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   // Align to page size.
247   uptr PageSize = GetPageSizeCached();
248   uptr bottom = stack & ~(PageSize - 1);
249   ssize += stack - bottom;
250   ssize = RoundUpTo(ssize, PageSize);
251   if (AddrIsInMem(bottom) && ssize)
252     PoisonShadow(bottom, ssize, 0);
253 }
254 
255 INTERCEPTOR(int, swapcontext, struct ucontext_t *oucp,
256             struct ucontext_t *ucp) {
257   static bool reported_warning = false;
258   if (!reported_warning) {
259     Report("WARNING: ASan doesn't fully support makecontext/swapcontext "
260            "functions and may produce false positives in some cases!\n");
261     reported_warning = true;
262   }
263   // Clear shadow memory for new context (it may share stack
264   // with current context).
265   uptr stack, ssize;
266   ReadContextStack(ucp, &stack, &ssize);
267   ClearShadowMemoryForContextStack(stack, ssize);
268 #if __has_attribute(__indirect_return__) && \
269     (defined(__x86_64__) || defined(__i386__))
270   int (*real_swapcontext)(struct ucontext_t *, struct ucontext_t *)
271     __attribute__((__indirect_return__))
272     = REAL(swapcontext);
273   int res = real_swapcontext(oucp, ucp);
274 #else
275   int res = REAL(swapcontext)(oucp, ucp);
276 #endif
277   // swapcontext technically does not return, but program may swap context to
278   // "oucp" later, that would look as if swapcontext() returned 0.
279   // We need to clear shadow for ucp once again, as it may be in arbitrary
280   // state.
281   ClearShadowMemoryForContextStack(stack, ssize);
282   return res;
283 }
284 #endif  // ASAN_INTERCEPT_SWAPCONTEXT
285 
286 #if SANITIZER_NETBSD
287 #define longjmp __longjmp14
288 #define siglongjmp __siglongjmp14
289 #endif
290 
291 INTERCEPTOR(void, longjmp, void *env, int val) {
292   __asan_handle_no_return();
293   REAL(longjmp)(env, val);
294 }
295 
296 #if ASAN_INTERCEPT__LONGJMP
297 INTERCEPTOR(void, _longjmp, void *env, int val) {
298   __asan_handle_no_return();
299   REAL(_longjmp)(env, val);
300 }
301 #endif
302 
303 #if ASAN_INTERCEPT___LONGJMP_CHK
304 INTERCEPTOR(void, __longjmp_chk, void *env, int val) {
305   __asan_handle_no_return();
306   REAL(__longjmp_chk)(env, val);
307 }
308 #endif
309 
310 #if ASAN_INTERCEPT_SIGLONGJMP
311 INTERCEPTOR(void, siglongjmp, void *env, int val) {
312   __asan_handle_no_return();
313   REAL(siglongjmp)(env, val);
314 }
315 #endif
316 
317 #if ASAN_INTERCEPT___CXA_THROW
318 INTERCEPTOR(void, __cxa_throw, void *a, void *b, void *c) {
319   CHECK(REAL(__cxa_throw));
320   __asan_handle_no_return();
321   REAL(__cxa_throw)(a, b, c);
322 }
323 #endif
324 
325 #if ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION
326 INTERCEPTOR(void, __cxa_rethrow_primary_exception, void *a) {
327   CHECK(REAL(__cxa_rethrow_primary_exception));
328   __asan_handle_no_return();
329   REAL(__cxa_rethrow_primary_exception)(a);
330 }
331 #endif
332 
333 #if ASAN_INTERCEPT__UNWIND_RAISEEXCEPTION
334 INTERCEPTOR(_Unwind_Reason_Code, _Unwind_RaiseException,
335             _Unwind_Exception *object) {
336   CHECK(REAL(_Unwind_RaiseException));
337   __asan_handle_no_return();
338   return REAL(_Unwind_RaiseException)(object);
339 }
340 #endif
341 
342 #if ASAN_INTERCEPT__SJLJ_UNWIND_RAISEEXCEPTION
343 INTERCEPTOR(_Unwind_Reason_Code, _Unwind_SjLj_RaiseException,
344             _Unwind_Exception *object) {
345   CHECK(REAL(_Unwind_SjLj_RaiseException));
346   __asan_handle_no_return();
347   return REAL(_Unwind_SjLj_RaiseException)(object);
348 }
349 #endif
350 
351 #if ASAN_INTERCEPT_INDEX
352 # if ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
353 INTERCEPTOR(char*, index, const char *string, int c)
354   ALIAS(WRAPPER_NAME(strchr));
355 # else
356 #  if SANITIZER_APPLE
357 DECLARE_REAL(char*, index, const char *string, int c)
358 OVERRIDE_FUNCTION(index, strchr);
359 #  else
360 DEFINE_REAL(char*, index, const char *string, int c)
361 #  endif
362 # endif
363 #endif  // ASAN_INTERCEPT_INDEX
364 
365 // For both strcat() and strncat() we need to check the validity of |to|
366 // argument irrespective of the |from| length.
