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
30 namespace __sanitizer {
31 using namespace __asan;
32
Die()33 void 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
52 SANITIZER_INTERFACE_ATTRIBUTE
CheckFailed(const char * file,int line,const char * cond,u64 v1,u64 v2)53 void 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 // FIXME: check for infinite recursion without a thread-local counter here.
57 PRINT_CURRENT_STACK();
58 ShowStatsAndAbort();
59 }
60
61 } // namespace __sanitizer
62
63 namespace __asan {
64
65 // -------------------------- Flags ------------------------- {{{1
66 static const int kDeafultMallocContextSize = 30;
67
68 static Flags asan_flags;
69
flags()70 Flags *flags() {
71 return &asan_flags;
72 }
73
ParseFlagsFromString(Flags * f,const char * str)74 static void ParseFlagsFromString(Flags *f, const char *str) {
75 ParseFlag(str, &f->quarantine_size, "quarantine_size");
76 ParseFlag(str, &f->symbolize, "symbolize");
77 ParseFlag(str, &f->verbosity, "verbosity");
78 ParseFlag(str, &f->redzone, "redzone");
79 CHECK(f->redzone >= 16);
80 CHECK(IsPowerOfTwo(f->redzone));
81
82 ParseFlag(str, &f->debug, "debug");
83 ParseFlag(str, &f->report_globals, "report_globals");
84 ParseFlag(str, &f->check_initialization_order, "initialization_order");
85 ParseFlag(str, &f->malloc_context_size, "malloc_context_size");
86 CHECK((uptr)f->malloc_context_size <= kStackTraceMax);
87
88 ParseFlag(str, &f->replace_str, "replace_str");
89 ParseFlag(str, &f->replace_intrin, "replace_intrin");
90 ParseFlag(str, &f->replace_cfallocator, "replace_cfallocator");
91 ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free");
92 ParseFlag(str, &f->use_fake_stack, "use_fake_stack");
93 ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size");
94 ParseFlag(str, &f->exitcode, "exitcode");
95 ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning");
96 ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying");
97 ParseFlag(str, &f->handle_segv, "handle_segv");
98 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack");
99 ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size");
100 ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit");
101 ParseFlag(str, &f->abort_on_error, "abort_on_error");
102 ParseFlag(str, &f->atexit, "atexit");
103 ParseFlag(str, &f->disable_core, "disable_core");
104 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix");
105 ParseFlag(str, &f->allow_reexec, "allow_reexec");
106 ParseFlag(str, &f->print_full_thread_history, "print_full_thread_history");
107 }
108
109 extern "C" {
110 SANITIZER_WEAK_ATTRIBUTE
111 SANITIZER_INTERFACE_ATTRIBUTE
__asan_default_options()112 const char* __asan_default_options() { return ""; }
113 } // extern "C"
114
InitializeFlags(Flags * f,const char * env)115 void InitializeFlags(Flags *f, const char *env) {
116 internal_memset(f, 0, sizeof(*f));
117
118 f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 26 : 1UL << 28;
119 f->symbolize = false;
120 f->verbosity = 0;
121 f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128;
122 f->debug = false;
123 f->report_globals = 1;
124 f->check_initialization_order = true;
125 f->malloc_context_size = kDeafultMallocContextSize;
126 f->replace_str = true;
127 f->replace_intrin = true;
128 f->replace_cfallocator = true;
129 f->mac_ignore_invalid_free = false;
130 f->use_fake_stack = true;
131 f->max_malloc_fill_size = 0;
132 f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
133 f->allow_user_poisoning = true;
134 f->sleep_before_dying = 0;
135 f->handle_segv = ASAN_NEEDS_SEGV;
136 f->use_sigaltstack = false;
137 f->check_malloc_usable_size = true;
138 f->unmap_shadow_on_exit = false;
139 f->abort_on_error = false;
140 f->atexit = false;
141 f->disable_core = (__WORDSIZE == 64);
142 f->strip_path_prefix = "";
143 f->allow_reexec = true;
144 f->print_full_thread_history = true;
145
146 // Override from user-specified string.
147 ParseFlagsFromString(f, __asan_default_options());
148 if (flags()->verbosity) {
149 Report("Using the defaults from __asan_default_options: %s\n",
150 __asan_default_options());
151 }
152
153 // Override from command line.
154 ParseFlagsFromString(f, env);
155 }
156
157 // -------------------------- Globals --------------------- {{{1
158 int asan_inited;
159 bool asan_init_is_running;
160 void (*death_callback)(void);
161
162 // -------------------------- Misc ---------------- {{{1
ShowStatsAndAbort()163 void ShowStatsAndAbort() {
164 __asan_print_accumulated_stats();
165 Die();
166 }
167
168 // ---------------------- mmap -------------------- {{{1
169 // Reserve memory range [beg, end].
