asan_rtl.cc revision 1.6 
1//===-- asan_rtl.cc -------------------------------------------------------===//
2//
3// This file is distributed under the University of Illinois Open Source
4// License. See LICENSE.TXT for details.
5//
6//===----------------------------------------------------------------------===//
7//
8// This file is a part of AddressSanitizer, an address sanity checker.
9//
10// Main file of the ASan run-time library.
11//===----------------------------------------------------------------------===//
12
13#include "asan_activation.h"
14#include "asan_allocator.h"
15#include "asan_interceptors.h"
16#include "asan_interface_internal.h"
17#include "asan_internal.h"
18#include "asan_mapping.h"
19#include "asan_poisoning.h"
20#include "asan_report.h"
21#include "asan_stack.h"
22#include "asan_stats.h"
23#include "asan_suppressions.h"
24#include "asan_thread.h"
25#include "sanitizer_common/sanitizer_atomic.h"
26#include "sanitizer_common/sanitizer_flags.h"
27#include "sanitizer_common/sanitizer_libc.h"
28#include "sanitizer_common/sanitizer_symbolizer.h"
29#include "lsan/lsan_common.h"
30#include "ubsan/ubsan_init.h"
31#include "ubsan/ubsan_platform.h"
32
33uptr __asan_shadow_memory_dynamic_address;  // Global interface symbol.
34int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
35uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
36
37namespace __asan {
38
39uptr AsanMappingProfile[kAsanMappingProfileSize];
40
41static 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.
45    while (1) { }
46  }
47  if (flags()->sleep_before_dying) {
48    Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
49    SleepForSeconds(flags()->sleep_before_dying);
50  }
51  if (flags()->unmap_shadow_on_exit) {
52    if (kMidMemBeg) {
53      UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
54      UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
55    } else {
56      UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
57    }
58  }
59}
60
61static void AsanCheckFailed(const char *file, int line, const char *cond,
62                            u64 v1, u64 v2) {
63  Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
64         line, cond, (uptr)v1, (uptr)v2);
65  // FIXME: check for infinite recursion without a thread-local counter here.
66  PRINT_CURRENT_STACK_CHECK();
67  Die();
68}
69
70// -------------------------- Globals --------------------- {{{1
71int asan_inited;
72bool asan_init_is_running;
73
74#if !ASAN_FIXED_MAPPING
75uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
76#endif
77
78// -------------------------- Misc ---------------- {{{1
79void ShowStatsAndAbort() {
80  __asan_print_accumulated_stats();
81  Die();
82}
83
84// ---------------------- mmap -------------------- {{{1
85// Reserve memory range [beg, end].
86// We need to use inclusive range because end+1 may not be representable.
87void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
88  CHECK_EQ((beg % GetMmapGranularity()), 0);
89  CHECK_EQ(((end + 1) % GetMmapGranularity()), 0);
90  uptr size = end - beg + 1;
91  DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
92  void *res = MmapFixedNoReserve(beg, size, name);
93  if (res != (void*)beg) {
94    Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
95           "Perhaps you're using ulimit -v\n", size);
96    Abort();
97  }
98  if (common_flags()->no_huge_pages_for_shadow)
99    NoHugePagesInRegion(beg, size);
100  if (common_flags()->use_madv_dontdump)
101    DontDumpShadowMemory(beg, size);
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 <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)          \
162                                        : *reinterpret_cast<u16 *>(sp);        \
163    if (UNLIKELY(s)) {                                                         \
164      if (UNLIKELY(size >= SHADOW_GRANULARITY ||                               \
165                   ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >=     \
166                       (s8)s)) {                                               \
167        if (__asan_test_only_reported_buggy_pointer) {                         \
168          *__asan_test_only_reported_buggy_pointer = addr;                     \
