1//===-- asan_rtl.cc -------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of AddressSanitizer, an address sanity checker.
11//
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_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
31int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
32uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
33
34namespace __asan {
35
36uptr AsanMappingProfile[kAsanMappingProfileSize];
37
38static void AsanDie() {
39  static atomic_uint32_t num_calls;
40  if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
41    // Don't die twice - run a busy loop.
42    while (1) { }
43  }
44  if (flags()->sleep_before_dying) {
45    Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
46    SleepForSeconds(flags()->sleep_before_dying);
47  }
48  if (flags()->unmap_shadow_on_exit) {
49    if (kMidMemBeg) {
50      UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
51      UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
52    } else {
53      UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
54    }
55  }
56  if (common_flags()->coverage)
57    __sanitizer_cov_dump();
58  if (death_callback)
59    death_callback();
60  if (flags()->abort_on_error)
61    Abort();
62  internal__exit(flags()->exitcode);
63}
64
65static void AsanCheckFailed(const char *file, int line, const char *cond,
66                            u64 v1, u64 v2) {
67  Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
68         line, cond, (uptr)v1, (uptr)v2);
69  // FIXME: check for infinite recursion without a thread-local counter here.
70  PRINT_CURRENT_STACK();
71  Die();
72}
73
74// -------------------------- Flags ------------------------- {{{1
75static const int kDefaultMallocContextSize = 30;
76
77Flags asan_flags_dont_use_directly;  // use via flags().
78
79static const char *MaybeCallAsanDefaultOptions() {
80  return (&__asan_default_options) ? __asan_default_options() : "";
81}
82
83static const char *MaybeUseAsanDefaultOptionsCompileDefinition() {
84#ifdef ASAN_DEFAULT_OPTIONS
85// Stringize the macro value.
86# define ASAN_STRINGIZE(x) #x
87# define ASAN_STRINGIZE_OPTIONS(options) ASAN_STRINGIZE(options)
88  return ASAN_STRINGIZE_OPTIONS(ASAN_DEFAULT_OPTIONS);
89#else
90  return "";
91#endif
92}
93
94static void ParseFlagsFromString(Flags *f, const char *str) {
95  CommonFlags *cf = common_flags();
96  ParseCommonFlagsFromString(cf, str);
97  CHECK((uptr)cf->malloc_context_size <= kStackTraceMax);
98  // Please write meaningful flag descriptions when adding new flags.
99  ParseFlag(str, &f->quarantine_size, "quarantine_size",
100            "Size (in bytes) of quarantine used to detect use-after-free "
101            "errors. Lower value may reduce memory usage but increase the "
102            "chance of false negatives.");
103  ParseFlag(str, &f->redzone, "redzone",
104            "Minimal size (in bytes) of redzones around heap objects. "
105            "Requirement: redzone >= 16, is a power of two.");
106  ParseFlag(str, &f->max_redzone, "max_redzone",
107            "Maximal size (in bytes) of redzones around heap objects.");
108  CHECK_GE(f->redzone, 16);
109  CHECK_GE(f->max_redzone, f->redzone);
110  CHECK_LE(f->max_redzone, 2048);
111  CHECK(IsPowerOfTwo(f->redzone));
112  CHECK(IsPowerOfTwo(f->max_redzone));
113
114  ParseFlag(str, &f->debug, "debug",
115      "If set, prints some debugging information and does additional checks.");
116  ParseFlag(str, &f->report_globals, "report_globals",
117      "Controls the way to handle globals (0 - don't detect buffer overflow on "
118      "globals, 1 - detect buffer overflow, 2 - print data about registered "
119      "globals).");
120
121  ParseFlag(str, &f->check_initialization_order,
122      "check_initialization_order",
123      "If set, attempts to catch initialization order issues.");
124
125  ParseFlag(str, &f->replace_str, "replace_str",
126      "If set, uses custom wrappers and replacements for libc string functions "
127      "to find more errors.");