367   INTERCEPTOR(char *, strcat, char *to, const char *from) {
368     void *ctx;
369     ASAN_INTERCEPTOR_ENTER(ctx, strcat);
370     ENSURE_ASAN_INITED();
371     if (flags()->replace_str) {
372       uptr from_length = internal_strlen(from);
373       ASAN_READ_RANGE(ctx, from, from_length + 1);
374       uptr to_length = internal_strlen(to);
375       ASAN_READ_STRING_OF_LEN(ctx, to, to_length, to_length);
376       ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
377       // If the copying actually happens, the |from| string should not overlap
378       // with the resulting string starting at |to|, which has a length of
379       // to_length + from_length + 1.
380       if (from_length > 0) {
381         CHECK_RANGES_OVERLAP("strcat", to, from_length + to_length + 1, from,
382                              from_length + 1);
383       }
384     }
385     return REAL(strcat)(to, from);
386   }
387 
388 INTERCEPTOR(char*, strncat, char *to, const char *from, uptr size) {
389   void *ctx;
390   ASAN_INTERCEPTOR_ENTER(ctx, strncat);
391   ENSURE_ASAN_INITED();
392   if (flags()->replace_str) {
393     uptr from_length = MaybeRealStrnlen(from, size);
394     uptr copy_length = Min(size, from_length + 1);
395     ASAN_READ_RANGE(ctx, from, copy_length);
396     uptr to_length = internal_strlen(to);
397     ASAN_READ_STRING_OF_LEN(ctx, to, to_length, to_length);
398     ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
399     if (from_length > 0) {
400       CHECK_RANGES_OVERLAP("strncat", to, to_length + copy_length + 1,
401                            from, copy_length);
402     }
403   }
404   return REAL(strncat)(to, from, size);
405 }
406 
407 INTERCEPTOR(char *, strcpy, char *to, const char *from) {
408   void *ctx;
409   ASAN_INTERCEPTOR_ENTER(ctx, strcpy);
410 #if SANITIZER_APPLE
411   if (UNLIKELY(!asan_inited))
412     return REAL(strcpy)(to, from);
413 #endif
414   // strcpy is called from malloc_default_purgeable_zone()
415   // in __asan::ReplaceSystemAlloc() on Mac.