169        } else {                                                               \
170          GET_CALLER_PC_BP_SP;                                                 \
171          ReportGenericError(pc, bp, sp, addr, is_write, size, exp_arg,        \
172                              fatal);                                          \
173        }                                                                      \
174      }                                                                        \
175    }
176
177#define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
178  extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
179  void __asan_##type##size(uptr addr) {                                        \
180    ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, true)            \
181  }                                                                            \
182  extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
183  void __asan_exp_##type##size(uptr addr, u32 exp) {                           \
184    ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, exp, true)          \
185  }                                                                            \
186  extern "C" NOINLINE INTERFACE_ATTRIBUTE                                      \
187  void __asan_##type##size ## _noabort(uptr addr) {                            \
188    ASAN_MEMORY_ACCESS_CALLBACK_BODY(type, is_write, size, 0, false)           \
189  }                                                                            \
190
191ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
192ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
193ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
194ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
195ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
196ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
197ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
198ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
199ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
200ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
201
202extern "C"
203NOINLINE INTERFACE_ATTRIBUTE
204void __asan_loadN(uptr addr, uptr size) {
205  if (__asan_region_is_poisoned(addr, size)) {
206    GET_CALLER_PC_BP_SP;
207    ReportGenericError(pc, bp, sp, addr, false, size, 0, true);
208  }
209}
210
211extern "C"
212NOINLINE INTERFACE_ATTRIBUTE
213void __asan_exp_loadN(uptr addr, uptr size, u32 exp) {
214  if (__asan_region_is_poisoned(addr, size)) {
215    GET_CALLER_PC_BP_SP;
216    ReportGenericError(pc, bp, sp, addr, false, size, exp, true);
217  }
218}
219
220extern "C"
221NOINLINE INTERFACE_ATTRIBUTE
222void __asan_loadN_noabort(uptr addr, uptr size) {
223  if (__asan_region_is_poisoned(addr, size)) {
224    GET_CALLER_PC_BP_SP;
225    ReportGenericError(pc, bp, sp, addr, false, size, 0, false);
226  }
227}
228
229extern "C"
230NOINLINE INTERFACE_ATTRIBUTE
231void __asan_storeN(uptr addr, uptr size) {
232  if (__asan_region_is_poisoned(addr, size)) {
233    GET_CALLER_PC_BP_SP;
234    ReportGenericError(pc, bp, sp, addr, true, size, 0, true);
235  }
236}
237
238extern "C"
239NOINLINE INTERFACE_ATTRIBUTE
240void __asan_exp_storeN(uptr addr, uptr size, u32 exp) {
241  if (__asan_region_is_poisoned(addr, size)) {
242    GET_CALLER_PC_BP_SP;
243    ReportGenericError(pc, bp, sp, addr, true, size, exp, true);
244  }
245}
246
247extern "C"
248NOINLINE INTERFACE_ATTRIBUTE
249void __asan_storeN_noabort(uptr addr, uptr size) {
250  if (__asan_region_is_poisoned(addr, size)) {
251    GET_CALLER_PC_BP_SP;
252    ReportGenericError(pc, bp, sp, addr, true, size, 0, false);
253  }
254}
255
256// Force the linker to keep the symbols for various ASan interface functions.
257// We want to keep those in the executable in order to let the instrumented
258// dynamic libraries access the symbol even if it is not used by the executable
259// itself. This should help if the build system is removing dead code at link
260// time.
261static NOINLINE void force_interface_symbols() {
262  volatile int fake_condition = 0;  // prevent dead condition elimination.
263  // __asan_report_* functions are noreturn, so we need a switch to prevent
264  // the compiler from removing any of them.
