xref: /freebsd/contrib/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp (revision 9c77fb6aaa366cbabc80ee1b834bcfe4df135491)
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_interceptors.h"
38 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
39 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
40 #include "sanitizer_common/sanitizer_stackdepot.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, SIZE_T n)
64 DECLARE_REAL(void *, memset, void *dest, int c, SIZE_T 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   return msan_memalign(alignment, size, &stack);
189 }
190 #define MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN INTERCEPT_FUNCTION(__libc_memalign)
191 #else
192 #define MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN
193 #endif
194 
195 INTERCEPTOR(void *, valloc, SIZE_T size) {
196   GET_MALLOC_STACK_TRACE;
197   return msan_valloc(size, &stack);
198 }
199 
200 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
201 INTERCEPTOR(void *, pvalloc, SIZE_T size) {
202   GET_MALLOC_STACK_TRACE;
203   return msan_pvalloc(size, &stack);
204 }
205 #define MSAN_MAYBE_INTERCEPT_PVALLOC INTERCEPT_FUNCTION(pvalloc)
206 #else
207 #define MSAN_MAYBE_INTERCEPT_PVALLOC
208 #endif
209 
210 INTERCEPTOR(void, free, void *ptr) {
211   if (UNLIKELY(!ptr))
212     return;
213   if (DlsymAlloc::PointerIsMine(ptr))
214     return DlsymAlloc::Free(ptr);
215   GET_MALLOC_STACK_TRACE;
216   MsanDeallocate(&stack, ptr);
217 }
218 
219 #if SANITIZER_INTERCEPT_FREE_SIZED
220 INTERCEPTOR(void, free_sized, void *ptr, uptr size) {
221   if (UNLIKELY(!ptr))
222     return;
223   if (DlsymAlloc::PointerIsMine(ptr))
224     return DlsymAlloc::Free(ptr);
225   GET_MALLOC_STACK_TRACE;
226   MsanDeallocate(&stack, ptr);
227 }
228 #  define MSAN_MAYBE_INTERCEPT_FREE_SIZED INTERCEPT_FUNCTION(free_sized)
229 #else
230 #  define MSAN_MAYBE_INTERCEPT_FREE_SIZED
231 #endif
232 
233 #if SANITIZER_INTERCEPT_FREE_ALIGNED_SIZED
234 INTERCEPTOR(void, free_aligned_sized, void *ptr, uptr alignment, uptr size) {
235   if (UNLIKELY(!ptr))
236     return;
237   if (DlsymAlloc::PointerIsMine(ptr))
238     return DlsymAlloc::Free(ptr);
239   GET_MALLOC_STACK_TRACE;
240   MsanDeallocate(&stack, ptr);
241 }
242 #  define MSAN_MAYBE_INTERCEPT_FREE_ALIGNED_SIZED \
243     INTERCEPT_FUNCTION(free_aligned_sized)
244 #else
245 #  define MSAN_MAYBE_INTERCEPT_FREE_ALIGNED_SIZED
246 #endif
247 
248 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
249 INTERCEPTOR(void, cfree, void *ptr) {
250   if (UNLIKELY(!ptr))
251     return;
252   if (DlsymAlloc::PointerIsMine(ptr))
253     return DlsymAlloc::Free(ptr);
254   GET_MALLOC_STACK_TRACE;
255   MsanDeallocate(&stack, ptr);
256 }
257 #  define MSAN_MAYBE_INTERCEPT_CFREE INTERCEPT_FUNCTION(cfree)
258 #else
259 #define MSAN_MAYBE_INTERCEPT_CFREE
260 #endif
261 
262 #if !SANITIZER_NETBSD
263 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
264   return __sanitizer_get_allocated_size(ptr);
265 }
266 #define MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE \
267   INTERCEPT_FUNCTION(malloc_usable_size)
268 #else
269 #define MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE
270 #endif
271 
272 #if (!SANITIZER_FREEBSD && !SANITIZER_NETBSD) || __GLIBC_PREREQ(2, 33)
273 template <class T>
274 static NOINLINE void clear_mallinfo(T *sret) {
275   ENSURE_MSAN_INITED();
276   internal_memset(sret, 0, sizeof(*sret));
277   __msan_unpoison(sret, sizeof(*sret));
278 }
279 #endif
280 
281 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
282 // Interceptors use NRVO and assume that sret will be pre-allocated in
283 // caller frame.
284 INTERCEPTOR(__sanitizer_struct_mallinfo, mallinfo,) {
285   __sanitizer_struct_mallinfo sret;
286   clear_mallinfo(&sret);
287   return sret;
288 }
289 #  define MSAN_MAYBE_INTERCEPT_MALLINFO INTERCEPT_FUNCTION(mallinfo)
290 #else
291 #  define MSAN_MAYBE_INTERCEPT_MALLINFO
292 #endif
293 
294 #if __GLIBC_PREREQ(2, 33)
295 INTERCEPTOR(__sanitizer_struct_mallinfo2, mallinfo2) {
296   __sanitizer_struct_mallinfo2 sret;
297   clear_mallinfo(&sret);
298   return sret;
299 }
300 #  define MSAN_MAYBE_INTERCEPT_MALLINFO2 INTERCEPT_FUNCTION(mallinfo2)
301 #else
302 #  define MSAN_MAYBE_INTERCEPT_MALLINFO2
303 #endif
304 
305 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
306 INTERCEPTOR(int, mallopt, int cmd, int value) {
307   return 0;
308 }
309 #define MSAN_MAYBE_INTERCEPT_MALLOPT INTERCEPT_FUNCTION(mallopt)
310 #else
311 #define MSAN_MAYBE_INTERCEPT_MALLOPT
312 #endif
313 
314 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
315 INTERCEPTOR(void, malloc_stats, void) {
316   // FIXME: implement, but don't call REAL(malloc_stats)!
317 }
318 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS INTERCEPT_FUNCTION(malloc_stats)
319 #else
320 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS
321 #endif
322 
323 INTERCEPTOR(char *, strcpy, char *dest, const char *src) {
324   ENSURE_MSAN_INITED();
325   GET_STORE_STACK_TRACE;
326   SIZE_T n = internal_strlen(src);
327   CHECK_UNPOISONED_STRING(src + n, 0);
328   char *res = REAL(strcpy)(dest, src);
329   CopyShadowAndOrigin(dest, src, n + 1, &stack);
330   return res;
331 }
332 
333 INTERCEPTOR(char *, strncpy, char *dest, const char *src, SIZE_T n) {
334   ENSURE_MSAN_INITED();
335   GET_STORE_STACK_TRACE;
336   SIZE_T copy_size = internal_strnlen(src, n);
337   if (copy_size < n)
338     copy_size++;  // trailing \0
339   char *res = REAL(strncpy)(dest, src, n);
340   CopyShadowAndOrigin(dest, src, copy_size, &stack);
341   __msan_unpoison(dest + copy_size, n - copy_size);
342   return res;
343 }
344 
345 #if !SANITIZER_NETBSD
346 INTERCEPTOR(char *, stpcpy, char *dest, const char *src) {
347   ENSURE_MSAN_INITED();
348   GET_STORE_STACK_TRACE;
349   SIZE_T n = internal_strlen(src);
350   CHECK_UNPOISONED_STRING(src + n, 0);
351   char *res = REAL(stpcpy)(dest, src);
352   CopyShadowAndOrigin(dest, src, n + 1, &stack);
353   return res;
354 }
355 
356 INTERCEPTOR(char *, stpncpy, char *dest, const char *src, SIZE_T n) {
357   ENSURE_MSAN_INITED();
358   GET_STORE_STACK_TRACE;
359   SIZE_T copy_size = Min(n, internal_strnlen(src, n) + 1);
360   char *res = REAL(stpncpy)(dest, src, n);
361   CopyShadowAndOrigin(dest, src, copy_size, &stack);
362   __msan_unpoison(dest + copy_size, n - copy_size);
363   return res;
364 }
365 #  define MSAN_MAYBE_INTERCEPT_STPCPY INTERCEPT_FUNCTION(stpcpy)
366 #  define MSAN_MAYBE_INTERCEPT_STPNCPY INTERCEPT_FUNCTION(stpncpy)
367 #else
368 #define MSAN_MAYBE_INTERCEPT_STPCPY
369 #  define MSAN_MAYBE_INTERCEPT_STPNCPY
370 #endif
371 
372 INTERCEPTOR(char *, strdup, char *src) {
373   ENSURE_MSAN_INITED();
374   GET_STORE_STACK_TRACE;
375   // On FreeBSD strdup() leverages strlen().
