msan_interceptors.cc revision 5cee73e486aaa617a9627bb69a6447d3369b62cc
1//===-- msan_interceptors.cc ----------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of MemorySanitizer.
11//
12// Interceptors for standard library functions.
13//
14// FIXME: move as many interceptors as possible into
15// sanitizer_common/sanitizer_common_interceptors.h
16//===----------------------------------------------------------------------===//
17
18#include "interception/interception.h"
19#include "msan.h"
20#include "sanitizer_common/sanitizer_platform_limits_posix.h"
21#include "sanitizer_common/sanitizer_allocator.h"
22#include "sanitizer_common/sanitizer_allocator_internal.h"
23#include "sanitizer_common/sanitizer_atomic.h"
24#include "sanitizer_common/sanitizer_common.h"
25#include "sanitizer_common/sanitizer_stackdepot.h"
26#include "sanitizer_common/sanitizer_libc.h"
27#include "sanitizer_common/sanitizer_linux.h"
28
29#include <stdarg.h>
30// ACHTUNG! No other system header includes in this file.
31// Ideally, we should get rid of stdarg.h as well.
32
33using namespace __msan;
34
35using __sanitizer::memory_order;
36using __sanitizer::atomic_load;
37using __sanitizer::atomic_store;
38using __sanitizer::atomic_uintptr_t;
39
40// True if this is a nested interceptor.
41static THREADLOCAL int in_interceptor_scope;
42
43struct InterceptorScope {
44  InterceptorScope() { ++in_interceptor_scope; }
45  ~InterceptorScope() { --in_interceptor_scope; }
46};
47
48bool IsInInterceptorScope() {
49  return in_interceptor_scope;
50}
51
52#define ENSURE_MSAN_INITED() do { \
53  CHECK(!msan_init_is_running); \
54  if (!msan_inited) { \
55    __msan_init(); \
56  } \
57} while (0)
58
59// Check that [x, x+n) range is unpoisoned.
60#define CHECK_UNPOISONED_0(x, n)                                             \
61  do {                                                                       \
62    sptr offset = __msan_test_shadow(x, n);                                  \
63    if (__msan::IsInSymbolizer()) break;                                     \
64    if (offset >= 0 && __msan::flags()->report_umrs) {                       \
65      GET_CALLER_PC_BP_SP;                                                   \
66      (void) sp;                                                             \
67      Printf("UMR in %s at offset %d inside [%p, +%d) \n", __FUNCTION__,     \
68             offset, x, n);                                                  \
69      __msan::PrintWarningWithOrigin(pc, bp,                                 \
70                                     __msan_get_origin((char *)x + offset)); \
71      if (__msan::flags()->halt_on_error) {                                  \
72        Printf("Exiting\n");                                                 \
73        Die();                                                               \
74      }                                                                      \
75    }                                                                        \
76  } while (0)
77
78// Check that [x, x+n) range is unpoisoned unless we are in a nested
79// interceptor.
80#define CHECK_UNPOISONED(x, n)                             \
81  do {                                                     \
82    if (!IsInInterceptorScope()) CHECK_UNPOISONED_0(x, n); \
83  } while (0);
84
85static void *fast_memset(void *ptr, int c, SIZE_T n);
86static void *fast_memcpy(void *dst, const void *src, SIZE_T n);
87
88INTERCEPTOR(SIZE_T, fread, void *ptr, SIZE_T size, SIZE_T nmemb, void *file) {
89  ENSURE_MSAN_INITED();
90  SIZE_T res = REAL(fread)(ptr, size, nmemb, file);
91  if (res > 0)
92    __msan_unpoison(ptr, res *size);
93  return res;
94}
95
96INTERCEPTOR(SIZE_T, fread_unlocked, void *ptr, SIZE_T size, SIZE_T nmemb,
97            void *file) {
98  ENSURE_MSAN_INITED();
99  SIZE_T res = REAL(fread_unlocked)(ptr, size, nmemb, file);
100  if (res > 0)
101    __msan_unpoison(ptr, res *size);
102  return res;
103}
104
105INTERCEPTOR(SSIZE_T, readlink, const char *path, char *buf, SIZE_T bufsiz) {
106  ENSURE_MSAN_INITED();
107  SSIZE_T res = REAL(readlink)(path, buf, bufsiz);
108  if (res > 0)
109    __msan_unpoison(buf, res);
110  return res;
111}
112
113INTERCEPTOR(void *, memcpy, void *dest, const void *src, SIZE_T n) {
114  return __msan_memcpy(dest, src, n);
115}
116
117INTERCEPTOR(void *, mempcpy, void *dest, const void *src, SIZE_T n) {
118  return (char *)__msan_memcpy(dest, src, n) + n;
119}
120
121INTERCEPTOR(void *, memmove, void *dest, const void *src, SIZE_T n) {
122  return __msan_memmove(dest, src, n);
123}
124
125INTERCEPTOR(void *, memset, void *s, int c, SIZE_T n) {
126  return __msan_memset(s, c, n);
127}
128
129INTERCEPTOR(void *, bcopy, const void *src, void *dest, SIZE_T n) {
130  return __msan_memmove(dest, src, n);
131}
132
133INTERCEPTOR(int, posix_memalign, void **memptr, SIZE_T alignment, SIZE_T size) {
134  GET_MALLOC_STACK_TRACE;
135  CHECK_EQ(alignment & (alignment - 1), 0);
136  CHECK_NE(memptr, 0);
137  *memptr = MsanReallocate(&stack, 0, size, alignment, false);
138  CHECK_NE(*memptr, 0);
139  __msan_unpoison(memptr, sizeof(*memptr));
140  return 0;
141}
142
143INTERCEPTOR(void *, memalign, SIZE_T boundary, SIZE_T size) {
144  GET_MALLOC_STACK_TRACE;
145  CHECK_EQ(boundary & (boundary - 1), 0);
146  void *ptr = MsanReallocate(&stack, 0, size, boundary, false);
147  return ptr;
148}
149
150INTERCEPTOR(void *, valloc, SIZE_T size) {
151  GET_MALLOC_STACK_TRACE;
152  void *ptr = MsanReallocate(&stack, 0, size, GetPageSizeCached(), false);
153  return ptr;
154}
155
156INTERCEPTOR(void *, pvalloc, SIZE_T size) {
157  GET_MALLOC_STACK_TRACE;
158  uptr PageSize = GetPageSizeCached();
159  size = RoundUpTo(size, PageSize);
160  if (size == 0) {
161    // pvalloc(0) should allocate one page.
162    size = PageSize;
163  }
164  void *ptr = MsanReallocate(&stack, 0, size, PageSize, false);
165  return ptr;
166}
167
168INTERCEPTOR(void, free, void *ptr) {
169  GET_MALLOC_STACK_TRACE;
170  if (ptr == 0) return;
171  MsanDeallocate(&stack, ptr);
172}
173
174INTERCEPTOR(SIZE_T, strlen, const char *s) {
175  ENSURE_MSAN_INITED();
176  SIZE_T res = REAL(strlen)(s);
177  CHECK_UNPOISONED(s, res + 1);
178  return res;
179}
180
181INTERCEPTOR(SIZE_T, strnlen, const char *s, SIZE_T n) {
182  ENSURE_MSAN_INITED();
183  SIZE_T res = REAL(strnlen)(s, n);
184  SIZE_T scan_size = (res == n) ? res : res + 1;
185  CHECK_UNPOISONED(s, scan_size);
186  return res;
187}
188
189// FIXME: Add stricter shadow checks in str* interceptors (ex.: strcpy should
190// check the shadow of the terminating \0 byte).
