xref: /freebsd/contrib/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 //===-- msan_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 MemorySanitizer.
10 //
11 // Interceptors for standard library functions.
12 //
13 // FIXME: move as many interceptors as possible into
14 // sanitizer_common/sanitizer_common_interceptors.h
15 //===----------------------------------------------------------------------===//
16 
17 #define SANITIZER_COMMON_NO_REDEFINE_BUILTINS
18 
19 #include "interception/interception.h"
20 #include "msan.h"
21 #include "msan_chained_origin_depot.h"
22 #include "msan_dl.h"
23 #include "msan_origin.h"
24 #include "msan_poisoning.h"
25 #include "msan_report.h"
26 #include "msan_thread.h"
27 #include "sanitizer_common/sanitizer_allocator.h"
28 #include "sanitizer_common/sanitizer_allocator_dlsym.h"
29 #include "sanitizer_common/sanitizer_allocator_interface.h"
30 #include "sanitizer_common/sanitizer_atomic.h"
31 #include "sanitizer_common/sanitizer_common.h"
32 #include "sanitizer_common/sanitizer_errno.h"
33 #include "sanitizer_common/sanitizer_errno_codes.h"
34 #include "sanitizer_common/sanitizer_glibc_version.h"
35 #include "sanitizer_common/sanitizer_libc.h"
36 #include "sanitizer_common/sanitizer_linux.h"
37 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
38 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
39 #include "sanitizer_common/sanitizer_stackdepot.h"
40 #include "sanitizer_common/sanitizer_tls_get_addr.h"
41 #include "sanitizer_common/sanitizer_vector.h"
42 
43 #if SANITIZER_NETBSD
44 #define fstat __fstat50
45 #define gettimeofday __gettimeofday50
46 #define getrusage __getrusage50
47 #define tzset __tzset50
48 #endif
49 
50 #include <stdarg.h>
51 // ACHTUNG! No other system header includes in this file.
52 // Ideally, we should get rid of stdarg.h as well.
53 
54 using namespace __msan;
55 
56 using __sanitizer::memory_order;
57 using __sanitizer::atomic_load;
58 using __sanitizer::atomic_store;
59 using __sanitizer::atomic_uintptr_t;
60 
61 DECLARE_REAL(SIZE_T, strlen, const char *s)
62 DECLARE_REAL(SIZE_T, strnlen, const char *s, SIZE_T maxlen)
63 DECLARE_REAL(void *, memcpy, void *dest, const void *src, uptr n)
64 DECLARE_REAL(void *, memset, void *dest, int c, uptr n)
65 
66 // True if this is a nested interceptor.
67 static THREADLOCAL int in_interceptor_scope;
68 
69 void __msan_scoped_disable_interceptor_checks() { ++in_interceptor_scope; }
70 void __msan_scoped_enable_interceptor_checks() { --in_interceptor_scope; }
71 
72 struct InterceptorScope {
73   InterceptorScope() { ++in_interceptor_scope; }
74   ~InterceptorScope() { --in_interceptor_scope; }
75 };
76 
77 bool IsInInterceptorScope() {
78   return in_interceptor_scope;
79 }
80 
81 struct DlsymAlloc : public DlSymAllocator<DlsymAlloc> {
82   static bool UseImpl() { return !msan_inited; }
83 };
84 
85 #define ENSURE_MSAN_INITED() do { \
86   CHECK(!msan_init_is_running); \
87   if (!msan_inited) { \
88     __msan_init(); \
89   } \
90 } while (0)
91 
92 // Check that [x, x+n) range is unpoisoned.
93 #define CHECK_UNPOISONED_0(x, n)                                  \
94   do {                                                            \
95     sptr __offset = __msan_test_shadow(x, n);                     \
96     if (__msan::IsInSymbolizerOrUnwider())                        \
97       break;                                                      \
98     if (__offset >= 0 && __msan::flags()->report_umrs) {          \
99       GET_CALLER_PC_BP;                                           \
100       ReportUMRInsideAddressRange(__func__, x, n, __offset);      \
101       __msan::PrintWarningWithOrigin(                             \
102           pc, bp, __msan_get_origin((const char *)x + __offset)); \
103       if (__msan::flags()->halt_on_error) {                       \
104         Printf("Exiting\n");                                      \
105         Die();                                                    \
106       }                                                           \
107     }                                                             \
108   } while (0)
109 
110 // Check that [x, x+n) range is unpoisoned unless we are in a nested
111 // interceptor.
112 #define CHECK_UNPOISONED(x, n)                             \
113   do {                                                     \
114     if (!IsInInterceptorScope()) CHECK_UNPOISONED_0(x, n); \
115   } while (0)
116 
117 #define CHECK_UNPOISONED_STRING_OF_LEN(x, len, n)               \
118   CHECK_UNPOISONED((x),                                         \
119     common_flags()->strict_string_checks ? (len) + 1 : (n) )
120 
121 #define CHECK_UNPOISONED_STRING(x, n)                           \
122     CHECK_UNPOISONED_STRING_OF_LEN((x), internal_strlen(x), (n))
123 
124 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
125 INTERCEPTOR(SIZE_T, fread_unlocked, void *ptr, SIZE_T size, SIZE_T nmemb,
126             void *file) {
127   ENSURE_MSAN_INITED();
128   SIZE_T res = REAL(fread_unlocked)(ptr, size, nmemb, file);
129   if (res > 0)
130     __msan_unpoison(ptr, res *size);
131   return res;
132 }
133 #define MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED INTERCEPT_FUNCTION(fread_unlocked)
134 #else
135 #define MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED
136 #endif
137 
138 #if !SANITIZER_NETBSD
139 INTERCEPTOR(void *, mempcpy, void *dest, const void *src, SIZE_T n) {
140   return (char *)__msan_memcpy(dest, src, n) + n;
141 }
142 #define MSAN_MAYBE_INTERCEPT_MEMPCPY INTERCEPT_FUNCTION(mempcpy)
143 #else
144 #define MSAN_MAYBE_INTERCEPT_MEMPCPY
145 #endif
146 
147 INTERCEPTOR(void *, memccpy, void *dest, const void *src, int c, SIZE_T n) {
148   ENSURE_MSAN_INITED();
149   void *res = REAL(memccpy)(dest, src, c, n);
150   CHECK(!res || (res >= dest && res <= (char *)dest + n));
151   SIZE_T sz = res ? (char *)res - (char *)dest : n;
152   CHECK_UNPOISONED(src, sz);
153   __msan_unpoison(dest, sz);
154   return res;
155 }
156 
157 INTERCEPTOR(void *, bcopy, const void *src, void *dest, SIZE_T n) {
158   return __msan_memmove(dest, src, n);
159 }
160 
161 INTERCEPTOR(int, posix_memalign, void **memptr, SIZE_T alignment, SIZE_T size) {
162   GET_MALLOC_STACK_TRACE;
163   CHECK_NE(memptr, 0);
164   int res = msan_posix_memalign(memptr, alignment, size, &stack);
165   if (!res)
166     __msan_unpoison(memptr, sizeof(*memptr));
167   return res;
168 }
169 
170 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
171 INTERCEPTOR(void *, memalign, SIZE_T alignment, SIZE_T size) {
172   GET_MALLOC_STACK_TRACE;
173   return msan_memalign(alignment, size, &stack);
174 }
175 #define MSAN_MAYBE_INTERCEPT_MEMALIGN INTERCEPT_FUNCTION(memalign)
176 #else
177 #define MSAN_MAYBE_INTERCEPT_MEMALIGN
178 #endif
179 
180 INTERCEPTOR(void *, aligned_alloc, SIZE_T alignment, SIZE_T size) {
181   GET_MALLOC_STACK_TRACE;
182   return msan_aligned_alloc(alignment, size, &stack);
183 }
184 
185 #if !SANITIZER_NETBSD
186 INTERCEPTOR(void *, __libc_memalign, SIZE_T alignment, SIZE_T size) {
187   GET_MALLOC_STACK_TRACE;
188   void *ptr = msan_memalign(alignment, size, &stack);
189   if (ptr)
190     DTLS_on_libc_memalign(ptr, size);
191   return ptr;
192 }
193 #define MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN INTERCEPT_FUNCTION(__libc_memalign)
194 #else
195 #define MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN
196 #endif
197 
198 INTERCEPTOR(void *, valloc, SIZE_T size) {
199   GET_MALLOC_STACK_TRACE;
200   return msan_valloc(size, &stack);
201 }
202 
203 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
204 INTERCEPTOR(void *, pvalloc, SIZE_T size) {
205   GET_MALLOC_STACK_TRACE;
206   return msan_pvalloc(size, &stack);
207 }
208 #define MSAN_MAYBE_INTERCEPT_PVALLOC INTERCEPT_FUNCTION(pvalloc)
209 #else
210 #define MSAN_MAYBE_INTERCEPT_PVALLOC
211 #endif
212 
213 INTERCEPTOR(void, free, void *ptr) {
214   if (UNLIKELY(!ptr))
215     return;
216   if (DlsymAlloc::PointerIsMine(ptr))
217     return DlsymAlloc::Free(ptr);
218   GET_MALLOC_STACK_TRACE;
219   MsanDeallocate(&stack, ptr);
220 }
221 
222 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
223 INTERCEPTOR(void, cfree, void *ptr) {
224   if (UNLIKELY(!ptr))
225     return;
226   if (DlsymAlloc::PointerIsMine(ptr))
227     return DlsymAlloc::Free(ptr);
228   GET_MALLOC_STACK_TRACE;
229   MsanDeallocate(&stack, ptr);
230 }
231 #  define MSAN_MAYBE_INTERCEPT_CFREE INTERCEPT_FUNCTION(cfree)
232 #else
233 #define MSAN_MAYBE_INTERCEPT_CFREE
234 #endif
235 
236 #if !SANITIZER_NETBSD
237 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
238   return __sanitizer_get_allocated_size(ptr);
239 }
240 #define MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE \
241   INTERCEPT_FUNCTION(malloc_usable_size)
242 #else
243 #define MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE
244 #endif
245 
246 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
247 // This function actually returns a struct by value, but we can't unpoison a
248 // temporary! The following is equivalent on all supported platforms but
249 // aarch64 (which uses a different register for sret value).  We have a test
250 // to confirm that.
