1 //===-- asan_interceptors.cpp ---------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of AddressSanitizer, an address sanity checker.
10 //
11 // Intercept various libc functions.
12 //===----------------------------------------------------------------------===//
13 
14 #include "asan_interceptors.h"
15 #include "asan_allocator.h"
16 #include "asan_internal.h"
17 #include "asan_mapping.h"
18 #include "asan_poisoning.h"
19 #include "asan_report.h"
20 #include "asan_stack.h"
21 #include "asan_stats.h"
22 #include "asan_suppressions.h"
23 #include "lsan/lsan_common.h"
24 #include "sanitizer_common/sanitizer_libc.h"
25 
26 // There is no general interception at all on Fuchsia.
27 // Only the functions in asan_interceptors_memintrinsics.cpp are
28 // really defined to replace libc functions.
29 #if !SANITIZER_FUCHSIA
30 
31 #  if SANITIZER_POSIX
32 #    include "sanitizer_common/sanitizer_posix.h"
33 #  endif
34 
35 #  if ASAN_INTERCEPT__UNWIND_RAISEEXCEPTION || \
36       ASAN_INTERCEPT__SJLJ_UNWIND_RAISEEXCEPTION
37 #    include <unwind.h>
38 #  endif
39 
40 #  if defined(__i386) && SANITIZER_LINUX
41 #    define ASAN_PTHREAD_CREATE_VERSION "GLIBC_2.1"
42 #  elif defined(__mips__) && SANITIZER_LINUX
43 #    define ASAN_PTHREAD_CREATE_VERSION "GLIBC_2.2"
44 #  endif
45 
46 namespace __asan {
47 
48 #define ASAN_READ_STRING_OF_LEN(ctx, s, len, n)                 \
49   ASAN_READ_RANGE((ctx), (s),                                   \
50     common_flags()->strict_string_checks ? (len) + 1 : (n))
51 
52 #  define ASAN_READ_STRING(ctx, s, n) \
53     ASAN_READ_STRING_OF_LEN((ctx), (s), internal_strlen(s), (n))
54 
55 static inline uptr MaybeRealStrnlen(const char *s, uptr maxlen) {
56 #if SANITIZER_INTERCEPT_STRNLEN
57   if (REAL(strnlen)) {
58     return REAL(strnlen)(s, maxlen);
59   }
60 #endif
61   return internal_strnlen(s, maxlen);
62 }
63 
64 void SetThreadName(const char *name) {
65   AsanThread *t = GetCurrentThread();
66   if (t)
67     asanThreadRegistry().SetThreadName(t->tid(), name);
68 }
69 
70 int OnExit() {
71   if (CAN_SANITIZE_LEAKS && common_flags()->detect_leaks &&
72       __lsan::HasReportedLeaks()) {
73     return common_flags()->exitcode;
74   }
75   // FIXME: ask frontend whether we need to return failure.
76   return 0;
77 }
78 
79 } // namespace __asan
80 
81 // ---------------------- Wrappers ---------------- {{{1
82 using namespace __asan;
83 
84 DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr)
85 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *)
86 
87 #define ASAN_INTERCEPTOR_ENTER(ctx, func)                                      \
88   AsanInterceptorContext _ctx = {#func};                                       \
89   ctx = (void *)&_ctx;                                                         \
90   (void) ctx;                                                                  \
91 
92 #define COMMON_INTERCEPT_FUNCTION(name) ASAN_INTERCEPT_FUNC(name)
93 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver) \
94   ASAN_INTERCEPT_FUNC_VER(name, ver)
95 #define COMMON_INTERCEPT_FUNCTION_VER_UNVERSIONED_FALLBACK(name, ver) \
96   ASAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)
97 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
98   ASAN_WRITE_RANGE(ctx, ptr, size)
99 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
100   ASAN_READ_RANGE(ctx, ptr, size)
101 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)                               \
102   ASAN_INTERCEPTOR_ENTER(ctx, func);                                           \
103   do {                                                                         \
104     if (asan_init_is_running)                                                  \
105       return REAL(func)(__VA_ARGS__);                                          \
106     if (SANITIZER_APPLE && UNLIKELY(!asan_inited))                               \
107       return REAL(func)(__VA_ARGS__);                                          \
108     ENSURE_ASAN_INITED();                                                      \
109   } while (false)
110 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
111   do {                                            \
112   } while (false)
113 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
114   do {                                         \
115   } while (false)
116 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
117   do {                                         \
118   } while (false)
119 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
120   do {                                                      \
121   } while (false)
122 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) SetThreadName(name)
123 // Should be asanThreadRegistry().SetThreadNameByUserId(thread, name)
124 // But asan does not remember UserId's for threads (pthread_t);
125 // and remembers all ever existed threads, so the linear search by UserId
126 // can be slow.