191
192INTERCEPTOR(char *, strcpy, char *dest, const char *src) {  // NOLINT
193  ENSURE_MSAN_INITED();
194  SIZE_T n = REAL(strlen)(src);
195  char *res = REAL(strcpy)(dest, src);  // NOLINT
196  __msan_copy_poison(dest, src, n + 1);
197  return res;
198}
199
200INTERCEPTOR(char *, strncpy, char *dest, const char *src, SIZE_T n) {  // NOLINT
201  ENSURE_MSAN_INITED();
202  SIZE_T copy_size = REAL(strnlen)(src, n);
203  if (copy_size < n)
204    copy_size++;  // trailing \0
205  char *res = REAL(strncpy)(dest, src, n);  // NOLINT
206  __msan_copy_poison(dest, src, copy_size);
207  return res;
208}
209
210INTERCEPTOR(char *, stpcpy, char *dest, const char *src) {  // NOLINT
211  ENSURE_MSAN_INITED();
212  SIZE_T n = REAL(strlen)(src);
213  char *res = REAL(stpcpy)(dest, src);  // NOLINT
214  __msan_copy_poison(dest, src, n + 1);
215  return res;
216}
217
218INTERCEPTOR(char *, strdup, char *src) {
219  ENSURE_MSAN_INITED();
220  SIZE_T n = REAL(strlen)(src);
221  char *res = REAL(strdup)(src);
222  __msan_copy_poison(res, src, n + 1);
223  return res;
224}
225
226INTERCEPTOR(char *, __strdup, char *src) {
227  ENSURE_MSAN_INITED();
228  SIZE_T n = REAL(strlen)(src);
229  char *res = REAL(__strdup)(src);
230  __msan_copy_poison(res, src, n + 1);
231  return res;
232}
233
234INTERCEPTOR(char *, strndup, char *src, SIZE_T n) {
235  ENSURE_MSAN_INITED();
236  SIZE_T copy_size = REAL(strnlen)(src, n);
237  char *res = REAL(strndup)(src, n);
238  __msan_copy_poison(res, src, copy_size);
239  __msan_unpoison(res + copy_size, 1); // \0
240  return res;
241}
242
243INTERCEPTOR(char *, __strndup, char *src, SIZE_T n) {
244  ENSURE_MSAN_INITED();
245  SIZE_T copy_size = REAL(strnlen)(src, n);
246  char *res = REAL(__strndup)(src, n);
247  __msan_copy_poison(res, src, copy_size);
248  __msan_unpoison(res + copy_size, 1); // \0
249  return res;
250}
251
252INTERCEPTOR(char *, gcvt, double number, SIZE_T ndigit, char *buf) {
253  ENSURE_MSAN_INITED();
254  char *res = REAL(gcvt)(number, ndigit, buf);
255  // DynamoRio tool will take care of unpoisoning gcvt result for us.
256  if (!__msan_has_dynamic_component()) {
257    SIZE_T n = REAL(strlen)(buf);
258    __msan_unpoison(buf, n + 1);
259  }
260  return res;
261}
262
263INTERCEPTOR(char *, strcat, char *dest, const char *src) {  // NOLINT
264  ENSURE_MSAN_INITED();
265  SIZE_T src_size = REAL(strlen)(src);
266  SIZE_T dest_size = REAL(strlen)(dest);
267  char *res = REAL(strcat)(dest, src);  // NOLINT
268  __msan_copy_poison(dest + dest_size, src, src_size + 1);
269  return res;
270}
271
272INTERCEPTOR(char *, strncat, char *dest, const char *src, SIZE_T n) {  // NOLINT
273  ENSURE_MSAN_INITED();
274  SIZE_T dest_size = REAL(strlen)(dest);
275  SIZE_T copy_size = REAL(strlen)(src);
276  if (copy_size < n)
277    copy_size++;  // trailing \0
278  char *res = REAL(strncat)(dest, src, n);  // NOLINT
279  __msan_copy_poison(dest + dest_size, src, copy_size);
280  return res;
281}
282
283INTERCEPTOR(long, strtol, const char *nptr, char **endptr,  // NOLINT
284            int base) {
285  ENSURE_MSAN_INITED();
286  long res = REAL(strtol)(nptr, endptr, base);  // NOLINT
287  if (!__msan_has_dynamic_component()) {
288    __msan_unpoison(endptr, sizeof(*endptr));
289  }
290  return res;
291}
292
293INTERCEPTOR(long long, strtoll, const char *nptr, char **endptr,  // NOLINT
294            int base) {
295  ENSURE_MSAN_INITED();
296  long res = REAL(strtoll)(nptr, endptr, base);  //NOLINT
297  if (!__msan_has_dynamic_component()) {
298    __msan_unpoison(endptr, sizeof(*endptr));
299  }
300  return res;
301}
302
303INTERCEPTOR(unsigned long, strtoul, const char *nptr, char **endptr,  // NOLINT
304            int base) {
305  ENSURE_MSAN_INITED();
306  unsigned long res = REAL(strtoul)(nptr, endptr, base);  // NOLINT
307  if (!__msan_has_dynamic_component()) {
308    __msan_unpoison(endptr, sizeof(*endptr));
309  }
310  return res;
311}
312
313INTERCEPTOR(unsigned long long, strtoull, const char *nptr,  // NOLINT
314            char **endptr, int base) {
315  ENSURE_MSAN_INITED();
316  unsigned long res = REAL(strtoull)(nptr, endptr, base);  // NOLINT
317  if (!__msan_has_dynamic_component()) {
318    __msan_unpoison(endptr, sizeof(*endptr));
319  }
320  return res;
321}
322
323INTERCEPTOR(double, strtod, const char *nptr, char **endptr) {  // NOLINT
324  ENSURE_MSAN_INITED();
325  double res = REAL(strtod)(nptr, endptr);  // NOLINT
326  if (!__msan_has_dynamic_component()) {
327    __msan_unpoison(endptr, sizeof(*endptr));
328  }
329  return res;
330}
331
332INTERCEPTOR(double, strtod_l, const char *nptr, char **endptr,
333            void *loc) {  // NOLINT
334  ENSURE_MSAN_INITED();
335  double res = REAL(strtod_l)(nptr, endptr, loc);  // NOLINT
336  if (!__msan_has_dynamic_component()) {
337    __msan_unpoison(endptr, sizeof(*endptr));
338  }
339  return res;
340}
341
342INTERCEPTOR(double, __strtod_l, const char *nptr, char **endptr,
343            void *loc) {  // NOLINT
344  ENSURE_MSAN_INITED();
345  double res = REAL(__strtod_l)(nptr, endptr, loc);  // NOLINT
346  if (!__msan_has_dynamic_component()) {
347    __msan_unpoison(endptr, sizeof(*endptr));
348  }
349  return res;
350}
351
352INTERCEPTOR(float, strtof, const char *nptr, char **endptr) {  // NOLINT
353  ENSURE_MSAN_INITED();
354  float res = REAL(strtof)(nptr, endptr);  // NOLINT
355  if (!__msan_has_dynamic_component()) {
356    __msan_unpoison(endptr, sizeof(*endptr));
357  }
358  return res;
359}
360
361INTERCEPTOR(float, strtof_l, const char *nptr, char **endptr,
362            void *loc) {  // NOLINT
363  ENSURE_MSAN_INITED();
364  float res = REAL(strtof_l)(nptr, endptr, loc);  // NOLINT
