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 #include "interception/interception.h"
18 #include "msan.h"
19 #include "msan_chained_origin_depot.h"
20 #include "msan_origin.h"
21 #include "msan_report.h"
22 #include "msan_thread.h"
23 #include "msan_poisoning.h"
24 #include "sanitizer_common/sanitizer_errno_codes.h"
25 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
26 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
27 #include "sanitizer_common/sanitizer_allocator.h"
28 #include "sanitizer_common/sanitizer_allocator_interface.h"
29 #include "sanitizer_common/sanitizer_allocator_internal.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_stackdepot.h"
34 #include "sanitizer_common/sanitizer_libc.h"
35 #include "sanitizer_common/sanitizer_linux.h"
36 #include "sanitizer_common/sanitizer_glibc_version.h"
37 #include "sanitizer_common/sanitizer_tls_get_addr.h"
38 #include "sanitizer_common/sanitizer_vector.h"
39 
40 #if SANITIZER_NETBSD
41 #define fstat __fstat50
42 #define gettimeofday __gettimeofday50
43 #define getrusage __getrusage50
44 #define tzset __tzset50
45 #endif
46 
47 #include <stdarg.h>
48 // ACHTUNG! No other system header includes in this file.
49 // Ideally, we should get rid of stdarg.h as well.
50 
51 using namespace __msan;
52 
53 using __sanitizer::memory_order;
54 using __sanitizer::atomic_load;
55 using __sanitizer::atomic_store;
56 using __sanitizer::atomic_uintptr_t;
57 
58 DECLARE_REAL(SIZE_T, strlen, const char *s)
59 DECLARE_REAL(SIZE_T, strnlen, const char *s, SIZE_T maxlen)
60 DECLARE_REAL(void *, memcpy, void *dest, const void *src, uptr n)
61 DECLARE_REAL(void *, memset, void *dest, int c, uptr n)
62 
63 // True if this is a nested interceptor.
64 static THREADLOCAL int in_interceptor_scope;
65 
__msan_scoped_disable_interceptor_checks()66 void __msan_scoped_disable_interceptor_checks() { ++in_interceptor_scope; }
__msan_scoped_enable_interceptor_checks()67 void __msan_scoped_enable_interceptor_checks() { --in_interceptor_scope; }
68 
69 struct InterceptorScope {
InterceptorScopeInterceptorScope70   InterceptorScope() { ++in_interceptor_scope; }
~InterceptorScopeInterceptorScope71   ~InterceptorScope() { --in_interceptor_scope; }
72 };
73 
IsInInterceptorScope()74 bool IsInInterceptorScope() {
75   return in_interceptor_scope;
76 }
77 
78 static uptr allocated_for_dlsym;
79 static const uptr kDlsymAllocPoolSize = 1024;
80 static uptr alloc_memory_for_dlsym[kDlsymAllocPoolSize];
81 
IsInDlsymAllocPool(const void * ptr)82 static bool IsInDlsymAllocPool(const void *ptr) {
83   uptr off = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
84   return off < sizeof(alloc_memory_for_dlsym);
85 }
86 
AllocateFromLocalPool(uptr size_in_bytes)87 static void *AllocateFromLocalPool(uptr size_in_bytes) {
88   uptr size_in_words = RoundUpTo(size_in_bytes, kWordSize) / kWordSize;
89   void *mem = (void *)&alloc_memory_for_dlsym[allocated_for_dlsym];
90   allocated_for_dlsym += size_in_words;
91   CHECK_LT(allocated_for_dlsym, kDlsymAllocPoolSize);
92   return mem;
93 }
94 
95 #define ENSURE_MSAN_INITED() do { \
96   CHECK(!msan_init_is_running); \
97   if (!msan_inited) { \
98     __msan_init(); \
99   } \
100 } while (0)
101 
102 // Check that [x, x+n) range is unpoisoned.
103 #define CHECK_UNPOISONED_0(x, n)                                  \
104   do {                                                            \
105     sptr __offset = __msan_test_shadow(x, n);                     \
106     if (__msan::IsInSymbolizer()) break;                          \
107     if (__offset >= 0 && __msan::flags()->report_umrs) {          \
108       GET_CALLER_PC_BP_SP;                                        \
109       (void)sp;                                                   \
110       ReportUMRInsideAddressRange(__func__, x, n, __offset);      \
111       __msan::PrintWarningWithOrigin(                             \
112           pc, bp, __msan_get_origin((const char *)x + __offset)); \
113       if (__msan::flags()->halt_on_error) {                       \
114         Printf("Exiting\n");                                      \
115         Die();                                                    \
116       }                                                           \
117     }                                                             \
118   } while (0)
119 
120 // Check that [x, x+n) range is unpoisoned unless we are in a nested
121 // interceptor.