128
129  ParseFlag(str, &f->replace_intrin, "replace_intrin",
130      "If set, uses custom wrappers for memset/memcpy/memmove intinsics.");
131  ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free",
132      "Ignore invalid free() calls to work around some bugs. Used on OS X "
133      "only.");
134  ParseFlag(str, &f->detect_stack_use_after_return,
135      "detect_stack_use_after_return",
136      "Enables stack-use-after-return checking at run-time.");
137  ParseFlag(str, &f->min_uar_stack_size_log, "min_uar_stack_size_log",
138      "Minimum fake stack size log.");
139  ParseFlag(str, &f->max_uar_stack_size_log, "max_uar_stack_size_log",
140      "Maximum fake stack size log.");
141  ParseFlag(str, &f->uar_noreserve, "uar_noreserve",
142      "Use mmap with 'norserve' flag to allocate fake stack.");
143  ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size",
144      "ASan allocator flag. max_malloc_fill_size is the maximal amount of "
145      "bytes that will be filled with malloc_fill_byte on malloc.");
146  ParseFlag(str, &f->malloc_fill_byte, "malloc_fill_byte",
147      "Value used to fill the newly allocated memory.");
148  ParseFlag(str, &f->exitcode, "exitcode",
149      "Override the program exit status if the tool found an error.");
150  ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning",
151      "If set, user may manually mark memory regions as poisoned or "
152      "unpoisoned.");
153  ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying",
154      "Number of seconds to sleep between printing an error report and "
155      "terminating the program. Useful for debugging purposes (e.g. when one "
156      "needs to attach gdb).");
157
158  ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size",
159      "Allows the users to work around the bug in Nvidia drivers prior to "
160      "295.*.");
161
162  ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit",
163      "If set, explicitly unmaps the (huge) shadow at exit.");
164  ParseFlag(str, &f->abort_on_error, "abort_on_error",
165      "If set, the tool calls abort() instead of _exit() after printing the "
166      "error report.");
167  ParseFlag(str, &f->print_stats, "print_stats",
168      "Print various statistics after printing an error message or if "
169      "atexit=1.");
170  ParseFlag(str, &f->print_legend, "print_legend",
171      "Print the legend for the shadow bytes.");
172  ParseFlag(str, &f->atexit, "atexit",
173      "If set, prints ASan exit stats even after program terminates "
174      "successfully.");
175
176  ParseFlag(str, &f->disable_core, "disable_core",
177      "Disable core dumping. By default, disable_core=1 on 64-bit to avoid "
178      "dumping a 16T+ core file. "
179      "Ignored on OSes that don't dump core by default.");
180
181  ParseFlag(str, &f->allow_reexec, "allow_reexec",
182      "Allow the tool to re-exec the program. This may interfere badly with "
183      "the debugger.");
184
185  ParseFlag(str, &f->print_full_thread_history,
186      "print_full_thread_history",
187      "If set, prints thread creation stacks for the threads involved in the "
188      "report and their ancestors up to the main thread.");
189
190  ParseFlag(str, &f->poison_heap, "poison_heap",
191      "Poison (or not) the heap memory on [de]allocation. Zero value is useful "
192      "for benchmarking the allocator or instrumentator.");
193
194  ParseFlag(str, &f->poison_partial, "poison_partial",
195      "If true, poison partially addressable 8-byte aligned words "
196      "(default=true). This flag affects heap and global buffers, but not "
197      "stack buffers.");
198
199  ParseFlag(str, &f->alloc_dealloc_mismatch, "alloc_dealloc_mismatch",
200      "Report errors on malloc/delete, new/free, new/delete[], etc.");
201  ParseFlag(str, &f->strict_memcmp, "strict_memcmp",
202      "If true, assume that memcmp(p1, p2, n) always reads n bytes before "
203      "comparing p1 and p2.");
204