376   InterceptorScope interceptor_scope;
377   SIZE_T n = internal_strlen(src);
378   CHECK_UNPOISONED_STRING(src + n, 0);
379   char *res = REAL(strdup)(src);
380   CopyShadowAndOrigin(res, src, n + 1, &stack);
381   return res;
382 }
383 
384 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
385 INTERCEPTOR(char *, __strdup, char *src) {
386   ENSURE_MSAN_INITED();
387   GET_STORE_STACK_TRACE;
388   SIZE_T n = internal_strlen(src);
389   CHECK_UNPOISONED_STRING(src + n, 0);
390   char *res = REAL(__strdup)(src);
391   CopyShadowAndOrigin(res, src, n + 1, &stack);
392   return res;
393 }
394 #define MSAN_MAYBE_INTERCEPT___STRDUP INTERCEPT_FUNCTION(__strdup)
395 #else
396 #define MSAN_MAYBE_INTERCEPT___STRDUP
397 #endif
398 
399 #if !SANITIZER_NETBSD
400 INTERCEPTOR(char *, gcvt, double number, SIZE_T ndigit, char *buf) {
401   ENSURE_MSAN_INITED();
402   char *res = REAL(gcvt)(number, ndigit, buf);
403   SIZE_T n = internal_strlen(buf);
404   __msan_unpoison(buf, n + 1);
405   return res;
406 }
407 #define MSAN_MAYBE_INTERCEPT_GCVT INTERCEPT_FUNCTION(gcvt)
408 #else
409 #define MSAN_MAYBE_INTERCEPT_GCVT
410 #endif
411 
412 INTERCEPTOR(char *, strcat, char *dest, const char *src) {
413   ENSURE_MSAN_INITED();
414   GET_STORE_STACK_TRACE;
415   SIZE_T src_size = internal_strlen(src);
416   SIZE_T dest_size = internal_strlen(dest);
417   CHECK_UNPOISONED_STRING(src + src_size, 0);
418   CHECK_UNPOISONED_STRING(dest + dest_size, 0);
419   char *res = REAL(strcat)(dest, src);
420   CopyShadowAndOrigin(dest + dest_size, src, src_size + 1, &stack);
421   return res;
422 }
423 
424 INTERCEPTOR(char *, strncat, char *dest, const char *src, SIZE_T n) {
425   ENSURE_MSAN_INITED();
426   GET_STORE_STACK_TRACE;
427   SIZE_T dest_size = internal_strlen(dest);
428   SIZE_T copy_size = internal_strnlen(src, n);
429   CHECK_UNPOISONED_STRING(dest + dest_size, 0);
430   char *res = REAL(strncat)(dest, src, n);
431   CopyShadowAndOrigin(dest + dest_size, src, copy_size, &stack);
432   __msan_unpoison(dest + dest_size + copy_size, 1); // \0
433   return res;
434 }
435 
436 // Hack: always pass nptr and endptr as part of __VA_ARGS_ to avoid having to
437 // deal with empty __VA_ARGS__ in the case of INTERCEPTOR_STRTO.
438 #define INTERCEPTOR_STRTO_BODY(ret_type, func, ...) \
439   ENSURE_MSAN_INITED();                             \
440   ret_type res = REAL(func)(__VA_ARGS__);           \
441   __msan_unpoison(endptr, sizeof(*endptr));         \
442   return res;
443 
444 // On s390x, long double return values are passed via implicit reference,
445 // which needs to be unpoisoned.  We make the implicit pointer explicit.
446 #define INTERCEPTOR_STRTO_SRET_BODY(func, sret, ...) \
447   ENSURE_MSAN_INITED();                              \
448   REAL(func)(sret, __VA_ARGS__);                     \
449   __msan_unpoison(sret, sizeof(*sret));              \
450   __msan_unpoison(endptr, sizeof(*endptr));
451 
452 #define INTERCEPTOR_STRTO(ret_type, func, char_type)                       \
453   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr) { \
454     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr);                  \
455   }
456 
457 #define INTERCEPTOR_STRTO_SRET(ret_type, func, char_type)                \
458   INTERCEPTOR(void, func, ret_type *sret, const char_type *nptr,         \
459               char_type **endptr) {                                      \
460     INTERCEPTOR_STRTO_SRET_BODY(func, sret, nptr, endptr);               \
461   }
462 
463 #define INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)                \
464   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
465               int base) {                                                \
466     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, base);          \
467   }
468 
469 #define INTERCEPTOR_STRTO_LOC(ret_type, func, char_type)                 \
470   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
471               void *loc) {                                               \
472     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, loc);           \
473   }
474 
475 #define INTERCEPTOR_STRTO_SRET_LOC(ret_type, func, char_type)            \
476   INTERCEPTOR(void, func, ret_type *sret, const char_type *nptr,         \
477               char_type **endptr, void *loc) {                           \
478     INTERCEPTOR_STRTO_SRET_BODY(func, sret, nptr, endptr, loc);          \
479   }
480 
481 #define INTERCEPTOR_STRTO_BASE_LOC(ret_type, func, char_type)            \
482   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
483               int base, void *loc) {                                     \
484     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, base, loc);     \
485   }
486 
487 #if SANITIZER_NETBSD
488 #define INTERCEPTORS_STRTO(ret_type, func, char_type)      \
489   INTERCEPTOR_STRTO(ret_type, func, char_type)             \
490   INTERCEPTOR_STRTO_LOC(ret_type, func##_l, char_type)
491 
492 #define INTERCEPTORS_STRTO_SRET(ret_type, func, char_type)      \
493   INTERCEPTOR_STRTO_SRET(ret_type, func, char_type)             \
494   INTERCEPTOR_STRTO_SRET_LOC(ret_type, func##_l, char_type)
495 
496 #define INTERCEPTORS_STRTO_BASE(ret_type, func, char_type)      \
497   INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)             \
498   INTERCEPTOR_STRTO_BASE_LOC(ret_type, func##_l, char_type)
499 
500 #else
501 #define INTERCEPTORS_STRTO(ret_type, func, char_type)      \
502   INTERCEPTOR_STRTO(ret_type, func, char_type)             \
503   INTERCEPTOR_STRTO_LOC(ret_type, func##_l, char_type)     \
504   INTERCEPTOR_STRTO_LOC(ret_type, __##func##_l, char_type) \
505   INTERCEPTOR_STRTO_LOC(ret_type, __##func##_internal, char_type)
506 
507 #define INTERCEPTORS_STRTO_SRET(ret_type, func, char_type)      \
508   INTERCEPTOR_STRTO_SRET(ret_type, func, char_type)             \
509   INTERCEPTOR_STRTO_SRET_LOC(ret_type, func##_l, char_type)     \
510   INTERCEPTOR_STRTO_SRET_LOC(ret_type, __##func##_l, char_type) \
511   INTERCEPTOR_STRTO_SRET_LOC(ret_type, __##func##_internal, char_type)
512 
513 #define INTERCEPTORS_STRTO_BASE(ret_type, func, char_type)      \
514   INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)             \
515   INTERCEPTOR_STRTO_BASE_LOC(ret_type, func##_l, char_type)     \
516   INTERCEPTOR_STRTO_BASE_LOC(ret_type, __##func##_l, char_type) \
517   INTERCEPTOR_STRTO_BASE_LOC(ret_type, __##func##_internal, char_type)
518 #endif
519 
520 INTERCEPTORS_STRTO(double, strtod, char)
521 INTERCEPTORS_STRTO(float, strtof, char)
522 #ifdef __s390x__
523 INTERCEPTORS_STRTO_SRET(long double, strtold, char)
524 #else
525 INTERCEPTORS_STRTO(long double, strtold, char)
526 #endif
527 INTERCEPTORS_STRTO_BASE(long, strtol, char)
528 INTERCEPTORS_STRTO_BASE(long long, strtoll, char)
529 INTERCEPTORS_STRTO_BASE(unsigned long, strtoul, char)
530 INTERCEPTORS_STRTO_BASE(unsigned long long, strtoull, char)
531 INTERCEPTORS_STRTO_BASE(u64, strtouq, char)
532 
533 INTERCEPTORS_STRTO(double, wcstod, wchar_t)
534 INTERCEPTORS_STRTO(float, wcstof, wchar_t)
535 #ifdef __s390x__
536 INTERCEPTORS_STRTO_SRET(long double, wcstold, wchar_t)
537 #else
538 INTERCEPTORS_STRTO(long double, wcstold, wchar_t)
539 #endif
540 INTERCEPTORS_STRTO_BASE(long, wcstol, wchar_t)
541 INTERCEPTORS_STRTO_BASE(long long, wcstoll, wchar_t)
542 INTERCEPTORS_STRTO_BASE(unsigned long, wcstoul, wchar_t)
543 INTERCEPTORS_STRTO_BASE(unsigned long long, wcstoull, wchar_t)
544 
545 #if SANITIZER_GLIBC
546 INTERCEPTORS_STRTO(double, __isoc23_strtod, char)
547 INTERCEPTORS_STRTO(float, __isoc23_strtof, char)
548 #ifdef __s390x__
549 INTERCEPTORS_STRTO_SRET(long double, __isoc23_strtold, char)
550 #else
551 INTERCEPTORS_STRTO(long double, __isoc23_strtold, char)
552 #endif
553 INTERCEPTORS_STRTO_BASE(long, __isoc23_strtol, char)
554 INTERCEPTORS_STRTO_BASE(long long, __isoc23_strtoll, char)
555 INTERCEPTORS_STRTO_BASE(unsigned long, __isoc23_strtoul, char)
556 INTERCEPTORS_STRTO_BASE(unsigned long long, __isoc23_strtoull, char)
557 INTERCEPTORS_STRTO_BASE(u64, __isoc23_strtouq, char)
558 
559 INTERCEPTORS_STRTO(double, __isoc23_wcstod, wchar_t)
560 INTERCEPTORS_STRTO(float, __isoc23_wcstof, wchar_t)
561 #ifdef __s390x__
562 INTERCEPTORS_STRTO_SRET(long double, __isoc23_wcstold, wchar_t)
563 #else
564 INTERCEPTORS_STRTO(long double, __isoc23_wcstold, wchar_t)
565 #endif
566 INTERCEPTORS_STRTO_BASE(long, __isoc23_wcstol, wchar_t)
567 INTERCEPTORS_STRTO_BASE(long long, __isoc23_wcstoll, wchar_t)
568 INTERCEPTORS_STRTO_BASE(unsigned long, __isoc23_wcstoul, wchar_t)
569 INTERCEPTORS_STRTO_BASE(unsigned long long, __isoc23_wcstoull, wchar_t)
570 #endif
571 
572 #if SANITIZER_NETBSD
573 #define INTERCEPT_STRTO(func) \
574   INTERCEPT_FUNCTION(func); \
575   INTERCEPT_FUNCTION(func##_l);
576 #else
577 #define INTERCEPT_STRTO(func) \
578   INTERCEPT_FUNCTION(func); \
579   INTERCEPT_FUNCTION(func##_l); \
580   INTERCEPT_FUNCTION(__##func##_l); \
581   INTERCEPT_FUNCTION(__##func##_internal);
582 
583 #define INTERCEPT_STRTO_VER(func, ver) \
584   INTERCEPT_FUNCTION_VER(func, ver); \
585   INTERCEPT_FUNCTION_VER(func##_l, ver); \
586   INTERCEPT_FUNCTION_VER(__##func##_l, ver); \
587   INTERCEPT_FUNCTION_VER(__##func##_internal, ver);
588 #endif
589 
590 
591 // FIXME: support *wprintf in common format interceptors.