416   if (asan_init_is_running) {
417     return REAL(strcpy)(to, from);
418   }
419   ENSURE_ASAN_INITED();
420   if (flags()->replace_str) {
421     uptr from_size = internal_strlen(from) + 1;
422     CHECK_RANGES_OVERLAP("strcpy", to, from_size, from, from_size);
423     ASAN_READ_RANGE(ctx, from, from_size);
424     ASAN_WRITE_RANGE(ctx, to, from_size);
425   }
426   return REAL(strcpy)(to, from);
427 }
428 
429 INTERCEPTOR(char*, strdup, const char *s) {
430   void *ctx;
431   ASAN_INTERCEPTOR_ENTER(ctx, strdup);
432   if (UNLIKELY(!asan_inited)) return internal_strdup(s);
433   ENSURE_ASAN_INITED();
434   uptr length = internal_strlen(s);
435   if (flags()->replace_str) {
436     ASAN_READ_RANGE(ctx, s, length + 1);
437   }
438   GET_STACK_TRACE_MALLOC;
439   void *new_mem = asan_malloc(length + 1, &stack);
440   REAL(memcpy)(new_mem, s, length + 1);
441   return reinterpret_cast<char*>(new_mem);
442 }
443 
444 #if ASAN_INTERCEPT___STRDUP
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 #endif // ASAN_INTERCEPT___STRDUP
460 
461 INTERCEPTOR(char*, strncpy, char *to, const char *from, uptr size) {
462   void *ctx;
463   ASAN_INTERCEPTOR_ENTER(ctx, strncpy);
464   ENSURE_ASAN_INITED();
465   if (flags()->replace_str) {
466     uptr from_size = Min(size, MaybeRealStrnlen(from, size) + 1);
467     CHECK_RANGES_OVERLAP("strncpy", to, from_size, from, from_size);
468     ASAN_READ_RANGE(ctx, from, from_size);
469     ASAN_WRITE_RANGE(ctx, to, size);
470   }
471   return REAL(strncpy)(to, from, size);
472 }
473 
474 INTERCEPTOR(long, strtol, const char *nptr, char **endptr, int base) {
475   void *ctx;
476   ASAN_INTERCEPTOR_ENTER(ctx, strtol);
477   ENSURE_ASAN_INITED();
478   if (!flags()->replace_str) {
479     return REAL(strtol)(nptr, endptr, base);
480   }
481   char *real_endptr;
482   long result = REAL(strtol)(nptr, &real_endptr, base);
483   StrtolFixAndCheck(ctx, nptr, endptr, real_endptr, base);
484   return result;
485 }
486 
487 INTERCEPTOR(int, atoi, const char *nptr) {
488   void *ctx;
489   ASAN_INTERCEPTOR_ENTER(ctx, atoi);
490 #if SANITIZER_APPLE
491   if (UNLIKELY(!asan_inited)) return REAL(atoi)(nptr);
492 #endif
493   ENSURE_ASAN_INITED();
494   if (!flags()->replace_str) {
495     return REAL(atoi)(nptr);
496   }
497   char *real_endptr;
498   // "man atoi" tells that behavior of atoi(nptr) is the same as
499   // strtol(nptr, 0, 10), i.e. it sets errno to ERANGE if the
500   // parsed integer can't be stored in *long* type (even if it's
501   // different from int). So, we just imitate this behavior.
502   int result = REAL(strtol)(nptr, &real_endptr, 10);
503   FixRealStrtolEndptr(nptr, &real_endptr);
504   ASAN_READ_STRING(ctx, nptr, (real_endptr - nptr) + 1);
505   return result;
506 }
507 
508 INTERCEPTOR(long, atol, const char *nptr) {
509   void *ctx;
510   ASAN_INTERCEPTOR_ENTER(ctx, atol);
511 #if SANITIZER_APPLE
512   if (UNLIKELY(!asan_inited)) return REAL(atol)(nptr);
513 #endif
514   ENSURE_ASAN_INITED();
515   if (!flags()->replace_str) {
516     return REAL(atol)(nptr);
517   }
518   char *real_endptr;
519   long result = REAL(strtol)(nptr, &real_endptr, 10);
520   FixRealStrtolEndptr(nptr, &real_endptr);
521   ASAN_READ_STRING(ctx, nptr, (real_endptr - nptr) + 1);