365  if (!__msan_has_dynamic_component()) {
366    __msan_unpoison(endptr, sizeof(*endptr));
367  }
368  return res;
369}
370
371INTERCEPTOR(float, __strtof_l, const char *nptr, char **endptr,
372            void *loc) {  // NOLINT
373  ENSURE_MSAN_INITED();
374  float res = REAL(__strtof_l)(nptr, endptr, loc);  // NOLINT
375  if (!__msan_has_dynamic_component()) {
376    __msan_unpoison(endptr, sizeof(*endptr));
377  }
378  return res;
379}
380
381INTERCEPTOR(long double, strtold, const char *nptr, char **endptr) {  // NOLINT
382  ENSURE_MSAN_INITED();
383  long double res = REAL(strtold)(nptr, endptr);  // NOLINT
384  if (!__msan_has_dynamic_component()) {
385    __msan_unpoison(endptr, sizeof(*endptr));
386  }
387  return res;
388}
389
390INTERCEPTOR(long double, strtold_l, const char *nptr, char **endptr,
391            void *loc) {  // NOLINT
392  ENSURE_MSAN_INITED();
393  long double res = REAL(strtold_l)(nptr, endptr, loc);  // NOLINT
394  if (!__msan_has_dynamic_component()) {
395    __msan_unpoison(endptr, sizeof(*endptr));
396  }
397  return res;
398}
399
400INTERCEPTOR(long double, __strtold_l, const char *nptr, char **endptr,
401            void *loc) {  // NOLINT
402  ENSURE_MSAN_INITED();
403  long double res = REAL(__strtold_l)(nptr, endptr, loc);  // NOLINT
404  if (!__msan_has_dynamic_component()) {
405    __msan_unpoison(endptr, sizeof(*endptr));
406  }
407  return res;
408}
409
410INTERCEPTOR(int, vasprintf, char **strp, const char *format, va_list ap) {
411  ENSURE_MSAN_INITED();
412  int res = REAL(vasprintf)(strp, format, ap);
413  if (res >= 0 && !__msan_has_dynamic_component()) {
414    __msan_unpoison(strp, sizeof(*strp));
415    __msan_unpoison(*strp, res + 1);
416  }
417  return res;
418}
419
420INTERCEPTOR(int, asprintf, char **strp, const char *format, ...) {  // NOLINT
421  ENSURE_MSAN_INITED();
422  va_list ap;
423  va_start(ap, format);
424  int res = vasprintf(strp, format, ap);  // NOLINT
425  va_end(ap);
426  return res;
427}
428
429INTERCEPTOR(int, vsnprintf, char *str, uptr size,
430            const char *format, va_list ap) {
431  ENSURE_MSAN_INITED();
432  int res = REAL(vsnprintf)(str, size, format, ap);
433  if (res >= 0 && !__msan_has_dynamic_component()) {
434    __msan_unpoison(str, res + 1);
435  }
436  return res;
437}
438
439INTERCEPTOR(int, vsprintf, char *str, const char *format, va_list ap) {
440  ENSURE_MSAN_INITED();
441  int res = REAL(vsprintf)(str, format, ap);
442  if (res >= 0 && !__msan_has_dynamic_component()) {
443    __msan_unpoison(str, res + 1);
444  }
445  return res;
446}
447
448INTERCEPTOR(int, vswprintf, void *str, uptr size, void *format, va_list ap) {
449  ENSURE_MSAN_INITED();
450  int res = REAL(vswprintf)(str, size, format, ap);
451  if (res >= 0 && !__msan_has_dynamic_component()) {
452    __msan_unpoison(str, 4 * (res + 1));
453  }
454  return res;
455}
456
457INTERCEPTOR(int, sprintf, char *str, const char *format, ...) {  // NOLINT
458  ENSURE_MSAN_INITED();
459  va_list ap;
460  va_start(ap, format);
461  int res = vsprintf(str, format, ap);  // NOLINT
462  va_end(ap);
463  return res;
464}
465
466INTERCEPTOR(int, snprintf, char *str, uptr size, const char *format, ...) {
467  ENSURE_MSAN_INITED();
468  va_list ap;
469  va_start(ap, format);
470  int res = vsnprintf(str, size, format, ap);
471  va_end(ap);
472  return res;
473}
474
475INTERCEPTOR(int, swprintf, void *str, uptr size, void *format, ...) {
476  ENSURE_MSAN_INITED();
477  va_list ap;
478  va_start(ap, format);
479  int res = vswprintf(str, size, format, ap);
480  va_end(ap);
481  return res;
482}
483
484// SIZE_T strftime(char *s, SIZE_T max, const char *format,const struct tm *tm);
485INTERCEPTOR(SIZE_T, strftime, char *s, SIZE_T max, const char *format,
486            void *tm) {
487  ENSURE_MSAN_INITED();
488  SIZE_T res = REAL(strftime)(s, max, format, tm);
489  if (res) __msan_unpoison(s, res + 1);
490  return res;
491}
492
493INTERCEPTOR(int, mbtowc, wchar_t *dest, const char *src, SIZE_T n) {
494  ENSURE_MSAN_INITED();
495  int res = REAL(mbtowc)(dest, src, n);
496  if (res != -1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
497  return res;
498}
499
500INTERCEPTOR(int, mbrtowc, wchar_t *dest, const char *src, SIZE_T n, void *ps) {
501  ENSURE_MSAN_INITED();
502  SIZE_T res = REAL(mbrtowc)(dest, src, n, ps);
503  if (res != (SIZE_T)-1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
504  return res;
505}
506
507INTERCEPTOR(SIZE_T, wcslen, const wchar_t *s) {
508  ENSURE_MSAN_INITED();
509  SIZE_T res = REAL(wcslen)(s);
510  CHECK_UNPOISONED(s, sizeof(wchar_t) * (res + 1));
511  return res;
512}
513
514// wchar_t *wcschr(const wchar_t *wcs, wchar_t wc);
515INTERCEPTOR(wchar_t *, wcschr, void *s, wchar_t wc, void *ps) {
516  ENSURE_MSAN_INITED();
517  wchar_t *res = REAL(wcschr)(s, wc, ps);
518  return res;
519}
520
521// wchar_t *wcscpy(wchar_t *dest, const wchar_t *src);
522INTERCEPTOR(wchar_t *, wcscpy, wchar_t *dest, const wchar_t *src) {
523  ENSURE_MSAN_INITED();
524  wchar_t *res = REAL(wcscpy)(dest, src);
525  __msan_copy_poison(dest, src, sizeof(wchar_t) * (REAL(wcslen)(src) + 1));
526  return res;
527}
528
529// wchar_t *wmemcpy(wchar_t *dest, const wchar_t *src, SIZE_T n);
530INTERCEPTOR(wchar_t *, wmemcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
531  ENSURE_MSAN_INITED();
532  wchar_t *res = REAL(wmemcpy)(dest, src, n);
533  __msan_copy_poison(dest, src, n * sizeof(wchar_t));
534  return res;
535}
536
537INTERCEPTOR(wchar_t *, wmempcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
538  ENSURE_MSAN_INITED();
539  wchar_t *res = REAL(wmempcpy)(dest, src, n);
540  __msan_copy_poison(dest, src, n * sizeof(wchar_t));