127 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
128   do {                                                         \
129   } while (false)
130 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
131 // Strict init-order checking is dlopen-hostile:
132 // https://github.com/google/sanitizers/issues/178
133 #  define COMMON_INTERCEPTOR_DLOPEN(filename, flag) \
134     ({                                              \
135       if (flags()->strict_init_order)               \
136         StopInitOrderChecking();                    \
137       CheckNoDeepBind(filename, flag);              \
138       REAL(dlopen)(filename, flag);                 \
139     })
140 #  define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
141 #  define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)
142 #  define COMMON_INTERCEPTOR_LIBRARY_UNLOADED()
143 #  define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!asan_inited)
144 #  define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end) \
145     if (AsanThread *t = GetCurrentThread()) {          \
146       *begin = t->tls_begin();                         \
147       *end = t->tls_end();                             \
148     } else {                                           \
149       *begin = *end = 0;                               \
150     }
151 
152 #define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size) \
153   do {                                                       \
154     ASAN_INTERCEPTOR_ENTER(ctx, memmove);                    \
155     ASAN_MEMMOVE_IMPL(ctx, to, from, size);                  \
156   } while (false)
157 
158 #define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size) \
159   do {                                                      \
160     ASAN_INTERCEPTOR_ENTER(ctx, memcpy);                    \
161     ASAN_MEMCPY_IMPL(ctx, to, from, size);                  \
162   } while (false)
163 
164 #define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size) \
165   do {                                                      \
166     ASAN_INTERCEPTOR_ENTER(ctx, memset);                    \
167     ASAN_MEMSET_IMPL(ctx, block, c, size);                  \
168   } while (false)
169 
170 #if CAN_SANITIZE_LEAKS
171 #define COMMON_INTERCEPTOR_STRERROR()                       \
172   __lsan::ScopedInterceptorDisabler disabler
173 #endif
174 
175 #include "sanitizer_common/sanitizer_common_interceptors.inc"
176 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
177 
178 // Syscall interceptors don't have contexts, we don't support suppressions
179 // for them.
180 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) ASAN_READ_RANGE(nullptr, p, s)
181 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) ASAN_WRITE_RANGE(nullptr, p, s)
182 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
183   do {                                       \
184     (void)(p);                               \
185     (void)(s);                               \
186   } while (false)
187 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
188   do {                                        \
189     (void)(p);                                \
190     (void)(s);                                \
191   } while (false)
192 #include "sanitizer_common/sanitizer_common_syscalls.inc"
193 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
194 
195 #if ASAN_INTERCEPT_PTHREAD_CREATE
196 static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {
197   AsanThread *t = (AsanThread *)arg;
198   SetCurrentThread(t);
199   return t->ThreadStart(GetTid());
200 }
201 
202 INTERCEPTOR(int, pthread_create, void *thread,
203     void *attr, void *(*start_routine)(void*), void *arg) {
204   EnsureMainThreadIDIsCorrect();
205   // Strict init-order checking is thread-hostile.
206   if (flags()->strict_init_order)
207     StopInitOrderChecking();
208   GET_STACK_TRACE_THREAD;
209   int detached = 0;
210   if (attr)
211     REAL(pthread_attr_getdetachstate)(attr, &detached);
212 
213   u32 current_tid = GetCurrentTidOrInvalid();
214   AsanThread *t =
215       AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
216 
217   int result;
218   {
219     // Ignore all allocations made by pthread_create: thread stack/TLS may be
220     // stored by pthread for future reuse even after thread destruction, and
221     // the linked list it's stored in doesn't even hold valid pointers to the
222     // objects, the latter are calculated by obscure pointer arithmetic.
223 #if CAN_SANITIZE_LEAKS
224     __lsan::ScopedInterceptorDisabler disabler;
225 #endif
226     result = REAL(pthread_create)(thread, attr, asan_thread_start, t);
227   }
228   if (result != 0) {
229     // If the thread didn't start delete the AsanThread to avoid leaking it.