205  ParseFlag(str, &f->strict_init_order, "strict_init_order",
206      "If true, assume that dynamic initializers can never access globals from "
207      "other modules, even if the latter are already initialized.");
208
209  ParseFlag(str, &f->start_deactivated, "start_deactivated",
210      "If true, ASan tweaks a bunch of other flags (quarantine, redzone, heap "
211      "poisoning) to reduce memory consumption as much as possible, and "
212      "restores them to original values when the first instrumented module is "
213      "loaded into the process. This is mainly intended to be used on "
214      "Android. ");
215
216  ParseFlag(str, &f->detect_invalid_pointer_pairs,
217      "detect_invalid_pointer_pairs",
218      "If non-zero, try to detect operations like <, <=, >, >= and - on "
219      "invalid pointer pairs (e.g. when pointers belong to different objects). "
220      "The bigger the value the harder we try.");
221
222  ParseFlag(str, &f->detect_container_overflow,
223      "detect_container_overflow",
224      "If true, honor the container overflow  annotations. "
225      "See https://code.google.com/p/address-sanitizer/wiki/ContainerOverflow");
226
227  ParseFlag(str, &f->detect_odr_violation, "detect_odr_violation",
228            "If >=2, detect violation of One-Definition-Rule (ODR); "
229            "If ==1, detect ODR-violation only if the two variables "
230            "have different sizes");
231}
232
233void InitializeFlags(Flags *f, const char *env) {
234  CommonFlags *cf = common_flags();
235  SetCommonFlagsDefaults(cf);
236  cf->detect_leaks = CAN_SANITIZE_LEAKS;
237  cf->external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
238  cf->malloc_context_size = kDefaultMallocContextSize;
239  cf->intercept_tls_get_addr = true;
240  cf->coverage = false;
241
242  internal_memset(f, 0, sizeof(*f));
243  f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28;
244  f->redzone = 16;
245  f->max_redzone = 2048;
246  f->debug = false;
247  f->report_globals = 1;
248  f->check_initialization_order = false;
249  f->replace_str = true;
250  f->replace_intrin = true;
251  f->mac_ignore_invalid_free = false;
252  f->detect_stack_use_after_return = false;  // Also needs the compiler flag.
253  f->min_uar_stack_size_log = 16;  // We can't do smaller anyway.
254  f->max_uar_stack_size_log = 20;  // 1Mb per size class, i.e. ~11Mb per thread.
255  f->uar_noreserve = false;
256  f->max_malloc_fill_size = 0x1000;  // By default, fill only the first 4K.
257  f->malloc_fill_byte = 0xbe;
258  f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
259  f->allow_user_poisoning = true;
260  f->sleep_before_dying = 0;
261  f->check_malloc_usable_size = true;
262  f->unmap_shadow_on_exit = false;
263  f->abort_on_error = false;
264  f->print_stats = false;
265  f->print_legend = true;
266  f->atexit = false;
267  f->disable_core = (SANITIZER_WORDSIZE == 64);
268  f->allow_reexec = true;
269  f->print_full_thread_history = true;
270  f->poison_heap = true;
271  f->poison_partial = true;
272  // Turn off alloc/dealloc mismatch checker on Mac and Windows for now.
273  // https://code.google.com/p/address-sanitizer/issues/detail?id=131
274  // https://code.google.com/p/address-sanitizer/issues/detail?id=309
275  // TODO(glider,timurrrr): Fix known issues and enable this back.
276  f->alloc_dealloc_mismatch = (SANITIZER_MAC == 0) && (SANITIZER_WINDOWS == 0);
277  f->strict_memcmp = true;
278  f->strict_init_order = false;
279  f->start_deactivated = false;
280  f->detect_invalid_pointer_pairs = 0;
281  f->detect_container_overflow = true;
282  f->detect_odr_violation = 2;
283
284  // Override from compile definition.
285  ParseFlagsFromString(f, MaybeUseAsanDefaultOptionsCompileDefinition());
286
287  // Override from user-specified string.
288  ParseFlagsFromString(f, MaybeCallAsanDefaultOptions());
289  VReport(1, "Using the defaults from __asan_default_options: %s\n",
290          MaybeCallAsanDefaultOptions());
291
292  // Override from command line.