265  // clang-format off
266  switch (fake_condition) {
267    case 1: __asan_report_load1(0); break;
268    case 2: __asan_report_load2(0); break;
269    case 3: __asan_report_load4(0); break;
270    case 4: __asan_report_load8(0); break;
271    case 5: __asan_report_load16(0); break;
272    case 6: __asan_report_load_n(0, 0); break;
273    case 7: __asan_report_store1(0); break;
274    case 8: __asan_report_store2(0); break;
275    case 9: __asan_report_store4(0); break;
276    case 10: __asan_report_store8(0); break;
277    case 11: __asan_report_store16(0); break;
278    case 12: __asan_report_store_n(0, 0); break;
279    case 13: __asan_report_exp_load1(0, 0); break;
280    case 14: __asan_report_exp_load2(0, 0); break;
281    case 15: __asan_report_exp_load4(0, 0); break;
282    case 16: __asan_report_exp_load8(0, 0); break;
283    case 17: __asan_report_exp_load16(0, 0); break;
284    case 18: __asan_report_exp_load_n(0, 0, 0); break;
285    case 19: __asan_report_exp_store1(0, 0); break;
286    case 20: __asan_report_exp_store2(0, 0); break;
287    case 21: __asan_report_exp_store4(0, 0); break;
288    case 22: __asan_report_exp_store8(0, 0); break;
289    case 23: __asan_report_exp_store16(0, 0); break;
290    case 24: __asan_report_exp_store_n(0, 0, 0); break;
291    case 25: __asan_register_globals(nullptr, 0); break;
292    case 26: __asan_unregister_globals(nullptr, 0); break;
293    case 27: __asan_set_death_callback(nullptr); break;
294    case 28: __asan_set_error_report_callback(nullptr); break;
295    case 29: __asan_handle_no_return(); break;
296    case 30: __asan_address_is_poisoned(nullptr); break;
297    case 31: __asan_poison_memory_region(nullptr, 0); break;
298    case 32: __asan_unpoison_memory_region(nullptr, 0); break;
299    case 34: __asan_before_dynamic_init(nullptr); break;
300    case 35: __asan_after_dynamic_init(); break;
301    case 36: __asan_poison_stack_memory(0, 0); break;
302    case 37: __asan_unpoison_stack_memory(0, 0); break;
303    case 38: __asan_region_is_poisoned(0, 0); break;
304    case 39: __asan_describe_address(0); break;
305    case 40: __asan_set_shadow_00(0, 0); break;
306    case 41: __asan_set_shadow_f1(0, 0); break;
307    case 42: __asan_set_shadow_f2(0, 0); break;
308    case 43: __asan_set_shadow_f3(0, 0); break;
309    case 44: __asan_set_shadow_f5(0, 0); break;
310    case 45: __asan_set_shadow_f8(0, 0); break;
311  }
312  // clang-format on
313}
314
315static void asan_atexit() {
316  Printf("AddressSanitizer exit stats:\n");
317  __asan_print_accumulated_stats();
318  // Print AsanMappingProfile.
319  for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
320    if (AsanMappingProfile[i] == 0) continue;
321    Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
322  }
323}
324
325static void InitializeHighMemEnd() {
326#if !ASAN_FIXED_MAPPING
327  kHighMemEnd = GetMaxVirtualAddress();
328  // Increase kHighMemEnd to make sure it's properly
329  // aligned together with kHighMemBeg:
330  kHighMemEnd |= SHADOW_GRANULARITY * GetMmapGranularity() - 1;
331#endif  // !ASAN_FIXED_MAPPING
332  CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
333}
334
335static void ProtectGap(uptr addr, uptr size) {
336  if (!flags()->protect_shadow_gap) {
337    // The shadow gap is unprotected, so there is a chance that someone
338    // is actually using this memory. Which means it needs a shadow...
339    uptr GapShadowBeg = RoundDownTo(MEM_TO_SHADOW(addr), GetPageSizeCached());
340    uptr GapShadowEnd =
341        RoundUpTo(MEM_TO_SHADOW(addr + size), GetPageSizeCached()) - 1;
342    if (Verbosity())
343      Printf("protect_shadow_gap=0:"
344             " not protecting shadow gap, allocating gap's shadow\n"
345             "|| `[%p, %p]` || ShadowGap's shadow ||\n", GapShadowBeg,
346             GapShadowEnd);
347    ReserveShadowMemoryRange(GapShadowBeg, GapShadowEnd,
348                             "unprotected gap shadow");
349    return;
350  }
351  void *res = MmapFixedNoAccess(addr, size, "shadow gap");
352  if (addr == (uptr)res)
353    return;
354  // A few pages at the start of the address space can not be protected.
355  // But we really want to protect as much as possible, to prevent this memory
356  // being returned as a result of a non-FIXED mmap().