592 INTERCEPTOR(int, vswprintf, void *str, uptr size, void *format, va_list ap) {
593   ENSURE_MSAN_INITED();
594   int res = REAL(vswprintf)(str, size, format, ap);
595   if (res >= 0) {
596     __msan_unpoison(str, 4 * (res + 1));
597   }
598   return res;
599 }
600 
601 INTERCEPTOR(int, swprintf, void *str, uptr size, void *format, ...) {
602   ENSURE_MSAN_INITED();
603   va_list ap;
604   va_start(ap, format);
605   int res = vswprintf(str, size, format, ap);
606   va_end(ap);
607   return res;
608 }
609 
610 #define INTERCEPTOR_STRFTIME_BODY(char_type, ret_type, func, s, ...) \
611   ENSURE_MSAN_INITED();                                              \
612   InterceptorScope interceptor_scope;                                \
613   ret_type res = REAL(func)(s, __VA_ARGS__);                         \
614   if (s) __msan_unpoison(s, sizeof(char_type) * (res + 1));          \
615   return res;
616 
617 INTERCEPTOR(SIZE_T, strftime, char *s, SIZE_T max, const char *format,
618             __sanitizer_tm *tm) {
619   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, strftime, s, max, format, tm);
620 }
621 
622 INTERCEPTOR(SIZE_T, strftime_l, char *s, SIZE_T max, const char *format,
623             __sanitizer_tm *tm, void *loc) {
624   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, strftime_l, s, max, format, tm, loc);
625 }
626 
627 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
628 INTERCEPTOR(SIZE_T, __strftime_l, char *s, SIZE_T max, const char *format,
629             __sanitizer_tm *tm, void *loc) {
630   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, __strftime_l, s, max, format, tm,
631                             loc);
632 }
633 #define MSAN_MAYBE_INTERCEPT___STRFTIME_L INTERCEPT_FUNCTION(__strftime_l)
634 #else
635 #define MSAN_MAYBE_INTERCEPT___STRFTIME_L
636 #endif
637 
638 INTERCEPTOR(SIZE_T, wcsftime, wchar_t *s, SIZE_T max, const wchar_t *format,
639             __sanitizer_tm *tm) {
640   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, wcsftime, s, max, format, tm);
641 }
642 
643 INTERCEPTOR(SIZE_T, wcsftime_l, wchar_t *s, SIZE_T max, const wchar_t *format,
644             __sanitizer_tm *tm, void *loc) {
645   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, wcsftime_l, s, max, format, tm,
646                             loc);
647 }
648 
649 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
650 INTERCEPTOR(SIZE_T, __wcsftime_l, wchar_t *s, SIZE_T max, const wchar_t *format,
651             __sanitizer_tm *tm, void *loc) {
652   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, __wcsftime_l, s, max, format, tm,
653                             loc);
654 }
655 #define MSAN_MAYBE_INTERCEPT___WCSFTIME_L INTERCEPT_FUNCTION(__wcsftime_l)
656 #else
657 #define MSAN_MAYBE_INTERCEPT___WCSFTIME_L
658 #endif
659 
660 INTERCEPTOR(int, mbtowc, wchar_t *dest, const char *src, SIZE_T n) {
661   ENSURE_MSAN_INITED();
662   int res = REAL(mbtowc)(dest, src, n);
663   if (res != -1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
664   return res;
665 }
666 
667 INTERCEPTOR(SIZE_T, mbrtowc, wchar_t *dest, const char *src, SIZE_T n,
668             void *ps) {
669   ENSURE_MSAN_INITED();
670   SIZE_T res = REAL(mbrtowc)(dest, src, n, ps);
671   if (res != (SIZE_T)-1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
672   return res;
673 }
674 
675 // wchar_t *wmemcpy(wchar_t *dest, const wchar_t *src, SIZE_T n);
676 INTERCEPTOR(wchar_t *, wmemcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
677   ENSURE_MSAN_INITED();
678   GET_STORE_STACK_TRACE;
679   wchar_t *res = REAL(wmemcpy)(dest, src, n);
680   CopyShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
681   return res;
682 }
683 
684 #if !SANITIZER_NETBSD
685 INTERCEPTOR(wchar_t *, wmempcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
686   ENSURE_MSAN_INITED();
687   GET_STORE_STACK_TRACE;
688   wchar_t *res = REAL(wmempcpy)(dest, src, n);
689   CopyShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
690   return res;
691 }
692 #define MSAN_MAYBE_INTERCEPT_WMEMPCPY INTERCEPT_FUNCTION(wmempcpy)
693 #else
694 #define MSAN_MAYBE_INTERCEPT_WMEMPCPY
695 #endif
696 
697 INTERCEPTOR(wchar_t *, wmemset, wchar_t *s, wchar_t c, SIZE_T n) {
698   CHECK(MEM_IS_APP(s));
699   ENSURE_MSAN_INITED();
700   wchar_t *res = REAL(wmemset)(s, c, n);
701   __msan_unpoison(s, n * sizeof(wchar_t));
702   return res;
703 }
704 
705 INTERCEPTOR(wchar_t *, wmemmove, wchar_t *dest, const wchar_t *src, SIZE_T n) {
706   ENSURE_MSAN_INITED();
707   GET_STORE_STACK_TRACE;
708   wchar_t *res = REAL(wmemmove)(dest, src, n);
709   MoveShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
710   return res;
711 }
712 
713 INTERCEPTOR(int, wcscmp, const wchar_t *s1, const wchar_t *s2) {
714   ENSURE_MSAN_INITED();
715   int res = REAL(wcscmp)(s1, s2);
716   return res;
717 }
718 
719 INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
720   ENSURE_MSAN_INITED();
721   int res = REAL(gettimeofday)(tv, tz);
722   if (tv)
723     __msan_unpoison(tv, 16);
724   if (tz)
725     __msan_unpoison(tz, 8);
726   return res;
727 }
728 
729 #if !SANITIZER_NETBSD
730 INTERCEPTOR(char *, fcvt, double x, int a, int *b, int *c) {
731   ENSURE_MSAN_INITED();
732   char *res = REAL(fcvt)(x, a, b, c);
733   __msan_unpoison(b, sizeof(*b));
734   __msan_unpoison(c, sizeof(*c));
735   if (res)
736     __msan_unpoison(res, internal_strlen(res) + 1);
737   return res;
738 }
739 #define MSAN_MAYBE_INTERCEPT_FCVT INTERCEPT_FUNCTION(fcvt)
740 #else
741 #define MSAN_MAYBE_INTERCEPT_FCVT
742 #endif
743 
744 INTERCEPTOR(char *, getenv, char *name) {
745   if (msan_init_is_running)
746     return REAL(getenv)(name);
747   ENSURE_MSAN_INITED();
748   char *res = REAL(getenv)(name);
749   if (res)
750     __msan_unpoison(res, internal_strlen(res) + 1);
751   return res;
752 }
753 
754 extern char **environ;
755 
756 static void UnpoisonEnviron() {
757   char **envp = environ;
758   for (; *envp; ++envp) {
759     __msan_unpoison(envp, sizeof(*envp));
760     __msan_unpoison(*envp, internal_strlen(*envp) + 1);
761   }
762   // Trailing NULL pointer.
