asan_rtl.cc revision 6d924facc5c979a0d25f484cffcdb51c766ed551 
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_allocator.h"
15#include "asan_interceptors.h"
16#include "asan_internal.h"
17#include "asan_lock.h"
18#include "asan_mapping.h"
19#include "asan_report.h"
20#include "asan_stack.h"
21#include "asan_stats.h"
22#include "asan_thread.h"
23#include "asan_thread_registry.h"
24#include "sanitizer/asan_interface.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
30namespace __sanitizer {
31using namespace __asan;
32
33void Die() {
34  static atomic_uint32_t num_calls;
35  if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
36    // Don't die twice - run a busy loop.
37    while (1) { }
38  }
39  if (flags()->sleep_before_dying) {
40    Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
41    SleepForSeconds(flags()->sleep_before_dying);
42  }
43  if (flags()->unmap_shadow_on_exit)
44    UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
45  if (death_callback)
46    death_callback();
47  if (flags()->abort_on_error)
48    Abort();
49  Exit(flags()->exitcode);
50}
51
52SANITIZER_INTERFACE_ATTRIBUTE
53void CheckFailed(const char *file, int line, const char *cond, u64 v1, u64 v2) {
54  Report("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n",
55             file, line, cond, (uptr)v1, (uptr)v2);
56  PRINT_CURRENT_STACK();
57  ShowStatsAndAbort();
58}
59
60}  // namespace __sanitizer
61
62namespace __asan {
63
64// -------------------------- Flags ------------------------- {{{1
65static const int kDeafultMallocContextSize = 30;
66
67static Flags asan_flags;
68
69Flags *flags() {
70  return &asan_flags;
71}
72
73static void ParseFlagsFromString(Flags *f, const char *str) {
74  ParseFlag(str, &f->quarantine_size, "quarantine_size");
75  ParseFlag(str, &f->symbolize, "symbolize");
76  ParseFlag(str, &f->verbosity, "verbosity");
77  ParseFlag(str, &f->redzone, "redzone");
78  CHECK(f->redzone >= 16);
79  CHECK(IsPowerOfTwo(f->redzone));
80
81  ParseFlag(str, &f->debug, "debug");
82  ParseFlag(str, &f->report_globals, "report_globals");
83  ParseFlag(str, &f->check_initialization_order, "initialization_order");
84  ParseFlag(str, &f->malloc_context_size, "malloc_context_size");
85  CHECK(f->malloc_context_size <= kStackTraceMax);
86
87  ParseFlag(str, &f->replace_str, "replace_str");
88  ParseFlag(str, &f->replace_intrin, "replace_intrin");
89  ParseFlag(str, &f->replace_cfallocator, "replace_cfallocator");
90  ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free");
91  ParseFlag(str, &f->use_fake_stack, "use_fake_stack");
92  ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size");
93  ParseFlag(str, &f->exitcode, "exitcode");
94  ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning");
95  ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying");
96  ParseFlag(str, &f->handle_segv, "handle_segv");
97  ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack");
98  ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size");
99  ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit");
100  ParseFlag(str, &f->abort_on_error, "abort_on_error");
101  ParseFlag(str, &f->atexit, "atexit");
102  ParseFlag(str, &f->disable_core, "disable_core");
103  ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix");
104  ParseFlag(str, &f->allow_reexec, "allow_reexec");
105  ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history");
106}
107
108extern "C" {
109SANITIZER_WEAK_ATTRIBUTE
110SANITIZER_INTERFACE_ATTRIBUTE
111const char* __asan_default_options() { return ""; }
112}  // extern "C"
113
114void InitializeFlags(Flags *f, const char *env) {
115  internal_memset(f, 0, sizeof(*f));
116
117  f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 24 : 1UL << 28;
118  f->symbolize = false;
119  f->verbosity = 0;
120  f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128;
121  f->debug = false;
122  f->report_globals = 1;
123  f->check_initialization_order = true;
124  f->malloc_context_size = kDeafultMallocContextSize;
125  f->replace_str = true;
126  f->replace_intrin = true;
127  f->replace_cfallocator = true;
128  f->mac_ignore_invalid_free = false;
129  f->use_fake_stack = true;
130  f->max_malloc_fill_size = 0;
131  f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
132  f->allow_user_poisoning = true;
133  f->sleep_before_dying = 0;
134  f->handle_segv = ASAN_NEEDS_SEGV;
135  f->use_sigaltstack = false;
136  f->check_malloc_usable_size = true;
137  f->unmap_shadow_on_exit = false;
138  f->abort_on_error = false;
139  f->atexit = false;
140  f->disable_core = (__WORDSIZE == 64);
141  f->strip_path_prefix = "";
142  f->allow_reexec = true;
143  f->print_full_thread_history = true;
144
145  // Override from user-specified string.