251 INTERCEPTOR(void, mallinfo, __sanitizer_struct_mallinfo *sret) {
252 #ifdef __aarch64__
253   uptr r8;
254   asm volatile("mov %0,x8" : "=r" (r8));
255   sret = reinterpret_cast<__sanitizer_struct_mallinfo*>(r8);
256 #endif
257   REAL(memset)(sret, 0, sizeof(*sret));
258   __msan_unpoison(sret, sizeof(*sret));
259 }
260 #define MSAN_MAYBE_INTERCEPT_MALLINFO INTERCEPT_FUNCTION(mallinfo)
261 #else
262 #define MSAN_MAYBE_INTERCEPT_MALLINFO
263 #endif
264 
265 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
266 INTERCEPTOR(int, mallopt, int cmd, int value) {
267   return 0;
268 }
269 #define MSAN_MAYBE_INTERCEPT_MALLOPT INTERCEPT_FUNCTION(mallopt)
270 #else
271 #define MSAN_MAYBE_INTERCEPT_MALLOPT
272 #endif
273 
274 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
275 INTERCEPTOR(void, malloc_stats, void) {
276   // FIXME: implement, but don't call REAL(malloc_stats)!
277 }
278 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS INTERCEPT_FUNCTION(malloc_stats)
279 #else
280 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS
281 #endif
282 
283 INTERCEPTOR(char *, strcpy, char *dest, const char *src) {
284   ENSURE_MSAN_INITED();
285   GET_STORE_STACK_TRACE;
286   SIZE_T n = internal_strlen(src);
287   CHECK_UNPOISONED_STRING(src + n, 0);
288   char *res = REAL(strcpy)(dest, src);
289   CopyShadowAndOrigin(dest, src, n + 1, &stack);
290   return res;
291 }
292 
293 INTERCEPTOR(char *, strncpy, char *dest, const char *src, SIZE_T n) {
294   ENSURE_MSAN_INITED();
295   GET_STORE_STACK_TRACE;
296   SIZE_T copy_size = internal_strnlen(src, n);
297   if (copy_size < n)
298     copy_size++;  // trailing \0
299   char *res = REAL(strncpy)(dest, src, n);
300   CopyShadowAndOrigin(dest, src, copy_size, &stack);
301   __msan_unpoison(dest + copy_size, n - copy_size);
302   return res;
303 }
304 
305 #if !SANITIZER_NETBSD
306 INTERCEPTOR(char *, stpcpy, char *dest, const char *src) {
307   ENSURE_MSAN_INITED();
308   GET_STORE_STACK_TRACE;
309   SIZE_T n = internal_strlen(src);
310   CHECK_UNPOISONED_STRING(src + n, 0);
311   char *res = REAL(stpcpy)(dest, src);
312   CopyShadowAndOrigin(dest, src, n + 1, &stack);
313   return res;
314 }
315 
316 INTERCEPTOR(char *, stpncpy, char *dest, const char *src, SIZE_T n) {
317   ENSURE_MSAN_INITED();
318   GET_STORE_STACK_TRACE;
319   SIZE_T copy_size = Min(n, internal_strnlen(src, n) + 1);
320   char *res = REAL(stpncpy)(dest, src, n);
321   CopyShadowAndOrigin(dest, src, copy_size, &stack);
322   __msan_unpoison(dest + copy_size, n - copy_size);
323   return res;
324 }
325 #  define MSAN_MAYBE_INTERCEPT_STPCPY INTERCEPT_FUNCTION(stpcpy)
326 #  define MSAN_MAYBE_INTERCEPT_STPNCPY INTERCEPT_FUNCTION(stpncpy)
327 #else
328 #define MSAN_MAYBE_INTERCEPT_STPCPY
329 #  define MSAN_MAYBE_INTERCEPT_STPNCPY
330 #endif
331 
332 INTERCEPTOR(char *, strdup, char *src) {
333   ENSURE_MSAN_INITED();
334   GET_STORE_STACK_TRACE;
335   // On FreeBSD strdup() leverages strlen().
336   InterceptorScope interceptor_scope;
337   SIZE_T n = internal_strlen(src);
338   CHECK_UNPOISONED_STRING(src + n, 0);
339   char *res = REAL(strdup)(src);
340   CopyShadowAndOrigin(res, src, n + 1, &stack);
341   return res;
342 }
343 
344 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
345 INTERCEPTOR(char *, __strdup, char *src) {
346   ENSURE_MSAN_INITED();
347   GET_STORE_STACK_TRACE;
348   SIZE_T n = internal_strlen(src);
349   CHECK_UNPOISONED_STRING(src + n, 0);
350   char *res = REAL(__strdup)(src);
351   CopyShadowAndOrigin(res, src, n + 1, &stack);
352   return res;
353 }
354 #define MSAN_MAYBE_INTERCEPT___STRDUP INTERCEPT_FUNCTION(__strdup)
355 #else
356 #define MSAN_MAYBE_INTERCEPT___STRDUP
357 #endif
358 
359 #if !SANITIZER_NETBSD
360 INTERCEPTOR(char *, gcvt, double number, SIZE_T ndigit, char *buf) {
361   ENSURE_MSAN_INITED();
362   char *res = REAL(gcvt)(number, ndigit, buf);
363   SIZE_T n = internal_strlen(buf);
364   __msan_unpoison(buf, n + 1);
365   return res;
366 }
367 #define MSAN_MAYBE_INTERCEPT_GCVT INTERCEPT_FUNCTION(gcvt)
368 #else
369 #define MSAN_MAYBE_INTERCEPT_GCVT
370 #endif
371 
372 INTERCEPTOR(char *, strcat, char *dest, const char *src) {
373   ENSURE_MSAN_INITED();
374   GET_STORE_STACK_TRACE;
375   SIZE_T src_size = internal_strlen(src);
376   SIZE_T dest_size = internal_strlen(dest);
377   CHECK_UNPOISONED_STRING(src + src_size, 0);
378   CHECK_UNPOISONED_STRING(dest + dest_size, 0);
379   char *res = REAL(strcat)(dest, src);
380   CopyShadowAndOrigin(dest + dest_size, src, src_size + 1, &stack);
381   return res;
382 }
383 
384 INTERCEPTOR(char *, strncat, char *dest, const char *src, SIZE_T n) {
385   ENSURE_MSAN_INITED();
386   GET_STORE_STACK_TRACE;
387   SIZE_T dest_size = internal_strlen(dest);
388   SIZE_T copy_size = internal_strnlen(src, n);
389   CHECK_UNPOISONED_STRING(dest + dest_size, 0);
390   char *res = REAL(strncat)(dest, src, n);
391   CopyShadowAndOrigin(dest + dest_size, src, copy_size, &stack);
392   __msan_unpoison(dest + dest_size + copy_size, 1); // \0
393   return res;
394 }
395 
396 // Hack: always pass nptr and endptr as part of __VA_ARGS_ to avoid having to
397 // deal with empty __VA_ARGS__ in the case of INTERCEPTOR_STRTO.
398 #define INTERCEPTOR_STRTO_BODY(ret_type, func, ...) \
399   ENSURE_MSAN_INITED();                             \
400   ret_type res = REAL(func)(__VA_ARGS__);           \
401   __msan_unpoison(endptr, sizeof(*endptr));         \
402   return res;
403 
404 #define INTERCEPTOR_STRTO(ret_type, func, char_type)                       \
405   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr) { \
406     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr);                  \
407   }
408 
409 #define INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)                \
410   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
411               int base) {                                                \
412     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, base);          \
413   }
414 
415 #define INTERCEPTOR_STRTO_LOC(ret_type, func, char_type)                 \
416   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
417               void *loc) {                                               \
418     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, loc);           \
419   }
420 
421 #define INTERCEPTOR_STRTO_BASE_LOC(ret_type, func, char_type)            \
422   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
423               int base, void *loc) {                                     \
424     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, base, loc);     \
425   }
426 
427 #if SANITIZER_NETBSD
428 #define INTERCEPTORS_STRTO(ret_type, func, char_type)      \
429   INTERCEPTOR_STRTO(ret_type, func, char_type)             \
430   INTERCEPTOR_STRTO_LOC(ret_type, func##_l, char_type)
431 
432 #define INTERCEPTORS_STRTO_BASE(ret_type, func, char_type)      \
433   INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)             \
434   INTERCEPTOR_STRTO_BASE_LOC(ret_type, func##_l, char_type)
435 
436 #else
437 #define INTERCEPTORS_STRTO(ret_type, func, char_type)      \
438   INTERCEPTOR_STRTO(ret_type, func, char_type)             \
439   INTERCEPTOR_STRTO_LOC(ret_type, func##_l, char_type)     \
440   INTERCEPTOR_STRTO_LOC(ret_type, __##func##_l, char_type) \
441   INTERCEPTOR_STRTO_LOC(ret_type, __##func##_internal, char_type)
442 
443 #define INTERCEPTORS_STRTO_BASE(ret_type, func, char_type)      \
444   INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)             \
445   INTERCEPTOR_STRTO_BASE_LOC(ret_type, func##_l, char_type)     \
446   INTERCEPTOR_STRTO_BASE_LOC(ret_type, __##func##_l, char_type) \
447   INTERCEPTOR_STRTO_BASE_LOC(ret_type, __##func##_internal, char_type)
448 #endif
449 
450 INTERCEPTORS_STRTO(double, strtod, char)
451 INTERCEPTORS_STRTO(float, strtof, char)
452 INTERCEPTORS_STRTO(long double, strtold, char)
453 INTERCEPTORS_STRTO_BASE(long, strtol, char)
454 INTERCEPTORS_STRTO_BASE(long long, strtoll, char)
455 INTERCEPTORS_STRTO_BASE(unsigned long, strtoul, char)
456 INTERCEPTORS_STRTO_BASE(unsigned long long, strtoull, char)
457 INTERCEPTORS_STRTO_BASE(u64, strtouq, char)
458 
459 INTERCEPTORS_STRTO(double, wcstod, wchar_t)
460 INTERCEPTORS_STRTO(float, wcstof, wchar_t)
461 INTERCEPTORS_STRTO(long double, wcstold, wchar_t)
462 INTERCEPTORS_STRTO_BASE(long, wcstol, wchar_t)
463 INTERCEPTORS_STRTO_BASE(long long, wcstoll, wchar_t)
464 INTERCEPTORS_STRTO_BASE(unsigned long, wcstoul, wchar_t)
465 INTERCEPTORS_STRTO_BASE(unsigned long long, wcstoull, wchar_t)
466 
467 #if SANITIZER_NETBSD
468 #define INTERCEPT_STRTO(func) \
469   INTERCEPT_FUNCTION(func); \
470   INTERCEPT_FUNCTION(func##_l);
471 #else
472 #define INTERCEPT_STRTO(func) \
473   INTERCEPT_FUNCTION(func); \
474   INTERCEPT_FUNCTION(func##_l); \
475   INTERCEPT_FUNCTION(__##func##_l); \
476   INTERCEPT_FUNCTION(__##func##_internal);
477 #endif
478 
479 
480 // FIXME: support *wprintf in common format interceptors.