763   __msan_unpoison(envp, sizeof(*envp));
764 }
765 
766 INTERCEPTOR(int, setenv, const char *name, const char *value, int overwrite) {
767   ENSURE_MSAN_INITED();
768   CHECK_UNPOISONED_STRING(name, 0);
769   int res = REAL(setenv)(name, value, overwrite);
770   if (!res) UnpoisonEnviron();
771   return res;
772 }
773 
774 INTERCEPTOR(int, putenv, char *string) {
775   ENSURE_MSAN_INITED();
776   int res = REAL(putenv)(string);
777   if (!res) UnpoisonEnviron();
778   return res;
779 }
780 
781 #define SANITIZER_STAT_LINUX (SANITIZER_LINUX && __GLIBC_PREREQ(2, 33))
782 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
783 INTERCEPTOR(int, fstat, int fd, void *buf) {
784   ENSURE_MSAN_INITED();
785   int res = REAL(fstat)(fd, buf);
786   if (!res)
787     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
788   return res;
789 }
790 #  define MSAN_MAYBE_INTERCEPT_FSTAT MSAN_INTERCEPT_FUNC(fstat)
791 #else
792 #define MSAN_MAYBE_INTERCEPT_FSTAT
793 #endif
794 
795 #if SANITIZER_STAT_LINUX
796 INTERCEPTOR(int, fstat64, int fd, void *buf) {
797   ENSURE_MSAN_INITED();
798   int res = REAL(fstat64)(fd, buf);
799   if (!res)
800     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
801   return res;
802 }
803 #  define MSAN_MAYBE_INTERCEPT_FSTAT64 MSAN_INTERCEPT_FUNC(fstat64)
804 #else
805 #  define MSAN_MAYBE_INTERCEPT_FSTAT64
806 #endif
807 
808 #if SANITIZER_GLIBC
809 INTERCEPTOR(int, __fxstat, int magic, int fd, void *buf) {
810   ENSURE_MSAN_INITED();
811   int res = REAL(__fxstat)(magic, fd, buf);
812   if (!res)
813     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
814   return res;
815 }
816 #  define MSAN_MAYBE_INTERCEPT___FXSTAT MSAN_INTERCEPT_FUNC(__fxstat)
817 #else
818 #define MSAN_MAYBE_INTERCEPT___FXSTAT
819 #endif
820 
821 #if SANITIZER_GLIBC
822 INTERCEPTOR(int, __fxstat64, int magic, int fd, void *buf) {
823   ENSURE_MSAN_INITED();
824   int res = REAL(__fxstat64)(magic, fd, buf);
825   if (!res)
826     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
827   return res;
828 }
829 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64 MSAN_INTERCEPT_FUNC(__fxstat64)
830 #else
831 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64
832 #endif
833 
834 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
835 INTERCEPTOR(int, fstatat, int fd, char *pathname, void *buf, int flags) {
836   ENSURE_MSAN_INITED();
837   int res = REAL(fstatat)(fd, pathname, buf, flags);
838   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
839   return res;
840 }
841 #  define MSAN_MAYBE_INTERCEPT_FSTATAT MSAN_INTERCEPT_FUNC(fstatat)
842 #else
843 #  define MSAN_MAYBE_INTERCEPT_FSTATAT
844 #endif
845 
846 #if SANITIZER_STAT_LINUX
847 INTERCEPTOR(int, fstatat64, int fd, char *pathname, void *buf, int flags) {
848   ENSURE_MSAN_INITED();
849   int res = REAL(fstatat64)(fd, pathname, buf, flags);
850   if (!res)
851     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
852   return res;
853 }
854 #  define MSAN_MAYBE_INTERCEPT_FSTATAT64 MSAN_INTERCEPT_FUNC(fstatat64)
855 #else
856 #  define MSAN_MAYBE_INTERCEPT_FSTATAT64
857 #endif
858 
859 #if SANITIZER_GLIBC
860 INTERCEPTOR(int, __fxstatat, int magic, int fd, char *pathname, void *buf,
861             int flags) {
862   ENSURE_MSAN_INITED();
863   int res = REAL(__fxstatat)(magic, fd, pathname, buf, flags);
864   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
865   return res;
866 }
867 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT MSAN_INTERCEPT_FUNC(__fxstatat)
868 #else
869 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT
870 #endif
871 
872 #if SANITIZER_GLIBC
873 INTERCEPTOR(int, __fxstatat64, int magic, int fd, char *pathname, void *buf,
874             int flags) {
875   ENSURE_MSAN_INITED();
876   int res = REAL(__fxstatat64)(magic, fd, pathname, buf, flags);
877   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
878   return res;
879 }
880 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64 MSAN_INTERCEPT_FUNC(__fxstatat64)
881 #else
882 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64
883 #endif
884 
885 INTERCEPTOR(int, pipe, int pipefd[2]) {
886   if (msan_init_is_running)
887     return REAL(pipe)(pipefd);
888   ENSURE_MSAN_INITED();
889   int res = REAL(pipe)(pipefd);
890   if (!res)
891     __msan_unpoison(pipefd, sizeof(int[2]));
892   return res;
893 }
894 
895 INTERCEPTOR(int, pipe2, int pipefd[2], int flags) {
896   ENSURE_MSAN_INITED();
897   int res = REAL(pipe2)(pipefd, flags);
898   if (!res)
899     __msan_unpoison(pipefd, sizeof(int[2]));
900   return res;
901 }
902 
903 INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int sv[2]) {
904   ENSURE_MSAN_INITED();
905   int res = REAL(socketpair)(domain, type, protocol, sv);
906   if (!res)
907     __msan_unpoison(sv, sizeof(int[2]));
908   return res;
909 }
910 
911 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
912 INTERCEPTOR(char *, fgets_unlocked, char *s, int size, void *stream) {
913   ENSURE_MSAN_INITED();
914   char *res = REAL(fgets_unlocked)(s, size, stream);
915   if (res)
916     __msan_unpoison(s, internal_strlen(s) + 1);
917   return res;
918 }
919 #define MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED INTERCEPT_FUNCTION(fgets_unlocked)
920 #else
921 #define MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED
922 #endif
923 
924 #define INTERCEPTOR_GETRLIMIT_BODY(func, resource, rlim)  \
925   if (msan_init_is_running)                               \
926     return REAL(getrlimit)(resource, rlim);               \
927   ENSURE_MSAN_INITED();                                   \
928   int res = REAL(func)(resource, rlim);                   \
929   if (!res)                                               \
930     __msan_unpoison(rlim, __sanitizer::struct_rlimit_sz); \
931   return res
932 
933 INTERCEPTOR(int, getrlimit, int resource, void *rlim) {
934   INTERCEPTOR_GETRLIMIT_BODY(getrlimit, resource, rlim);
935 }
936 
937 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
938 INTERCEPTOR(int, __getrlimit, int resource, void *rlim) {
939   INTERCEPTOR_GETRLIMIT_BODY(__getrlimit, resource, rlim);
940 }
941 
942 INTERCEPTOR(int, getrlimit64, int resource, void *rlim) {
943   if (msan_init_is_running) return REAL(getrlimit64)(resource, rlim);
944   ENSURE_MSAN_INITED();
945   int res = REAL(getrlimit64)(resource, rlim);
946   if (!res) __msan_unpoison(rlim, __sanitizer::struct_rlimit64_sz);
947   return res;
948 }
949 
950 INTERCEPTOR(int, prlimit, int pid, int resource, void *new_rlimit,
951             void *old_rlimit) {
952   if (msan_init_is_running)
953     return REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
954   ENSURE_MSAN_INITED();
955   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit_sz);
956   int res = REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
957   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit_sz);
958   return res;
959 }
960 
961 INTERCEPTOR(int, prlimit64, int pid, int resource, void *new_rlimit,
962             void *old_rlimit) {
963   if (msan_init_is_running)
964     return REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
965   ENSURE_MSAN_INITED();
966   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit64_sz);
967   int res = REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
968   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit64_sz);
969   return res;
970 }
971 
972 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT INTERCEPT_FUNCTION(__getrlimit)
973 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64 INTERCEPT_FUNCTION(getrlimit64)
974 #define MSAN_MAYBE_INTERCEPT_PRLIMIT INTERCEPT_FUNCTION(prlimit)
975 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64 INTERCEPT_FUNCTION(prlimit64)
976 #else
977 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT
978 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64
979 #define MSAN_MAYBE_INTERCEPT_PRLIMIT
980 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64
981 #endif
982 
983 INTERCEPTOR(int, gethostname, char *name, SIZE_T len) {
984   ENSURE_MSAN_INITED();
985   int res = REAL(gethostname)(name, len);
986   if (!res || (res == -1 && errno == errno_ENAMETOOLONG)) {
987     SIZE_T real_len = internal_strnlen(name, len);
988     if (real_len < len)
989       ++real_len;
990     __msan_unpoison(name, real_len);
991   }
992   return res;
993 }
994 
995 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
996 INTERCEPTOR(int, epoll_wait, int epfd, void *events, int maxevents,
997     int timeout) {
998   ENSURE_MSAN_INITED();
999   int res = REAL(epoll_wait)(epfd, events, maxevents, timeout);
1000   if (res > 0) {
1001     __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
1002   }
1003   return res;
1004 }
1005 #define MSAN_MAYBE_INTERCEPT_EPOLL_WAIT INTERCEPT_FUNCTION(epoll_wait)
1006 #else
1007 #define MSAN_MAYBE_INTERCEPT_EPOLL_WAIT
1008 #endif
1009 
1010 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
1011 INTERCEPTOR(int, epoll_pwait, int epfd, void *events, int maxevents,
1012     int timeout, void *sigmask) {
1013   ENSURE_MSAN_INITED();
1014   int res = REAL(epoll_pwait)(epfd, events, maxevents, timeout, sigmask);
1015   if (res > 0) {
1016     __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
1017   }
1018   return res;
1019 }
1020 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT INTERCEPT_FUNCTION(epoll_pwait)
1021 #else
1022 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT
1023 #endif
1024 
1025 INTERCEPTOR(void *, calloc, SIZE_T nmemb, SIZE_T size) {
1026   GET_MALLOC_STACK_TRACE;
1027   if (DlsymAlloc::Use())
1028     return DlsymAlloc::Callocate(nmemb, size);
1029   return msan_calloc(nmemb, size, &stack);
1030 }
1031 
1032 INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
1033   if (DlsymAlloc::Use() || DlsymAlloc::PointerIsMine(ptr))
1034     return DlsymAlloc::Realloc(ptr, size);
1035   GET_MALLOC_STACK_TRACE;
1036   return msan_realloc(ptr, size, &stack);
1037 }
1038 
1039 INTERCEPTOR(void *, reallocarray, void *ptr, SIZE_T nmemb, SIZE_T size) {
1040   GET_MALLOC_STACK_TRACE;
1041   return msan_reallocarray(ptr, nmemb, size, &stack);
1042 }
1043 
1044 INTERCEPTOR(void *, malloc, SIZE_T size) {
1045   if (DlsymAlloc::Use())
1046     return DlsymAlloc::Allocate(size);
1047   GET_MALLOC_STACK_TRACE;
1048   return msan_malloc(size, &stack);
1049 }
1050 
1051 void __msan_allocated_memory(const void *data, uptr size) {
1052   if (flags()->poison_in_malloc) {
1053     GET_MALLOC_STACK_TRACE;
1054     stack.tag = STACK_TRACE_TAG_POISON;
1055     PoisonMemory(data, size, &stack);
1056   }
1057 }
1058 
1059 void __msan_copy_shadow(void *dest, const void *src, uptr n) {
1060   GET_STORE_STACK_TRACE;
1061   MoveShadowAndOrigin(dest, src, n, &stack);
1062 }
1063 
1064 void __sanitizer_dtor_callback(const void *data, uptr size) {
1065   if (flags()->poison_in_dtor) {
1066     GET_MALLOC_STACK_TRACE;
1067     stack.tag = STACK_TRACE_TAG_POISON;
1068     PoisonMemory(data, size, &stack);
1069   }
1070 }
1071 
1072 void __sanitizer_dtor_callback_fields(const void *data, uptr size) {
1073   if (flags()->poison_in_dtor) {
1074     GET_MALLOC_STACK_TRACE;
1075     stack.tag = STACK_TRACE_TAG_FIELDS;
1076     PoisonMemory(data, size, &stack);
1077   }
1078 }
1079 
1080 void __sanitizer_dtor_callback_vptr(const void *data) {
1081   if (flags()->poison_in_dtor) {
1082     GET_MALLOC_STACK_TRACE;
1083     stack.tag = STACK_TRACE_TAG_VPTR;
1084     PoisonMemory(data, sizeof(void *), &stack);
1085   }
1086 }
1087 
1088 template <class Mmap>
1089 static void *mmap_interceptor(Mmap real_mmap, void *addr, SIZE_T length,
1090                               int prot, int flags, int fd, OFF64_T offset) {
1091   SIZE_T rounded_length = RoundUpTo(length, GetPageSize());
1092   void *end_addr = (char *)addr + (rounded_length - 1);
1093   if (addr && (!MEM_IS_APP(addr) || !MEM_IS_APP(end_addr))) {
1094     if (flags & map_fixed) {
1095       errno = errno_EINVAL;
1096       return (void *)-1;
1097     } else {
1098       addr = nullptr;
1099     }
1100   }
1101   void *res = real_mmap(addr, length, prot, flags, fd, offset);
1102   if (res != (void *)-1) {
1103     void *end_res = (char *)res + (rounded_length - 1);
1104     if (MEM_IS_APP(res) && MEM_IS_APP(end_res)) {
1105       __msan_unpoison(res, rounded_length);
1106     } else {
1107       // Application has attempted to map more memory than is supported by
1108       // MSAN. Act as if we ran out of memory.