541  return res;
542}
543
544INTERCEPTOR(wchar_t *, wmemset, wchar_t *s, wchar_t c, SIZE_T n) {
545  CHECK(MEM_IS_APP(s));
546  ENSURE_MSAN_INITED();
547  wchar_t *res = (wchar_t *)fast_memset(s, c, n * sizeof(wchar_t));
548  __msan_unpoison(s, n * sizeof(wchar_t));
549  return res;
550}
551
552INTERCEPTOR(wchar_t *, wmemmove, wchar_t *dest, const wchar_t *src, SIZE_T n) {
553  ENSURE_MSAN_INITED();
554  wchar_t *res = REAL(wmemmove)(dest, src, n);
555  __msan_move_poison(dest, src, n * sizeof(wchar_t));
556  return res;
557}
558
559INTERCEPTOR(int, wcscmp, const wchar_t *s1, const wchar_t *s2) {
560  ENSURE_MSAN_INITED();
561  int res = REAL(wcscmp)(s1, s2);
562  return res;
563}
564
565INTERCEPTOR(double, wcstod, const wchar_t *nptr, wchar_t **endptr) {
566  ENSURE_MSAN_INITED();
567  double res = REAL(wcstod)(nptr, endptr);
568  __msan_unpoison(endptr, sizeof(*endptr));
569  return res;
570}
571
572INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
573  ENSURE_MSAN_INITED();
574  int res = REAL(gettimeofday)(tv, tz);
575  if (tv)
576    __msan_unpoison(tv, 16);
577  if (tz)
578    __msan_unpoison(tz, 8);
579  return res;
580}
581
582INTERCEPTOR(char *, fcvt, double x, int a, int *b, int *c) {
583  ENSURE_MSAN_INITED();
584  char *res = REAL(fcvt)(x, a, b, c);
585  if (!__msan_has_dynamic_component()) {
586    __msan_unpoison(b, sizeof(*b));
587    __msan_unpoison(c, sizeof(*c));
588  }
589  return res;
590}
591
592INTERCEPTOR(char *, getenv, char *name) {
593  ENSURE_MSAN_INITED();
594  char *res = REAL(getenv)(name);
595  if (!__msan_has_dynamic_component()) {
596    if (res)
597      __msan_unpoison(res, REAL(strlen)(res) + 1);
598  }
599  return res;
600}
601
602extern char **environ;
603
604static void UnpoisonEnviron() {
605  char **envp = environ;
606  for (; *envp; ++envp) {
607    __msan_unpoison(envp, sizeof(*envp));
608    __msan_unpoison(*envp, REAL(strlen)(*envp) + 1);
609  }
610  // Trailing NULL pointer.
611  __msan_unpoison(envp, sizeof(*envp));
612}
613
614INTERCEPTOR(int, setenv, const char *name, const char *value, int overwrite) {
615  ENSURE_MSAN_INITED();
616  int res = REAL(setenv)(name, value, overwrite);
617  if (!res) UnpoisonEnviron();
618  return res;
619}
620
621INTERCEPTOR(int, putenv, char *string) {
622  ENSURE_MSAN_INITED();
623  int res = REAL(putenv)(string);
624  if (!res) UnpoisonEnviron();
625  return res;
626}
627
628INTERCEPTOR(int, __fxstat, int magic, int fd, void *buf) {
629  ENSURE_MSAN_INITED();
630  int res = REAL(__fxstat)(magic, fd, buf);
631  if (!res)
632    __msan_unpoison(buf, __sanitizer::struct_stat_sz);
633  return res;
634}
635
636INTERCEPTOR(int, __fxstat64, int magic, int fd, void *buf) {
637  ENSURE_MSAN_INITED();
638  int res = REAL(__fxstat64)(magic, fd, buf);
639  if (!res)
640    __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
641  return res;
642}
643
644INTERCEPTOR(int, __fxstatat, int magic, int fd, char *pathname, void *buf,
645            int flags) {
646  ENSURE_MSAN_INITED();
647  int res = REAL(__fxstatat)(magic, fd, pathname, buf, flags);
648  if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
649  return res;
650}
651
652INTERCEPTOR(int, __fxstatat64, int magic, int fd, char *pathname, void *buf,
653            int flags) {
654  ENSURE_MSAN_INITED();
655  int res = REAL(__fxstatat64)(magic, fd, pathname, buf, flags);
656  if (!res) __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
657  return res;
658}
659
660INTERCEPTOR(int, __xstat, int magic, char *path, void *buf) {
661  ENSURE_MSAN_INITED();
662  int res = REAL(__xstat)(magic, path, buf);
663  if (!res)
664    __msan_unpoison(buf, __sanitizer::struct_stat_sz);
665  return res;
666}
667
668INTERCEPTOR(int, __xstat64, int magic, char *path, void *buf) {
669  ENSURE_MSAN_INITED();
670  int res = REAL(__xstat64)(magic, path, buf);
671  if (!res)
672    __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
673  return res;
674}
675
676INTERCEPTOR(int, __lxstat, int magic, char *path, void *buf) {
677  ENSURE_MSAN_INITED();
678  int res = REAL(__lxstat)(magic, path, buf);
679  if (!res)
680    __msan_unpoison(buf, __sanitizer::struct_stat_sz);
681  return res;
682}
683
684INTERCEPTOR(int, __lxstat64, int magic, char *path, void *buf) {
685  ENSURE_MSAN_INITED();
686  int res = REAL(__lxstat64)(magic, path, buf);
687  if (!res)
688    __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
689  return res;
690}
691
692INTERCEPTOR(int, pipe, int pipefd[2]) {
693  if (msan_init_is_running)
694    return REAL(pipe)(pipefd);
695  ENSURE_MSAN_INITED();
696  int res = REAL(pipe)(pipefd);
697  if (!res)
698    __msan_unpoison(pipefd, sizeof(int[2]));
699  return res;
700}
701
702INTERCEPTOR(int, pipe2, int pipefd[2], int flags) {
703  ENSURE_MSAN_INITED();
704  int res = REAL(pipe2)(pipefd, flags);
705  if (!res)
706    __msan_unpoison(pipefd, sizeof(int[2]));
707  return res;
708}
709
710INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int sv[2]) {
711  ENSURE_MSAN_INITED();
712  int res = REAL(socketpair)(domain, type, protocol, sv);
713  if (!res)
714    __msan_unpoison(sv, sizeof(int[2]));
715  return res;
716}
717
718INTERCEPTOR(char *, fgets, char *s, int size, void *stream) {
719  ENSURE_MSAN_INITED();
720  char *res = REAL(fgets)(s, size, stream);
721  if (res)
722    __msan_unpoison(s, REAL(strlen)(s) + 1);
723  return res;
724}
725
726INTERCEPTOR(char *, fgets_unlocked, char *s, int size, void *stream) {
727  ENSURE_MSAN_INITED();
728  char *res = REAL(fgets_unlocked)(s, size, stream);
729  if (res)
730    __msan_unpoison(s, REAL(strlen)(s) + 1);
731  return res;
732}
733