122 #define CHECK_UNPOISONED(x, n)                             \
123   do {                                                     \
124     if (!IsInInterceptorScope()) CHECK_UNPOISONED_0(x, n); \
125   } while (0)
126 
127 #define CHECK_UNPOISONED_STRING_OF_LEN(x, len, n)               \
128   CHECK_UNPOISONED((x),                                         \
129     common_flags()->strict_string_checks ? (len) + 1 : (n) )
130 
131 #define CHECK_UNPOISONED_STRING(x, n)                           \
132     CHECK_UNPOISONED_STRING_OF_LEN((x), internal_strlen(x), (n))
133 
134 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(SIZE_T,fread_unlocked,void * ptr,SIZE_T size,SIZE_T nmemb,void * file)135 INTERCEPTOR(SIZE_T, fread_unlocked, void *ptr, SIZE_T size, SIZE_T nmemb,
136             void *file) {
137   ENSURE_MSAN_INITED();
138   SIZE_T res = REAL(fread_unlocked)(ptr, size, nmemb, file);
139   if (res > 0)
140     __msan_unpoison(ptr, res *size);
141   return res;
142 }
143 #define MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED INTERCEPT_FUNCTION(fread_unlocked)
144 #else
145 #define MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED
146 #endif
147 
148 #if !SANITIZER_NETBSD
INTERCEPTOR(void *,mempcpy,void * dest,const void * src,SIZE_T n)149 INTERCEPTOR(void *, mempcpy, void *dest, const void *src, SIZE_T n) {
150   return (char *)__msan_memcpy(dest, src, n) + n;
151 }
152 #define MSAN_MAYBE_INTERCEPT_MEMPCPY INTERCEPT_FUNCTION(mempcpy)
153 #else
154 #define MSAN_MAYBE_INTERCEPT_MEMPCPY
155 #endif
156 
INTERCEPTOR(void *,memccpy,void * dest,const void * src,int c,SIZE_T n)157 INTERCEPTOR(void *, memccpy, void *dest, const void *src, int c, SIZE_T n) {
158   ENSURE_MSAN_INITED();
159   void *res = REAL(memccpy)(dest, src, c, n);
160   CHECK(!res || (res >= dest && res <= (char *)dest + n));
161   SIZE_T sz = res ? (char *)res - (char *)dest : n;
162   CHECK_UNPOISONED(src, sz);
163   __msan_unpoison(dest, sz);
164   return res;
165 }
166 
INTERCEPTOR(void *,bcopy,const void * src,void * dest,SIZE_T n)167 INTERCEPTOR(void *, bcopy, const void *src, void *dest, SIZE_T n) {
168   return __msan_memmove(dest, src, n);
169 }
170 
INTERCEPTOR(int,posix_memalign,void ** memptr,SIZE_T alignment,SIZE_T size)171 INTERCEPTOR(int, posix_memalign, void **memptr, SIZE_T alignment, SIZE_T size) {
172   GET_MALLOC_STACK_TRACE;
173   CHECK_NE(memptr, 0);
174   int res = msan_posix_memalign(memptr, alignment, size, &stack);
175   if (!res)
176     __msan_unpoison(memptr, sizeof(*memptr));
177   return res;
178 }
179 
180 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(void *,memalign,SIZE_T alignment,SIZE_T size)181 INTERCEPTOR(void *, memalign, SIZE_T alignment, SIZE_T size) {
182   GET_MALLOC_STACK_TRACE;
183   return msan_memalign(alignment, size, &stack);
184 }
185 #define MSAN_MAYBE_INTERCEPT_MEMALIGN INTERCEPT_FUNCTION(memalign)
186 #else
187 #define MSAN_MAYBE_INTERCEPT_MEMALIGN
188 #endif
189 
INTERCEPTOR(void *,aligned_alloc,SIZE_T alignment,SIZE_T size)190 INTERCEPTOR(void *, aligned_alloc, SIZE_T alignment, SIZE_T size) {
191   GET_MALLOC_STACK_TRACE;
192   return msan_aligned_alloc(alignment, size, &stack);
193 }
194 
195 #if !SANITIZER_NETBSD