293  ParseFlagsFromString(f, env);
294  if (common_flags()->help) {
295    PrintFlagDescriptions();
296  }
297
298  if (!CAN_SANITIZE_LEAKS && cf->detect_leaks) {
299    Report("%s: detect_leaks is not supported on this platform.\n",
300           SanitizerToolName);
301    cf->detect_leaks = false;
302  }
303
304  // Make "strict_init_order" imply "check_initialization_order".
305  // TODO(samsonov): Use a single runtime flag for an init-order checker.
306  if (f->strict_init_order) {
307    f->check_initialization_order = true;
308  }
309}
310
311// Parse flags that may change between startup and activation.
312// On Android they come from a system property.
313// On other platforms this is no-op.
314void ParseExtraActivationFlags() {
315  char buf[100];
316  GetExtraActivationFlags(buf, sizeof(buf));
317  ParseFlagsFromString(flags(), buf);
318  if (buf[0] != '\0')
319    VReport(1, "Extra activation flags: %s\n", buf);
320}
321
322// -------------------------- Globals --------------------- {{{1
323int asan_inited;
324bool asan_init_is_running;
325void (*death_callback)(void);
326
327#if !ASAN_FIXED_MAPPING
328uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;
329#endif
330
331// -------------------------- Misc ---------------- {{{1
332void ShowStatsAndAbort() {
333  __asan_print_accumulated_stats();
334  Die();
335}
336
337// ---------------------- mmap -------------------- {{{1
338// Reserve memory range [beg, end].
339static void ReserveShadowMemoryRange(uptr beg, uptr end) {
340  CHECK_EQ((beg % GetPageSizeCached()), 0);
341  CHECK_EQ(((end + 1) % GetPageSizeCached()), 0);
342  uptr size = end - beg + 1;
343  DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
344  void *res = MmapFixedNoReserve(beg, size);
345  if (res != (void*)beg) {
346    Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
347           "Perhaps you're using ulimit -v\n", size);
348    Abort();
349  }
350}
351
352// --------------- LowLevelAllocateCallbac ---------- {{{1
353static void OnLowLevelAllocate(uptr ptr, uptr size) {
354  PoisonShadow(ptr, size, kAsanInternalHeapMagic);
355}
356
357// -------------------------- Run-time entry ------------------- {{{1
358// exported functions
359#define ASAN_REPORT_ERROR(type, is_write, size)                     \
360extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
361void __asan_report_ ## type ## size(uptr addr);                \
362void __asan_report_ ## type ## size(uptr addr) {               \
363  GET_CALLER_PC_BP_SP;                                              \
364  __asan_report_error(pc, bp, sp, addr, is_write, size);            \
365}
366
367ASAN_REPORT_ERROR(load, false, 1)
368ASAN_REPORT_ERROR(load, false, 2)
369ASAN_REPORT_ERROR(load, false, 4)
370ASAN_REPORT_ERROR(load, false, 8)
371ASAN_REPORT_ERROR(load, false, 16)
372ASAN_REPORT_ERROR(store, true, 1)
373ASAN_REPORT_ERROR(store, true, 2)
374ASAN_REPORT_ERROR(store, true, 4)
375ASAN_REPORT_ERROR(store, true, 8)
376ASAN_REPORT_ERROR(store, true, 16)
377
378#define ASAN_REPORT_ERROR_N(type, is_write)                    \
379extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
380void __asan_report_ ## type ## _n(uptr addr, uptr size);       \
381void __asan_report_ ## type ## _n(uptr addr, uptr size) {      \