734INTERCEPTOR(int, getrlimit, int resource, void *rlim) {
735  if (msan_init_is_running)
736    return REAL(getrlimit)(resource, rlim);
737  ENSURE_MSAN_INITED();
738  int res = REAL(getrlimit)(resource, rlim);
739  if (!res)
740    __msan_unpoison(rlim, __sanitizer::struct_rlimit_sz);
741  return res;
742}
743
744INTERCEPTOR(int, getrlimit64, int resource, void *rlim) {
745  if (msan_init_is_running)
746    return REAL(getrlimit64)(resource, rlim);
747  ENSURE_MSAN_INITED();
748  int res = REAL(getrlimit64)(resource, rlim);
749  if (!res)
750    __msan_unpoison(rlim, __sanitizer::struct_rlimit64_sz);
751  return res;
752}
753
754INTERCEPTOR(int, uname, void *utsname) {
755  ENSURE_MSAN_INITED();
756  int res = REAL(uname)(utsname);
757  if (!res) {
758    __msan_unpoison(utsname, __sanitizer::struct_utsname_sz);
759  }
760  return res;
761}
762
763INTERCEPTOR(int, gethostname, char *name, SIZE_T len) {
764  ENSURE_MSAN_INITED();
765  int res = REAL(gethostname)(name, len);
766  if (!res) {
767    SIZE_T real_len = REAL(strnlen)(name, len);
768    if (real_len < len)
769      ++real_len;
770    __msan_unpoison(name, real_len);
771  }
772  return res;
773}
774
775INTERCEPTOR(int, epoll_wait, int epfd, void *events, int maxevents,
776    int timeout) {
777  ENSURE_MSAN_INITED();
778  int res = REAL(epoll_wait)(epfd, events, maxevents, timeout);
779  if (res > 0) {
780    __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
781  }
782  return res;
783}
784
785INTERCEPTOR(int, epoll_pwait, int epfd, void *events, int maxevents,
786    int timeout, void *sigmask) {
787  ENSURE_MSAN_INITED();
788  int res = REAL(epoll_pwait)(epfd, events, maxevents, timeout, sigmask);
789  if (res > 0) {
790    __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
791  }
792  return res;
793}
794
795INTERCEPTOR(SSIZE_T, recv, int fd, void *buf, SIZE_T len, int flags) {
796  ENSURE_MSAN_INITED();
797  SSIZE_T res = REAL(recv)(fd, buf, len, flags);
798  if (res > 0)
799    __msan_unpoison(buf, res);
800  return res;
801}
802
803INTERCEPTOR(SSIZE_T, recvfrom, int fd, void *buf, SIZE_T len, int flags,
804            void *srcaddr, int *addrlen) {
805  ENSURE_MSAN_INITED();
806  SIZE_T srcaddr_sz;
807  if (srcaddr) srcaddr_sz = *addrlen;
808  SSIZE_T res = REAL(recvfrom)(fd, buf, len, flags, srcaddr, addrlen);
809  if (res > 0) {
810    __msan_unpoison(buf, res);
811    if (srcaddr) {
812      SIZE_T sz = *addrlen;
813      __msan_unpoison(srcaddr, (sz < srcaddr_sz) ? sz : srcaddr_sz);
814    }
815  }
816  return res;
817}
818
819INTERCEPTOR(void *, calloc, SIZE_T nmemb, SIZE_T size) {
820  if (CallocShouldReturnNullDueToOverflow(size, nmemb))
821    return AllocatorReturnNull();
822  GET_MALLOC_STACK_TRACE;
823  if (!msan_inited) {
824    // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
825    const SIZE_T kCallocPoolSize = 1024;
826    static uptr calloc_memory_for_dlsym[kCallocPoolSize];
827    static SIZE_T allocated;
828    SIZE_T size_in_words = ((nmemb * size) + kWordSize - 1) / kWordSize;
829    void *mem = (void*)&calloc_memory_for_dlsym[allocated];
830    allocated += size_in_words;
831    CHECK(allocated < kCallocPoolSize);
832    return mem;
833  }
834  return MsanReallocate(&stack, 0, nmemb * size, sizeof(u64), true);
835}
836
837INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
838  GET_MALLOC_STACK_TRACE;
839  return MsanReallocate(&stack, ptr, size, sizeof(u64), false);
840}
841
842INTERCEPTOR(void *, malloc, SIZE_T size) {
843  GET_MALLOC_STACK_TRACE;
844  return MsanReallocate(&stack, 0, size, sizeof(u64), false);
845}
846
847void __msan_allocated_memory(const void* data, uptr size) {
848  GET_MALLOC_STACK_TRACE;
849  if (flags()->poison_in_malloc)
850    __msan_poison(data, size);
851  if (__msan_get_track_origins()) {
852    u32 stack_id = StackDepotPut(stack.trace, stack.size);
853    CHECK(stack_id);
854    CHECK_EQ((stack_id >> 31), 0);  // Higher bit is occupied by stack origins.
855    __msan_set_origin(data, size, stack_id);
856  }
857}
858
859INTERCEPTOR(void *, mmap, void *addr, SIZE_T length, int prot, int flags,
860            int fd, OFF_T offset) {
861  ENSURE_MSAN_INITED();
862  void *res = REAL(mmap)(addr, length, prot, flags, fd, offset);
863  if (res != (void*)-1)
864    __msan_unpoison(res, RoundUpTo(length, GetPageSize()));
865  return res;
866}
867
868INTERCEPTOR(void *, mmap64, void *addr, SIZE_T length, int prot, int flags,
869            int fd, OFF64_T offset) {
870  ENSURE_MSAN_INITED();
871  void *res = REAL(mmap64)(addr, length, prot, flags, fd, offset);
872  if (res != (void*)-1)
873    __msan_unpoison(res, RoundUpTo(length, GetPageSize()));
874  return res;
875}
876
877struct dlinfo {
878  char *dli_fname;
879  void *dli_fbase;
880  char *dli_sname;
881  void *dli_saddr;
882};
883
884INTERCEPTOR(int, dladdr, void *addr, dlinfo *info) {
885  ENSURE_MSAN_INITED();
886  int res = REAL(dladdr)(addr, info);
887  if (res != 0) {
888    __msan_unpoison(info, sizeof(*info));
889    if (info->dli_fname)
890      __msan_unpoison(info->dli_fname, REAL(strlen)(info->dli_fname) + 1);
891    if (info->dli_sname)
892      __msan_unpoison(info->dli_sname, REAL(strlen)(info->dli_sname) + 1);
893  }
894  return res;
895}
896
897// dlopen() ultimately calls mmap() down inside the loader, which generally
898// doesn't participate in dynamic symbol resolution.  Therefore we won't
899// intercept its calls to mmap, and we have to hook it here.  The loader
900// initializes the module before returning, so without the dynamic component, we
901// won't be able to clear the shadow before the initializers.  Fixing this would
902// require putting our own initializer first to clear the shadow.