522   return result;
523 }
524 
525 #if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
526 INTERCEPTOR(long long, strtoll, const char *nptr, char **endptr, int base) {
527   void *ctx;
528   ASAN_INTERCEPTOR_ENTER(ctx, strtoll);
529   ENSURE_ASAN_INITED();
530   if (!flags()->replace_str) {
531     return REAL(strtoll)(nptr, endptr, base);
532   }
533   char *real_endptr;
534   long long result = REAL(strtoll)(nptr, &real_endptr, base);
535   StrtolFixAndCheck(ctx, nptr, endptr, real_endptr, base);
536   return result;
537 }
538 
539 INTERCEPTOR(long long, atoll, const char *nptr) {
540   void *ctx;
541   ASAN_INTERCEPTOR_ENTER(ctx, atoll);
542   ENSURE_ASAN_INITED();
543   if (!flags()->replace_str) {
544     return REAL(atoll)(nptr);
545   }
546   char *real_endptr;
547   long long result = REAL(strtoll)(nptr, &real_endptr, 10);
548   FixRealStrtolEndptr(nptr, &real_endptr);
549   ASAN_READ_STRING(ctx, nptr, (real_endptr - nptr) + 1);
550   return result;
551 }
552 #endif  // ASAN_INTERCEPT_ATOLL_AND_STRTOLL
553 
554 #if ASAN_INTERCEPT___CXA_ATEXIT || ASAN_INTERCEPT_ATEXIT
555 static void AtCxaAtexit(void *unused) {
556   (void)unused;
557   StopInitOrderChecking();
558 }
559 #endif
560 
561 #if ASAN_INTERCEPT___CXA_ATEXIT
562 INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
563             void *dso_handle) {
564 #if SANITIZER_APPLE
565   if (UNLIKELY(!asan_inited)) return REAL(__cxa_atexit)(func, arg, dso_handle);
566 #endif
567   ENSURE_ASAN_INITED();
568 #if CAN_SANITIZE_LEAKS
569   __lsan::ScopedInterceptorDisabler disabler;
570 #endif
571   int res = REAL(__cxa_atexit)(func, arg, dso_handle);
572   REAL(__cxa_atexit)(AtCxaAtexit, nullptr, nullptr);
573   return res;
574 }
575 #endif  // ASAN_INTERCEPT___CXA_ATEXIT
576 
577 #if ASAN_INTERCEPT_ATEXIT
578 INTERCEPTOR(int, atexit, void (*func)()) {
579   ENSURE_ASAN_INITED();
580 #if CAN_SANITIZE_LEAKS
581   __lsan::ScopedInterceptorDisabler disabler;
582 #endif
583   // Avoid calling real atexit as it is unreachable on at least on Linux.
584   int res = REAL(__cxa_atexit)((void (*)(void *a))func, nullptr, nullptr);
585   REAL(__cxa_atexit)(AtCxaAtexit, nullptr, nullptr);
586   return res;
587 }
588 #endif
589 
590 #if ASAN_INTERCEPT_PTHREAD_ATFORK
591 extern "C" {
592 extern int _pthread_atfork(void (*prepare)(), void (*parent)(),
593                            void (*child)());
594 };
595 
596 INTERCEPTOR(int, pthread_atfork, void (*prepare)(), void (*parent)(),
597             void (*child)()) {
598 #if CAN_SANITIZE_LEAKS
599   __lsan::ScopedInterceptorDisabler disabler;
600 #endif
601   // REAL(pthread_atfork) cannot be called due to symbol indirections at least
602   // on NetBSD
603   return _pthread_atfork(prepare, parent, child);
604 }
605 #endif
606 
607 #if ASAN_INTERCEPT_VFORK
608 DEFINE_REAL(int, vfork)
609 DECLARE_EXTERN_INTERCEPTOR_AND_WRAPPER(int, vfork)
610 #endif
611 
612 // ---------------------- InitializeAsanInterceptors ---------------- {{{1
613 namespace __asan {
614 void InitializeAsanInterceptors() {
615   static bool was_called_once;
616   CHECK(!was_called_once);
617   was_called_once = true;
618   InitializeCommonInterceptors();
619   InitializeSignalInterceptors();
620 
621   // Intercept str* functions.