382  GET_CALLER_PC_BP_SP;                                         \
383  __asan_report_error(pc, bp, sp, addr, is_write, size);       \
384}
385
386ASAN_REPORT_ERROR_N(load, false)
387ASAN_REPORT_ERROR_N(store, true)
388
389#define ASAN_MEMORY_ACCESS_CALLBACK(type, is_write, size)                      \
390  extern "C" NOINLINE INTERFACE_ATTRIBUTE void __asan_##type##size(uptr addr); \
391  void __asan_##type##size(uptr addr) {                                        \
392    uptr sp = MEM_TO_SHADOW(addr);                                             \
393    uptr s = size <= SHADOW_GRANULARITY ? *reinterpret_cast<u8 *>(sp)          \
394                                        : *reinterpret_cast<u16 *>(sp);        \
395    if (UNLIKELY(s)) {                                                         \
396      if (UNLIKELY(size >= SHADOW_GRANULARITY ||                               \
397                   ((s8)((addr & (SHADOW_GRANULARITY - 1)) + size - 1)) >=     \
398                       (s8)s)) {                                               \
399        if (__asan_test_only_reported_buggy_pointer) {                         \
400          *__asan_test_only_reported_buggy_pointer = addr;                     \
401        } else {                                                               \
402          GET_CALLER_PC_BP_SP;                                                 \
403          __asan_report_error(pc, bp, sp, addr, is_write, size);               \
404        }                                                                      \
405      }                                                                        \
406    }                                                                          \
407  }
408
409ASAN_MEMORY_ACCESS_CALLBACK(load, false, 1)
410ASAN_MEMORY_ACCESS_CALLBACK(load, false, 2)
411ASAN_MEMORY_ACCESS_CALLBACK(load, false, 4)
412ASAN_MEMORY_ACCESS_CALLBACK(load, false, 8)
413ASAN_MEMORY_ACCESS_CALLBACK(load, false, 16)
414ASAN_MEMORY_ACCESS_CALLBACK(store, true, 1)
415ASAN_MEMORY_ACCESS_CALLBACK(store, true, 2)
416ASAN_MEMORY_ACCESS_CALLBACK(store, true, 4)
417ASAN_MEMORY_ACCESS_CALLBACK(store, true, 8)
418ASAN_MEMORY_ACCESS_CALLBACK(store, true, 16)
419
420extern "C"
421NOINLINE INTERFACE_ATTRIBUTE void __asan_loadN(uptr addr, uptr size) {
422  if (__asan_region_is_poisoned(addr, size)) {
423    GET_CALLER_PC_BP_SP;
424    __asan_report_error(pc, bp, sp, addr, false, size);
425  }
426}
427
428extern "C"
429NOINLINE INTERFACE_ATTRIBUTE void __asan_storeN(uptr addr, uptr size) {
430  if (__asan_region_is_poisoned(addr, size)) {
431    GET_CALLER_PC_BP_SP;
432    __asan_report_error(pc, bp, sp, addr, true, size);
433  }
434}
435
436// Force the linker to keep the symbols for various ASan interface functions.
437// We want to keep those in the executable in order to let the instrumented
438// dynamic libraries access the symbol even if it is not used by the executable
439// itself. This should help if the build system is removing dead code at link
440// time.
441static NOINLINE void force_interface_symbols() {
442  volatile int fake_condition = 0;  // prevent dead condition elimination.
443  // __asan_report_* functions are noreturn, so we need a switch to prevent
444  // the compiler from removing any of them.