ReserveShadowMemoryRange(uptr beg,uptr end)170 static void ReserveShadowMemoryRange(uptr beg, uptr end) {
171 CHECK((beg % kPageSize) == 0);
172 CHECK(((end + 1) % kPageSize) == 0);
173 uptr size = end - beg + 1;
174 void *res = MmapFixedNoReserve(beg, size);
175 if (res != (void*)beg) {
176 Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
177 "Perhaps you're using ulimit -v\n", size);
178 Abort();
179 }
180 }
181
182 // --------------- LowLevelAllocateCallbac ---------- {{{1
OnLowLevelAllocate(uptr ptr,uptr size)183 static void OnLowLevelAllocate(uptr ptr, uptr size) {
184 PoisonShadow(ptr, size, kAsanInternalHeapMagic);
185 }
186
187 // -------------------------- Run-time entry ------------------- {{{1
188 // exported functions
189 #define ASAN_REPORT_ERROR(type, is_write, size) \
190 extern "C" NOINLINE INTERFACE_ATTRIBUTE \
191 void __asan_report_ ## type ## size(uptr addr); \
192 void __asan_report_ ## type ## size(uptr addr) { \
193 GET_CALLER_PC_BP_SP; \
194 __asan_report_error(pc, bp, sp, addr, is_write, size); \
195 }
196
197 ASAN_REPORT_ERROR(load, false, 1)
198 ASAN_REPORT_ERROR(load, false, 2)
199 ASAN_REPORT_ERROR(load, false, 4)
200 ASAN_REPORT_ERROR(load, false, 8)
201 ASAN_REPORT_ERROR(load, false, 16)
202 ASAN_REPORT_ERROR(store, true, 1)
203 ASAN_REPORT_ERROR(store, true, 2)
204 ASAN_REPORT_ERROR(store, true, 4)
205 ASAN_REPORT_ERROR(store, true, 8)
206 ASAN_REPORT_ERROR(store, true, 16)
207
208 // Force the linker to keep the symbols for various ASan interface functions.
209 // We want to keep those in the executable in order to let the instrumented
210 // dynamic libraries access the symbol even if it is not used by the executable
211 // itself. This should help if the build system is removing dead code at link
212 // time.
force_interface_symbols()213 static NOINLINE void force_interface_symbols() {
214 volatile int fake_condition = 0; // prevent dead condition elimination.
215 // __asan_report_* functions are noreturn, so we need a switch to prevent
216 // the compiler from removing any of them.
217 switch (fake_condition) {
218 case 1: __asan_report_load1(0); break;
219 case 2: __asan_report_load2(0); break;
220 case 3: __asan_report_load4(0); break;
221 case 4: __asan_report_load8(0); break;
222 case 5: __asan_report_load16(0); break;
223 case 6: __asan_report_store1(0); break;
224 case 7: __asan_report_store2(0); break;
225 case 8: __asan_report_store4(0); break;
226 case 9: __asan_report_store8(0); break;
227 case 10: __asan_report_store16(0); break;
228 case 11: __asan_register_global(0, 0, 0); break;
229 case 12: __asan_register_globals(0, 0); break;
230 case 13: __asan_unregister_globals(0, 0); break;
231 case 14: __asan_set_death_callback(0); break;
232 case 15: __asan_set_error_report_callback(0); break;
233 case 16: __asan_handle_no_return(); break;
234 case 17: __asan_address_is_poisoned(0); break;
235 case 18: __asan_get_allocated_size(0); break;
236 case 19: __asan_get_current_allocated_bytes(); break;
237 case 20: __asan_get_estimated_allocated_size(0); break;
238 case 21: __asan_get_free_bytes(); break;
239 case 22: __asan_get_heap_size(); break;
240 case 23: __asan_get_ownership(0); break;
241 case 24: __asan_get_unmapped_bytes(); break;
242 case 25: __asan_poison_memory_region(0, 0); break;
243 case 26: __asan_unpoison_memory_region(0, 0); break;
244 case 27: __asan_set_error_exit_code(0); break;
245 case 28: __asan_stack_free(0, 0, 0); break;
246 case 29: __asan_stack_malloc(0, 0); break;
247 case 30: __asan_set_on_error_callback(0); break;
248 case 31: __asan_default_options(); break;
249 case 32: __asan_before_dynamic_init(0, 0); break;
250 case 33: __asan_after_dynamic_init(); break;
251 case 34: __asan_malloc_hook(0, 0); break;
252 case 35: __asan_free_hook(0); break;
253 case 36: __asan_set_symbolize_callback(0); break;
254 }
255 }
256
asan_atexit()257 static void asan_atexit() {
258 Printf("AddressSanitizer exit stats:\n");
259 __asan_print_accumulated_stats();
260 }
261
262 } // namespace __asan
263
264 // ---------------------- Interface ---------------- {{{1
265 using namespace __asan; // NOLINT
266
__asan_set_error_exit_code(int exit_code)267 int NOINLINE __asan_set_error_exit_code(int exit_code) {
268 int old = flags()->exitcode;
269 flags()->exitcode = exit_code;
270 return old;
271 }
272
__asan_handle_no_return()273 void NOINLINE __asan_handle_no_return() {
274 int local_stack;
275 AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
276 CHECK(curr_thread);
277 uptr top = curr_thread->stack_top();
278 uptr bottom = ((uptr)&local_stack - kPageSize) & ~(kPageSize-1);
279 PoisonShadow(bottom, top - bottom, 0);
280 }
281
__asan_set_death_callback(void (* callback)(void))282 void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
283 death_callback = callback;
284 }
285
__asan_init()286 void __asan_init() {
287 if (asan_inited) return;
288 CHECK(!asan_init_is_running && "ASan init calls itself!");
289 asan_init_is_running = true;
290
291 // Make sure we are not statically linked.