INTERCEPTOR(void *,__libc_memalign,SIZE_T alignment,SIZE_T size)196 INTERCEPTOR(void *, __libc_memalign, SIZE_T alignment, SIZE_T size) {
197   GET_MALLOC_STACK_TRACE;
198   void *ptr = msan_memalign(alignment, size, &stack);
199   if (ptr)
200     DTLS_on_libc_memalign(ptr, size);
201   return ptr;
202 }
203 #define MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN INTERCEPT_FUNCTION(__libc_memalign)
204 #else
205 #define MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN
206 #endif
207 
INTERCEPTOR(void *,valloc,SIZE_T size)208 INTERCEPTOR(void *, valloc, SIZE_T size) {
209   GET_MALLOC_STACK_TRACE;
210   return msan_valloc(size, &stack);
211 }
212 
213 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(void *,pvalloc,SIZE_T size)214 INTERCEPTOR(void *, pvalloc, SIZE_T size) {
215   GET_MALLOC_STACK_TRACE;
216   return msan_pvalloc(size, &stack);
217 }
218 #define MSAN_MAYBE_INTERCEPT_PVALLOC INTERCEPT_FUNCTION(pvalloc)
219 #else
220 #define MSAN_MAYBE_INTERCEPT_PVALLOC
221 #endif
222 
INTERCEPTOR(void,free,void * ptr)223 INTERCEPTOR(void, free, void *ptr) {
224   GET_MALLOC_STACK_TRACE;
225   if (!ptr || UNLIKELY(IsInDlsymAllocPool(ptr))) return;
226   MsanDeallocate(&stack, ptr);
227 }
228 
229 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(void,cfree,void * ptr)230 INTERCEPTOR(void, cfree, void *ptr) {
231   GET_MALLOC_STACK_TRACE;
232   if (!ptr || UNLIKELY(IsInDlsymAllocPool(ptr))) return;
233   MsanDeallocate(&stack, ptr);
234 }
235 #define MSAN_MAYBE_INTERCEPT_CFREE INTERCEPT_FUNCTION(cfree)
236 #else
237 #define MSAN_MAYBE_INTERCEPT_CFREE
238 #endif
239 
240 #if !SANITIZER_NETBSD
INTERCEPTOR(uptr,malloc_usable_size,void * ptr)241 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
242   return __sanitizer_get_allocated_size(ptr);
243 }
244 #define MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE \
245   INTERCEPT_FUNCTION(malloc_usable_size)
246 #else
247 #define MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE
248 #endif
249 
250 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
251 // This function actually returns a struct by value, but we can't unpoison a
252 // temporary! The following is equivalent on all supported platforms but
253 // aarch64 (which uses a different register for sret value).  We have a test
254 // to confirm that.
INTERCEPTOR(void,mallinfo,__sanitizer_struct_mallinfo * sret)255 INTERCEPTOR(void, mallinfo, __sanitizer_struct_mallinfo *sret) {
256 #ifdef __aarch64__
257   uptr r8;
258   asm volatile("mov %0,x8" : "=r" (r8));
259   sret = reinterpret_cast<__sanitizer_struct_mallinfo*>(r8);
260 #endif
261   REAL(memset)(sret, 0, sizeof(*sret));
262   __msan_unpoison(sret, sizeof(*sret));
263 }
264 #define MSAN_MAYBE_INTERCEPT_MALLINFO INTERCEPT_FUNCTION(mallinfo)
265 #else
266 #define MSAN_MAYBE_INTERCEPT_MALLINFO
267 #endif
268 
269 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,mallopt,int cmd,int value)270 INTERCEPTOR(int, mallopt, int cmd, int value) {
271   return 0;
272 }
273 #define MSAN_MAYBE_INTERCEPT_MALLOPT INTERCEPT_FUNCTION(mallopt)
274 #else
275 #define MSAN_MAYBE_INTERCEPT_MALLOPT
276 #endif
277 
278 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(void,malloc_stats,void)279 INTERCEPTOR(void, malloc_stats, void) {
280   // FIXME: implement, but don't call REAL(malloc_stats)!
