SHADOW_SCALE);
351 Printf("SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY);
352 Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET);
353 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
355 CHECK(kMidShadowBeg > kLowShadowEnd &&
356 kMidMemBeg > kMidShadowEnd &&
357 kHighShadowBeg > kMidMemEnd);
360 static void AsanInitInternal() {
361 if (LIKELY(asan_inited)) return;
362 SanitizerToolName = "AddressSanitizer";
363 CHECK(!asan_init_is_running && "ASan init calls itself!");
364 asan_init_is_running = true;
366 // Initialize flags. This must be done early, because most of the
367 // initialization steps look at flags().
372 AsanCheckIncompatibleRT();
373 AsanCheckDynamicRTPrereqs();
375 SetCanPoisonMemory(flags()->poison_heap);
376 SetMallocContextSize(common_flags()->malloc_context_size);
378 InitializeHighMemEnd();
380 // Make sure we are not statically linked.
381 AsanDoesNotSupportStaticLinkage();
383 // Install tool-specific callbacks in sanitizer_common.
384 SetDieCallback(AsanDie);
385 SetCheckFailedCallback(AsanCheckFailed);
386 SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
388 __sanitizer_set_report_path(common_flags()->log_path);
390 // Enable UAR detection, if required.
391 __asan_option_detect_stack_use_after_return =
392 flags()->detect_stack_use_after_return;
394 // Re-exec ourselves if we need to set additional env or command line args.
397 // Setup internal allocator callback.
398 SetLowLevelAllocateCallback(OnLowLevelAllocate);
400 InitializeAsanInterceptors();
402 // Enable system log ("adb logcat") on Android.
403 // Doing this before interceptors are initialized crashes in:
404 // AsanInitInternal -> android_log_write -> __interceptor_strcmp
407 ReplaceSystemMalloc();
409 uptr shadow_start = kLowShadowBeg;
411 shadow_start -= GetMmapGranularity();
412 bool full_shadow_is_available =
413 MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
415 #if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) && \
417 if (!full_shadow_is_available) {
418 kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
419 kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
423 if (Verbosity()) PrintAddressSpaceLayout();
425 DisableCoreDumperIfNecessary();
427 if (full_shadow_is_available) {
428 // mmap the low shadow plus at least one page at the left.
430 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
431 // mmap the high shadow.
432 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
434 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
435 CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
436 } else if (kMidMemBeg &&
437 MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
438 MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
439 CHECK(kLowShadowBeg != kLowShadowEnd);
440 // mmap the low shadow plus at least one page at the left.
441 ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
442 // mmap the mid shadow.
443 ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
444 // mmap the high shadow.
445 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
447 ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
448 ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
449 ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
451 Report("Shadow memory range interleaves with an existing memory mapping. "
452 "ASan cannot proceed correctly. ABORTING.\n");
453 Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
454 shadow_start, kHighShadowEnd);
459 AsanTSDInit(PlatformTSDDtor);
460 InstallDeadlySignalHandlers(AsanOnSIGSEGV);
462 AllocatorOptions allocator_options;
463 allocator_options.SetFrom(flags(), common_flags());
464 InitializeAllocator(allocator_options);
466 MaybeStartBackgroudThread();
467 SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback);
469 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
470 // should be set to 1 prior to initializing the threads.
472 asan_init_is_running = false;
477 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
479 // Now that ASan runtime is (mostly) initialized, deactivate it if
480 // necessary, so that it can be re-activated when requested.
481 if (flags()->start_deactivated)
487 // Create main thread.
488 AsanThread *main_thread = AsanThread::Create(
489 /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ 0,
490 /* stack */ nullptr, /* detached */ true);
491 CHECK_EQ(0, main_thread->tid());
492 SetCurrentThread(main_thread);
493 main_thread->ThreadStart(internal_getpid(),
494 /* signal_thread_is_registered */ nullptr);
495 force_interface_symbols(); // no-op.
496 SanitizerInitializeUnwinder();
498 #if CAN_SANITIZE_LEAKS
499 __lsan::InitCommonLsan();
500 if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
501 Atexit(__lsan::DoLeakCheck);
503 #endif // CAN_SANITIZE_LEAKS
506 __ubsan::InitAsPlugin();
509 InitializeSuppressions();
511 VReport(1, "AddressSanitizer Init done\n");
514 // Initialize as requested from some part of ASan runtime library (interceptors,
516 void AsanInitFromRtl() {
521 // Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
522 // (and thus normal initializers from .preinit_array or modules haven't run).
524 class AsanInitializer {
531 static AsanInitializer asan_initializer;
532 #endif // ASAN_DYNAMIC
534 } // namespace __asan
536 // ---------------------- Interface ---------------- {{{1
537 using namespace __asan; // NOLINT
539 int NOINLINE __asan_set_error_exit_code(int exit_code) {
540 int old = flags()->exitcode;
541 flags()->exitcode = exit_code;
545 void NOINLINE __asan_handle_no_return() {
547 AsanThread *curr_thread = GetCurrentThread();
549 uptr PageSize = GetPageSizeCached();
550 uptr top = curr_thread->stack_top();
551 uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1);
552 static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M
553 if (top - bottom > kMaxExpectedCleanupSize) {
554 static bool reported_warning = false;
555 if (reported_warning)
557 reported_warning = true;
558 Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
559 "stack top: %p; bottom %p; size: %p (%zd)\n"
560 "False positive error reports may follow\n"
562 "http://code.google.com/p/address-sanitizer/issues/detail?id=189\n",
563 top, bottom, top - bottom, top - bottom);
566 PoisonShadow(bottom, top - bottom, 0);
567 if (curr_thread->has_fake_stack())
568 curr_thread->fake_stack()->HandleNoReturn();
571 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
572 SetUserDieCallback(callback);
575 // Initialize as requested from instrumented application code.
576 // We use this call as a trigger to wake up ASan from deactivated state.