481 INTERCEPTOR(int, vswprintf, void *str, uptr size, void *format, va_list ap) {
482   ENSURE_MSAN_INITED();
483   int res = REAL(vswprintf)(str, size, format, ap);
484   if (res >= 0) {
485     __msan_unpoison(str, 4 * (res + 1));
486   }
487   return res;
488 }
489 
490 INTERCEPTOR(int, swprintf, void *str, uptr size, void *format, ...) {
491   ENSURE_MSAN_INITED();
492   va_list ap;
493   va_start(ap, format);
494   int res = vswprintf(str, size, format, ap);
495   va_end(ap);
496   return res;
497 }
498 
499 #define INTERCEPTOR_STRFTIME_BODY(char_type, ret_type, func, s, ...) \
500   ENSURE_MSAN_INITED();                                              \
501   InterceptorScope interceptor_scope;                                \
502   ret_type res = REAL(func)(s, __VA_ARGS__);                         \
503   if (s) __msan_unpoison(s, sizeof(char_type) * (res + 1));          \
504   return res;
505 
506 INTERCEPTOR(SIZE_T, strftime, char *s, SIZE_T max, const char *format,
507             __sanitizer_tm *tm) {
508   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, strftime, s, max, format, tm);
509 }
510 
511 INTERCEPTOR(SIZE_T, strftime_l, char *s, SIZE_T max, const char *format,
512             __sanitizer_tm *tm, void *loc) {
513   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, strftime_l, s, max, format, tm, loc);
514 }
515 
516 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
517 INTERCEPTOR(SIZE_T, __strftime_l, char *s, SIZE_T max, const char *format,
518             __sanitizer_tm *tm, void *loc) {
519   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, __strftime_l, s, max, format, tm,
520                             loc);
521 }
522 #define MSAN_MAYBE_INTERCEPT___STRFTIME_L INTERCEPT_FUNCTION(__strftime_l)
523 #else
524 #define MSAN_MAYBE_INTERCEPT___STRFTIME_L
525 #endif
526 
527 INTERCEPTOR(SIZE_T, wcsftime, wchar_t *s, SIZE_T max, const wchar_t *format,
528             __sanitizer_tm *tm) {
529   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, wcsftime, s, max, format, tm);
530 }
531 
532 INTERCEPTOR(SIZE_T, wcsftime_l, wchar_t *s, SIZE_T max, const wchar_t *format,
533             __sanitizer_tm *tm, void *loc) {
534   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, wcsftime_l, s, max, format, tm,
535                             loc);
536 }
537 
538 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
539 INTERCEPTOR(SIZE_T, __wcsftime_l, wchar_t *s, SIZE_T max, const wchar_t *format,
540             __sanitizer_tm *tm, void *loc) {
541   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, __wcsftime_l, s, max, format, tm,
542                             loc);
543 }
544 #define MSAN_MAYBE_INTERCEPT___WCSFTIME_L INTERCEPT_FUNCTION(__wcsftime_l)
545 #else
546 #define MSAN_MAYBE_INTERCEPT___WCSFTIME_L
547 #endif
548 
549 INTERCEPTOR(int, mbtowc, wchar_t *dest, const char *src, SIZE_T n) {
550   ENSURE_MSAN_INITED();
551   int res = REAL(mbtowc)(dest, src, n);
552   if (res != -1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
553   return res;
554 }
555 
556 INTERCEPTOR(SIZE_T, mbrtowc, wchar_t *dest, const char *src, SIZE_T n,
557             void *ps) {
558   ENSURE_MSAN_INITED();
559   SIZE_T res = REAL(mbrtowc)(dest, src, n, ps);
560   if (res != (SIZE_T)-1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
561   return res;
562 }
563 
564 // wchar_t *wmemcpy(wchar_t *dest, const wchar_t *src, SIZE_T n);
565 INTERCEPTOR(wchar_t *, wmemcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
566   ENSURE_MSAN_INITED();
567   GET_STORE_STACK_TRACE;
568   wchar_t *res = REAL(wmemcpy)(dest, src, n);
569   CopyShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
570   return res;
571 }
572 
573 #if !SANITIZER_NETBSD
574 INTERCEPTOR(wchar_t *, wmempcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
575   ENSURE_MSAN_INITED();
576   GET_STORE_STACK_TRACE;
577   wchar_t *res = REAL(wmempcpy)(dest, src, n);
578   CopyShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
579   return res;
580 }
581 #define MSAN_MAYBE_INTERCEPT_WMEMPCPY INTERCEPT_FUNCTION(wmempcpy)
582 #else
583 #define MSAN_MAYBE_INTERCEPT_WMEMPCPY
584 #endif
585 
586 INTERCEPTOR(wchar_t *, wmemset, wchar_t *s, wchar_t c, SIZE_T n) {
587   CHECK(MEM_IS_APP(s));
588   ENSURE_MSAN_INITED();
589   wchar_t *res = REAL(wmemset)(s, c, n);
590   __msan_unpoison(s, n * sizeof(wchar_t));
591   return res;
592 }
593 
594 INTERCEPTOR(wchar_t *, wmemmove, wchar_t *dest, const wchar_t *src, SIZE_T n) {
595   ENSURE_MSAN_INITED();
596   GET_STORE_STACK_TRACE;
597   wchar_t *res = REAL(wmemmove)(dest, src, n);
598   MoveShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
599   return res;
600 }
601 
602 INTERCEPTOR(int, wcscmp, const wchar_t *s1, const wchar_t *s2) {
603   ENSURE_MSAN_INITED();
604   int res = REAL(wcscmp)(s1, s2);
605   return res;
606 }
607 
608 INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
609   ENSURE_MSAN_INITED();
610   int res = REAL(gettimeofday)(tv, tz);
611   if (tv)
612     __msan_unpoison(tv, 16);
613   if (tz)
614     __msan_unpoison(tz, 8);
615   return res;
616 }
617 
618 #if !SANITIZER_NETBSD
619 INTERCEPTOR(char *, fcvt, double x, int a, int *b, int *c) {
620   ENSURE_MSAN_INITED();
621   char *res = REAL(fcvt)(x, a, b, c);
622   __msan_unpoison(b, sizeof(*b));
623   __msan_unpoison(c, sizeof(*c));
624   if (res)
625     __msan_unpoison(res, internal_strlen(res) + 1);
626   return res;
627 }
628 #define MSAN_MAYBE_INTERCEPT_FCVT INTERCEPT_FUNCTION(fcvt)
629 #else
630 #define MSAN_MAYBE_INTERCEPT_FCVT
631 #endif
632 
633 INTERCEPTOR(char *, getenv, char *name) {
634   if (msan_init_is_running)
635     return REAL(getenv)(name);
636   ENSURE_MSAN_INITED();
637   char *res = REAL(getenv)(name);
638   if (res)
639     __msan_unpoison(res, internal_strlen(res) + 1);
640   return res;
641 }
642 
643 extern char **environ;
644 
645 static void UnpoisonEnviron() {
646   char **envp = environ;
647   for (; *envp; ++envp) {
648     __msan_unpoison(envp, sizeof(*envp));
649     __msan_unpoison(*envp, internal_strlen(*envp) + 1);
650   }
651   // Trailing NULL pointer.