292 AsanDoesNotSupportStaticLinkage();
293
294 SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
295
296 // Initialize flags. This must be done early, because most of the
297 // initialization steps look at flags().
298 const char *options = GetEnv("ASAN_OPTIONS");
299 InitializeFlags(flags(), options);
300
301 if (flags()->verbosity && options) {
302 Report("Parsed ASAN_OPTIONS: %s\n", options);
303 }
304
305 // Re-exec ourselves if we need to set additional env or command line args.
306 MaybeReexec();
307
308 // Setup internal allocator callback.
309 SetLowLevelAllocateCallback(OnLowLevelAllocate);
310
311 if (flags()->atexit) {
312 Atexit(asan_atexit);
313 }
314
315 // interceptors
316 InitializeAsanInterceptors();
317
318 ReplaceSystemMalloc();
319 ReplaceOperatorsNewAndDelete();
320
321 if (flags()->verbosity) {
322 Printf("|| `[%p, %p]` || HighMem ||\n",
323 (void*)kHighMemBeg, (void*)kHighMemEnd);
324 Printf("|| `[%p, %p]` || HighShadow ||\n",
325 (void*)kHighShadowBeg, (void*)kHighShadowEnd);
326 Printf("|| `[%p, %p]` || ShadowGap ||\n",
327 (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);
332 Printf("MemToShadow(shadow): %p %p %p %p\n",
333 (void*)MEM_TO_SHADOW(kLowShadowBeg),
334 (void*)MEM_TO_SHADOW(kLowShadowEnd),
335 (void*)MEM_TO_SHADOW(kHighShadowBeg),
336 (void*)MEM_TO_SHADOW(kHighShadowEnd));
337 Printf("red_zone=%zu\n", (uptr)flags()->redzone);
338 Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size);
339
340 Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
341 Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
342 Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
343 CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
344 }
345
346 if (flags()->disable_core) {
347 DisableCoreDumper();
348 }
349
350 uptr shadow_start = kLowShadowBeg;
351 if (kLowShadowBeg > 0) shadow_start -= kMmapGranularity;
352 uptr shadow_end = kHighShadowEnd;
353 if (MemoryRangeIsAvailable(shadow_start, shadow_end)) {
354 if (kLowShadowBeg != kLowShadowEnd) {
355 // mmap the low shadow plus at least one page.
356 ReserveShadowMemoryRange(kLowShadowBeg - kMmapGranularity, kLowShadowEnd);
357 }
358 // mmap the high shadow.
359 ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
360 // protect the gap
361 void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
362 CHECK(prot == (void*)kShadowGapBeg);
363 } else {
364 Report("Shadow memory range interleaves with an existing memory mapping. "
365 "ASan cannot proceed correctly. ABORTING.\n");
366 DumpProcessMap();
367 Die();
368 }
369
370 InstallSignalHandlers();
371 // Start symbolizer process if necessary.
372 if (flags()->symbolize) {
373 const char *external_symbolizer = GetEnv("ASAN_SYMBOLIZER_PATH");
374 if (external_symbolizer) {
375 InitializeExternalSymbolizer(external_symbolizer);
376 }
377 }
378 #ifdef _WIN32
379 __asan_set_symbolize_callback(WinSymbolize);
380 #endif // _WIN32
381
382 // On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
383 // should be set to 1 prior to initializing the threads.
384 asan_inited = 1;
385 asan_init_is_running = false;
386
387 asanThreadRegistry().Init();
388 asanThreadRegistry().GetMain()->ThreadStart();
389 force_interface_symbols(); // no-op.
390
391 if (flags()->verbosity) {
392 Report("AddressSanitizer Init done\n");
393 }
394 }
395
396 #if defined(ASAN_USE_PREINIT_ARRAY)
397 // On Linux, we force __asan_init to be called before anyone else
398 // by placing it into .preinit_array section.
399 // FIXME: do we have anything like this on Mac?
400 __attribute__((section(".preinit_array")))
401 typeof(__asan_init) *__asan_preinit =__asan_init;
402 #elif defined(_WIN32) && defined(_DLL)
403 // On Windows, when using dynamic CRT (/MD), we can put a pointer
404 // to __asan_init into the global list of C initializers.
405 // See crt0dat.c in the CRT sources for the details.
406 #pragma section(".CRT$XIB", long, read) // NOLINT
407 __declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init;
408 #endif
409