281 }
282 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS INTERCEPT_FUNCTION(malloc_stats)
283 #else
284 #define MSAN_MAYBE_INTERCEPT_MALLOC_STATS
285 #endif
286 
INTERCEPTOR(char *,strcpy,char * dest,const char * src)287 INTERCEPTOR(char *, strcpy, char *dest, const char *src) {
288   ENSURE_MSAN_INITED();
289   GET_STORE_STACK_TRACE;
290   SIZE_T n = REAL(strlen)(src);
291   CHECK_UNPOISONED_STRING(src + n, 0);
292   char *res = REAL(strcpy)(dest, src);
293   CopyShadowAndOrigin(dest, src, n + 1, &stack);
294   return res;
295 }
296 
INTERCEPTOR(char *,strncpy,char * dest,const char * src,SIZE_T n)297 INTERCEPTOR(char *, strncpy, char *dest, const char *src, SIZE_T n) {
298   ENSURE_MSAN_INITED();
299   GET_STORE_STACK_TRACE;
300   SIZE_T copy_size = REAL(strnlen)(src, n);
301   if (copy_size < n)
302     copy_size++;  // trailing \0
303   char *res = REAL(strncpy)(dest, src, n);
304   CopyShadowAndOrigin(dest, src, copy_size, &stack);
305   __msan_unpoison(dest + copy_size, n - copy_size);
306   return res;
307 }
308 
309 #if !SANITIZER_NETBSD
INTERCEPTOR(char *,stpcpy,char * dest,const char * src)310 INTERCEPTOR(char *, stpcpy, char *dest, const char *src) {
311   ENSURE_MSAN_INITED();
312   GET_STORE_STACK_TRACE;
313   SIZE_T n = REAL(strlen)(src);
314   CHECK_UNPOISONED_STRING(src + n, 0);
315   char *res = REAL(stpcpy)(dest, src);
316   CopyShadowAndOrigin(dest, src, n + 1, &stack);
317   return res;
318 }
319 #define MSAN_MAYBE_INTERCEPT_STPCPY INTERCEPT_FUNCTION(stpcpy)
320 #else
321 #define MSAN_MAYBE_INTERCEPT_STPCPY
322 #endif
323 
INTERCEPTOR(char *,strdup,char * src)324 INTERCEPTOR(char *, strdup, char *src) {
325   ENSURE_MSAN_INITED();
326   GET_STORE_STACK_TRACE;
327   // On FreeBSD strdup() leverages strlen().
328   InterceptorScope interceptor_scope;
329   SIZE_T n = REAL(strlen)(src);
330   CHECK_UNPOISONED_STRING(src + n, 0);
331   char *res = REAL(strdup)(src);
332   CopyShadowAndOrigin(res, src, n + 1, &stack);
333   return res;
334 }
335 
336 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(char *,__strdup,char * src)337 INTERCEPTOR(char *, __strdup, char *src) {
338   ENSURE_MSAN_INITED();
339   GET_STORE_STACK_TRACE;
340   SIZE_T n = REAL(strlen)(src);
341   CHECK_UNPOISONED_STRING(src + n, 0);
342   char *res = REAL(__strdup)(src);
343   CopyShadowAndOrigin(res, src, n + 1, &stack);
344   return res;
345 }
346 #define MSAN_MAYBE_INTERCEPT___STRDUP INTERCEPT_FUNCTION(__strdup)
347 #else
348 #define MSAN_MAYBE_INTERCEPT___STRDUP
349 #endif
350 
351 #if !SANITIZER_NETBSD
INTERCEPTOR(char *,gcvt,double number,SIZE_T ndigit,char * buf)352 INTERCEPTOR(char *, gcvt, double number, SIZE_T ndigit, char *buf) {
353   ENSURE_MSAN_INITED();
354   char *res = REAL(gcvt)(number, ndigit, buf);
355   SIZE_T n = REAL(strlen)(buf);
356   __msan_unpoison(buf, n + 1);
357   return res;
358 }
359 #define MSAN_MAYBE_INTERCEPT_GCVT INTERCEPT_FUNCTION(gcvt)
360 #else
361 #define MSAN_MAYBE_INTERCEPT_GCVT
362 #endif
363 
INTERCEPTOR(char *,strcat,char * dest,const char * src)364 INTERCEPTOR(char *, strcat, char *dest, const char *src) {
365   ENSURE_MSAN_INITED();
366   GET_STORE_STACK_TRACE;
367   SIZE_T src_size = REAL(strlen)(src);
368   SIZE_T dest_size = REAL(strlen)(dest);
369   CHECK_UNPOISONED_STRING(src + src_size, 0);
370   CHECK_UNPOISONED_STRING(dest + dest_size, 0);
371   char *res = REAL(strcat)(dest, src);
372   CopyShadowAndOrigin(dest + dest_size, src, src_size + 1, &stack);
373   return res;
374 }
375 
INTERCEPTOR(char *,strncat,char * dest,const char * src,SIZE_T n)376 INTERCEPTOR(char *, strncat, char *dest, const char *src, SIZE_T n) {
377   ENSURE_MSAN_INITED();
378   GET_STORE_STACK_TRACE;
379   SIZE_T dest_size = REAL(strlen)(dest);
380   SIZE_T copy_size = REAL(strnlen)(src, n);
381   CHECK_UNPOISONED_STRING(dest + dest_size, 0);
382   char *res = REAL(strncat)(dest, src, n);
383   CopyShadowAndOrigin(dest + dest_size, src, copy_size, &stack);
384   __msan_unpoison(dest + dest_size + copy_size, 1); // \0
385   return res;
386 }
387 
388 // Hack: always pass nptr and endptr as part of __VA_ARGS_ to avoid having to
389 // deal with empty __VA_ARGS__ in the case of INTERCEPTOR_STRTO.