1109       internal_munmap(res, length);
1110       errno = errno_ENOMEM;
1111       return (void *)-1;
1112     }
1113   }
1114   return res;
1115 }
1116 
1117 INTERCEPTOR(int, getrusage, int who, void *usage) {
1118   ENSURE_MSAN_INITED();
1119   int res = REAL(getrusage)(who, usage);
1120   if (res == 0) {
1121     __msan_unpoison(usage, __sanitizer::struct_rusage_sz);
1122   }
1123   return res;
1124 }
1125 
1126 class SignalHandlerScope {
1127  public:
1128   SignalHandlerScope() {
1129     if (MsanThread *t = GetCurrentThread())
1130       t->EnterSignalHandler();
1131   }
1132   ~SignalHandlerScope() {
1133     if (MsanThread *t = GetCurrentThread())
1134       t->LeaveSignalHandler();
1135   }
1136 };
1137 
1138 // sigactions_mu guarantees atomicity of sigaction() and signal() calls.
1139 // Access to sigactions[] is gone with relaxed atomics to avoid data race with
1140 // the signal handler.
1141 const int kMaxSignals = 1024;
1142 static atomic_uintptr_t sigactions[kMaxSignals];
1143 static StaticSpinMutex sigactions_mu;
1144 
1145 static void SignalHandler(int signo) {
1146   SignalHandlerScope signal_handler_scope;
1147   ScopedThreadLocalStateBackup stlsb;
1148   UnpoisonParam(1);
1149 
1150   typedef void (*signal_cb)(int x);
1151   signal_cb cb =
1152       (signal_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
1153   cb(signo);
1154 }
1155 
1156 static void SignalAction(int signo, void *si, void *uc) {
1157   SignalHandlerScope signal_handler_scope;
1158   ScopedThreadLocalStateBackup stlsb;
1159   UnpoisonParam(3);
1160   __msan_unpoison(si, sizeof(__sanitizer_siginfo));
1161   __msan_unpoison(uc, ucontext_t_sz(uc));
1162 
1163   typedef void (*sigaction_cb)(int, void *, void *);
1164   sigaction_cb cb =
1165       (sigaction_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
1166   cb(signo, si, uc);
1167   CHECK_UNPOISONED(uc, ucontext_t_sz(uc));
1168 }
1169 
1170 static void read_sigaction(const __sanitizer_sigaction *act) {
1171   CHECK_UNPOISONED(&act->sa_flags, sizeof(act->sa_flags));
1172   if (act->sa_flags & __sanitizer::sa_siginfo)
1173     CHECK_UNPOISONED(&act->sigaction, sizeof(act->sigaction));
1174   else
1175     CHECK_UNPOISONED(&act->handler, sizeof(act->handler));
1176   CHECK_UNPOISONED(&act->sa_mask, sizeof(act->sa_mask));
1177 }
1178 
1179 extern "C" int pthread_attr_init(void *attr);
1180 extern "C" int pthread_attr_destroy(void *attr);
1181 
1182 static void *MsanThreadStartFunc(void *arg) {
1183   MsanThread *t = (MsanThread *)arg;
1184   SetCurrentThread(t);
1185   t->Init();
1186   SetSigProcMask(&t->starting_sigset_, nullptr);
1187   return t->ThreadStart();
1188 }
1189 
1190 INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*),
1191             void * param) {
1192   ENSURE_MSAN_INITED(); // for GetTlsSize()
1193   __sanitizer_pthread_attr_t myattr;
1194   if (!attr) {
1195     pthread_attr_init(&myattr);
1196     attr = &myattr;
1197   }
1198 
1199   AdjustStackSize(attr);
1200 
1201   MsanThread *t = MsanThread::Create(callback, param);
1202   ScopedBlockSignals block(&t->starting_sigset_);
1203   int res = REAL(pthread_create)(th, attr, MsanThreadStartFunc, t);
1204 
1205   if (attr == &myattr)
1206     pthread_attr_destroy(&myattr);
1207   if (!res) {
1208     __msan_unpoison(th, __sanitizer::pthread_t_sz);
1209   }
1210   return res;
1211 }
1212 
1213 INTERCEPTOR(int, pthread_key_create, __sanitizer_pthread_key_t *key,
1214             void (*dtor)(void *value)) {
1215   if (msan_init_is_running) return REAL(pthread_key_create)(key, dtor);
1216   ENSURE_MSAN_INITED();
1217   int res = REAL(pthread_key_create)(key, dtor);
1218   if (!res && key)
1219     __msan_unpoison(key, sizeof(*key));
1220   return res;
1221 }
1222 
1223 #if SANITIZER_NETBSD
1224 INTERCEPTOR(int, __libc_thr_keycreate, __sanitizer_pthread_key_t *m,
1225             void (*dtor)(void *value))
1226 ALIAS(WRAP(pthread_key_create));
1227 #endif
1228 
1229 INTERCEPTOR(int, pthread_join, void *thread, void **retval) {
1230   ENSURE_MSAN_INITED();
1231   int res = REAL(pthread_join)(thread, retval);
1232   if (!res && retval)
1233     __msan_unpoison(retval, sizeof(*retval));
1234   return res;
1235 }
1236 
1237 #if SANITIZER_GLIBC
1238 INTERCEPTOR(int, pthread_tryjoin_np, void *thread, void **retval) {
1239   ENSURE_MSAN_INITED();
1240   int res = REAL(pthread_tryjoin_np)(thread, retval);
1241   if (!res && retval)
1242     __msan_unpoison(retval, sizeof(*retval));
1243   return res;
1244 }
1245 
1246 INTERCEPTOR(int, pthread_timedjoin_np, void *thread, void **retval,
1247             const struct timespec *abstime) {
1248   int res = REAL(pthread_timedjoin_np)(thread, retval, abstime);
1249   if (!res && retval)
1250     __msan_unpoison(retval, sizeof(*retval));
1251   return res;
1252 }
1253 #endif
1254 
1255 DEFINE_INTERNAL_PTHREAD_FUNCTIONS
1256 
1257 extern char *tzname[2];
1258 
1259 INTERCEPTOR(void, tzset, int fake) {
1260   ENSURE_MSAN_INITED();
1261   InterceptorScope interceptor_scope;
1262   REAL(tzset)(fake);
1263   if (tzname[0])
1264     __msan_unpoison(tzname[0], internal_strlen(tzname[0]) + 1);
1265   if (tzname[1])
1266     __msan_unpoison(tzname[1], internal_strlen(tzname[1]) + 1);
1267   return;
1268 }
1269 
1270 struct MSanAtExitRecord {
1271   void (*func)(void *arg);
1272   void *arg;
1273 };
1274 
1275 struct InterceptorContext {
1276   Mutex atexit_mu;
1277   Vector<struct MSanAtExitRecord *> AtExitStack;
1278 
1279   InterceptorContext()
1280       : AtExitStack() {
1281   }
1282 };
1283 
1284 alignas(64) static char interceptor_placeholder[sizeof(InterceptorContext)];
1285 InterceptorContext *interceptor_ctx() {
1286   return reinterpret_cast<InterceptorContext*>(&interceptor_placeholder[0]);
1287 }
1288 
1289 void MSanAtExitWrapper() {
1290   MSanAtExitRecord *r;
1291   {
1292     Lock l(&interceptor_ctx()->atexit_mu);
1293 
1294     uptr element = interceptor_ctx()->AtExitStack.Size() - 1;
1295     r = interceptor_ctx()->AtExitStack[element];
1296     interceptor_ctx()->AtExitStack.PopBack();
1297   }
1298 
1299   UnpoisonParam(1);
1300   ((void(*)())r->func)();
1301   InternalFree(r);
1302 }
1303 
1304 void MSanCxaAtExitWrapper(void *arg) {
1305   UnpoisonParam(1);
1306   MSanAtExitRecord *r = (MSanAtExitRecord *)arg;
1307   // libc before 2.27 had race which caused occasional double handler execution
1308   // https://sourceware.org/ml/libc-alpha/2017-08/msg01204.html
1309   if (!r->func)
1310     return;
1311   r->func(r->arg);
1312   r->func = nullptr;
1313 }
1314 
1315 static int setup_at_exit_wrapper(void(*f)(), void *arg, void *dso);
1316 
1317 // Unpoison argument shadow for C++ module destructors.