445  switch (fake_condition) {
446    case 1: __asan_report_load1(0); break;
447    case 2: __asan_report_load2(0); break;
448    case 3: __asan_report_load4(0); break;
449    case 4: __asan_report_load8(0); break;
450    case 5: __asan_report_load16(0); break;
451    case 6: __asan_report_store1(0); break;
452    case 7: __asan_report_store2(0); break;
453    case 8: __asan_report_store4(0); break;
454    case 9: __asan_report_store8(0); break;
455    case 10: __asan_report_store16(0); break;
456    case 12: __asan_register_globals(0, 0); break;
457    case 13: __asan_unregister_globals(0, 0); break;
458    case 14: __asan_set_death_callback(0); break;
459    case 15: __asan_set_error_report_callback(0); break;
460    case 16: __asan_handle_no_return(); break;
461    case 17: __asan_address_is_poisoned(0); break;
462    case 18: __asan_get_allocated_size(0); break;
463    case 19: __asan_get_current_allocated_bytes(); break;
464    case 20: __asan_get_estimated_allocated_size(0); break;
465    case 21: __asan_get_free_bytes(); break;
466    case 22: __asan_get_heap_size(); break;
467    case 23: __asan_get_ownership(0); break;
468    case 24: __asan_get_unmapped_bytes(); break;
469    case 25: __asan_poison_memory_region(0, 0); break;
470    case 26: __asan_unpoison_memory_region(0, 0); break;
471    case 27: __asan_set_error_exit_code(0); break;
472    case 30: __asan_before_dynamic_init(0); break;
473    case 31: __asan_after_dynamic_init(); break;
474    case 32: __asan_poison_stack_memory(0, 0); break;
475    case 33: __asan_unpoison_stack_memory(0, 0); break;
476    case 34: __asan_region_is_poisoned(0, 0); break;
477    case 35: __asan_describe_address(0); break;
478  }
479}
480
481static void asan_atexit() {
482  Printf("AddressSanitizer exit stats:\n");
483  __asan_print_accumulated_stats();
484  // Print AsanMappingProfile.
485  for (uptr i = 0; i < kAsanMappingProfileSize; i++) {
486    if (AsanMappingProfile[i] == 0) continue;
487    Printf("asan_mapping.h:%zd -- %zd\n", i, AsanMappingProfile[i]);
488  }
489}
490
491static void InitializeHighMemEnd() {
492#if !ASAN_FIXED_MAPPING
493  kHighMemEnd = GetMaxVirtualAddress();
494  // Increase kHighMemEnd to make sure it's properly
495  // aligned together with kHighMemBeg:
496  kHighMemEnd |= SHADOW_GRANULARITY * GetPageSizeCached() - 1;
497#endif  // !ASAN_FIXED_MAPPING
498  CHECK_EQ((kHighMemBeg % GetPageSizeCached()), 0);
499}
500
501static void ProtectGap(uptr a, uptr size) {
502  CHECK_EQ(a, (uptr)Mprotect(a, size));
503}
504
505static void PrintAddressSpaceLayout() {
506  Printf("|| `[%p, %p]` || HighMem    ||\n",
507         (void*)kHighMemBeg, (void*)kHighMemEnd);
508  Printf("|| `[%p, %p]` || HighShadow ||\n",
509         (void*)kHighShadowBeg, (void*)kHighShadowEnd);
510  if (kMidMemBeg) {
511    Printf("|| `[%p, %p]` || ShadowGap3 ||\n",
512           (void*)kShadowGap3Beg, (void*)kShadowGap3End);
513    Printf("|| `[%p, %p]` || MidMem     ||\n",
514           (void*)kMidMemBeg, (void*)kMidMemEnd);
515    Printf("|| `[%p, %p]` || ShadowGap2 ||\n",
516           (void*)kShadowGap2Beg, (void*)kShadowGap2End);
517    Printf("|| `[%p, %p]` || MidShadow  ||\n",
518           (void*)kMidShadowBeg, (void*)kMidShadowEnd);
519  }
520  Printf("|| `[%p, %p]` || ShadowGap  ||\n",
521         (void*)kShadowGapBeg, (void*)kShadowGapEnd);
522  if (kLowShadowBeg) {
523    Printf("|| `[%p, %p]` || LowShadow  ||\n",
524           (void*)kLowShadowBeg, (void*)kLowShadowEnd);
525    Printf("|| `[%p, %p]` || LowMem     ||\n",
526           (void*)kLowMemBeg, (void*)kLowMemEnd);
527  }
528  Printf("MemToShadow(shadow): %p %p %p %p",
529         (void*)MEM_TO_SHADOW(kLowShadowBeg),
530         (void*)MEM_TO_SHADOW(kLowShadowEnd),
531         (void*)MEM_TO_SHADOW(kHighShadowBeg),
532         (void*)MEM_TO_SHADOW(kHighShadowEnd));
533  if (kMidMemBeg) {
534    Printf(" %p %p",
535           (void*)MEM_TO_SHADOW(kMidShadowBeg),
536           (void*)MEM_TO_SHADOW(kMidShadowEnd));
537  }
538  Printf("\n");
539  Printf("redzone=%zu\n", (uptr)flags()->redzone);
540  Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
541  Printf("quarantine_size=%zuM\n", (uptr)flags()->quarantine_size >> 20);
542  Printf("malloc_context_size=%zu\n",
543         (uptr)common_flags()->malloc_context_size);
544
545  Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
546  Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
547  Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
548  CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
549  if (kMidMemBeg)
550    CHECK(kMidShadowBeg > kLowShadowEnd &&
551          kMidMemBeg > kMidShadowEnd &&
552          kHighShadowBeg > kMidMemEnd);
553}
554
555static void AsanInitInternal() {
556  if (LIKELY(asan_inited)) return;
557  SanitizerToolName = "AddressSanitizer";
558  CHECK(!asan_init_is_running && "ASan init calls itself!");
559  asan_init_is_running = true;
560
561  // Initialize flags. This must be done early, because most of the
562  // initialization steps look at flags().