390 #define INTERCEPTOR_STRTO_BODY(ret_type, func, ...) \
391   ENSURE_MSAN_INITED();                             \
392   ret_type res = REAL(func)(__VA_ARGS__);           \
393   __msan_unpoison(endptr, sizeof(*endptr));         \
394   return res;
395 
396 #define INTERCEPTOR_STRTO(ret_type, func, char_type)                       \
397   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr) { \
398     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr);                  \
399   }
400 
401 #define INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)                \
402   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
403               int base) {                                                \
404     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, base);          \
405   }
406 
407 #define INTERCEPTOR_STRTO_LOC(ret_type, func, char_type)                 \
408   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
409               void *loc) {                                               \
410     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, loc);           \
411   }
412 
413 #define INTERCEPTOR_STRTO_BASE_LOC(ret_type, func, char_type)            \
414   INTERCEPTOR(ret_type, func, const char_type *nptr, char_type **endptr, \
415               int base, void *loc) {                                     \
416     INTERCEPTOR_STRTO_BODY(ret_type, func, nptr, endptr, base, loc);     \
417   }
418 
419 #if SANITIZER_NETBSD
420 #define INTERCEPTORS_STRTO(ret_type, func, char_type)      \
421   INTERCEPTOR_STRTO(ret_type, func, char_type)             \
422   INTERCEPTOR_STRTO_LOC(ret_type, func##_l, char_type)
423 
424 #define INTERCEPTORS_STRTO_BASE(ret_type, func, char_type)      \
425   INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)             \
426   INTERCEPTOR_STRTO_BASE_LOC(ret_type, func##_l, char_type)
427 
428 #else
429 #define INTERCEPTORS_STRTO(ret_type, func, char_type)      \
430   INTERCEPTOR_STRTO(ret_type, func, char_type)             \
431   INTERCEPTOR_STRTO_LOC(ret_type, func##_l, char_type)     \
432   INTERCEPTOR_STRTO_LOC(ret_type, __##func##_l, char_type) \
433   INTERCEPTOR_STRTO_LOC(ret_type, __##func##_internal, char_type)
434 
435 #define INTERCEPTORS_STRTO_BASE(ret_type, func, char_type)      \
436   INTERCEPTOR_STRTO_BASE(ret_type, func, char_type)             \
437   INTERCEPTOR_STRTO_BASE_LOC(ret_type, func##_l, char_type)     \
438   INTERCEPTOR_STRTO_BASE_LOC(ret_type, __##func##_l, char_type) \
439   INTERCEPTOR_STRTO_BASE_LOC(ret_type, __##func##_internal, char_type)
440 #endif
441 
INTERCEPTORS_STRTO(double,strtod,char)442 INTERCEPTORS_STRTO(double, strtod, char)
443 INTERCEPTORS_STRTO(float, strtof, char)
444 INTERCEPTORS_STRTO(long double, strtold, char)
445 INTERCEPTORS_STRTO_BASE(long, strtol, char)
446 INTERCEPTORS_STRTO_BASE(long long, strtoll, char)
447 INTERCEPTORS_STRTO_BASE(unsigned long, strtoul, char)
448 INTERCEPTORS_STRTO_BASE(unsigned long long, strtoull, char)
449 INTERCEPTORS_STRTO_BASE(u64, strtouq, char)
450 
451 INTERCEPTORS_STRTO(double, wcstod, wchar_t)
452 INTERCEPTORS_STRTO(float, wcstof, wchar_t)
453 INTERCEPTORS_STRTO(long double, wcstold, wchar_t)
454 INTERCEPTORS_STRTO_BASE(long, wcstol, wchar_t)
455 INTERCEPTORS_STRTO_BASE(long long, wcstoll, wchar_t)
456 INTERCEPTORS_STRTO_BASE(unsigned long, wcstoul, wchar_t)
457 INTERCEPTORS_STRTO_BASE(unsigned long long, wcstoull, wchar_t)
458 
459 #if SANITIZER_NETBSD
460 #define INTERCEPT_STRTO(func) \
461   INTERCEPT_FUNCTION(func); \
462   INTERCEPT_FUNCTION(func##_l);
463 #else
464 #define INTERCEPT_STRTO(func) \
465   INTERCEPT_FUNCTION(func); \
466   INTERCEPT_FUNCTION(func##_l); \
467   INTERCEPT_FUNCTION(__##func##_l); \
468   INTERCEPT_FUNCTION(__##func##_internal);
469 #endif
470 
471 
472 // FIXME: support *wprintf in common format interceptors.