1318 INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
1319             void *dso_handle) {
1320   if (msan_init_is_running) return REAL(__cxa_atexit)(func, arg, dso_handle);
1321   return setup_at_exit_wrapper((void(*)())func, arg, dso_handle);
1322 }
1323 
1324 // Unpoison argument shadow for C++ module destructors.
1325 INTERCEPTOR(int, atexit, void (*func)()) {
1326   // Avoid calling real atexit as it is unreachable on at least on Linux.
1327   if (msan_init_is_running)
1328     return REAL(__cxa_atexit)((void (*)(void *a))func, 0, 0);
1329   return setup_at_exit_wrapper((void(*)())func, 0, 0);
1330 }
1331 
1332 static int setup_at_exit_wrapper(void(*f)(), void *arg, void *dso) {
1333   ENSURE_MSAN_INITED();
1334   MSanAtExitRecord *r =
1335       (MSanAtExitRecord *)InternalAlloc(sizeof(MSanAtExitRecord));
1336   r->func = (void(*)(void *a))f;
1337   r->arg = arg;
1338   int res;
1339   if (!dso) {
1340     // NetBSD does not preserve the 2nd argument if dso is equal to 0
1341     // Store ctx in a local stack-like structure
1342 
1343     Lock l(&interceptor_ctx()->atexit_mu);
1344 
1345     res = REAL(__cxa_atexit)((void (*)(void *a))MSanAtExitWrapper, 0, 0);
1346     if (!res) {
1347       interceptor_ctx()->AtExitStack.PushBack(r);
1348     }
1349   } else {
1350     res = REAL(__cxa_atexit)(MSanCxaAtExitWrapper, r, dso);
1351   }
1352   return res;
1353 }
1354 
1355 // NetBSD ships with openpty(3) in -lutil, that needs to be prebuilt explicitly
1356 // with MSan.
1357 #if SANITIZER_LINUX
1358 INTERCEPTOR(int, openpty, int *aparent, int *aworker, char *name,
1359             const void *termp, const void *winp) {
1360   ENSURE_MSAN_INITED();
1361   InterceptorScope interceptor_scope;
1362   int res = REAL(openpty)(aparent, aworker, name, termp, winp);
1363   if (!res) {
1364     __msan_unpoison(aparent, sizeof(*aparent));
1365     __msan_unpoison(aworker, sizeof(*aworker));
1366   }
1367   return res;
1368 }
1369 #define MSAN_MAYBE_INTERCEPT_OPENPTY INTERCEPT_FUNCTION(openpty)
1370 #else
1371 #define MSAN_MAYBE_INTERCEPT_OPENPTY
1372 #endif
1373 
1374 // NetBSD ships with forkpty(3) in -lutil, that needs to be prebuilt explicitly
1375 // with MSan.
1376 #if SANITIZER_LINUX
1377 INTERCEPTOR(int, forkpty, int *aparent, char *name, const void *termp,
1378             const void *winp) {
1379   ENSURE_MSAN_INITED();
1380   InterceptorScope interceptor_scope;
1381   int res = REAL(forkpty)(aparent, name, termp, winp);
1382   if (res != -1)
1383     __msan_unpoison(aparent, sizeof(*aparent));
1384   return res;
1385 }
1386 #define MSAN_MAYBE_INTERCEPT_FORKPTY INTERCEPT_FUNCTION(forkpty)
1387 #else
1388 #define MSAN_MAYBE_INTERCEPT_FORKPTY
1389 #endif
1390 
1391 struct MSanInterceptorContext {
1392   bool in_interceptor_scope;
1393 };
1394 
1395 namespace __msan {
1396 
1397 int OnExit() {
1398   // FIXME: ask frontend whether we need to return failure.
1399   return 0;
1400 }
1401 
1402 } // namespace __msan
1403 
1404 // A version of CHECK_UNPOISONED using a saved scope value. Used in common
1405 // interceptors.
1406 #define CHECK_UNPOISONED_CTX(ctx, x, n)                         \
1407   do {                                                          \
1408     if (!((MSanInterceptorContext *)ctx)->in_interceptor_scope) \
1409       CHECK_UNPOISONED_0(x, n);                                 \
1410   } while (0)
1411 
1412 #define MSAN_INTERCEPT_FUNC(name)                                       \
1413   do {                                                                  \
1414     if (!INTERCEPT_FUNCTION(name))                                      \
1415       VReport(1, "MemorySanitizer: failed to intercept '%s'\n", #name); \
1416   } while (0)
1417 
1418 #define MSAN_INTERCEPT_FUNC_VER(name, ver)                                 \
1419   do {                                                                     \
1420     if (!INTERCEPT_FUNCTION_VER(name, ver))                                \
1421       VReport(1, "MemorySanitizer: failed to intercept '%s@@%s'\n", #name, \
1422               ver);                                                        \
1423   } while (0)
1424 #define MSAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)             \
1425   do {                                                                      \
1426     if (!INTERCEPT_FUNCTION_VER(name, ver) && !INTERCEPT_FUNCTION(name))    \
1427       VReport(1, "MemorySanitizer: failed to intercept '%s@@%s' or '%s'\n", \
1428               #name, ver, #name);                                           \
1429   } while (0)
1430 
1431 #define COMMON_INTERCEPT_FUNCTION(name) MSAN_INTERCEPT_FUNC(name)
1432 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver) \
1433   MSAN_INTERCEPT_FUNC_VER(name, ver)
1434 #define COMMON_INTERCEPT_FUNCTION_VER_UNVERSIONED_FALLBACK(name, ver) \
1435   MSAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)
1436 #define COMMON_INTERCEPTOR_UNPOISON_PARAM(count)  \
1437   UnpoisonParam(count)
1438 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
1439   __msan_unpoison(ptr, size)
1440 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
1441   CHECK_UNPOISONED_CTX(ctx, ptr, size)
1442 #define COMMON_INTERCEPTOR_INITIALIZE_RANGE(ptr, size) \
1443   __msan_unpoison(ptr, size)
1444 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)              \
1445   if (msan_init_is_running)                                   \
1446     return REAL(func)(__VA_ARGS__);                           \
1447   ENSURE_MSAN_INITED();                                       \
1448   MSanInterceptorContext msan_ctx = {IsInInterceptorScope()}; \
1449   ctx = (void *)&msan_ctx;                                    \
1450   (void)ctx;                                                  \
1451   InterceptorScope interceptor_scope;                         \
1452   __msan_unpoison(__errno_location(), sizeof(int));
1453 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
1454   do {                                            \
1455   } while (false)
1456 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
1457   do {                                         \
1458   } while (false)
1459 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
1460   do {                                         \
1461   } while (false)
1462 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
1463   do {                                                      \
1464   } while (false)
1465 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
1466   do {                                                \
1467   } while (false)  // FIXME
1468 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
1469   do {                                                         \
1470   } while (false)  // FIXME
1471 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
1472 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
1473 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)                    \
1474   do {                                                                         \
1475     link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE((handle));                   \
1476     if (filename && map)                                                       \
1477       ForEachMappedRegion(map, __msan_unpoison);                               \
1478   } while (false)
1479 
1480 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!msan_inited)
1481 
1482 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
1483   if (MsanThread *t = GetCurrentThread()) {                                    \
1484     *begin = t->tls_begin();                                                   \
1485     *end = t->tls_end();                                                       \
1486   } else {                                                                     \
1487     *begin = *end = 0;                                                         \
1488   }
1489 
1490 #define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size) \
1491   {                                                         \
1492     (void)ctx;                                              \
1493     return __msan_memset(block, c, size);                   \
1494   }
1495 #define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size) \
1496   {                                                          \
1497     (void)ctx;                                               \
1498     return __msan_memmove(to, from, size);                   \
1499   }
1500 #define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size) \
1501   {                                                         \
1502     (void)ctx;                                              \