357  if (addr == kZeroBaseShadowStart) {
358    uptr step = GetMmapGranularity();
359    while (size > step && addr < kZeroBaseMaxShadowStart) {
360      addr += step;
361      size -= step;
362      void *res = MmapFixedNoAccess(addr, size, "shadow gap");
363      if (addr == (uptr)res)
364        return;
365    }
366  }
367
368  Report("ERROR: Failed to protect the shadow gap. "
369         "ASan cannot proceed correctly. ABORTING.\n");
370  DumpProcessMap();
371  Die();
372}
373
374static void PrintAddressSpaceLayout() {
375  Printf("|| `[%p, %p]` || HighMem    ||\n",
376         (void*)kHighMemBeg, (void*)kHighMemEnd);
377  Printf("|| `[%p, %p]` || HighShadow ||\n",
378         (void*)kHighShadowBeg, (void*)kHighShadowEnd);
379  if (kMidMemBeg) {
380    Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
381           (void*)kShadowGap3Beg, (void*)kShadowGap3End);
382    Printf("|| `[%p, %p]` || MidMem     ||\n",
383           (void*)kMidMemBeg, (void*)kMidMemEnd);
384    Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
385           (void*)kShadowGap2Beg, (void*)kShadowGap2End);
386    Printf("|| `[%p, %p]` || MidShadow  ||\n",
387           (void*)kMidShadowBeg, (void*)kMidShadowEnd);
388  }
389  Printf("|| `[%p, %p]` || ShadowGap  ||\n",
390         (void*)kShadowGapBeg, (void*)kShadowGapEnd);
391  if (kLowShadowBeg) {
392    Printf("|| `[%p, %p]` || LowShadow  ||\n",
393           (void*)kLowShadowBeg, (void*)kLowShadowEnd);
394    Printf("|| `[%p, %p]` || LowMem     ||\n",
395           (void*)kLowMemBeg, (void*)kLowMemEnd);
396  }
397  Printf("MemToShadow(shadow): %p %p %p %p",
398         (void*)MEM_TO_SHADOW(kLowShadowBeg),
399         (void*)MEM_TO_SHADOW(kLowShadowEnd),
400         (void*)MEM_TO_SHADOW(kHighShadowBeg),
401         (void*)MEM_TO_SHADOW(kHighShadowEnd));
402  if (kMidMemBeg) {
403    Printf(" %p %p",
404           (void*)MEM_TO_SHADOW(kMidShadowBeg),
405           (void*)MEM_TO_SHADOW(kMidShadowEnd));
406  }
407  Printf("\n");
408  Printf("redzone=%zu\n", (uptr)flags()->redzone);
409  Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
410  Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
411  Printf("malloc_context_size=%zu\n",
412         (uptr)common_flags()->malloc_context_size);
413
414  Printf("SHADOW_SCALE: %d\n", (int)SHADOW_SCALE);
415  Printf("SHADOW_GRANULARITY: %d\n", (int)SHADOW_GRANULARITY);
416  Printf("SHADOW_OFFSET: 0x%zx\n", (uptr)SHADOW_OFFSET);
417  CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
418  if (kMidMemBeg)
419    CHECK(kMidShadowBeg > kLowShadowEnd &&
420          kMidMemBeg > kMidShadowEnd &&
421          kHighShadowBeg > kMidMemEnd);
422}
423
424static void AsanInitInternal() {
425  if (LIKELY(asan_inited)) return;
426  SanitizerToolName = "AddressSanitizer";
427  CHECK(!asan_init_is_running && "ASan init calls itself!");
428  asan_init_is_running = true;
429
430  CacheBinaryName();
431
432  // Initialize flags. This must be done early, because most of the
433  // initialization steps look at flags().
434  InitializeFlags();
435
436  AsanCheckIncompatibleRT();
437  AsanCheckDynamicRTPrereqs();
438  AvoidCVE_2016_2143();
439
440  SetCanPoisonMemory(flags()->poison_heap);
441  SetMallocContextSize(common_flags()->malloc_context_size);
442
443  InitializePlatformExceptionHandlers();
444
445  InitializeHighMemEnd();
446
447  // Make sure we are not statically linked.