652   __msan_unpoison(envp, sizeof(*envp));
653 }
654 
655 INTERCEPTOR(int, setenv, const char *name, const char *value, int overwrite) {
656   ENSURE_MSAN_INITED();
657   CHECK_UNPOISONED_STRING(name, 0);
658   int res = REAL(setenv)(name, value, overwrite);
659   if (!res) UnpoisonEnviron();
660   return res;
661 }
662 
663 INTERCEPTOR(int, putenv, char *string) {
664   ENSURE_MSAN_INITED();
665   int res = REAL(putenv)(string);
666   if (!res) UnpoisonEnviron();
667   return res;
668 }
669 
670 #define SANITIZER_STAT_LINUX (SANITIZER_LINUX && __GLIBC_PREREQ(2, 33))
671 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
672 INTERCEPTOR(int, fstat, int fd, void *buf) {
673   ENSURE_MSAN_INITED();
674   int res = REAL(fstat)(fd, buf);
675   if (!res)
676     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
677   return res;
678 }
679 #  define MSAN_MAYBE_INTERCEPT_FSTAT MSAN_INTERCEPT_FUNC(fstat)
680 #else
681 #define MSAN_MAYBE_INTERCEPT_FSTAT
682 #endif
683 
684 #if SANITIZER_STAT_LINUX
685 INTERCEPTOR(int, fstat64, int fd, void *buf) {
686   ENSURE_MSAN_INITED();
687   int res = REAL(fstat64)(fd, buf);
688   if (!res)
689     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
690   return res;
691 }
692 #  define MSAN_MAYBE_INTERCEPT_FSTAT64 MSAN_INTERCEPT_FUNC(fstat64)
693 #else
694 #  define MSAN_MAYBE_INTERCEPT_FSTAT64
695 #endif
696 
697 #if SANITIZER_GLIBC
698 INTERCEPTOR(int, __fxstat, int magic, int fd, void *buf) {
699   ENSURE_MSAN_INITED();
700   int res = REAL(__fxstat)(magic, fd, buf);
701   if (!res)
702     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
703   return res;
704 }
705 #  define MSAN_MAYBE_INTERCEPT___FXSTAT MSAN_INTERCEPT_FUNC(__fxstat)
706 #else
707 #define MSAN_MAYBE_INTERCEPT___FXSTAT
708 #endif
709 
710 #if SANITIZER_GLIBC
711 INTERCEPTOR(int, __fxstat64, int magic, int fd, void *buf) {
712   ENSURE_MSAN_INITED();
713   int res = REAL(__fxstat64)(magic, fd, buf);
714   if (!res)
715     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
716   return res;
717 }
718 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64 MSAN_INTERCEPT_FUNC(__fxstat64)
719 #else
720 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64
721 #endif
722 
723 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
724 INTERCEPTOR(int, fstatat, int fd, char *pathname, void *buf, int flags) {
725   ENSURE_MSAN_INITED();
726   int res = REAL(fstatat)(fd, pathname, buf, flags);
727   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
728   return res;
729 }
730 #  define MSAN_MAYBE_INTERCEPT_FSTATAT MSAN_INTERCEPT_FUNC(fstatat)
731 #else
732 #  define MSAN_MAYBE_INTERCEPT_FSTATAT
733 #endif
734 
735 #if SANITIZER_STAT_LINUX
736 INTERCEPTOR(int, fstatat64, int fd, char *pathname, void *buf, int flags) {
737   ENSURE_MSAN_INITED();
738   int res = REAL(fstatat64)(fd, pathname, buf, flags);
739   if (!res)
740     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
741   return res;
742 }
743 #  define MSAN_MAYBE_INTERCEPT_FSTATAT64 MSAN_INTERCEPT_FUNC(fstatat64)
744 #else
745 #  define MSAN_MAYBE_INTERCEPT_FSTATAT64
746 #endif
747 
748 #if SANITIZER_GLIBC
749 INTERCEPTOR(int, __fxstatat, int magic, int fd, char *pathname, void *buf,
750             int flags) {
751   ENSURE_MSAN_INITED();
752   int res = REAL(__fxstatat)(magic, fd, pathname, buf, flags);
753   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
754   return res;
755 }
756 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT MSAN_INTERCEPT_FUNC(__fxstatat)
757 #else
758 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT
759 #endif
760 
761 #if SANITIZER_GLIBC
762 INTERCEPTOR(int, __fxstatat64, int magic, int fd, char *pathname, void *buf,
763             int flags) {
764   ENSURE_MSAN_INITED();
765   int res = REAL(__fxstatat64)(magic, fd, pathname, buf, flags);
766   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
767   return res;
768 }
769 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64 MSAN_INTERCEPT_FUNC(__fxstatat64)
770 #else
771 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64
772 #endif
773 
774 INTERCEPTOR(int, pipe, int pipefd[2]) {
775   if (msan_init_is_running)
776     return REAL(pipe)(pipefd);
777   ENSURE_MSAN_INITED();
778   int res = REAL(pipe)(pipefd);
779   if (!res)
780     __msan_unpoison(pipefd, sizeof(int[2]));
781   return res;
782 }
783 
784 INTERCEPTOR(int, pipe2, int pipefd[2], int flags) {
785   ENSURE_MSAN_INITED();
786   int res = REAL(pipe2)(pipefd, flags);
787   if (!res)
788     __msan_unpoison(pipefd, sizeof(int[2]));
789   return res;
790 }
791 
792 INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int sv[2]) {
793   ENSURE_MSAN_INITED();
794   int res = REAL(socketpair)(domain, type, protocol, sv);
795   if (!res)
796     __msan_unpoison(sv, sizeof(int[2]));
797   return res;
798 }
799 
800 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
801 INTERCEPTOR(char *, fgets_unlocked, char *s, int size, void *stream) {
802   ENSURE_MSAN_INITED();
803   char *res = REAL(fgets_unlocked)(s, size, stream);
804   if (res)
805     __msan_unpoison(s, internal_strlen(s) + 1);
806   return res;
807 }
808 #define MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED INTERCEPT_FUNCTION(fgets_unlocked)
809 #else
810 #define MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED
811 #endif
812 
813 #define INTERCEPTOR_GETRLIMIT_BODY(func, resource, rlim)  \
814   if (msan_init_is_running)                               \
815     return REAL(getrlimit)(resource, rlim);               \
816   ENSURE_MSAN_INITED();                                   \
817   int res = REAL(func)(resource, rlim);                   \
818   if (!res)                                               \
819     __msan_unpoison(rlim, __sanitizer::struct_rlimit_sz); \
820   return res
821 
822 INTERCEPTOR(int, getrlimit, int resource, void *rlim) {
823   INTERCEPTOR_GETRLIMIT_BODY(getrlimit, resource, rlim);
824 }
825 
826 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
827 INTERCEPTOR(int, __getrlimit, int resource, void *rlim) {
828   INTERCEPTOR_GETRLIMIT_BODY(__getrlimit, resource, rlim);
829 }
830 
831 INTERCEPTOR(int, getrlimit64, int resource, void *rlim) {
832   if (msan_init_is_running) return REAL(getrlimit64)(resource, rlim);
833   ENSURE_MSAN_INITED();
834   int res = REAL(getrlimit64)(resource, rlim);
835   if (!res) __msan_unpoison(rlim, __sanitizer::struct_rlimit64_sz);
836   return res;
837 }
838 
839 INTERCEPTOR(int, prlimit, int pid, int resource, void *new_rlimit,
840             void *old_rlimit) {
841   if (msan_init_is_running)
842     return REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
843   ENSURE_MSAN_INITED();
844   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit_sz);
845   int res = REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
846   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit_sz);
847   return res;
848 }
849 
850 INTERCEPTOR(int, prlimit64, int pid, int resource, void *new_rlimit,
851             void *old_rlimit) {
852   if (msan_init_is_running)
853     return REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
854   ENSURE_MSAN_INITED();
855   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit64_sz);
856   int res = REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
857   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit64_sz);
858   return res;
859 }
860 
861 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT INTERCEPT_FUNCTION(__getrlimit)
862 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64 INTERCEPT_FUNCTION(getrlimit64)
863 #define MSAN_MAYBE_INTERCEPT_PRLIMIT INTERCEPT_FUNCTION(prlimit)
864 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64 INTERCEPT_FUNCTION(prlimit64)
865 #else
866 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT
867 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64
868 #define MSAN_MAYBE_INTERCEPT_PRLIMIT
869 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64
870 #endif
871 
872 INTERCEPTOR(int, gethostname, char *name, SIZE_T len) {
873   ENSURE_MSAN_INITED();
874   int res = REAL(gethostname)(name, len);
875   if (!res || (res == -1 && errno == errno_ENAMETOOLONG)) {
876     SIZE_T real_len = internal_strnlen(name, len);
877     if (real_len < len)
878       ++real_len;
879     __msan_unpoison(name, real_len);
880   }
881   return res;
882 }
883 
884 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
885 INTERCEPTOR(int, epoll_wait, int epfd, void *events, int maxevents,
886     int timeout) {
887   ENSURE_MSAN_INITED();
888   int res = REAL(epoll_wait)(epfd, events, maxevents, timeout);
889   if (res > 0) {
890     __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
891   }
892   return res;
893 }
894 #define MSAN_MAYBE_INTERCEPT_EPOLL_WAIT INTERCEPT_FUNCTION(epoll_wait)
895 #else
896 #define MSAN_MAYBE_INTERCEPT_EPOLL_WAIT
897 #endif
898 
899 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
900 INTERCEPTOR(int, epoll_pwait, int epfd, void *events, int maxevents,
901     int timeout, void *sigmask) {
902   ENSURE_MSAN_INITED();
903   int res = REAL(epoll_pwait)(epfd, events, maxevents, timeout, sigmask);
904   if (res > 0) {
905     __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
906   }
907   return res;
908 }
909 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT INTERCEPT_FUNCTION(epoll_pwait)
910 #else
911 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT
912 #endif
913 
914 INTERCEPTOR(void *, calloc, SIZE_T nmemb, SIZE_T size) {
915   GET_MALLOC_STACK_TRACE;
916   if (DlsymAlloc::Use())
917     return DlsymAlloc::Callocate(nmemb, size);
918   return msan_calloc(nmemb, size, &stack);
919 }
920 
921 INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
922   if (DlsymAlloc::Use() || DlsymAlloc::PointerIsMine(ptr))
923     return DlsymAlloc::Realloc(ptr, size);
924   GET_MALLOC_STACK_TRACE;
925   return msan_realloc(ptr, size, &stack);
926 }
927 
928 INTERCEPTOR(void *, reallocarray, void *ptr, SIZE_T nmemb, SIZE_T size) {
929   GET_MALLOC_STACK_TRACE;
930   return msan_reallocarray(ptr, nmemb, size, &stack);
931 }
932 
933 INTERCEPTOR(void *, malloc, SIZE_T size) {
934   if (DlsymAlloc::Use())
935     return DlsymAlloc::Allocate(size);
936   GET_MALLOC_STACK_TRACE;
937   return msan_malloc(size, &stack);
938 }
939 
940 void __msan_allocated_memory(const void *data, uptr size) {
941   if (flags()->poison_in_malloc) {
942     GET_MALLOC_STACK_TRACE;
943     stack.tag = STACK_TRACE_TAG_POISON;
944     PoisonMemory(data, size, &stack);
945   }
946 }
947 
948 void __msan_copy_shadow(void *dest, const void *src, uptr n) {
949   GET_STORE_STACK_TRACE;
950   MoveShadowAndOrigin(dest, src, n, &stack);
951 }
952 
953 void __sanitizer_dtor_callback(const void *data, uptr size) {
954   if (flags()->poison_in_dtor) {
955     GET_MALLOC_STACK_TRACE;
956     stack.tag = STACK_TRACE_TAG_POISON;
957     PoisonMemory(data, size, &stack);
958   }
959 }
960 
961 void __sanitizer_dtor_callback_fields(const void *data, uptr size) {
962   if (flags()->poison_in_dtor) {
963     GET_MALLOC_STACK_TRACE;
964     stack.tag = STACK_TRACE_TAG_FIELDS;
965     PoisonMemory(data, size, &stack);
966   }
967 }
968 
969 void __sanitizer_dtor_callback_vptr(const void *data) {
970   if (flags()->poison_in_dtor) {
971     GET_MALLOC_STACK_TRACE;
972     stack.tag = STACK_TRACE_TAG_VPTR;
973     PoisonMemory(data, sizeof(void *), &stack);
974   }
975 }
976 
977 template <class Mmap>
978 static void *mmap_interceptor(Mmap real_mmap, void *addr, SIZE_T length,
979                               int prot, int flags, int fd, OFF64_T offset) {
980   SIZE_T rounded_length = RoundUpTo(length, GetPageSize());
981   void *end_addr = (char *)addr + (rounded_length - 1);
982   if (addr && (!MEM_IS_APP(addr) || !MEM_IS_APP(end_addr))) {
983     if (flags & map_fixed) {
984       errno = errno_EINVAL;
985       return (void *)-1;
986     } else {
987       addr = nullptr;
988     }
989   }
990   void *res = real_mmap(addr, length, prot, flags, fd, offset);
991   if (res != (void *)-1) {
992     void *end_res = (char *)res + (rounded_length - 1);
993     if (MEM_IS_APP(res) && MEM_IS_APP(end_res)) {
994       __msan_unpoison(res, rounded_length);
995     } else {
996       // Application has attempted to map more memory than is supported by
997       // MSAN. Act as if we ran out of memory.