146  ParseFlagsFromString(f, __asan_default_options());
147  if (flags()->verbosity) {
148    Report("Using the defaults from __asan_default_options: %s\n",
149           __asan_default_options());
150  }
151
152  // Override from command line.
153  ParseFlagsFromString(f, env);
154}
155
156// -------------------------- Globals --------------------- {{{1
157int asan_inited;
158bool asan_init_is_running;
159void (*death_callback)(void);
160
161// -------------------------- Misc ---------------- {{{1
162void ShowStatsAndAbort() {
163  __asan_print_accumulated_stats();
164  Die();
165}
166
167// ---------------------- mmap -------------------- {{{1
168// Reserve memory range [beg, end].
169static void ReserveShadowMemoryRange(uptr beg, uptr end) {
170  CHECK((beg % kPageSize) == 0);
171  CHECK(((end + 1) % kPageSize) == 0);
172  uptr size = end - beg + 1;
173  void *res = MmapFixedNoReserve(beg, size);
174  CHECK(res == (void*)beg && "ReserveShadowMemoryRange failed");
175}
176
177// --------------- LowLevelAllocateCallbac ---------- {{{1
178static void OnLowLevelAllocate(uptr ptr, uptr size) {
179  PoisonShadow(ptr, size, kAsanInternalHeapMagic);
180}
181
182// -------------------------- Run-time entry ------------------- {{{1
183// exported functions
184#define ASAN_REPORT_ERROR(type, is_write, size)                     \
185extern "C" NOINLINE INTERFACE_ATTRIBUTE                        \
186void __asan_report_ ## type ## size(uptr addr);                \
187void __asan_report_ ## type ## size(uptr addr) {               \
188  GET_CALLER_PC_BP_SP;                                              \
189  __asan_report_error(pc, bp, sp, addr, is_write, size);            \
190}
191
192ASAN_REPORT_ERROR(load, false, 1)
193ASAN_REPORT_ERROR(load, false, 2)
194ASAN_REPORT_ERROR(load, false, 4)
195ASAN_REPORT_ERROR(load, false, 8)
196ASAN_REPORT_ERROR(load, false, 16)
197ASAN_REPORT_ERROR(store, true, 1)
198ASAN_REPORT_ERROR(store, true, 2)
199ASAN_REPORT_ERROR(store, true, 4)
200ASAN_REPORT_ERROR(store, true, 8)
201ASAN_REPORT_ERROR(store, true, 16)
202
203// Force the linker to keep the symbols for various ASan interface functions.
204// We want to keep those in the executable in order to let the instrumented
205// dynamic libraries access the symbol even if it is not used by the executable
206// itself. This should help if the build system is removing dead code at link
207// time.
208static NOINLINE void force_interface_symbols() {
209  volatile int fake_condition = 0;  // prevent dead condition elimination.
210  // __asan_report_* functions are noreturn, so we need a switch to prevent
211  // the compiler from removing any of them.