230     // Note AsanThreadContexts never get destroyed so the AsanThreadContext
231     // that was just created for the AsanThread is wasted.
232     t->Destroy();
233   }
234   return result;
235 }
236 
237 INTERCEPTOR(int, pthread_join, void *t, void **arg) {
238   return real_pthread_join(t, arg);
239 }
240 
241 DEFINE_REAL_PTHREAD_FUNCTIONS
242 #endif  // ASAN_INTERCEPT_PTHREAD_CREATE
243 
244 #if ASAN_INTERCEPT_SWAPCONTEXT
245 static void ClearShadowMemoryForContextStack(uptr stack, uptr ssize) {
246   // Only clear if we know the stack. This should be true only for contexts
247   // created with makecontext().
248   if (!ssize)
249     return;
250   // Align to page size.
251   uptr PageSize = GetPageSizeCached();
252   uptr bottom = RoundDownTo(stack, PageSize);
253   if (!AddrIsInMem(bottom))
254     return;
255   ssize += stack - bottom;
256   ssize = RoundUpTo(ssize, PageSize);
257   PoisonShadow(bottom, ssize, 0);
258 }
259 
260 INTERCEPTOR(int, getcontext, struct ucontext_t *ucp) {
261   // API does not requires to have ucp clean, and sets only part of fields. We
262   // use ucp->uc_stack to unpoison new stack. We prefer to have zeroes then
263   // uninitialized bytes.
264   ResetContextStack(ucp);
265   return REAL(getcontext)(ucp);
266 }
267 
268 INTERCEPTOR(int, swapcontext, struct ucontext_t *oucp,
269             struct ucontext_t *ucp) {
270   static bool reported_warning = false;
271   if (!reported_warning) {
272     Report("WARNING: ASan doesn't fully support makecontext/swapcontext "
273            "functions and may produce false positives in some cases!\n");
274     reported_warning = true;
275   }
276   // Clear shadow memory for new context (it may share stack
277   // with current context).
278   uptr stack, ssize;
279   ReadContextStack(ucp, &stack, &ssize);
280   ClearShadowMemoryForContextStack(stack, ssize);
281 
282   // See getcontext interceptor.
283   ResetContextStack(oucp);
284 
285 #    if __has_attribute(__indirect_return__) && \
286         (defined(__x86_64__) || defined(__i386__))
287   int (*real_swapcontext)(struct ucontext_t *, struct ucontext_t *)
288       __attribute__((__indirect_return__)) = REAL(swapcontext);
289   int res = real_swapcontext(oucp, ucp);
290 #    else
291   int res = REAL(swapcontext)(oucp, ucp);
292 #    endif
293   // swapcontext technically does not return, but program may swap context to
294   // "oucp" later, that would look as if swapcontext() returned 0.
295   // We need to clear shadow for ucp once again, as it may be in arbitrary
296   // state.
297   ClearShadowMemoryForContextStack(stack, ssize);
298   return res;
299 }
300 #endif  // ASAN_INTERCEPT_SWAPCONTEXT
301 
302 #if SANITIZER_NETBSD
303 #define longjmp __longjmp14
304 #define siglongjmp __siglongjmp14
305 #endif
306 
307 INTERCEPTOR(void, longjmp, void *env, int val) {
308   __asan_handle_no_return();
309   REAL(longjmp)(env, val);
310 }
311 
312 #if ASAN_INTERCEPT__LONGJMP
313 INTERCEPTOR(void, _longjmp, void *env, int val) {
314   __asan_handle_no_return();
315   REAL(_longjmp)(env, val);
316 }
317 #endif
318 
319 #if ASAN_INTERCEPT___LONGJMP_CHK
320 INTERCEPTOR(void, __longjmp_chk, void *env, int val) {
321   __asan_handle_no_return();
322   REAL(__longjmp_chk)(env, val);
323 }
324 #endif
325 
326 #if ASAN_INTERCEPT_SIGLONGJMP
327 INTERCEPTOR(void, siglongjmp, void *env, int val) {
328   __asan_handle_no_return();
329   REAL(siglongjmp)(env, val);
330 }
331 #endif
332 
333 #if ASAN_INTERCEPT___CXA_THROW
334 INTERCEPTOR(void, __cxa_throw, void *a, void *b, void *c) {
335   CHECK(REAL(__cxa_throw));