903INTERCEPTOR(void *, dlopen, const char *filename, int flag) {
904  ENSURE_MSAN_INITED();
905  EnterLoader();
906  link_map *map = (link_map *)REAL(dlopen)(filename, flag);
907  ExitLoader();
908  if (!__msan_has_dynamic_component() && map) {
909    // If msandr didn't clear the shadow before the initializers ran, we do it
910    // ourselves afterwards.
911    ForEachMappedRegion(map, __msan_unpoison);
912  }
913  return (void *)map;
914}
915
916typedef int (*dl_iterate_phdr_cb)(__sanitizer_dl_phdr_info *info, SIZE_T size,
917                                  void *data);
918struct dl_iterate_phdr_data {
919  dl_iterate_phdr_cb callback;
920  void *data;
921};
922
923static int msan_dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
924                                   void *data) {
925  if (info) {
926    __msan_unpoison(info, size);
927    if (info->dlpi_name)
928      __msan_unpoison(info->dlpi_name, REAL(strlen)(info->dlpi_name) + 1);
929  }
930  dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
931  UnpoisonParam(3);
932  return cbdata->callback(info, size, cbdata->data);
933}
934
935INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb callback, void *data) {
936  ENSURE_MSAN_INITED();
937  EnterLoader();
938  dl_iterate_phdr_data cbdata;
939  cbdata.callback = callback;
940  cbdata.data = data;
941  int res = REAL(dl_iterate_phdr)(msan_dl_iterate_phdr_cb, (void *)&cbdata);
942  ExitLoader();
943  return res;
944}
945
946INTERCEPTOR(int, getrusage, int who, void *usage) {
947  ENSURE_MSAN_INITED();
948  int res = REAL(getrusage)(who, usage);
949  if (res == 0) {
950    __msan_unpoison(usage, __sanitizer::struct_rusage_sz);
951  }
952  return res;
953}
954
955// sigactions_mu guarantees atomicity of sigaction() and signal() calls.
956// Access to sigactions[] is gone with relaxed atomics to avoid data race with
957// the signal handler.
958const int kMaxSignals = 1024;
959static atomic_uintptr_t sigactions[kMaxSignals];
960static StaticSpinMutex sigactions_mu;
961
962static void SignalHandler(int signo) {
963  ScopedThreadLocalStateBackup stlsb;
964  UnpoisonParam(1);
965
966  typedef void (*signal_cb)(int x);
967  signal_cb cb =
968      (signal_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
969  cb(signo);
970}
971
972static void SignalAction(int signo, void *si, void *uc) {
973  ScopedThreadLocalStateBackup stlsb;
974  UnpoisonParam(3);
975  __msan_unpoison(si, sizeof(__sanitizer_sigaction));
976  __msan_unpoison(uc, __sanitizer::ucontext_t_sz);
977
978  typedef void (*sigaction_cb)(int, void *, void *);
979  sigaction_cb cb =
980      (sigaction_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
981  cb(signo, si, uc);
982}
983
984INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
985            __sanitizer_sigaction *oldact) {
986  ENSURE_MSAN_INITED();
987  // FIXME: check that *act is unpoisoned.
988  // That requires intercepting all of sigemptyset, sigfillset, etc.
989  int res;
990  if (flags()->wrap_signals) {
991    SpinMutexLock lock(&sigactions_mu);
992    CHECK_LT(signo, kMaxSignals);
993    uptr old_cb = atomic_load(&sigactions[signo], memory_order_relaxed);
994    __sanitizer_sigaction new_act;
995    __sanitizer_sigaction *pnew_act = act ? &new_act : 0;
996    if (act) {
997      internal_memcpy(pnew_act, act, sizeof(__sanitizer_sigaction));
998      uptr cb = (uptr)pnew_act->sa_sigaction;
999      uptr new_cb = (pnew_act->sa_flags & __sanitizer::sa_siginfo)
1000                        ? (uptr)SignalAction
1001                        : (uptr)SignalHandler;
1002      if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1003        atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1004        pnew_act->sa_sigaction = (void (*)(int, void *, void *))new_cb;
1005      }
1006    }
1007    res = REAL(sigaction)(signo, pnew_act, oldact);
1008    if (res == 0 && oldact) {
1009      uptr cb = (uptr)oldact->sa_sigaction;
1010      if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1011        oldact->sa_sigaction = (void (*)(int, void *, void *))old_cb;
1012      }
1013    }
1014  } else {
1015    res = REAL(sigaction)(signo, act, oldact);
1016  }
1017
1018  if (res == 0 && oldact) {
1019    __msan_unpoison(oldact, sizeof(__sanitizer_sigaction));
1020  }
1021  return res;
1022}
1023
1024INTERCEPTOR(int, signal, int signo, uptr cb) {
1025  ENSURE_MSAN_INITED();
1026  if (flags()->wrap_signals) {
1027    CHECK_LT(signo, kMaxSignals);
1028    SpinMutexLock lock(&sigactions_mu);
1029    if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1030      atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1031      cb = (uptr) SignalHandler;
1032    }
1033    return REAL(signal)(signo, cb);
1034  } else {
1035    return REAL(signal)(signo, cb);
1036  }
1037}
1038
1039extern "C" int pthread_attr_init(void *attr);
1040extern "C" int pthread_attr_destroy(void *attr);
1041extern "C" int pthread_attr_setstacksize(void *attr, uptr stacksize);
1042extern "C" int pthread_attr_getstack(void *attr, uptr *stack, uptr *stacksize);
1043
1044INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*),
1045            void * param) {
1046  ENSURE_MSAN_INITED(); // for GetTlsSize()
1047  __sanitizer_pthread_attr_t myattr;
1048  if (attr == 0) {
1049    pthread_attr_init(&myattr);
1050    attr = &myattr;
1051  }
1052
1053  AdjustStackSizeLinux(attr);
1054
1055  int res = REAL(pthread_create)(th, attr, callback, param);
1056  if (attr == &myattr)
1057    pthread_attr_destroy(&myattr);
1058  if (!res) {
1059    __msan_unpoison(th, __sanitizer::pthread_t_sz);
1060  }
1061  return res;
1062}
1063
1064INTERCEPTOR(int, pthread_key_create, __sanitizer_pthread_key_t *key,
1065            void (*dtor)(void *value)) {
1066  ENSURE_MSAN_INITED();
1067  int res = REAL(pthread_key_create)(key, dtor);
1068  if (!res && key)
1069    __msan_unpoison(key, sizeof(*key));
1070  return res;
1071}
1072
1073INTERCEPTOR(int, pthread_join, void *th, void **retval) {
1074  ENSURE_MSAN_INITED();
1075  int res = REAL(pthread_join)(th, retval);
1076  if (!res && retval)
1077    __msan_unpoison(retval, sizeof(*retval));
1078  return res;
1079}
1080
1081extern char *tzname[2];
1082
1083INTERCEPTOR(void, tzset) {
1084  ENSURE_MSAN_INITED();
1085  REAL(tzset)();
1086  if (tzname[0])
1087    __msan_unpoison(tzname[0], REAL(strlen)(tzname[0]) + 1);
1088  if (tzname[1])
1089    __msan_unpoison(tzname[1], REAL(strlen)(tzname[1]) + 1);
1090  return;
1091}
1092
1093struct MSanAtExitRecord {
1094  void (*func)(void *arg);
1095  void *arg;
1096};
1097
1098void MSanAtExitWrapper(void *arg) {
1099  UnpoisonParam(1);
1100  MSanAtExitRecord *r = (MSanAtExitRecord *)arg;
1101  r->func(r->arg);
1102  InternalFree(r);
1103}
1104
1105// Unpoison argument shadow for C++ module destructors.