212  switch (fake_condition) {
213    case 1: __asan_report_load1(0); break;
214    case 2: __asan_report_load2(0); break;
215    case 3: __asan_report_load4(0); break;
216    case 4: __asan_report_load8(0); break;
217    case 5: __asan_report_load16(0); break;
218    case 6: __asan_report_store1(0); break;
219    case 7: __asan_report_store2(0); break;
220    case 8: __asan_report_store4(0); break;
221    case 9: __asan_report_store8(0); break;
222    case 10: __asan_report_store16(0); break;
223    case 11: __asan_register_global(0, 0, 0); break;
224    case 12: __asan_register_globals(0, 0); break;
225    case 13: __asan_unregister_globals(0, 0); break;
226    case 14: __asan_set_death_callback(0); break;
227    case 15: __asan_set_error_report_callback(0); break;
228    case 16: __asan_handle_no_return(); break;
229    case 17: __asan_address_is_poisoned(0); break;
230    case 18: __asan_get_allocated_size(0); break;
231    case 19: __asan_get_current_allocated_bytes(); break;
232    case 20: __asan_get_estimated_allocated_size(0); break;
233    case 21: __asan_get_free_bytes(); break;
234    case 22: __asan_get_heap_size(); break;
235    case 23: __asan_get_ownership(0); break;
236    case 24: __asan_get_unmapped_bytes(); break;
237    case 25: __asan_poison_memory_region(0, 0); break;
238    case 26: __asan_unpoison_memory_region(0, 0); break;
239    case 27: __asan_set_error_exit_code(0); break;
240    case 28: __asan_stack_free(0, 0, 0); break;
241    case 29: __asan_stack_malloc(0, 0); break;
242    case 30: __asan_set_on_error_callback(0); break;
243    case 31: __asan_default_options(); break;
244    case 32: __asan_before_dynamic_init(0, 0); break;
245    case 33: __asan_after_dynamic_init(); break;
246    case 34: __asan_malloc_hook(0, 0); break;
247    case 35: __asan_free_hook(0); break;
248    case 36: __asan_set_symbolize_callback(0); break;
249  }
250}
251
252static void asan_atexit() {
253  Printf("AddressSanitizer exit stats:\n");
254  __asan_print_accumulated_stats();
255}
256
257}  // namespace __asan
258
259// ---------------------- Interface ---------------- {{{1
260using namespace __asan;  // NOLINT
261
262int NOINLINE __asan_set_error_exit_code(int exit_code) {
263  int old = flags()->exitcode;
264  flags()->exitcode = exit_code;
265  return old;
266}
267
268void NOINLINE __asan_handle_no_return() {
269  int local_stack;
270  AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
271  CHECK(curr_thread);
272  uptr top = curr_thread->stack_top();
273  uptr bottom = ((uptr)&local_stack - kPageSize) & ~(kPageSize-1);
274  PoisonShadow(bottom, top - bottom, 0);
275}
276
277void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
278  death_callback = callback;
279}
280
281void __asan_init() {
282  if (asan_inited) return;
283  CHECK(!asan_init_is_running && "ASan init calls itself!");
284  asan_init_is_running = true;
285
286  // Make sure we are not statically linked.
287  AsanDoesNotSupportStaticLinkage();
288
289  SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
290
291  // Initialize flags. This must be done early, because most of the
292  // initialization steps look at flags().
293  const char *options = GetEnv("ASAN_OPTIONS");
294  InitializeFlags(flags(), options);
295
296  if (flags()->verbosity && options) {
297    Report("Parsed ASAN_OPTIONS: %s\n", options);
298  }
299
300  // Re-exec ourselves if we need to set additional env or command line args.
301  MaybeReexec();
302
303  // Setup internal allocator callback.