336   __asan_handle_no_return();
337   REAL(__cxa_throw)(a, b, c);
338 }
339 #endif
340 
341 #if ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION
342 INTERCEPTOR(void, __cxa_rethrow_primary_exception, void *a) {
343   CHECK(REAL(__cxa_rethrow_primary_exception));
344   __asan_handle_no_return();
345   REAL(__cxa_rethrow_primary_exception)(a);
346 }
347 #endif
348 
349 #if ASAN_INTERCEPT__UNWIND_RAISEEXCEPTION
350 INTERCEPTOR(_Unwind_Reason_Code, _Unwind_RaiseException,
351             _Unwind_Exception *object) {
352   CHECK(REAL(_Unwind_RaiseException));
353   __asan_handle_no_return();
354   return REAL(_Unwind_RaiseException)(object);
355 }
356 #endif
357 
358 #if ASAN_INTERCEPT__SJLJ_UNWIND_RAISEEXCEPTION
359 INTERCEPTOR(_Unwind_Reason_Code, _Unwind_SjLj_RaiseException,
360             _Unwind_Exception *object) {
361   CHECK(REAL(_Unwind_SjLj_RaiseException));
362   __asan_handle_no_return();
363   return REAL(_Unwind_SjLj_RaiseException)(object);
364 }
365 #endif
366 
367 #if ASAN_INTERCEPT_INDEX
368 # if ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
369 INTERCEPTOR(char*, index, const char *string, int c)
370   ALIAS(WRAPPER_NAME(strchr));
371 # else
372 #  if SANITIZER_APPLE
373 DECLARE_REAL(char*, index, const char *string, int c)
374 OVERRIDE_FUNCTION(index, strchr);
375 #  else
376 DEFINE_REAL(char*, index, const char *string, int c)
377 #  endif
378 # endif
379 #endif  // ASAN_INTERCEPT_INDEX
380 
381 // For both strcat() and strncat() we need to check the validity of |to|
382 // argument irrespective of the |from| length.
383   INTERCEPTOR(char *, strcat, char *to, const char *from) {
384     void *ctx;
385     ASAN_INTERCEPTOR_ENTER(ctx, strcat);
386     ENSURE_ASAN_INITED();
387     if (flags()->replace_str) {
388       uptr from_length = internal_strlen(from);
389       ASAN_READ_RANGE(ctx, from, from_length + 1);
390       uptr to_length = internal_strlen(to);
391       ASAN_READ_STRING_OF_LEN(ctx, to, to_length, to_length);
392       ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
393       // If the copying actually happens, the |from| string should not overlap
394       // with the resulting string starting at |to|, which has a length of
395       // to_length + from_length + 1.
396       if (from_length > 0) {
397         CHECK_RANGES_OVERLAP("strcat", to, from_length + to_length + 1, from,
398                              from_length + 1);
399       }
400     }
401     return REAL(strcat)(to, from);
402   }
403 
404 INTERCEPTOR(char*, strncat, char *to, const char *from, uptr size) {
405   void *ctx;
406   ASAN_INTERCEPTOR_ENTER(ctx, strncat);
407   ENSURE_ASAN_INITED();
408   if (flags()->replace_str) {
409     uptr from_length = MaybeRealStrnlen(from, size);
410     uptr copy_length = Min(size, from_length + 1);
411     ASAN_READ_RANGE(ctx, from, copy_length);
412     uptr to_length = internal_strlen(to);
413     ASAN_READ_STRING_OF_LEN(ctx, to, to_length, to_length);
414     ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
415     if (from_length > 0) {
416       CHECK_RANGES_OVERLAP("strncat", to, to_length + copy_length + 1,
417                            from, copy_length);
418     }
419   }
420   return REAL(strncat)(to, from, size);
421 }
422 
423 INTERCEPTOR(char *, strcpy, char *to, const char *from) {
424   void *ctx;
425   ASAN_INTERCEPTOR_ENTER(ctx, strcpy);
426 #if SANITIZER_APPLE
427   if (UNLIKELY(!asan_inited))
428     return REAL(strcpy)(to, from);
429 #endif
430   // strcpy is called from malloc_default_purgeable_zone()
431   // in __asan::ReplaceSystemAlloc() on Mac.