473 INTERCEPTOR(int, vswprintf, void *str, uptr size, void *format, va_list ap) {
474   ENSURE_MSAN_INITED();
475   int res = REAL(vswprintf)(str, size, format, ap);
476   if (res >= 0) {
477     __msan_unpoison(str, 4 * (res + 1));
478   }
479   return res;
480 }
481 
INTERCEPTOR(int,swprintf,void * str,uptr size,void * format,...)482 INTERCEPTOR(int, swprintf, void *str, uptr size, void *format, ...) {
483   ENSURE_MSAN_INITED();
484   va_list ap;
485   va_start(ap, format);
486   int res = vswprintf(str, size, format, ap);
487   va_end(ap);
488   return res;
489 }
490 
491 #define INTERCEPTOR_STRFTIME_BODY(char_type, ret_type, func, s, ...) \
492   ENSURE_MSAN_INITED();                                              \
493   InterceptorScope interceptor_scope;                                \
494   ret_type res = REAL(func)(s, __VA_ARGS__);                         \
495   if (s) __msan_unpoison(s, sizeof(char_type) * (res + 1));          \
496   return res;
497 
INTERCEPTOR(SIZE_T,strftime,char * s,SIZE_T max,const char * format,__sanitizer_tm * tm)498 INTERCEPTOR(SIZE_T, strftime, char *s, SIZE_T max, const char *format,
499             __sanitizer_tm *tm) {
500   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, strftime, s, max, format, tm);
501 }
502 
INTERCEPTOR(SIZE_T,strftime_l,char * s,SIZE_T max,const char * format,__sanitizer_tm * tm,void * loc)503 INTERCEPTOR(SIZE_T, strftime_l, char *s, SIZE_T max, const char *format,
504             __sanitizer_tm *tm, void *loc) {
505   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, strftime_l, s, max, format, tm, loc);
506 }
507 
508 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(SIZE_T,__strftime_l,char * s,SIZE_T max,const char * format,__sanitizer_tm * tm,void * loc)509 INTERCEPTOR(SIZE_T, __strftime_l, char *s, SIZE_T max, const char *format,
510             __sanitizer_tm *tm, void *loc) {
511   INTERCEPTOR_STRFTIME_BODY(char, SIZE_T, __strftime_l, s, max, format, tm,
512                             loc);
513 }
514 #define MSAN_MAYBE_INTERCEPT___STRFTIME_L INTERCEPT_FUNCTION(__strftime_l)
515 #else
516 #define MSAN_MAYBE_INTERCEPT___STRFTIME_L
517 #endif
518 
INTERCEPTOR(SIZE_T,wcsftime,wchar_t * s,SIZE_T max,const wchar_t * format,__sanitizer_tm * tm)519 INTERCEPTOR(SIZE_T, wcsftime, wchar_t *s, SIZE_T max, const wchar_t *format,
520             __sanitizer_tm *tm) {
521   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, wcsftime, s, max, format, tm);
522 }
523 
INTERCEPTOR(SIZE_T,wcsftime_l,wchar_t * s,SIZE_T max,const wchar_t * format,__sanitizer_tm * tm,void * loc)524 INTERCEPTOR(SIZE_T, wcsftime_l, wchar_t *s, SIZE_T max, const wchar_t *format,
525             __sanitizer_tm *tm, void *loc) {
526   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, wcsftime_l, s, max, format, tm,
527                             loc);
528 }
529 
530 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(SIZE_T,__wcsftime_l,wchar_t * s,SIZE_T max,const wchar_t * format,__sanitizer_tm * tm,void * loc)531 INTERCEPTOR(SIZE_T, __wcsftime_l, wchar_t *s, SIZE_T max, const wchar_t *format,
532             __sanitizer_tm *tm, void *loc) {
533   INTERCEPTOR_STRFTIME_BODY(wchar_t, SIZE_T, __wcsftime_l, s, max, format, tm,
534                             loc);
535 }
536 #define MSAN_MAYBE_INTERCEPT___WCSFTIME_L INTERCEPT_FUNCTION(__wcsftime_l)
537 #else
538 #define MSAN_MAYBE_INTERCEPT___WCSFTIME_L
539 #endif
540 
INTERCEPTOR(int,mbtowc,wchar_t * dest,const char * src,SIZE_T n)541 INTERCEPTOR(int, mbtowc, wchar_t *dest, const char *src, SIZE_T n) {
542   ENSURE_MSAN_INITED();
543   int res = REAL(mbtowc)(dest, src, n);
544   if (res != -1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