998       internal_munmap(res, length);
999       errno = errno_ENOMEM;
1000       return (void *)-1;
1001     }
1002   }
1003   return res;
1004 }
1005 
1006 INTERCEPTOR(int, getrusage, int who, void *usage) {
1007   ENSURE_MSAN_INITED();
1008   int res = REAL(getrusage)(who, usage);
1009   if (res == 0) {
1010     __msan_unpoison(usage, __sanitizer::struct_rusage_sz);
1011   }
1012   return res;
1013 }
1014 
1015 class SignalHandlerScope {
1016  public:
1017   SignalHandlerScope() {
1018     if (MsanThread *t = GetCurrentThread())
1019       t->EnterSignalHandler();
1020   }
1021   ~SignalHandlerScope() {
1022     if (MsanThread *t = GetCurrentThread())
1023       t->LeaveSignalHandler();
1024   }
1025 };
1026 
1027 // sigactions_mu guarantees atomicity of sigaction() and signal() calls.
1028 // Access to sigactions[] is gone with relaxed atomics to avoid data race with
1029 // the signal handler.
1030 const int kMaxSignals = 1024;
1031 static atomic_uintptr_t sigactions[kMaxSignals];
1032 static StaticSpinMutex sigactions_mu;
1033 
1034 static void SignalHandler(int signo) {
1035   SignalHandlerScope signal_handler_scope;
1036   ScopedThreadLocalStateBackup stlsb;
1037   UnpoisonParam(1);
1038 
1039   typedef void (*signal_cb)(int x);
1040   signal_cb cb =
1041       (signal_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
1042   cb(signo);
1043 }
1044 
1045 static void SignalAction(int signo, void *si, void *uc) {
1046   SignalHandlerScope signal_handler_scope;
1047   ScopedThreadLocalStateBackup stlsb;
1048   UnpoisonParam(3);
1049   __msan_unpoison(si, sizeof(__sanitizer_sigaction));
1050   __msan_unpoison(uc, ucontext_t_sz(uc));
1051 
1052   typedef void (*sigaction_cb)(int, void *, void *);
1053   sigaction_cb cb =
1054       (sigaction_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
1055   cb(signo, si, uc);
1056   CHECK_UNPOISONED(uc, ucontext_t_sz(uc));
1057 }
1058 
1059 static void read_sigaction(const __sanitizer_sigaction *act) {
1060   CHECK_UNPOISONED(&act->sa_flags, sizeof(act->sa_flags));
1061   if (act->sa_flags & __sanitizer::sa_siginfo)
1062     CHECK_UNPOISONED(&act->sigaction, sizeof(act->sigaction));
1063   else
1064     CHECK_UNPOISONED(&act->handler, sizeof(act->handler));
1065   CHECK_UNPOISONED(&act->sa_mask, sizeof(act->sa_mask));
1066 }
1067 
1068 extern "C" int pthread_attr_init(void *attr);
1069 extern "C" int pthread_attr_destroy(void *attr);
1070 
1071 static void *MsanThreadStartFunc(void *arg) {
1072   MsanThread *t = (MsanThread *)arg;
1073   SetCurrentThread(t);
1074   t->Init();
1075   SetSigProcMask(&t->starting_sigset_, nullptr);
1076   return t->ThreadStart();
1077 }
1078 
1079 INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*),
1080             void * param) {
1081   ENSURE_MSAN_INITED(); // for GetTlsSize()
1082   __sanitizer_pthread_attr_t myattr;
1083   if (!attr) {
1084     pthread_attr_init(&myattr);
1085     attr = &myattr;
1086   }
1087 
1088   AdjustStackSize(attr);
1089 
1090   MsanThread *t = MsanThread::Create(callback, param);
1091   ScopedBlockSignals block(&t->starting_sigset_);
1092   int res = REAL(pthread_create)(th, attr, MsanThreadStartFunc, t);
1093 
1094   if (attr == &myattr)
1095     pthread_attr_destroy(&myattr);
1096   if (!res) {
1097     __msan_unpoison(th, __sanitizer::pthread_t_sz);
1098   }
1099   return res;
1100 }
1101 
1102 INTERCEPTOR(int, pthread_key_create, __sanitizer_pthread_key_t *key,
1103             void (*dtor)(void *value)) {
1104   if (msan_init_is_running) return REAL(pthread_key_create)(key, dtor);
1105   ENSURE_MSAN_INITED();
1106   int res = REAL(pthread_key_create)(key, dtor);
1107   if (!res && key)
1108     __msan_unpoison(key, sizeof(*key));
1109   return res;
1110 }
1111 
1112 #if SANITIZER_NETBSD
1113 INTERCEPTOR(int, __libc_thr_keycreate, __sanitizer_pthread_key_t *m,
1114             void (*dtor)(void *value))
1115 ALIAS(WRAP(pthread_key_create));
1116 #endif
1117 
1118 INTERCEPTOR(int, pthread_join, void *thread, void **retval) {
1119   ENSURE_MSAN_INITED();
1120   int res = REAL(pthread_join)(thread, retval);
1121   if (!res && retval)
1122     __msan_unpoison(retval, sizeof(*retval));
1123   return res;
1124 }
1125 
1126 #if SANITIZER_GLIBC
1127 INTERCEPTOR(int, pthread_tryjoin_np, void *thread, void **retval) {
1128   ENSURE_MSAN_INITED();
1129   int res = REAL(pthread_tryjoin_np)(thread, retval);
1130   if (!res && retval)
1131     __msan_unpoison(retval, sizeof(*retval));
1132   return res;
1133 }
1134 
1135 INTERCEPTOR(int, pthread_timedjoin_np, void *thread, void **retval,
1136             const struct timespec *abstime) {
1137   int res = REAL(pthread_timedjoin_np)(thread, retval, abstime);
1138   if (!res && retval)
1139     __msan_unpoison(retval, sizeof(*retval));
1140   return res;
1141 }
1142 #endif
1143 
1144 DEFINE_REAL_PTHREAD_FUNCTIONS
1145 
1146 extern char *tzname[2];
1147 
1148 INTERCEPTOR(void, tzset, int fake) {
1149   ENSURE_MSAN_INITED();
1150   InterceptorScope interceptor_scope;
1151   REAL(tzset)(fake);
1152   if (tzname[0])
1153     __msan_unpoison(tzname[0], internal_strlen(tzname[0]) + 1);
1154   if (tzname[1])
1155     __msan_unpoison(tzname[1], internal_strlen(tzname[1]) + 1);
1156   return;
1157 }
1158 
1159 struct MSanAtExitRecord {
1160   void (*func)(void *arg);
1161   void *arg;
1162 };
1163 
1164 struct InterceptorContext {
1165   Mutex atexit_mu;
1166   Vector<struct MSanAtExitRecord *> AtExitStack;
1167 
1168   InterceptorContext()
1169       : AtExitStack() {
1170   }
1171 };
1172 
1173 static ALIGNED(64) char interceptor_placeholder[sizeof(InterceptorContext)];
1174 InterceptorContext *interceptor_ctx() {
1175   return reinterpret_cast<InterceptorContext*>(&interceptor_placeholder[0]);
1176 }
1177 
1178 void MSanAtExitWrapper() {
1179   MSanAtExitRecord *r;
1180   {
1181     Lock l(&interceptor_ctx()->atexit_mu);
1182 
1183     uptr element = interceptor_ctx()->AtExitStack.Size() - 1;
1184     r = interceptor_ctx()->AtExitStack[element];
1185     interceptor_ctx()->AtExitStack.PopBack();
1186   }
1187 
1188   UnpoisonParam(1);
1189   ((void(*)())r->func)();
1190   InternalFree(r);
1191 }
1192 
1193 void MSanCxaAtExitWrapper(void *arg) {
1194   UnpoisonParam(1);
1195   MSanAtExitRecord *r = (MSanAtExitRecord *)arg;
1196   // libc before 2.27 had race which caused occasional double handler execution
1197   // https://sourceware.org/ml/libc-alpha/2017-08/msg01204.html
1198   if (!r->func)
1199     return;
1200   r->func(r->arg);
1201   r->func = nullptr;
1202 }
1203 
1204 static int setup_at_exit_wrapper(void(*f)(), void *arg, void *dso);
1205 
1206 // Unpoison argument shadow for C++ module destructors.