432   if (asan_init_is_running) {
433     return REAL(strcpy)(to, from);
434   }
435   ENSURE_ASAN_INITED();
436   if (flags()->replace_str) {
437     uptr from_size = internal_strlen(from) + 1;
438     CHECK_RANGES_OVERLAP("strcpy", to, from_size, from, from_size);
439     ASAN_READ_RANGE(ctx, from, from_size);
440     ASAN_WRITE_RANGE(ctx, to, from_size);
441   }
442   return REAL(strcpy)(to, from);
443 }
444 
445 INTERCEPTOR(char*, strdup, const char *s) {
446   void *ctx;
447   ASAN_INTERCEPTOR_ENTER(ctx, strdup);
448   if (UNLIKELY(!asan_inited)) return internal_strdup(s);
449   ENSURE_ASAN_INITED();
450   uptr length = internal_strlen(s);
451   if (flags()->replace_str) {
452     ASAN_READ_RANGE(ctx, s, length + 1);
453   }
454   GET_STACK_TRACE_MALLOC;
455   void *new_mem = asan_malloc(length + 1, &stack);
456   REAL(memcpy)(new_mem, s, length + 1);
457   return reinterpret_cast<char*>(new_mem);
458 }
459 
460 #if ASAN_INTERCEPT___STRDUP
461 INTERCEPTOR(char*, __strdup, const char *s) {
462   void *ctx;
463   ASAN_INTERCEPTOR_ENTER(ctx, strdup);
464   if (UNLIKELY(!asan_inited)) return internal_strdup(s);
465   ENSURE_ASAN_INITED();
466   uptr length = internal_strlen(s);
467   if (flags()->replace_str) {
468     ASAN_READ_RANGE(ctx, s, length + 1);
469   }
470   GET_STACK_TRACE_MALLOC;
471   void *new_mem = asan_malloc(length + 1, &stack);
472   REAL(memcpy)(new_mem, s, length + 1);
473   return reinterpret_cast<char*>(new_mem);
474 }
475 #endif // ASAN_INTERCEPT___STRDUP
476 
477 INTERCEPTOR(char*, strncpy, char *to, const char *from, uptr size) {
478   void *ctx;
479   ASAN_INTERCEPTOR_ENTER(ctx, strncpy);
480   ENSURE_ASAN_INITED();
481   if (flags()->replace_str) {
482     uptr from_size = Min(size, MaybeRealStrnlen(from, size) + 1);
483     CHECK_RANGES_OVERLAP("strncpy", to, from_size, from, from_size);
484     ASAN_READ_RANGE(ctx, from, from_size);
485     ASAN_WRITE_RANGE(ctx, to, size);
486   }
487   return REAL(strncpy)(to, from, size);
488 }
489 
490 INTERCEPTOR(long, strtol, const char *nptr, char **endptr, int base) {
491   void *ctx;
492   ASAN_INTERCEPTOR_ENTER(ctx, strtol);
493   ENSURE_ASAN_INITED();
494   if (!flags()->replace_str) {
495     return REAL(strtol)(nptr, endptr, base);
496   }
497   char *real_endptr;
498   long result = REAL(strtol)(nptr, &real_endptr, base);
499   StrtolFixAndCheck(ctx, nptr, endptr, real_endptr, base);
500   return result;
501 }
502 
503 INTERCEPTOR(int, atoi, const char *nptr) {
504   void *ctx;
505   ASAN_INTERCEPTOR_ENTER(ctx, atoi);
506 #if SANITIZER_APPLE
507   if (UNLIKELY(!asan_inited)) return REAL(atoi)(nptr);
508 #endif
509   ENSURE_ASAN_INITED();
510   if (!flags()->replace_str) {
511     return REAL(atoi)(nptr);
512   }
513   char *real_endptr;
514   // "man atoi" tells that behavior of atoi(nptr) is the same as
515   // strtol(nptr, 0, 10), i.e. it sets errno to ERANGE if the
516   // parsed integer can't be stored in *long* type (even if it's
517   // different from int). So, we just imitate this behavior.