622   ASAN_INTERCEPT_FUNC(strcat);
623   ASAN_INTERCEPT_FUNC(strcpy);
624   ASAN_INTERCEPT_FUNC(strncat);
625   ASAN_INTERCEPT_FUNC(strncpy);
626   ASAN_INTERCEPT_FUNC(strdup);
627 #if ASAN_INTERCEPT___STRDUP
628   ASAN_INTERCEPT_FUNC(__strdup);
629 #endif
630 #if ASAN_INTERCEPT_INDEX && ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
631   ASAN_INTERCEPT_FUNC(index);
632 #endif
633 
634   ASAN_INTERCEPT_FUNC(atoi);
635   ASAN_INTERCEPT_FUNC(atol);
636   ASAN_INTERCEPT_FUNC(strtol);
637 #if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
638   ASAN_INTERCEPT_FUNC(atoll);
639   ASAN_INTERCEPT_FUNC(strtoll);
640 #endif
641 
642   // Intecept jump-related functions.
643   ASAN_INTERCEPT_FUNC(longjmp);
644 
645 #if ASAN_INTERCEPT_SWAPCONTEXT
646   ASAN_INTERCEPT_FUNC(swapcontext);
647 #endif
648 #if ASAN_INTERCEPT__LONGJMP
649   ASAN_INTERCEPT_FUNC(_longjmp);
650 #endif
651 #if ASAN_INTERCEPT___LONGJMP_CHK
652   ASAN_INTERCEPT_FUNC(__longjmp_chk);
653 #endif
654 #if ASAN_INTERCEPT_SIGLONGJMP
655   ASAN_INTERCEPT_FUNC(siglongjmp);
656 #endif
657 
658   // Intercept exception handling functions.
659 #if ASAN_INTERCEPT___CXA_THROW
660   ASAN_INTERCEPT_FUNC(__cxa_throw);
661 #endif
662 #if ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION
663   ASAN_INTERCEPT_FUNC(__cxa_rethrow_primary_exception);
664 #endif
665   // Indirectly intercept std::rethrow_exception.
666 #if ASAN_INTERCEPT__UNWIND_RAISEEXCEPTION
667   INTERCEPT_FUNCTION(_Unwind_RaiseException);
668 #endif
669   // Indirectly intercept std::rethrow_exception.
670 #if ASAN_INTERCEPT__UNWIND_SJLJ_RAISEEXCEPTION
671   INTERCEPT_FUNCTION(_Unwind_SjLj_RaiseException);
672 #endif
673 
674   // Intercept threading-related functions
675 #if ASAN_INTERCEPT_PTHREAD_CREATE
676 // TODO: this should probably have an unversioned fallback for newer arches?
677 #if defined(ASAN_PTHREAD_CREATE_VERSION)
678   ASAN_INTERCEPT_FUNC_VER(pthread_create, ASAN_PTHREAD_CREATE_VERSION);
679 #else
680   ASAN_INTERCEPT_FUNC(pthread_create);
681 #endif
682   ASAN_INTERCEPT_FUNC(pthread_join);
683 #endif
684 
685   // Intercept atexit function.
686 #if ASAN_INTERCEPT___CXA_ATEXIT
687   ASAN_INTERCEPT_FUNC(__cxa_atexit);
688 #endif
689 
690 #if ASAN_INTERCEPT_ATEXIT
691   ASAN_INTERCEPT_FUNC(atexit);
692 #endif
693 
694 #if ASAN_INTERCEPT_PTHREAD_ATFORK
695   ASAN_INTERCEPT_FUNC(pthread_atfork);
696 #endif
697 
698 #if ASAN_INTERCEPT_VFORK
699   ASAN_INTERCEPT_FUNC(vfork);
700 #endif
701 
702   InitializePlatformInterceptors();
703 
704   VReport(1, "AddressSanitizer: libc interceptors initialized\n");
705 }
706 
707 } // namespace __asan
708 
709 #endif  // !SANITIZER_FUCHSIA
710