563  const char *options = GetEnv("ASAN_OPTIONS");
564  InitializeFlags(flags(), options);
565
566  InitializeHighMemEnd();
567
568  // Make sure we are not statically linked.
569  AsanDoesNotSupportStaticLinkage();
570
571  // Install tool-specific callbacks in sanitizer_common.
572  SetDieCallback(AsanDie);
573  SetCheckFailedCallback(AsanCheckFailed);
574  SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
575
576  if (!flags()->start_deactivated)
577    ParseExtraActivationFlags();
578
579  __sanitizer_set_report_path(common_flags()->log_path);
580  __asan_option_detect_stack_use_after_return =
581      flags()->detect_stack_use_after_return;
582  CHECK_LE(flags()->min_uar_stack_size_log, flags()->max_uar_stack_size_log);
583
584  if (options) {
585    VReport(1, "Parsed ASAN_OPTIONS: %s\n", options);
586  }
587
588  if (flags()->start_deactivated)
589    AsanStartDeactivated();
590
591  // Re-exec ourselves if we need to set additional env or command line args.
592  MaybeReexec();
593
594  // Setup internal allocator callback.
595  SetLowLevelAllocateCallback(OnLowLevelAllocate);
596
597  InitializeAsanInterceptors();
598
599  ReplaceSystemMalloc();
600
601  uptr shadow_start = kLowShadowBeg;
602  if (kLowShadowBeg)
603    shadow_start -= GetMmapGranularity();
604  bool full_shadow_is_available =
605      MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
606
607#if SANITIZER_LINUX && defined(__x86_64__) && !ASAN_FIXED_MAPPING
608  if (!full_shadow_is_available) {
609    kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
610    kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
611  }
612#endif
613
614  if (common_flags()->verbosity)
615    PrintAddressSpaceLayout();
616
617  if (flags()->disable_core) {
618    DisableCoreDumper();
619  }
620
621  if (full_shadow_is_available) {
622    // mmap the low shadow plus at least one page at the left.
623    if (kLowShadowBeg)
624      ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
625    // mmap the high shadow.
626    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
627    // protect the gap.
628    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
629    CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
630  } else if (kMidMemBeg &&
631      MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
632      MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
633    CHECK(kLowShadowBeg != kLowShadowEnd);
634    // mmap the low shadow plus at least one page at the left.
635    ReserveShadowMemoryRange(shadow_start, kLowShadowEnd);
636    // mmap the mid shadow.
637    ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd);
638    // mmap the high shadow.
639    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
640    // protect the gaps.
641    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
642    ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
643    ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
644  } else {
645    Report("Shadow memory range interleaves with an existing memory mapping. "
646           "ASan cannot proceed correctly. ABORTING.\n");
647    DumpProcessMap();
648    Die();
649  }
650
651  AsanTSDInit(PlatformTSDDtor);
652  InstallDeadlySignalHandlers(AsanOnSIGSEGV);
653
654  // Allocator should be initialized before starting external symbolizer, as
655  // fork() on Mac locks the allocator.