518   int result = REAL(strtol)(nptr, &real_endptr, 10);
519   FixRealStrtolEndptr(nptr, &real_endptr);
520   ASAN_READ_STRING(ctx, nptr, (real_endptr - nptr) + 1);
521   return result;
522 }
523 
524 INTERCEPTOR(long, atol, const char *nptr) {
525   void *ctx;
526   ASAN_INTERCEPTOR_ENTER(ctx, atol);
527 #if SANITIZER_APPLE
528   if (UNLIKELY(!asan_inited)) return REAL(atol)(nptr);
529 #endif
530   ENSURE_ASAN_INITED();
531   if (!flags()->replace_str) {
532     return REAL(atol)(nptr);
533   }
534   char *real_endptr;
535   long result = REAL(strtol)(nptr, &real_endptr, 10);
536   FixRealStrtolEndptr(nptr, &real_endptr);
537   ASAN_READ_STRING(ctx, nptr, (real_endptr - nptr) + 1);
538   return result;
539 }
540 
541 #if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
542 INTERCEPTOR(long long, strtoll, const char *nptr, char **endptr, int base) {
543   void *ctx;
544   ASAN_INTERCEPTOR_ENTER(ctx, strtoll);
545   ENSURE_ASAN_INITED();
546   if (!flags()->replace_str) {
547     return REAL(strtoll)(nptr, endptr, base);
548   }
549   char *real_endptr;
550   long long result = REAL(strtoll)(nptr, &real_endptr, base);
551   StrtolFixAndCheck(ctx, nptr, endptr, real_endptr, base);
552   return result;
553 }
554 
555 INTERCEPTOR(long long, atoll, const char *nptr) {
556   void *ctx;
557   ASAN_INTERCEPTOR_ENTER(ctx, atoll);
558   ENSURE_ASAN_INITED();
559   if (!flags()->replace_str) {
560     return REAL(atoll)(nptr);
561   }
562   char *real_endptr;
563   long long result = REAL(strtoll)(nptr, &real_endptr, 10);
564   FixRealStrtolEndptr(nptr, &real_endptr);
565   ASAN_READ_STRING(ctx, nptr, (real_endptr - nptr) + 1);
566   return result;
567 }
568 #endif  // ASAN_INTERCEPT_ATOLL_AND_STRTOLL
569 
570 #if ASAN_INTERCEPT___CXA_ATEXIT || ASAN_INTERCEPT_ATEXIT
571 static void AtCxaAtexit(void *unused) {
572   (void)unused;
573   StopInitOrderChecking();
574 }
575 #endif
576 
577 #if ASAN_INTERCEPT___CXA_ATEXIT
578 INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
579             void *dso_handle) {
580 #if SANITIZER_APPLE
581   if (UNLIKELY(!asan_inited)) return REAL(__cxa_atexit)(func, arg, dso_handle);
582 #endif
583   ENSURE_ASAN_INITED();
584 #if CAN_SANITIZE_LEAKS
585   __lsan::ScopedInterceptorDisabler disabler;
586 #endif
587   int res = REAL(__cxa_atexit)(func, arg, dso_handle);
588   REAL(__cxa_atexit)(AtCxaAtexit, nullptr, nullptr);
589   return res;
590 }
591 #endif  // ASAN_INTERCEPT___CXA_ATEXIT
592 
593 #if ASAN_INTERCEPT_ATEXIT
594 INTERCEPTOR(int, atexit, void (*func)()) {
595   ENSURE_ASAN_INITED();
596 #if CAN_SANITIZE_LEAKS
597   __lsan::ScopedInterceptorDisabler disabler;
598 #endif
599   // Avoid calling real atexit as it is unreachable on at least on Linux.
600   int res = REAL(__cxa_atexit)((void (*)(void *a))func, nullptr, nullptr);
601   REAL(__cxa_atexit)(AtCxaAtexit, nullptr, nullptr);
602   return res;
603 }
604 #endif
605 
606 #if ASAN_INTERCEPT_PTHREAD_ATFORK
607 extern "C" {
608 extern int _pthread_atfork(void (*prepare)(), void (*parent)(),
609                            void (*child)());
610 };
611 
612 INTERCEPTOR(int, pthread_atfork, void (*prepare)(), void (*parent)(),
613             void (*child)()) {
614 #if CAN_SANITIZE_LEAKS
615   __lsan::ScopedInterceptorDisabler disabler;
616 #endif
617   // REAL(pthread_atfork) cannot be called due to symbol indirections at least
618   // on NetBSD
619   return _pthread_atfork(prepare, parent, child);
620 }
621 #endif
622 
623 #if ASAN_INTERCEPT_VFORK
624 DEFINE_REAL(int, vfork)
625 DECLARE_EXTERN_INTERCEPTOR_AND_WRAPPER(int, vfork)
626 #endif
627 
628 // ---------------------- InitializeAsanInterceptors ---------------- {{{1
629 namespace __asan {
630 void InitializeAsanInterceptors() {
631   static bool was_called_once;
632   CHECK(!was_called_once);
633   was_called_once = true;
634   InitializeCommonInterceptors();
635   InitializeSignalInterceptors();
636 
637   // Intercept str* functions.