448  AsanDoesNotSupportStaticLinkage();
449
450  // Install tool-specific callbacks in sanitizer_common.
451  AddDieCallback(AsanDie);
452  SetCheckFailedCallback(AsanCheckFailed);
453  SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
454
455  __sanitizer_set_report_path(common_flags()->log_path);
456
457  __asan_option_detect_stack_use_after_return =
458      flags()->detect_stack_use_after_return;
459
460  // Re-exec ourselves if we need to set additional env or command line args.
461  MaybeReexec();
462
463  // Setup internal allocator callback.
464  SetLowLevelAllocateCallback(OnLowLevelAllocate);
465
466  InitializeAsanInterceptors();
467
468  // Enable system log ("adb logcat") on Android.
469  // Doing this before interceptors are initialized crashes in:
470  // AsanInitInternal -> android_log_write -> __interceptor_strcmp
471  AndroidLogInit();
472
473  ReplaceSystemMalloc();
474
475  // Set the shadow memory address to uninitialized.
476  __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
477
478  uptr shadow_start = kLowShadowBeg;
479  // Detect if a dynamic shadow address must used and find a available location
480  // when necessary. When dynamic address is used, the macro |kLowShadowBeg|
481  // expands to |__asan_shadow_memory_dynamic_address| which is
482  // |kDefaultShadowSentinel|.
483  if (shadow_start == kDefaultShadowSentinel) {
484    __asan_shadow_memory_dynamic_address = 0;
485    CHECK_EQ(0, kLowShadowBeg);
486
487    uptr granularity = GetMmapGranularity();
488    uptr alignment = 8 * granularity;
489    uptr left_padding = granularity;
490    uptr space_size = kHighShadowEnd + left_padding;
491
492    shadow_start = FindAvailableMemoryRange(space_size, alignment, granularity);
493    CHECK_NE((uptr)0, shadow_start);
494    CHECK(IsAligned(shadow_start, alignment));
495  }
496  // Update the shadow memory address (potentially) used by instrumentation.
497  __asan_shadow_memory_dynamic_address = shadow_start;
498
499  if (kLowShadowBeg)
500    shadow_start -= GetMmapGranularity();
501  bool full_shadow_is_available =
502      MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
503
504#if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) &&                \
505    !ASAN_FIXED_MAPPING
506  if (!full_shadow_is_available) {
507    kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
508    kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
509  }
510#endif
511
512  if (Verbosity()) PrintAddressSpaceLayout();
513
514  DisableCoreDumperIfNecessary();
515
516  if (full_shadow_is_available) {
517    // mmap the low shadow plus at least one page at the left.
518    if (kLowShadowBeg)
519      ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
520    // mmap the high shadow.
521    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
522    // protect the gap.
523    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
524    CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
525  } else if (kMidMemBeg &&
526      MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
527      MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
528    CHECK(kLowShadowBeg != kLowShadowEnd);
529    // mmap the low shadow plus at least one page at the left.
530    ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
531    // mmap the mid shadow.
532    ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
533    // mmap the high shadow.
534    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
535    // protect the gaps.
536    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
537    ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
538    ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
539  } else {
540    Report("Shadow memory range interleaves with an existing memory mapping. "
541           "ASan cannot proceed correctly. ABORTING.\n");
542    Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
543           shadow_start, kHighShadowEnd);
544    DumpProcessMap();
545    Die();
546  }
547
548  AsanTSDInit(PlatformTSDDtor);
549  InstallDeadlySignalHandlers(AsanOnDeadlySignal);
550
551  AllocatorOptions allocator_options;
552  allocator_options.SetFrom(flags(), common_flags());
553  InitializeAllocator(allocator_options);
554
555  MaybeStartBackgroudThread();
556  SetSoftRssLimitExceededCallback(AsanSoftRssLimitExceededCallback);
557
558  // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
559  // should be set to 1 prior to initializing the threads.