656  InitializeAllocator();
657
658  Symbolizer::Init(common_flags()->external_symbolizer_path);
659
660  // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
661  // should be set to 1 prior to initializing the threads.
662  asan_inited = 1;
663  asan_init_is_running = false;
664
665  if (flags()->atexit)
666    Atexit(asan_atexit);
667
668  if (common_flags()->coverage) {
669    __sanitizer_cov_init();
670    Atexit(__sanitizer_cov_dump);
671  }
672
673  // interceptors
674  InitTlsSize();
675
676  // Create main thread.
677  AsanThread *main_thread = AsanThread::Create(0, 0);
678  CreateThreadContextArgs create_main_args = { main_thread, 0 };
679  u32 main_tid = asanThreadRegistry().CreateThread(
680      0, true, 0, &create_main_args);
681  CHECK_EQ(0, main_tid);
682  SetCurrentThread(main_thread);
683  main_thread->ThreadStart(internal_getpid());
684  force_interface_symbols();  // no-op.
685  SanitizerInitializeUnwinder();
686
687#if CAN_SANITIZE_LEAKS
688  __lsan::InitCommonLsan();
689  if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
690    Atexit(__lsan::DoLeakCheck);
691  }
692#endif  // CAN_SANITIZE_LEAKS
693
694  VReport(1, "AddressSanitizer Init done\n");
695}
696
697// Initialize as requested from some part of ASan runtime library (interceptors,
698// allocator, etc).
699void AsanInitFromRtl() {
700  AsanInitInternal();
701}
702
703#if ASAN_DYNAMIC
704// Initialize runtime in case it's LD_PRELOAD-ed into unsanitized executable
705// (and thus normal initializer from .preinit_array haven't run).
706
707class AsanInitializer {
708public:  // NOLINT
709  AsanInitializer() {
710    AsanCheckIncompatibleRT();
711    AsanCheckDynamicRTPrereqs();
712    if (UNLIKELY(!asan_inited))
713      __asan_init();
714  }
715};
716
717static AsanInitializer asan_initializer;
718#endif  // ASAN_DYNAMIC
719
720}  // namespace __asan
721
722// ---------------------- Interface ---------------- {{{1
723using namespace __asan;  // NOLINT
724
725#if !SANITIZER_SUPPORTS_WEAK_HOOKS
726extern "C" {
727SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
728const char* __asan_default_options() { return ""; }
729}  // extern "C"
730#endif
731
732int NOINLINE __asan_set_error_exit_code(int exit_code) {
733  int old = flags()->exitcode;
734  flags()->exitcode = exit_code;
735  return old;
736}
737
738void NOINLINE __asan_handle_no_return() {
739  int local_stack;
740  AsanThread *curr_thread = GetCurrentThread();
741  CHECK(curr_thread);
742  uptr PageSize = GetPageSizeCached();
743  uptr top = curr_thread->stack_top();
744  uptr bottom = ((uptr)&local_stack - PageSize) & ~(PageSize-1);
745  static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
746  if (top - bottom > kMaxExpectedCleanupSize) {
747    static bool reported_warning = false;
748    if (reported_warning)
749      return;
750    reported_warning = true;
751    Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
752           "stack top: %p; bottom %p; size: %p (%zd)\n"
753           "False positive error reports may follow\n"
754           "For details see "
755           "http://code.google.com/p/address-sanitizer/issues/detail?id=189\n",
756           top, bottom, top - bottom, top - bottom);
757    return;
758  }
759  PoisonShadow(bottom, top - bottom, 0);
760  if (curr_thread->has_fake_stack())
761    curr_thread->fake_stack()->HandleNoReturn();
762}
763
764void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
765  death_callback = callback;
766}
767
768// Initialize as requested from instrumented application code.
769// We use this call as a trigger to wake up ASan from deactivated state.
770void __asan_init() {
771  AsanCheckIncompatibleRT();
772  AsanActivate();
773  AsanInitInternal();
774}
775