1106INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
1107            void *dso_handle) {
1108  if (msan_init_is_running) return REAL(__cxa_atexit)(func, arg, dso_handle);
1109  ENSURE_MSAN_INITED();
1110  MSanAtExitRecord *r =
1111      (MSanAtExitRecord *)InternalAlloc(sizeof(MSanAtExitRecord));
1112  r->func = func;
1113  r->arg = arg;
1114  return REAL(__cxa_atexit)(MSanAtExitWrapper, r, dso_handle);
1115}
1116
1117struct MSanInterceptorContext {
1118  bool in_interceptor_scope;
1119};
1120
1121namespace __msan {
1122
1123int OnExit() {
1124  // FIXME: ask frontend whether we need to return failure.
1125  return 0;
1126}
1127
1128}  // namespace __msan
1129
1130// A version of CHECK_UNPOISED using a saved scope value. Used in common
1131// interceptors.
1132#define CHECK_UNPOISONED_CTX(ctx, x, n)                         \
1133  do {                                                          \
1134    if (!((MSanInterceptorContext *)ctx)->in_interceptor_scope) \
1135      CHECK_UNPOISONED_0(x, n);                                 \
1136  } while (0)
1137
1138#define COMMON_INTERCEPTOR_UNPOISON_PARAM(ctx, count)  \
1139  UnpoisonParam(count)
1140#define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
1141  __msan_unpoison(ptr, size)
1142#define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
1143  CHECK_UNPOISONED_CTX(ctx, ptr, size)
1144#define COMMON_INTERCEPTOR_INITIALIZE_RANGE(ctx, ptr, size) \
1145  __msan_unpoison(ptr, size)
1146#define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)              \
1147  if (msan_init_is_running) return REAL(func)(__VA_ARGS__);   \
1148  MSanInterceptorContext msan_ctx = {IsInInterceptorScope()}; \
1149  ctx = (void *)&msan_ctx;                                    \
1150  (void)ctx;                                                  \
1151  InterceptorScope interceptor_scope;                         \
1152  ENSURE_MSAN_INITED();
1153#define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
1154  do {                                         \
1155  } while (false)
1156#define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
1157  do {                                         \
1158  } while (false)
1159#define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
1160  do {                                                      \
1161  } while (false)
1162#define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
1163  do {                                                \
1164  } while (false)  // FIXME
1165#define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
1166#define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
1167#include "sanitizer_common/sanitizer_common_interceptors.inc"
1168
1169#define COMMON_SYSCALL_PRE_READ_RANGE(p, s) CHECK_UNPOISONED(p, s)
1170#define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
1171  do {                                       \
1172  } while (false)
1173#define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
1174  do {                                       \
1175  } while (false)
1176#define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) __msan_unpoison(p, s)
1177#include "sanitizer_common/sanitizer_common_syscalls.inc"
1178
1179// static
1180void *fast_memset(void *ptr, int c, SIZE_T n) {
1181  // hack until we have a really fast internal_memset
1182  if (sizeof(uptr) == 8 &&
1183      (n % 8) == 0 &&
1184      ((uptr)ptr % 8) == 0 &&
1185      (c == 0 || c == -1)) {
1186    // Printf("memset %p %zd %x\n", ptr, n, c);
1187    uptr to_store = c ? -1L : 0L;
1188    uptr *p = (uptr*)ptr;
1189    for (SIZE_T i = 0; i < n / 8; i++)
1190      p[i] = to_store;
1191    return ptr;
1192  }
1193  return internal_memset(ptr, c, n);
1194}
1195
1196// static
1197void *fast_memcpy(void *dst, const void *src, SIZE_T n) {
1198  // Same hack as in fast_memset above.
1199  if (sizeof(uptr) == 8 &&
1200      (n % 8) == 0 &&
1201      ((uptr)dst % 8) == 0 &&
1202      ((uptr)src % 8) == 0) {
1203    uptr *d = (uptr*)dst;
1204    uptr *s = (uptr*)src;
1205    for (SIZE_T i = 0; i < n / 8; i++)
1206      d[i] = s[i];
1207    return dst;
1208  }
1209  return internal_memcpy(dst, src, n);
1210}
1211
1212// These interface functions reside here so that they can use
1213// fast_memset, etc.
1214void __msan_unpoison(const void *a, uptr size) {
1215  if (!MEM_IS_APP(a)) return;
1216  fast_memset((void*)MEM_TO_SHADOW((uptr)a), 0, size);
1217}
1218
1219void __msan_poison(const void *a, uptr size) {
1220  if (!MEM_IS_APP(a)) return;
1221  fast_memset((void*)MEM_TO_SHADOW((uptr)a),
1222              __msan::flags()->poison_heap_with_zeroes ? 0 : -1, size);
1223}
1224
1225void __msan_poison_stack(void *a, uptr size) {
1226  if (!MEM_IS_APP(a)) return;
1227  fast_memset((void*)MEM_TO_SHADOW((uptr)a),
1228              __msan::flags()->poison_stack_with_zeroes ? 0 : -1, size);
1229}
1230
1231void __msan_clear_and_unpoison(void *a, uptr size) {
1232  fast_memset(a, 0, size);
1233  fast_memset((void*)MEM_TO_SHADOW((uptr)a), 0, size);
1234}
1235
1236void __msan_copy_origin(void *dst, const void *src, uptr size) {
1237  if (!__msan_get_track_origins()) return;
1238  if (!MEM_IS_APP(dst) || !MEM_IS_APP(src)) return;
1239  uptr d = MEM_TO_ORIGIN(dst);
1240  uptr s = MEM_TO_ORIGIN(src);
1241  uptr beg = d & ~3UL;  // align down.
1242  uptr end = (d + size + 3) & ~3UL;  // align up.
1243  s = s & ~3UL;  // align down.