560  asan_inited = 1;
561  asan_init_is_running = false;
562
563  if (flags()->atexit)
564    Atexit(asan_atexit);
565
566  InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
567
568  // Now that ASan runtime is (mostly) initialized, deactivate it if
569  // necessary, so that it can be re-activated when requested.
570  if (flags()->start_deactivated)
571    AsanDeactivate();
572
573  // interceptors
574  InitTlsSize();
575
576  // Create main thread.
577  AsanThread *main_thread = AsanThread::Create(
578      /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ 0,
579      /* stack */ nullptr, /* detached */ true);
580  CHECK_EQ(0, main_thread->tid());
581  SetCurrentThread(main_thread);
582  main_thread->ThreadStart(internal_getpid(),
583                           /* signal_thread_is_registered */ nullptr);
584  force_interface_symbols();  // no-op.
585  SanitizerInitializeUnwinder();
586
587  if (CAN_SANITIZE_LEAKS) {
588    __lsan::InitCommonLsan();
589    if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
590      Atexit(__lsan::DoLeakCheck);
591    }
592  }
593
594#if CAN_SANITIZE_UB
595  __ubsan::InitAsPlugin();
596#endif
597
598  InitializeSuppressions();
599
600  if (CAN_SANITIZE_LEAKS) {
601    // LateInitialize() calls dlsym, which can allocate an error string buffer
602    // in the TLS.  Let's ignore the allocation to avoid reporting a leak.
603    __lsan::ScopedInterceptorDisabler disabler;
604    Symbolizer::LateInitialize();
605  } else {
606    Symbolizer::LateInitialize();
607  }
608
609  VReport(1, "AddressSanitizer Init done\n");
610}
611
612// Initialize as requested from some part of ASan runtime library (interceptors,
613// allocator, etc).
614void AsanInitFromRtl() {
615  AsanInitInternal();
616}
617
618#if ASAN_DYNAMIC
619// Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
620// (and thus normal initializers from .preinit_array or modules haven't run).
621
622class AsanInitializer {
623public:  // NOLINT
624  AsanInitializer() {
625    AsanInitFromRtl();
626  }
627};
628
629static AsanInitializer asan_initializer;
630#endif  // ASAN_DYNAMIC
631
632} // namespace __asan
633
634// ---------------------- Interface ---------------- {{{1
635using namespace __asan;  // NOLINT
636
637void NOINLINE __asan_handle_no_return() {
638  if (asan_init_is_running)
639    return;
640
641  int local_stack;
642  AsanThread *curr_thread = GetCurrentThread();
643  uptr PageSize = GetPageSizeCached();
644  uptr top, bottom;
645  if (curr_thread) {
646    top = curr_thread->stack_top();
647    bottom = ((uptr)&local_stack - PageSize) & ~(PageSize - 1);
648  } else {
649    // If we haven't seen this thread, try asking the OS for stack bounds.
650    uptr tls_addr, tls_size, stack_size;
651    GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr,
652                         &tls_size);
653    top = bottom + stack_size;
654  }
655  static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
656  if (top - bottom > kMaxExpectedCleanupSize) {
657    static bool reported_warning = false;
658    if (reported_warning)
659      return;
660    reported_warning = true;
661    Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
662           "stack top: %p; bottom %p; size: %p (%zd)\n"
663           "False positive error reports may follow\n"
664           "For details see "
665           "https://github.com/google/sanitizers/issues/189\n",
666           top, bottom, top - bottom, top - bottom);
667    return;
668  }
669  PoisonShadow(bottom, top - bottom, 0);
670  if (curr_thread && curr_thread->has_fake_stack())
671    curr_thread->fake_stack()->HandleNoReturn();
672}
673
674void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
675  SetUserDieCallback(callback);
676}
677
678// Initialize as requested from instrumented application code.
679// We use this call as a trigger to wake up ASan from deactivated state.
680void __asan_init() {
681  AsanActivate();
682  AsanInitInternal();
683}
684
685void __asan_version_mismatch_check() {
686  // Do nothing.
687}
688