1207 INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
1208             void *dso_handle) {
1209   if (msan_init_is_running) return REAL(__cxa_atexit)(func, arg, dso_handle);
1210   return setup_at_exit_wrapper((void(*)())func, arg, dso_handle);
1211 }
1212 
1213 // Unpoison argument shadow for C++ module destructors.
1214 INTERCEPTOR(int, atexit, void (*func)()) {
1215   // Avoid calling real atexit as it is unreachable on at least on Linux.
1216   if (msan_init_is_running)
1217     return REAL(__cxa_atexit)((void (*)(void *a))func, 0, 0);
1218   return setup_at_exit_wrapper((void(*)())func, 0, 0);
1219 }
1220 
1221 static int setup_at_exit_wrapper(void(*f)(), void *arg, void *dso) {
1222   ENSURE_MSAN_INITED();
1223   MSanAtExitRecord *r =
1224       (MSanAtExitRecord *)InternalAlloc(sizeof(MSanAtExitRecord));
1225   r->func = (void(*)(void *a))f;
1226   r->arg = arg;
1227   int res;
1228   if (!dso) {
1229     // NetBSD does not preserve the 2nd argument if dso is equal to 0
1230     // Store ctx in a local stack-like structure
1231 
1232     Lock l(&interceptor_ctx()->atexit_mu);
1233 
1234     res = REAL(__cxa_atexit)((void (*)(void *a))MSanAtExitWrapper, 0, 0);
1235     if (!res) {
1236       interceptor_ctx()->AtExitStack.PushBack(r);
1237     }
1238   } else {
1239     res = REAL(__cxa_atexit)(MSanCxaAtExitWrapper, r, dso);
1240   }
1241   return res;
1242 }
1243 
1244 static void BeforeFork() {
1245   StackDepotLockAll();
1246   ChainedOriginDepotLockAll();
1247 }
1248 
1249 static void AfterFork() {
1250   ChainedOriginDepotUnlockAll();
1251   StackDepotUnlockAll();
1252 }
1253 
1254 INTERCEPTOR(int, fork, void) {
1255   ENSURE_MSAN_INITED();
1256   BeforeFork();
1257   int pid = REAL(fork)();
1258   AfterFork();
1259   return pid;
1260 }
1261 
1262 // NetBSD ships with openpty(3) in -lutil, that needs to be prebuilt explicitly
1263 // with MSan.
1264 #if SANITIZER_LINUX
1265 INTERCEPTOR(int, openpty, int *aparent, int *aworker, char *name,
1266             const void *termp, const void *winp) {
1267   ENSURE_MSAN_INITED();
1268   InterceptorScope interceptor_scope;
1269   int res = REAL(openpty)(aparent, aworker, name, termp, winp);
1270   if (!res) {
1271     __msan_unpoison(aparent, sizeof(*aparent));
1272     __msan_unpoison(aworker, sizeof(*aworker));
1273   }
1274   return res;
1275 }
1276 #define MSAN_MAYBE_INTERCEPT_OPENPTY INTERCEPT_FUNCTION(openpty)
1277 #else
1278 #define MSAN_MAYBE_INTERCEPT_OPENPTY
1279 #endif
1280 
1281 // NetBSD ships with forkpty(3) in -lutil, that needs to be prebuilt explicitly
1282 // with MSan.
1283 #if SANITIZER_LINUX
1284 INTERCEPTOR(int, forkpty, int *aparent, char *name, const void *termp,
1285             const void *winp) {
1286   ENSURE_MSAN_INITED();
1287   InterceptorScope interceptor_scope;
1288   int res = REAL(forkpty)(aparent, name, termp, winp);
1289   if (res != -1)
1290     __msan_unpoison(aparent, sizeof(*aparent));
1291   return res;
1292 }
1293 #define MSAN_MAYBE_INTERCEPT_FORKPTY INTERCEPT_FUNCTION(forkpty)
1294 #else
1295 #define MSAN_MAYBE_INTERCEPT_FORKPTY
1296 #endif
1297 
1298 struct MSanInterceptorContext {
1299   bool in_interceptor_scope;
1300 };
1301 
1302 namespace __msan {
1303 
1304 int OnExit() {
1305   // FIXME: ask frontend whether we need to return failure.
1306   return 0;
1307 }
1308 
1309 } // namespace __msan
1310 
1311 // A version of CHECK_UNPOISONED using a saved scope value. Used in common
1312 // interceptors.
1313 #define CHECK_UNPOISONED_CTX(ctx, x, n)                         \
1314   do {                                                          \
1315     if (!((MSanInterceptorContext *)ctx)->in_interceptor_scope) \
1316       CHECK_UNPOISONED_0(x, n);                                 \
1317   } while (0)
1318 
1319 #define MSAN_INTERCEPT_FUNC(name)                                       \
1320   do {                                                                  \
1321     if (!INTERCEPT_FUNCTION(name))                                      \
1322       VReport(1, "MemorySanitizer: failed to intercept '%s'\n", #name); \
1323   } while (0)
1324 
1325 #define MSAN_INTERCEPT_FUNC_VER(name, ver)                                 \
1326   do {                                                                     \
1327     if (!INTERCEPT_FUNCTION_VER(name, ver))                                \
1328       VReport(1, "MemorySanitizer: failed to intercept '%s@@%s'\n", #name, \
1329               ver);                                                        \
1330   } while (0)
1331 #define MSAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)             \
1332   do {                                                                      \
1333     if (!INTERCEPT_FUNCTION_VER(name, ver) && !INTERCEPT_FUNCTION(name))    \
1334       VReport(1, "MemorySanitizer: failed to intercept '%s@@%s' or '%s'\n", \
1335               #name, ver, #name);                                           \
1336   } while (0)
1337 
1338 #define COMMON_INTERCEPT_FUNCTION(name) MSAN_INTERCEPT_FUNC(name)
1339 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver) \
1340   MSAN_INTERCEPT_FUNC_VER(name, ver)
1341 #define COMMON_INTERCEPT_FUNCTION_VER_UNVERSIONED_FALLBACK(name, ver) \
1342   MSAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)
1343 #define COMMON_INTERCEPTOR_UNPOISON_PARAM(count)  \
1344   UnpoisonParam(count)
1345 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
1346   __msan_unpoison(ptr, size)
1347 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
1348   CHECK_UNPOISONED_CTX(ctx, ptr, size)
1349 #define COMMON_INTERCEPTOR_INITIALIZE_RANGE(ptr, size) \
1350   __msan_unpoison(ptr, size)
1351 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)              \
1352   if (msan_init_is_running)                                   \
1353     return REAL(func)(__VA_ARGS__);                           \
1354   ENSURE_MSAN_INITED();                                       \
1355   MSanInterceptorContext msan_ctx = {IsInInterceptorScope()}; \
1356   ctx = (void *)&msan_ctx;                                    \
1357   (void)ctx;                                                  \
1358   InterceptorScope interceptor_scope;                         \
1359   __msan_unpoison(__errno_location(), sizeof(int));
1360 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
1361   do {                                            \
1362   } while (false)
1363 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
1364   do {                                         \
1365   } while (false)
1366 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
1367   do {                                         \
1368   } while (false)
1369 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
1370   do {                                                      \
1371   } while (false)
1372 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
1373   do {                                                \
1374   } while (false)  // FIXME
1375 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
1376   do {                                                         \
1377   } while (false)  // FIXME
1378 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
1379 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
1380 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)                    \
1381   do {                                                                         \
1382     link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE((handle));                   \
1383     if (filename && map)                                                       \
1384       ForEachMappedRegion(map, __msan_unpoison);                               \
1385   } while (false)
1386 
1387 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!msan_inited)
1388 
1389 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
1390   if (MsanThread *t = GetCurrentThread()) {                                    \
1391     *begin = t->tls_begin();                                                   \
1392     *end = t->tls_end();                                                       \
1393   } else {                                                                     \
1394     *begin = *end = 0;                                                         \
1395   }
1396 
1397 #define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size) \
1398   {                                                         \
1399     (void)ctx;                                              \
1400     return __msan_memset(block, c, size);                   \
1401   }
1402 #define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size) \
1403   {                                                          \
1404     (void)ctx;                                               \
1405     return __msan_memmove(to, from, size);                   \
1406   }