1244  fast_memcpy((void*)beg, (void*)s, end - beg);
1245}
1246
1247void __msan_copy_poison(void *dst, const void *src, uptr size) {
1248  if (!MEM_IS_APP(dst)) return;
1249  if (!MEM_IS_APP(src)) return;
1250  fast_memcpy((void*)MEM_TO_SHADOW((uptr)dst),
1251              (void*)MEM_TO_SHADOW((uptr)src), size);
1252  __msan_copy_origin(dst, src, size);
1253}
1254
1255void __msan_move_poison(void *dst, const void *src, uptr size) {
1256  if (!MEM_IS_APP(dst)) return;
1257  if (!MEM_IS_APP(src)) return;
1258  internal_memmove((void*)MEM_TO_SHADOW((uptr)dst),
1259         (void*)MEM_TO_SHADOW((uptr)src), size);
1260  __msan_copy_origin(dst, src, size);
1261}
1262
1263void *__msan_memcpy(void *dest, const void *src, SIZE_T n) {
1264  ENSURE_MSAN_INITED();
1265  void *res = fast_memcpy(dest, src, n);
1266  __msan_copy_poison(dest, src, n);
1267  return res;
1268}
1269
1270void *__msan_memset(void *s, int c, SIZE_T n) {
1271  ENSURE_MSAN_INITED();
1272  void *res = fast_memset(s, c, n);
1273  __msan_unpoison(s, n);
1274  return res;
1275}
1276
1277void *__msan_memmove(void *dest, const void *src, SIZE_T n) {
1278  ENSURE_MSAN_INITED();
1279  void *res = REAL(memmove)(dest, src, n);
1280  __msan_move_poison(dest, src, n);
1281  return res;
1282}
1283
1284namespace __msan {
1285void InitializeInterceptors() {
1286  static int inited = 0;
1287  CHECK_EQ(inited, 0);
1288  SANITIZER_COMMON_INTERCEPTORS_INIT;
1289
1290  INTERCEPT_FUNCTION(mmap);
1291  INTERCEPT_FUNCTION(mmap64);
1292  INTERCEPT_FUNCTION(posix_memalign);
1293  INTERCEPT_FUNCTION(memalign);
1294  INTERCEPT_FUNCTION(valloc);
1295  INTERCEPT_FUNCTION(pvalloc);
1296  INTERCEPT_FUNCTION(malloc);
1297  INTERCEPT_FUNCTION(calloc);
1298  INTERCEPT_FUNCTION(realloc);
1299  INTERCEPT_FUNCTION(free);
1300  INTERCEPT_FUNCTION(fread);
1301  INTERCEPT_FUNCTION(fread_unlocked);
1302  INTERCEPT_FUNCTION(readlink);
1303  INTERCEPT_FUNCTION(memcpy);
1304  INTERCEPT_FUNCTION(mempcpy);
1305  INTERCEPT_FUNCTION(memset);
1306  INTERCEPT_FUNCTION(memmove);
1307  INTERCEPT_FUNCTION(bcopy);
1308  INTERCEPT_FUNCTION(wmemset);
1309  INTERCEPT_FUNCTION(wmemcpy);
1310  INTERCEPT_FUNCTION(wmempcpy);
1311  INTERCEPT_FUNCTION(wmemmove);
1312  INTERCEPT_FUNCTION(strcpy);  // NOLINT
1313  INTERCEPT_FUNCTION(stpcpy);  // NOLINT
1314  INTERCEPT_FUNCTION(strdup);
1315  INTERCEPT_FUNCTION(__strdup);
1316  INTERCEPT_FUNCTION(strndup);
1317  INTERCEPT_FUNCTION(__strndup);
1318  INTERCEPT_FUNCTION(strncpy);  // NOLINT
1319  INTERCEPT_FUNCTION(strlen);
1320  INTERCEPT_FUNCTION(strnlen);
1321  INTERCEPT_FUNCTION(gcvt);
1322  INTERCEPT_FUNCTION(strcat);  // NOLINT
1323  INTERCEPT_FUNCTION(strncat);  // NOLINT
1324  INTERCEPT_FUNCTION(strtol);
1325  INTERCEPT_FUNCTION(strtoll);
1326  INTERCEPT_FUNCTION(strtoul);
1327  INTERCEPT_FUNCTION(strtoull);
1328  INTERCEPT_FUNCTION(strtod);
1329  INTERCEPT_FUNCTION(strtod_l);
1330  INTERCEPT_FUNCTION(__strtod_l);
1331  INTERCEPT_FUNCTION(strtof);
1332  INTERCEPT_FUNCTION(strtof_l);
1333  INTERCEPT_FUNCTION(__strtof_l);
1334  INTERCEPT_FUNCTION(strtold);
1335  INTERCEPT_FUNCTION(strtold_l);
1336  INTERCEPT_FUNCTION(__strtold_l);
1337  INTERCEPT_FUNCTION(vasprintf);
1338  INTERCEPT_FUNCTION(asprintf);
1339  INTERCEPT_FUNCTION(vsprintf);
1340  INTERCEPT_FUNCTION(vsnprintf);
1341  INTERCEPT_FUNCTION(vswprintf);
1342  INTERCEPT_FUNCTION(sprintf);  // NOLINT
1343  INTERCEPT_FUNCTION(snprintf);
1344  INTERCEPT_FUNCTION(swprintf);
1345  INTERCEPT_FUNCTION(strftime);
1346  INTERCEPT_FUNCTION(mbtowc);
1347  INTERCEPT_FUNCTION(mbrtowc);
1348  INTERCEPT_FUNCTION(wcslen);
1349  INTERCEPT_FUNCTION(wcschr);
1350  INTERCEPT_FUNCTION(wcscpy);
1351  INTERCEPT_FUNCTION(wcscmp);
1352  INTERCEPT_FUNCTION(wcstod);
1353  INTERCEPT_FUNCTION(getenv);
1354  INTERCEPT_FUNCTION(setenv);
1355  INTERCEPT_FUNCTION(putenv);
1356  INTERCEPT_FUNCTION(gettimeofday);
1357  INTERCEPT_FUNCTION(fcvt);
1358  INTERCEPT_FUNCTION(__fxstat);
1359  INTERCEPT_FUNCTION(__fxstatat);
1360  INTERCEPT_FUNCTION(__xstat);
1361  INTERCEPT_FUNCTION(__lxstat);
1362  INTERCEPT_FUNCTION(__fxstat64);
1363  INTERCEPT_FUNCTION(__fxstatat64);
1364  INTERCEPT_FUNCTION(__xstat64);
1365  INTERCEPT_FUNCTION(__lxstat64);
1366  INTERCEPT_FUNCTION(pipe);
1367  INTERCEPT_FUNCTION(pipe2);
1368  INTERCEPT_FUNCTION(socketpair);
1369  INTERCEPT_FUNCTION(fgets);
1370  INTERCEPT_FUNCTION(fgets_unlocked);
1371  INTERCEPT_FUNCTION(getrlimit);
1372  INTERCEPT_FUNCTION(getrlimit64);
1373  INTERCEPT_FUNCTION(uname);
1374  INTERCEPT_FUNCTION(gethostname);
1375  INTERCEPT_FUNCTION(epoll_wait);
1376  INTERCEPT_FUNCTION(epoll_pwait);
1377  INTERCEPT_FUNCTION(recv);
1378  INTERCEPT_FUNCTION(recvfrom);
1379  INTERCEPT_FUNCTION(dladdr);
1380  INTERCEPT_FUNCTION(dlopen);
1381  INTERCEPT_FUNCTION(dl_iterate_phdr);
1382  INTERCEPT_FUNCTION(getrusage);
1383  INTERCEPT_FUNCTION(sigaction);
1384  INTERCEPT_FUNCTION(signal);
1385  INTERCEPT_FUNCTION(pthread_create);
1386  INTERCEPT_FUNCTION(pthread_key_create);
1387  INTERCEPT_FUNCTION(pthread_join);
1388  INTERCEPT_FUNCTION(tzset);
1389  INTERCEPT_FUNCTION(__cxa_atexit);
1390  inited = 1;
1391}
1392}  // namespace __msan
1393