545   return res;
546 }
547 
INTERCEPTOR(SIZE_T,mbrtowc,wchar_t * dest,const char * src,SIZE_T n,void * ps)548 INTERCEPTOR(SIZE_T, mbrtowc, wchar_t *dest, const char *src, SIZE_T n,
549             void *ps) {
550   ENSURE_MSAN_INITED();
551   SIZE_T res = REAL(mbrtowc)(dest, src, n, ps);
552   if (res != (SIZE_T)-1 && dest) __msan_unpoison(dest, sizeof(wchar_t));
553   return res;
554 }
555 
556 // wchar_t *wmemcpy(wchar_t *dest, const wchar_t *src, SIZE_T n);
INTERCEPTOR(wchar_t *,wmemcpy,wchar_t * dest,const wchar_t * src,SIZE_T n)557 INTERCEPTOR(wchar_t *, wmemcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
558   ENSURE_MSAN_INITED();
559   GET_STORE_STACK_TRACE;
560   wchar_t *res = REAL(wmemcpy)(dest, src, n);
561   CopyShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
562   return res;
563 }
564 
565 #if !SANITIZER_NETBSD
INTERCEPTOR(wchar_t *,wmempcpy,wchar_t * dest,const wchar_t * src,SIZE_T n)566 INTERCEPTOR(wchar_t *, wmempcpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
567   ENSURE_MSAN_INITED();
568   GET_STORE_STACK_TRACE;
569   wchar_t *res = REAL(wmempcpy)(dest, src, n);
570   CopyShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
571   return res;
572 }
573 #define MSAN_MAYBE_INTERCEPT_WMEMPCPY INTERCEPT_FUNCTION(wmempcpy)
574 #else
575 #define MSAN_MAYBE_INTERCEPT_WMEMPCPY
576 #endif
577 
INTERCEPTOR(wchar_t *,wmemset,wchar_t * s,wchar_t c,SIZE_T n)578 INTERCEPTOR(wchar_t *, wmemset, wchar_t *s, wchar_t c, SIZE_T n) {
579   CHECK(MEM_IS_APP(s));
580   ENSURE_MSAN_INITED();
581   wchar_t *res = REAL(wmemset)(s, c, n);
582   __msan_unpoison(s, n * sizeof(wchar_t));
583   return res;
584 }
585 
INTERCEPTOR(wchar_t *,wmemmove,wchar_t * dest,const wchar_t * src,SIZE_T n)586 INTERCEPTOR(wchar_t *, wmemmove, wchar_t *dest, const wchar_t *src, SIZE_T n) {
587   ENSURE_MSAN_INITED();
588   GET_STORE_STACK_TRACE;
589   wchar_t *res = REAL(wmemmove)(dest, src, n);
590   MoveShadowAndOrigin(dest, src, n * sizeof(wchar_t), &stack);
591   return res;
592 }
593 
INTERCEPTOR(int,wcscmp,const wchar_t * s1,const wchar_t * s2)594 INTERCEPTOR(int, wcscmp, const wchar_t *s1, const wchar_t *s2) {
595   ENSURE_MSAN_INITED();
596   int res = REAL(wcscmp)(s1, s2);
597   return res;
598 }
599 
INTERCEPTOR(int,gettimeofday,void * tv,void * tz)600 INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
601   ENSURE_MSAN_INITED();
602   int res = REAL(gettimeofday)(tv, tz);
603   if (tv)
604     __msan_unpoison(tv, 16);
605   if (tz)
606     __msan_unpoison(tz, 8);
607   return res;
608 }
609 
610 #if !SANITIZER_NETBSD
INTERCEPTOR(char *,fcvt,double x,int a,int * b,int * c)611 INTERCEPTOR(char *, fcvt, double x, int a, int *b, int *c) {
612   ENSURE_MSAN_INITED();
613   char *res = REAL(fcvt)(x, a, b, c);
614   __msan_unpoison(b, sizeof(*b));
615   __msan_unpoison(c, sizeof(*c));
616   if (res) __msan_unpoison(res, REAL(strlen)(res) + 1);
617   return res;
618 }
619 #define MSAN_MAYBE_INTERCEPT_FCVT INTERCEPT_FUNCTION(fcvt)
620 #else
621 #define MSAN_MAYBE_INTERCEPT_FCVT
622 #endif
623 
INTERCEPTOR(char *,getenv,char * name)624 INTERCEPTOR(char *, getenv, char *name) {
625   if (msan_init_is_running)
626     return REAL(getenv)(name);
627   ENSURE_MSAN_INITED();
628   char *res = REAL(getenv)(name);
629   if (res) __msan_unpoison(res, REAL(strlen)(res) + 1);
630   return res;
631 }
632 
633 extern char **environ;
634 
UnpoisonEnviron()635 static void UnpoisonEnviron() {
636   char **envp = environ;
637   for (; *envp; ++envp) {
638     __msan_unpoison(envp, sizeof(*envp));
639     __msan_unpoison(*envp, REAL(strlen)(*envp) + 1);
640   }
641   // Trailing NULL pointer.