1407 #define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size) \
1408   {                                                         \
1409     (void)ctx;                                              \
1410     return __msan_memcpy(to, from, size);                   \
1411   }
1412 
1413 #define COMMON_INTERCEPTOR_COPY_STRING(ctx, to, from, size) \
1414   do {                                                      \
1415     GET_STORE_STACK_TRACE;                                  \
1416     CopyShadowAndOrigin(to, from, size, &stack);            \
1417     __msan_unpoison(to + size, 1);                          \
1418   } while (false)
1419 
1420 #define COMMON_INTERCEPTOR_MMAP_IMPL(ctx, mmap, addr, length, prot, flags, fd, \
1421                                      offset)                                   \
1422   do {                                                                         \
1423     return mmap_interceptor(REAL(mmap), addr, sz, prot, flags, fd, off);       \
1424   } while (false)
1425 
1426 #include "sanitizer_common/sanitizer_platform_interceptors.h"
1427 #include "sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc"
1428 #include "sanitizer_common/sanitizer_common_interceptors.inc"
1429 
1430 static uptr signal_impl(int signo, uptr cb);
1431 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
1432                           __sanitizer_sigaction *oldact);
1433 
1434 #define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
1435   { return sigaction_impl(signo, act, oldact); }
1436 
1437 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
1438   {                                                          \
1439     handler = signal_impl(signo, handler);                   \
1440     InterceptorScope interceptor_scope;                      \
1441     return REAL(func)(signo, handler);                       \
1442   }
1443 
1444 #define SIGNAL_INTERCEPTOR_ENTER() ENSURE_MSAN_INITED()
1445 
1446 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
1447 
1448 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
1449                           __sanitizer_sigaction *oldact) {
1450   ENSURE_MSAN_INITED();
1451   if (signo <= 0 || signo >= kMaxSignals) {
1452     errno = errno_EINVAL;
1453     return -1;
1454   }
1455   if (act) read_sigaction(act);
1456   int res;
1457   if (flags()->wrap_signals) {
1458     SpinMutexLock lock(&sigactions_mu);
1459     uptr old_cb = atomic_load(&sigactions[signo], memory_order_relaxed);
1460     __sanitizer_sigaction new_act;
1461     __sanitizer_sigaction *pnew_act = act ? &new_act : nullptr;
1462     if (act) {
1463       REAL(memcpy)(pnew_act, act, sizeof(__sanitizer_sigaction));
1464       uptr cb = (uptr)pnew_act->sigaction;
1465       uptr new_cb = (pnew_act->sa_flags & __sanitizer::sa_siginfo)
1466                         ? (uptr)SignalAction
1467                         : (uptr)SignalHandler;
1468       if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1469         atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1470         pnew_act->sigaction = (decltype(pnew_act->sigaction))new_cb;
1471       }
1472     }
1473     res = REAL(SIGACTION_SYMNAME)(signo, pnew_act, oldact);
1474     if (res == 0 && oldact) {
1475       uptr cb = (uptr)oldact->sigaction;
1476       if (cb == (uptr)SignalAction || cb == (uptr)SignalHandler) {
1477         oldact->sigaction = (decltype(oldact->sigaction))old_cb;
1478       }
1479     }
1480   } else {
1481     res = REAL(SIGACTION_SYMNAME)(signo, act, oldact);
1482   }
1483 
1484   if (res == 0 && oldact) {
1485     __msan_unpoison(oldact, sizeof(__sanitizer_sigaction));
1486   }
1487   return res;
1488 }
1489 
1490 static uptr signal_impl(int signo, uptr cb) {
1491   ENSURE_MSAN_INITED();
1492   if (signo <= 0 || signo >= kMaxSignals) {
1493     errno = errno_EINVAL;
1494     return -1;
1495   }
1496   if (flags()->wrap_signals) {
1497     SpinMutexLock lock(&sigactions_mu);
1498     if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1499       atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1500       cb = (uptr)&SignalHandler;
1501     }
1502   }
1503   return cb;
1504 }
1505 
1506 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) CHECK_UNPOISONED(p, s)
1507 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
1508   do {                                       \
1509   } while (false)
1510 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
1511   do {                                       \
1512   } while (false)
1513 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) __msan_unpoison(p, s)
1514 #include "sanitizer_common/sanitizer_common_syscalls.inc"
1515 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
1516 
1517 INTERCEPTOR(const char *, strsignal, int sig) {
1518   void *ctx;
1519   COMMON_INTERCEPTOR_ENTER(ctx, strsignal, sig);
1520   const char *res = REAL(strsignal)(sig);
1521   if (res)
1522     __msan_unpoison(res, internal_strlen(res) + 1);
1523   return res;
1524 }
1525 
1526 INTERCEPTOR(int, dladdr, void *addr, void *info) {
1527   void *ctx;
1528   COMMON_INTERCEPTOR_ENTER(ctx, dladdr, addr, info);
1529   int res = REAL(dladdr)(addr, info);
1530   if (res != 0)
1531     UnpoisonDllAddrInfo(info);
1532   return res;
1533 }
1534 
1535 #if SANITIZER_GLIBC
1536 INTERCEPTOR(int, dladdr1, void *addr, void *info, void **extra_info,
1537             int flags) {
1538   void *ctx;
1539   COMMON_INTERCEPTOR_ENTER(ctx, dladdr1, addr, info, extra_info, flags);
1540   int res = REAL(dladdr1)(addr, info, extra_info, flags);
1541   if (res != 0) {
1542     UnpoisonDllAddrInfo(info);
1543     UnpoisonDllAddr1ExtraInfo(extra_info, flags);
1544   }
1545   return res;
1546 }
1547 #  define MSAN_MAYBE_INTERCEPT_DLADDR1 MSAN_INTERCEPT_FUNC(dladdr1)
1548 #else
1549 #define MSAN_MAYBE_INTERCEPT_DLADDR1
1550 #endif
1551 
1552 INTERCEPTOR(char *, dlerror, int fake) {
1553   void *ctx;
1554   COMMON_INTERCEPTOR_ENTER(ctx, dlerror, fake);
1555   char *res = REAL(dlerror)(fake);
1556   if (res)
1557     __msan_unpoison(res, internal_strlen(res) + 1);
1558   return res;
1559 }
1560 
1561 typedef int (*dl_iterate_phdr_cb)(__sanitizer_dl_phdr_info *info, SIZE_T size,
1562                                   void *data);
1563 struct dl_iterate_phdr_data {
1564   dl_iterate_phdr_cb callback;
1565   void *data;
1566 };
1567 
1568 static int msan_dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
1569                                    void *data) {
1570   if (info) {
1571     __msan_unpoison(info, size);
1572     if (info->dlpi_phdr && info->dlpi_phnum)
1573       __msan_unpoison(info->dlpi_phdr, struct_ElfW_Phdr_sz * info->dlpi_phnum);
1574     if (info->dlpi_name)
1575       __msan_unpoison(info->dlpi_name, internal_strlen(info->dlpi_name) + 1);
1576   }
1577   dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
1578   UnpoisonParam(3);
1579   return cbdata->callback(info, size, cbdata->data);
1580 }
1581 
1582 INTERCEPTOR(void *, shmat, int shmid, const void *shmaddr, int shmflg) {
1583   ENSURE_MSAN_INITED();
1584   void *p = REAL(shmat)(shmid, shmaddr, shmflg);
1585   if (p != (void *)-1) {
1586     __sanitizer_shmid_ds ds;
1587     int res = REAL(shmctl)(shmid, shmctl_ipc_stat, &ds);
1588     if (!res) {
1589       __msan_unpoison(p, ds.shm_segsz);
1590     }
1591   }
1592   return p;
1593 }
1594 
1595 INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb callback, void *data) {
1596   void *ctx;
1597   COMMON_INTERCEPTOR_ENTER(ctx, dl_iterate_phdr, callback, data);
1598   dl_iterate_phdr_data cbdata;
1599   cbdata.callback = callback;
1600   cbdata.data = data;
1601   int res = REAL(dl_iterate_phdr)(msan_dl_iterate_phdr_cb, (void *)&cbdata);
1602   return res;
1603 }
1604 
1605 // wchar_t *wcschr(const wchar_t *wcs, wchar_t wc);
1606 INTERCEPTOR(wchar_t *, wcschr, void *s, wchar_t wc, void *ps) {
1607   ENSURE_MSAN_INITED();
1608   wchar_t *res = REAL(wcschr)(s, wc, ps);
1609   return res;
1610 }
1611 
1612 // wchar_t *wcscpy(wchar_t *dest, const wchar_t *src);
1613 INTERCEPTOR(wchar_t *, wcscpy, wchar_t *dest, const wchar_t *src) {
1614   ENSURE_MSAN_INITED();
1615   GET_STORE_STACK_TRACE;
1616   wchar_t *res = REAL(wcscpy)(dest, src);
1617   CopyShadowAndOrigin(dest, src, sizeof(wchar_t) * (internal_wcslen(src) + 1),
1618                       &stack);
1619   return res;
1620 }
1621 
1622 INTERCEPTOR(wchar_t *, wcsncpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
1623   ENSURE_MSAN_INITED();
1624   GET_STORE_STACK_TRACE;
1625   SIZE_T copy_size = internal_wcsnlen(src, n);
1626   if (copy_size < n) copy_size++;           // trailing \0
1627   wchar_t *res = REAL(wcsncpy)(dest, src, n);
1628   CopyShadowAndOrigin(dest, src, copy_size * sizeof(wchar_t), &stack);
1629   __msan_unpoison(dest + copy_size, (n - copy_size) * sizeof(wchar_t));
1630   return res;
1631 }
1632 
1633 // These interface functions reside here so that they can use
1634 // REAL(memset), etc.