1503     return __msan_memcpy(to, from, size);                   \
1504   }
1505 
1506 #define COMMON_INTERCEPTOR_COPY_STRING(ctx, to, from, size) \
1507   do {                                                      \
1508     GET_STORE_STACK_TRACE;                                  \
1509     CopyShadowAndOrigin(to, from, size, &stack);            \
1510     __msan_unpoison(to + size, 1);                          \
1511   } while (false)
1512 
1513 #define COMMON_INTERCEPTOR_MMAP_IMPL(ctx, mmap, addr, length, prot, flags, fd, \
1514                                      offset)                                   \
1515   do {                                                                         \
1516     return mmap_interceptor(REAL(mmap), addr, sz, prot, flags, fd, off);       \
1517   } while (false)
1518 
1519 #include "sanitizer_common/sanitizer_platform_interceptors.h"
1520 #include "sanitizer_common/sanitizer_common_interceptors_memintrinsics.inc"
1521 #include "sanitizer_common/sanitizer_common_interceptors.inc"
1522 
1523 static uptr signal_impl(int signo, uptr cb);
1524 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
1525                           __sanitizer_sigaction *oldact);
1526 
1527 #define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
1528   { return sigaction_impl(signo, act, oldact); }
1529 
1530 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
1531   {                                                          \
1532     handler = signal_impl(signo, handler);                   \
1533     InterceptorScope interceptor_scope;                      \
1534     return REAL(func)(signo, handler);                       \
1535   }
1536 
1537 #define SIGNAL_INTERCEPTOR_ENTER() ENSURE_MSAN_INITED()
1538 
1539 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
1540 
1541 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
1542                           __sanitizer_sigaction *oldact) {
1543   ENSURE_MSAN_INITED();
1544   if (signo <= 0 || signo >= kMaxSignals) {
1545     errno = errno_EINVAL;
1546     return -1;
1547   }
1548   if (act) read_sigaction(act);
1549   int res;
1550   if (flags()->wrap_signals) {
1551     SpinMutexLock lock(&sigactions_mu);
1552     uptr old_cb = atomic_load(&sigactions[signo], memory_order_relaxed);
1553     __sanitizer_sigaction new_act;
1554     __sanitizer_sigaction *pnew_act = act ? &new_act : nullptr;
1555     if (act) {
1556       REAL(memcpy)(pnew_act, act, sizeof(__sanitizer_sigaction));
1557       uptr cb = (uptr)pnew_act->sigaction;
1558       uptr new_cb = (pnew_act->sa_flags & __sanitizer::sa_siginfo)
1559                         ? (uptr)SignalAction
1560                         : (uptr)SignalHandler;
1561       if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1562         atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1563         pnew_act->sigaction = (decltype(pnew_act->sigaction))new_cb;
1564       }
1565     }
1566     res = REAL(SIGACTION_SYMNAME)(signo, pnew_act, oldact);
1567     if (res == 0 && oldact) {
1568       uptr cb = (uptr)oldact->sigaction;
1569       if (cb == (uptr)SignalAction || cb == (uptr)SignalHandler) {
1570         oldact->sigaction = (decltype(oldact->sigaction))old_cb;
1571       }
1572     }
1573   } else {
1574     res = REAL(SIGACTION_SYMNAME)(signo, act, oldact);
1575   }
1576 
1577   if (res == 0 && oldact) {
1578     __msan_unpoison(oldact, sizeof(__sanitizer_sigaction));
1579   }
1580   return res;
1581 }
1582 
1583 static uptr signal_impl(int signo, uptr cb) {
1584   ENSURE_MSAN_INITED();
1585   if (signo <= 0 || signo >= kMaxSignals) {
1586     errno = errno_EINVAL;
1587     return -1;
1588   }
1589   if (flags()->wrap_signals) {
1590     SpinMutexLock lock(&sigactions_mu);
1591     if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1592       atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1593       cb = (uptr)&SignalHandler;
1594     }
1595   }
1596   return cb;
1597 }
1598 
1599 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) CHECK_UNPOISONED(p, s)
1600 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
1601   do {                                       \
1602   } while (false)
1603 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
1604   do {                                       \
1605   } while (false)
1606 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) __msan_unpoison(p, s)
1607 #include "sanitizer_common/sanitizer_common_syscalls.inc"
1608 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
1609 
1610 INTERCEPTOR(const char *, strsignal, int sig) {
1611   void *ctx;
1612   COMMON_INTERCEPTOR_ENTER(ctx, strsignal, sig);
1613   const char *res = REAL(strsignal)(sig);
1614   if (res)
1615     __msan_unpoison(res, internal_strlen(res) + 1);
1616   return res;
1617 }
1618 
1619 INTERCEPTOR(int, dladdr, void *addr, void *info) {
1620   void *ctx;
1621   COMMON_INTERCEPTOR_ENTER(ctx, dladdr, addr, info);
1622   int res = REAL(dladdr)(addr, info);
1623   if (res != 0)
1624     UnpoisonDllAddrInfo(info);
1625   return res;
1626 }
1627 
1628 #if SANITIZER_GLIBC
1629 INTERCEPTOR(int, dladdr1, void *addr, void *info, void **extra_info,
1630             int flags) {
1631   void *ctx;
1632   COMMON_INTERCEPTOR_ENTER(ctx, dladdr1, addr, info, extra_info, flags);
1633   int res = REAL(dladdr1)(addr, info, extra_info, flags);
1634   if (res != 0) {
1635     UnpoisonDllAddrInfo(info);
1636     UnpoisonDllAddr1ExtraInfo(extra_info, flags);
1637   }
1638   return res;
1639 }
1640 #  define MSAN_MAYBE_INTERCEPT_DLADDR1 MSAN_INTERCEPT_FUNC(dladdr1)
1641 #else
1642 #define MSAN_MAYBE_INTERCEPT_DLADDR1
1643 #endif
1644 
1645 INTERCEPTOR(char *, dlerror, int fake) {
1646   void *ctx;
1647   COMMON_INTERCEPTOR_ENTER(ctx, dlerror, fake);
1648   char *res = REAL(dlerror)(fake);
1649   if (res)
1650     __msan_unpoison(res, internal_strlen(res) + 1);
1651   return res;
1652 }
1653 
1654 typedef int (*dl_iterate_phdr_cb)(__sanitizer_dl_phdr_info *info, SIZE_T size,
1655                                   void *data);
1656 struct dl_iterate_phdr_data {
1657   dl_iterate_phdr_cb callback;
1658   void *data;
1659 };
1660 
1661 static int msan_dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
1662                                    void *data) {
1663   if (info) {
1664     __msan_unpoison(info, size);
1665     if (info->dlpi_phdr && info->dlpi_phnum)
1666       __msan_unpoison(info->dlpi_phdr, struct_ElfW_Phdr_sz * info->dlpi_phnum);
1667     if (info->dlpi_name)
1668       __msan_unpoison(info->dlpi_name, internal_strlen(info->dlpi_name) + 1);
1669   }
1670   dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
1671   UnpoisonParam(3);
1672   return cbdata->callback(info, size, cbdata->data);
1673 }
1674 
1675 INTERCEPTOR(void *, shmat, int shmid, const void *shmaddr, int shmflg) {
1676   ENSURE_MSAN_INITED();
1677   void *p = REAL(shmat)(shmid, shmaddr, shmflg);
1678   if (p != (void *)-1) {
1679     __sanitizer_shmid_ds ds;
1680     int res = REAL(shmctl)(shmid, shmctl_ipc_stat, &ds);
1681     if (!res) {
1682       __msan_unpoison(p, ds.shm_segsz);
1683     }
1684   }
1685   return p;
1686 }
1687 
1688 INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb callback, void *data) {
1689   void *ctx;
1690   COMMON_INTERCEPTOR_ENTER(ctx, dl_iterate_phdr, callback, data);
1691   dl_iterate_phdr_data cbdata;
1692   cbdata.callback = callback;
1693   cbdata.data = data;
1694   int res = REAL(dl_iterate_phdr)(msan_dl_iterate_phdr_cb, (void *)&cbdata);
1695   return res;
1696 }
1697 
1698 // wchar_t *wcschr(const wchar_t *wcs, wchar_t wc);
1699 INTERCEPTOR(wchar_t *, wcschr, void *s, wchar_t wc, void *ps) {
1700   ENSURE_MSAN_INITED();
1701   wchar_t *res = REAL(wcschr)(s, wc, ps);
1702   return res;
1703 }
1704 
1705 // wchar_t *wcscpy(wchar_t *dest, const wchar_t *src);
1706 INTERCEPTOR(wchar_t *, wcscpy, wchar_t *dest, const wchar_t *src) {
1707   ENSURE_MSAN_INITED();
1708   GET_STORE_STACK_TRACE;
1709   wchar_t *res = REAL(wcscpy)(dest, src);
1710   CopyShadowAndOrigin(dest, src, sizeof(wchar_t) * (internal_wcslen(src) + 1),
1711                       &stack);
1712   return res;
1713 }
1714 
1715 INTERCEPTOR(wchar_t *, wcsncpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
1716   ENSURE_MSAN_INITED();
1717   GET_STORE_STACK_TRACE;
1718   SIZE_T copy_size = internal_wcsnlen(src, n);
1719   if (copy_size < n) copy_size++;           // trailing \0
1720   wchar_t *res = REAL(wcsncpy)(dest, src, n);
1721   CopyShadowAndOrigin(dest, src, copy_size * sizeof(wchar_t), &stack);
1722   __msan_unpoison(dest + copy_size, (n - copy_size) * sizeof(wchar_t));
1723   return res;
1724 }
1725 
1726 // These interface functions reside here so that they can use
1727 // REAL(memset), etc.