638   ASAN_INTERCEPT_FUNC(strcat);
639   ASAN_INTERCEPT_FUNC(strcpy);
640   ASAN_INTERCEPT_FUNC(strncat);
641   ASAN_INTERCEPT_FUNC(strncpy);
642   ASAN_INTERCEPT_FUNC(strdup);
643 #if ASAN_INTERCEPT___STRDUP
644   ASAN_INTERCEPT_FUNC(__strdup);
645 #endif
646 #if ASAN_INTERCEPT_INDEX && ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
647   ASAN_INTERCEPT_FUNC(index);
648 #endif
649 
650   ASAN_INTERCEPT_FUNC(atoi);
651   ASAN_INTERCEPT_FUNC(atol);
652   ASAN_INTERCEPT_FUNC(strtol);
653 #if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
654   ASAN_INTERCEPT_FUNC(atoll);
655   ASAN_INTERCEPT_FUNC(strtoll);
656 #endif
657 
658   // Intecept jump-related functions.
659   ASAN_INTERCEPT_FUNC(longjmp);
660 
661 #if ASAN_INTERCEPT_SWAPCONTEXT
662   ASAN_INTERCEPT_FUNC(getcontext);
663   ASAN_INTERCEPT_FUNC(swapcontext);
664 #endif
665 #if ASAN_INTERCEPT__LONGJMP
666   ASAN_INTERCEPT_FUNC(_longjmp);
667 #endif
668 #if ASAN_INTERCEPT___LONGJMP_CHK
669   ASAN_INTERCEPT_FUNC(__longjmp_chk);
670 #endif
671 #if ASAN_INTERCEPT_SIGLONGJMP
672   ASAN_INTERCEPT_FUNC(siglongjmp);
673 #endif
674 
675   // Intercept exception handling functions.
676 #if ASAN_INTERCEPT___CXA_THROW
677   ASAN_INTERCEPT_FUNC(__cxa_throw);
678 #endif
679 #if ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION
680   ASAN_INTERCEPT_FUNC(__cxa_rethrow_primary_exception);
681 #endif
682   // Indirectly intercept std::rethrow_exception.
683 #if ASAN_INTERCEPT__UNWIND_RAISEEXCEPTION
684   INTERCEPT_FUNCTION(_Unwind_RaiseException);
685 #endif
686   // Indirectly intercept std::rethrow_exception.
687 #if ASAN_INTERCEPT__UNWIND_SJLJ_RAISEEXCEPTION
688   INTERCEPT_FUNCTION(_Unwind_SjLj_RaiseException);
689 #endif
690 
691   // Intercept threading-related functions
692 #if ASAN_INTERCEPT_PTHREAD_CREATE
693 // TODO: this should probably have an unversioned fallback for newer arches?
694 #if defined(ASAN_PTHREAD_CREATE_VERSION)
695   ASAN_INTERCEPT_FUNC_VER(pthread_create, ASAN_PTHREAD_CREATE_VERSION);
696 #else
697   ASAN_INTERCEPT_FUNC(pthread_create);
698 #endif
699   ASAN_INTERCEPT_FUNC(pthread_join);
700 #endif
701 
702   // Intercept atexit function.
703 #if ASAN_INTERCEPT___CXA_ATEXIT
704   ASAN_INTERCEPT_FUNC(__cxa_atexit);
705 #endif
706 
707 #if ASAN_INTERCEPT_ATEXIT
708   ASAN_INTERCEPT_FUNC(atexit);
709 #endif
710 
711 #if ASAN_INTERCEPT_PTHREAD_ATFORK
712   ASAN_INTERCEPT_FUNC(pthread_atfork);
713 #endif
714 
715 #if ASAN_INTERCEPT_VFORK
716   ASAN_INTERCEPT_FUNC(vfork);
717 #endif
718 
719   InitializePlatformInterceptors();
720 
721   VReport(1, "AddressSanitizer: libc interceptors initialized\n");
722 }
723 
724 } // namespace __asan
725 
726 #endif  // !SANITIZER_FUCHSIA
727