1635 void __msan_unpoison(const void *a, uptr size) {
1636   if (!MEM_IS_APP(a)) return;
1637   SetShadow(a, size, 0);
1638 }
1639 
1640 void __msan_poison(const void *a, uptr size) {
1641   if (!MEM_IS_APP(a)) return;
1642   SetShadow(a, size, __msan::flags()->poison_heap_with_zeroes ? 0 : -1);
1643 }
1644 
1645 void __msan_poison_stack(void *a, uptr size) {
1646   if (!MEM_IS_APP(a)) return;
1647   SetShadow(a, size, __msan::flags()->poison_stack_with_zeroes ? 0 : -1);
1648 }
1649 
1650 void __msan_unpoison_param(uptr n) { UnpoisonParam(n); }
1651 
1652 void __msan_clear_and_unpoison(void *a, uptr size) {
1653   REAL(memset)(a, 0, size);
1654   SetShadow(a, size, 0);
1655 }
1656 
1657 void *__msan_memcpy(void *dest, const void *src, SIZE_T n) {
1658   if (!msan_inited) return internal_memcpy(dest, src, n);
1659   if (msan_init_is_running || __msan::IsInSymbolizerOrUnwider())
1660     return REAL(memcpy)(dest, src, n);
1661   ENSURE_MSAN_INITED();
1662   GET_STORE_STACK_TRACE;
1663   void *res = REAL(memcpy)(dest, src, n);
1664   CopyShadowAndOrigin(dest, src, n, &stack);
1665   return res;
1666 }
1667 
1668 void *__msan_memset(void *s, int c, SIZE_T n) {
1669   if (!msan_inited) return internal_memset(s, c, n);
1670   if (msan_init_is_running) return REAL(memset)(s, c, n);
1671   ENSURE_MSAN_INITED();
1672   void *res = REAL(memset)(s, c, n);
1673   __msan_unpoison(s, n);
1674   return res;
1675 }
1676 
1677 void *__msan_memmove(void *dest, const void *src, SIZE_T n) {
1678   if (!msan_inited) return internal_memmove(dest, src, n);
1679   if (msan_init_is_running) return REAL(memmove)(dest, src, n);
1680   ENSURE_MSAN_INITED();
1681   GET_STORE_STACK_TRACE;
1682   void *res = REAL(memmove)(dest, src, n);
1683   MoveShadowAndOrigin(dest, src, n, &stack);
1684   return res;
1685 }
1686 
1687 void __msan_unpoison_string(const char* s) {
1688   if (!MEM_IS_APP(s)) return;
1689   __msan_unpoison(s, internal_strlen(s) + 1);
1690 }
1691 
1692 namespace __msan {
1693 
1694 void InitializeInterceptors() {
1695   static int inited = 0;
1696   CHECK_EQ(inited, 0);
1697 
1698   new(interceptor_ctx()) InterceptorContext();
1699 
1700   InitializeCommonInterceptors();
1701   InitializeSignalInterceptors();
1702 
1703   INTERCEPT_FUNCTION(posix_memalign);
1704   MSAN_MAYBE_INTERCEPT_MEMALIGN;
1705   MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN;
1706   INTERCEPT_FUNCTION(valloc);
1707   MSAN_MAYBE_INTERCEPT_PVALLOC;
1708   INTERCEPT_FUNCTION(malloc);
1709   INTERCEPT_FUNCTION(calloc);
1710   INTERCEPT_FUNCTION(realloc);
1711   INTERCEPT_FUNCTION(reallocarray);
1712   INTERCEPT_FUNCTION(free);
1713   MSAN_MAYBE_INTERCEPT_CFREE;
1714   MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE;
1715   MSAN_MAYBE_INTERCEPT_MALLINFO;
1716   MSAN_MAYBE_INTERCEPT_MALLOPT;
1717   MSAN_MAYBE_INTERCEPT_MALLOC_STATS;
1718   INTERCEPT_FUNCTION(fread);
1719   MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED;
1720   INTERCEPT_FUNCTION(memccpy);
1721   MSAN_MAYBE_INTERCEPT_MEMPCPY;
1722   INTERCEPT_FUNCTION(bcopy);
1723   INTERCEPT_FUNCTION(wmemset);
1724   INTERCEPT_FUNCTION(wmemcpy);
1725   MSAN_MAYBE_INTERCEPT_WMEMPCPY;
1726   INTERCEPT_FUNCTION(wmemmove);
1727   INTERCEPT_FUNCTION(strcpy);
1728   MSAN_MAYBE_INTERCEPT_STPCPY;
1729   MSAN_MAYBE_INTERCEPT_STPNCPY;
1730   INTERCEPT_FUNCTION(strdup);
1731   MSAN_MAYBE_INTERCEPT___STRDUP;
1732   INTERCEPT_FUNCTION(strncpy);
1733   MSAN_MAYBE_INTERCEPT_GCVT;
1734   INTERCEPT_FUNCTION(strcat);
1735   INTERCEPT_FUNCTION(strncat);
1736   INTERCEPT_STRTO(strtod);
1737   INTERCEPT_STRTO(strtof);
1738   INTERCEPT_STRTO(strtold);
1739   INTERCEPT_STRTO(strtol);
1740   INTERCEPT_STRTO(strtoul);
1741   INTERCEPT_STRTO(strtoll);
1742   INTERCEPT_STRTO(strtoull);
1743   INTERCEPT_STRTO(strtouq);
1744   INTERCEPT_STRTO(wcstod);
1745   INTERCEPT_STRTO(wcstof);
1746   INTERCEPT_STRTO(wcstold);
1747   INTERCEPT_STRTO(wcstol);
1748   INTERCEPT_STRTO(wcstoul);
1749   INTERCEPT_STRTO(wcstoll);
1750   INTERCEPT_STRTO(wcstoull);
1751 #ifdef SANITIZER_NLDBL_VERSION
1752   INTERCEPT_FUNCTION_VER(vswprintf, SANITIZER_NLDBL_VERSION);
1753   INTERCEPT_FUNCTION_VER(swprintf, SANITIZER_NLDBL_VERSION);
1754 #else
1755   INTERCEPT_FUNCTION(vswprintf);
1756   INTERCEPT_FUNCTION(swprintf);
1757 #endif
1758   INTERCEPT_FUNCTION(strftime);
1759   INTERCEPT_FUNCTION(strftime_l);
1760   MSAN_MAYBE_INTERCEPT___STRFTIME_L;
1761   INTERCEPT_FUNCTION(wcsftime);
1762   INTERCEPT_FUNCTION(wcsftime_l);
1763   MSAN_MAYBE_INTERCEPT___WCSFTIME_L;
1764   INTERCEPT_FUNCTION(mbtowc);
1765   INTERCEPT_FUNCTION(mbrtowc);
1766   INTERCEPT_FUNCTION(wcslen);
1767   INTERCEPT_FUNCTION(wcsnlen);
1768   INTERCEPT_FUNCTION(wcschr);
1769   INTERCEPT_FUNCTION(wcscpy);
1770   INTERCEPT_FUNCTION(wcsncpy);
1771   INTERCEPT_FUNCTION(wcscmp);
1772   INTERCEPT_FUNCTION(getenv);
1773   INTERCEPT_FUNCTION(setenv);
1774   INTERCEPT_FUNCTION(putenv);
1775   INTERCEPT_FUNCTION(gettimeofday);
1776   MSAN_MAYBE_INTERCEPT_FCVT;
1777   MSAN_MAYBE_INTERCEPT_FSTAT;
1778   MSAN_MAYBE_INTERCEPT_FSTAT64;
1779   MSAN_MAYBE_INTERCEPT___FXSTAT;
1780   MSAN_MAYBE_INTERCEPT_FSTATAT;
1781   MSAN_MAYBE_INTERCEPT_FSTATAT64;
1782   MSAN_MAYBE_INTERCEPT___FXSTATAT;
1783   MSAN_MAYBE_INTERCEPT___FXSTAT64;
1784   MSAN_MAYBE_INTERCEPT___FXSTATAT64;
1785   INTERCEPT_FUNCTION(pipe);
1786   INTERCEPT_FUNCTION(pipe2);
1787   INTERCEPT_FUNCTION(socketpair);
1788   MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED;
1789   INTERCEPT_FUNCTION(getrlimit);
1790   MSAN_MAYBE_INTERCEPT___GETRLIMIT;
1791   MSAN_MAYBE_INTERCEPT_GETRLIMIT64;
1792   MSAN_MAYBE_INTERCEPT_PRLIMIT;
1793   MSAN_MAYBE_INTERCEPT_PRLIMIT64;
1794   INTERCEPT_FUNCTION(gethostname);
1795   MSAN_MAYBE_INTERCEPT_EPOLL_WAIT;
1796   MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT;
1797   INTERCEPT_FUNCTION(strsignal);
1798   INTERCEPT_FUNCTION(dladdr);
1799   MSAN_MAYBE_INTERCEPT_DLADDR1;
1800   INTERCEPT_FUNCTION(dlerror);
1801   INTERCEPT_FUNCTION(dl_iterate_phdr);
1802   INTERCEPT_FUNCTION(getrusage);
1803 #if defined(__mips__)
1804   INTERCEPT_FUNCTION_VER(pthread_create, "GLIBC_2.2");
1805 #else
1806   INTERCEPT_FUNCTION(pthread_create);
1807 #endif
1808   INTERCEPT_FUNCTION(pthread_join);
1809   INTERCEPT_FUNCTION(pthread_key_create);
1810 #if SANITIZER_GLIBC
1811   INTERCEPT_FUNCTION(pthread_tryjoin_np);
1812   INTERCEPT_FUNCTION(pthread_timedjoin_np);
1813 #endif
1814 
1815 #if SANITIZER_NETBSD
1816   INTERCEPT_FUNCTION(__libc_thr_keycreate);
1817 #endif
1818 
1819   INTERCEPT_FUNCTION(pthread_join);
1820   INTERCEPT_FUNCTION(tzset);
1821   INTERCEPT_FUNCTION(atexit);
1822   INTERCEPT_FUNCTION(__cxa_atexit);
1823   INTERCEPT_FUNCTION(shmat);
1824   INTERCEPT_FUNCTION(fork);
1825   MSAN_MAYBE_INTERCEPT_OPENPTY;
1826   MSAN_MAYBE_INTERCEPT_FORKPTY;
1827 
1828   inited = 1;
1829 }
1830 } // namespace __msan
1831