304  SetLowLevelAllocateCallback(OnLowLevelAllocate);
305
306  if (flags()->atexit) {
307    Atexit(asan_atexit);
308  }
309
310  // interceptors
311  InitializeAsanInterceptors();
312
313  ReplaceSystemMalloc();
314  ReplaceOperatorsNewAndDelete();
315
316  if (flags()->verbosity) {
317    Printf("|| `[%p, %p]` || HighMem    ||\n",
318           (void*)kHighMemBeg, (void*)kHighMemEnd);
319    Printf("|| `[%p, %p]` || HighShadow ||\n",
320           (void*)kHighShadowBeg, (void*)kHighShadowEnd);
321    Printf("|| `[%p, %p]` || ShadowGap  ||\n",
322           (void*)kShadowGapBeg, (void*)kShadowGapEnd);
323    Printf("|| `[%p, %p]` || LowShadow  ||\n",
324           (void*)kLowShadowBeg, (void*)kLowShadowEnd);
325    Printf("|| `[%p, %p]` || LowMem     ||\n",
326           (void*)kLowMemBeg, (void*)kLowMemEnd);
327    Printf("MemToShadow(shadow): %p %p %p %p\n",
328           (void*)MEM_TO_SHADOW(kLowShadowBeg),
329           (void*)MEM_TO_SHADOW(kLowShadowEnd),
330           (void*)MEM_TO_SHADOW(kHighShadowBeg),
331           (void*)MEM_TO_SHADOW(kHighShadowEnd));
332    Printf("red_zone=%zu\n", (uptr)flags()->redzone);
333    Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size);
334
335    Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
336    Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
337    Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
338    CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
339  }
340
341  if (flags()->disable_core) {
342    DisableCoreDumper();
343  }
344
345  uptr shadow_start = kLowShadowBeg;
346  if (kLowShadowBeg > 0) shadow_start -= kMmapGranularity;
347  uptr shadow_end = kHighShadowEnd;
348  if (MemoryRangeIsAvailable(shadow_start, shadow_end)) {
349    if (kLowShadowBeg != kLowShadowEnd) {
350      // mmap the low shadow plus at least one page.
351      ReserveShadowMemoryRange(kLowShadowBeg - kMmapGranularity, kLowShadowEnd);
352    }
353    // mmap the high shadow.
354    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
355    // protect the gap
356    void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
357    CHECK(prot == (void*)kShadowGapBeg);
358  } else {
359    Report("Shadow memory range interleaves with an existing memory mapping. "
360           "ASan cannot proceed correctly. ABORTING.\n");
361    DumpProcessMap();
362    Die();
363  }
364
365  InstallSignalHandlers();
366  // Start symbolizer process if necessary.
367  if (flags()->symbolize) {
368    const char *external_symbolizer = GetEnv("ASAN_SYMBOLIZER_PATH");
369    if (external_symbolizer) {
370      InitializeExternalSymbolizer(external_symbolizer);
371    }
372  }
373#ifdef _WIN32
374  __asan_set_symbolize_callback(WinSymbolize);
375#endif  // _WIN32
376
377  // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
378  // should be set to 1 prior to initializing the threads.
379  asan_inited = 1;
380  asan_init_is_running = false;
381
382  asanThreadRegistry().Init();
383  asanThreadRegistry().GetMain()->ThreadStart();
384  force_interface_symbols();  // no-op.
385
386  if (flags()->verbosity) {
387    Report("AddressSanitizer Init done\n");
388  }
389}
390
391#if defined(ASAN_USE_PREINIT_ARRAY)
392  // On Linux, we force __asan_init to be called before anyone else
393  // by placing it into .preinit_array section.
394  // FIXME: do we have anything like this on Mac?
395  __attribute__((section(".preinit_array")))
396    typeof(__asan_init) *__asan_preinit =__asan_init;
397#elif defined(_WIN32) && defined(_DLL)
398  // On Windows, when using dynamic CRT (/MD), we can put a pointer
399  // to __asan_init into the global list of C initializers.
400  // See crt0dat.c in the CRT sources for the details.
401  #pragma section(".CRT$XIB", long, read)  // NOLINT
402  __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init;
403#endif
404