1728 void __msan_unpoison(const void *a, uptr size) {
1729   if (!MEM_IS_APP(a)) return;
1730   SetShadow(a, size, 0);
1731 }
1732 
1733 void __msan_poison(const void *a, uptr size) {
1734   if (!MEM_IS_APP(a)) return;
1735   SetShadow(a, size, __msan::flags()->poison_heap_with_zeroes ? 0 : -1);
1736 }
1737 
1738 void __msan_poison_stack(void *a, uptr size) {
1739   if (!MEM_IS_APP(a)) return;
1740   SetShadow(a, size, __msan::flags()->poison_stack_with_zeroes ? 0 : -1);
1741 }
1742 
1743 void __msan_unpoison_param(uptr n) { UnpoisonParam(n); }
1744 
1745 void __msan_clear_and_unpoison(void *a, uptr size) {
1746   REAL(memset)(a, 0, size);
1747   SetShadow(a, size, 0);
1748 }
1749 
1750 void *__msan_memcpy(void *dest, const void *src, SIZE_T n) {
1751   if (!msan_inited) return internal_memcpy(dest, src, n);
1752   if (msan_init_is_running || __msan::IsInSymbolizerOrUnwider())
1753     return REAL(memcpy)(dest, src, n);
1754   ENSURE_MSAN_INITED();
1755   GET_STORE_STACK_TRACE;
1756   void *res = REAL(memcpy)(dest, src, n);
1757   CopyShadowAndOrigin(dest, src, n, &stack);
1758   return res;
1759 }
1760 
1761 void *__msan_memset(void *s, int c, SIZE_T n) {
1762   if (!msan_inited) return internal_memset(s, c, n);
1763   if (msan_init_is_running) return REAL(memset)(s, c, n);
1764   ENSURE_MSAN_INITED();
1765   void *res = REAL(memset)(s, c, n);
1766   __msan_unpoison(s, n);
1767   return res;
1768 }
1769 
1770 void *__msan_memmove(void *dest, const void *src, SIZE_T n) {
1771   if (!msan_inited) return internal_memmove(dest, src, n);
1772   if (msan_init_is_running) return REAL(memmove)(dest, src, n);
1773   ENSURE_MSAN_INITED();
1774   GET_STORE_STACK_TRACE;
1775   void *res = REAL(memmove)(dest, src, n);
1776   MoveShadowAndOrigin(dest, src, n, &stack);
1777   return res;
1778 }
1779 
1780 void __msan_unpoison_string(const char* s) {
1781   if (!MEM_IS_APP(s)) return;
1782   __msan_unpoison(s, internal_strlen(s) + 1);
1783 }
1784 
1785 namespace __msan {
1786 
1787 void InitializeInterceptors() {
1788   static int inited = 0;
1789   CHECK_EQ(inited, 0);
1790 
1791   __interception::DoesNotSupportStaticLinking();
1792 
1793   new(interceptor_ctx()) InterceptorContext();
1794 
1795   InitializeCommonInterceptors();
1796   InitializeSignalInterceptors();
1797 
1798   INTERCEPT_FUNCTION(posix_memalign);
1799   MSAN_MAYBE_INTERCEPT_MEMALIGN;
1800   MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN;
1801   INTERCEPT_FUNCTION(valloc);
1802   MSAN_MAYBE_INTERCEPT_PVALLOC;
1803   INTERCEPT_FUNCTION(malloc);
1804   INTERCEPT_FUNCTION(calloc);
1805   INTERCEPT_FUNCTION(realloc);
1806   INTERCEPT_FUNCTION(reallocarray);
1807   INTERCEPT_FUNCTION(free);
1808   MSAN_MAYBE_INTERCEPT_FREE_SIZED;
1809   MSAN_MAYBE_INTERCEPT_FREE_ALIGNED_SIZED;
1810   MSAN_MAYBE_INTERCEPT_CFREE;
1811   MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE;
1812   MSAN_MAYBE_INTERCEPT_MALLINFO;
1813   MSAN_MAYBE_INTERCEPT_MALLINFO2;
1814   MSAN_MAYBE_INTERCEPT_MALLOPT;
1815   MSAN_MAYBE_INTERCEPT_MALLOC_STATS;
1816   INTERCEPT_FUNCTION(fread);
1817   MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED;
1818   INTERCEPT_FUNCTION(memccpy);
1819   MSAN_MAYBE_INTERCEPT_MEMPCPY;
1820   INTERCEPT_FUNCTION(bcopy);
1821   INTERCEPT_FUNCTION(wmemset);
1822   INTERCEPT_FUNCTION(wmemcpy);
1823   MSAN_MAYBE_INTERCEPT_WMEMPCPY;
1824   INTERCEPT_FUNCTION(wmemmove);
1825   INTERCEPT_FUNCTION(strcpy);
1826   MSAN_MAYBE_INTERCEPT_STPCPY;
1827   MSAN_MAYBE_INTERCEPT_STPNCPY;
1828   INTERCEPT_FUNCTION(strdup);
1829   MSAN_MAYBE_INTERCEPT___STRDUP;
1830   INTERCEPT_FUNCTION(strncpy);
1831   MSAN_MAYBE_INTERCEPT_GCVT;
1832   INTERCEPT_FUNCTION(strcat);
1833   INTERCEPT_FUNCTION(strncat);
1834   INTERCEPT_STRTO(strtod);
1835   INTERCEPT_STRTO(strtof);
1836 #ifdef SANITIZER_NLDBL_VERSION
1837   INTERCEPT_STRTO_VER(strtold, SANITIZER_NLDBL_VERSION);
1838 #else
1839   INTERCEPT_STRTO(strtold);
1840 #endif
1841   INTERCEPT_STRTO(strtol);
1842   INTERCEPT_STRTO(strtoul);
1843   INTERCEPT_STRTO(strtoll);
1844   INTERCEPT_STRTO(strtoull);
1845   INTERCEPT_STRTO(strtouq);
1846   INTERCEPT_STRTO(wcstod);
1847   INTERCEPT_STRTO(wcstof);
1848 #ifdef SANITIZER_NLDBL_VERSION
1849   INTERCEPT_STRTO_VER(wcstold, SANITIZER_NLDBL_VERSION);
1850 #else
1851   INTERCEPT_STRTO(wcstold);
1852 #endif
1853   INTERCEPT_STRTO(wcstol);
1854   INTERCEPT_STRTO(wcstoul);
1855   INTERCEPT_STRTO(wcstoll);
1856   INTERCEPT_STRTO(wcstoull);
1857 #if SANITIZER_GLIBC
1858   INTERCEPT_STRTO(__isoc23_strtod);
1859   INTERCEPT_STRTO(__isoc23_strtof);
1860   INTERCEPT_STRTO(__isoc23_strtold);
1861   INTERCEPT_STRTO(__isoc23_strtol);
1862   INTERCEPT_STRTO(__isoc23_strtoul);
1863   INTERCEPT_STRTO(__isoc23_strtoll);
1864   INTERCEPT_STRTO(__isoc23_strtoull);
1865   INTERCEPT_STRTO(__isoc23_strtouq);
1866   INTERCEPT_STRTO(__isoc23_wcstod);
1867   INTERCEPT_STRTO(__isoc23_wcstof);
1868   INTERCEPT_STRTO(__isoc23_wcstold);
1869   INTERCEPT_STRTO(__isoc23_wcstol);
1870   INTERCEPT_STRTO(__isoc23_wcstoul);
1871   INTERCEPT_STRTO(__isoc23_wcstoll);
1872   INTERCEPT_STRTO(__isoc23_wcstoull);
1873 #endif
1874 
1875 #ifdef SANITIZER_NLDBL_VERSION
1876   INTERCEPT_FUNCTION_VER(vswprintf, SANITIZER_NLDBL_VERSION);
1877   INTERCEPT_FUNCTION_VER(swprintf, SANITIZER_NLDBL_VERSION);
1878 #else
1879   INTERCEPT_FUNCTION(vswprintf);
1880   INTERCEPT_FUNCTION(swprintf);
1881 #endif
1882   INTERCEPT_FUNCTION(strftime);
1883   INTERCEPT_FUNCTION(strftime_l);
1884   MSAN_MAYBE_INTERCEPT___STRFTIME_L;
1885   INTERCEPT_FUNCTION(wcsftime);
1886   INTERCEPT_FUNCTION(wcsftime_l);
1887   MSAN_MAYBE_INTERCEPT___WCSFTIME_L;
1888   INTERCEPT_FUNCTION(mbtowc);
1889   INTERCEPT_FUNCTION(mbrtowc);
1890   INTERCEPT_FUNCTION(wcslen);
1891   INTERCEPT_FUNCTION(wcsnlen);
1892   INTERCEPT_FUNCTION(wcschr);
1893   INTERCEPT_FUNCTION(wcscpy);
1894   INTERCEPT_FUNCTION(wcsncpy);
1895   INTERCEPT_FUNCTION(wcscmp);
1896   INTERCEPT_FUNCTION(getenv);
1897   INTERCEPT_FUNCTION(setenv);
1898   INTERCEPT_FUNCTION(putenv);
1899   INTERCEPT_FUNCTION(gettimeofday);
1900   MSAN_MAYBE_INTERCEPT_FCVT;
1901   MSAN_MAYBE_INTERCEPT_FSTAT;
1902   MSAN_MAYBE_INTERCEPT_FSTAT64;
1903   MSAN_MAYBE_INTERCEPT___FXSTAT;
1904   MSAN_MAYBE_INTERCEPT_FSTATAT;
1905   MSAN_MAYBE_INTERCEPT_FSTATAT64;
1906   MSAN_MAYBE_INTERCEPT___FXSTATAT;
1907   MSAN_MAYBE_INTERCEPT___FXSTAT64;
1908   MSAN_MAYBE_INTERCEPT___FXSTATAT64;
1909   INTERCEPT_FUNCTION(pipe);
1910   INTERCEPT_FUNCTION(pipe2);
1911   INTERCEPT_FUNCTION(socketpair);
1912   MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED;
1913   INTERCEPT_FUNCTION(getrlimit);
1914   MSAN_MAYBE_INTERCEPT___GETRLIMIT;
1915   MSAN_MAYBE_INTERCEPT_GETRLIMIT64;
1916   MSAN_MAYBE_INTERCEPT_PRLIMIT;
1917   MSAN_MAYBE_INTERCEPT_PRLIMIT64;
1918   INTERCEPT_FUNCTION(gethostname);
1919   MSAN_MAYBE_INTERCEPT_EPOLL_WAIT;
1920   MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT;
1921   INTERCEPT_FUNCTION(strsignal);
1922   INTERCEPT_FUNCTION(dladdr);
1923   MSAN_MAYBE_INTERCEPT_DLADDR1;
1924   INTERCEPT_FUNCTION(dlerror);
1925   INTERCEPT_FUNCTION(dl_iterate_phdr);
1926   INTERCEPT_FUNCTION(getrusage);
1927 #if defined(__mips__)
1928   INTERCEPT_FUNCTION_VER(pthread_create, "GLIBC_2.2");
1929 #else
1930   INTERCEPT_FUNCTION(pthread_create);
1931 #endif
1932   INTERCEPT_FUNCTION(pthread_join);
1933   INTERCEPT_FUNCTION(pthread_key_create);
1934 #if SANITIZER_GLIBC
1935   INTERCEPT_FUNCTION(pthread_tryjoin_np);
1936   INTERCEPT_FUNCTION(pthread_timedjoin_np);
1937 #endif
1938 
1939 #if SANITIZER_NETBSD
1940   INTERCEPT_FUNCTION(__libc_thr_keycreate);
1941 #endif
1942 
1943   INTERCEPT_FUNCTION(pthread_join);
1944   INTERCEPT_FUNCTION(tzset);
1945   INTERCEPT_FUNCTION(atexit);
1946   INTERCEPT_FUNCTION(__cxa_atexit);
1947   INTERCEPT_FUNCTION(shmat);
1948   MSAN_MAYBE_INTERCEPT_OPENPTY;
1949   MSAN_MAYBE_INTERCEPT_FORKPTY;
1950 
1951   inited = 1;
1952 }
1953 } // namespace __msan
1954