642   __msan_unpoison(envp, sizeof(*envp));
643 }
644 
INTERCEPTOR(int,setenv,const char * name,const char * value,int overwrite)645 INTERCEPTOR(int, setenv, const char *name, const char *value, int overwrite) {
646   ENSURE_MSAN_INITED();
647   CHECK_UNPOISONED_STRING(name, 0);
648   int res = REAL(setenv)(name, value, overwrite);
649   if (!res) UnpoisonEnviron();
650   return res;
651 }
652 
INTERCEPTOR(int,putenv,char * string)653 INTERCEPTOR(int, putenv, char *string) {
654   ENSURE_MSAN_INITED();
655   int res = REAL(putenv)(string);
656   if (!res) UnpoisonEnviron();
657   return res;
658 }
659 
660 #define SANITIZER_STAT_LINUX (SANITIZER_LINUX && __GLIBC_PREREQ(2, 33))
661 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
INTERCEPTOR(int,fstat,int fd,void * buf)662 INTERCEPTOR(int, fstat, int fd, void *buf) {
663   ENSURE_MSAN_INITED();
664   int res = REAL(fstat)(fd, buf);
665   if (!res)
666     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
667   return res;
668 }
669 #  define MSAN_MAYBE_INTERCEPT_FSTAT MSAN_INTERCEPT_FUNC(fstat)
670 #else
671 #define MSAN_MAYBE_INTERCEPT_FSTAT
672 #endif
673 
674 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,__fxstat,int magic,int fd,void * buf)675 INTERCEPTOR(int, __fxstat, int magic, int fd, void *buf) {
676   ENSURE_MSAN_INITED();
677   int res = REAL(__fxstat)(magic, fd, buf);
678   if (!res)
679     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
680   return res;
681 }
682 #  define MSAN_MAYBE_INTERCEPT___FXSTAT MSAN_INTERCEPT_FUNC(__fxstat)
683 #else
684 #define MSAN_MAYBE_INTERCEPT___FXSTAT
685 #endif
686 
687 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,__fxstat64,int magic,int fd,void * buf)688 INTERCEPTOR(int, __fxstat64, int magic, int fd, void *buf) {
689   ENSURE_MSAN_INITED();
690   int res = REAL(__fxstat64)(magic, fd, buf);
691   if (!res)
692     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
693   return res;
694 }
695 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64 MSAN_INTERCEPT_FUNC(__fxstat64)
696 #else
697 #  define MSAN_MAYBE_INTERCEPT___FXSTAT64
698 #endif
699 
700 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_STAT_LINUX
INTERCEPTOR(int,fstatat,int fd,char * pathname,void * buf,int flags)701 INTERCEPTOR(int, fstatat, int fd, char *pathname, void *buf, int flags) {
702   ENSURE_MSAN_INITED();
703   int res = REAL(fstatat)(fd, pathname, buf, flags);
704   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
705   return res;
706 }
707 #  define MSAN_MAYBE_INTERCEPT_FSTATAT MSAN_INTERCEPT_FUNC(fstatat)
708 #else
709 #  define MSAN_MAYBE_INTERCEPT_FSTATAT
710 #endif
711 
712 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,__fxstatat,int magic,int fd,char * pathname,void * buf,int flags)713 INTERCEPTOR(int, __fxstatat, int magic, int fd, char *pathname, void *buf,
714             int flags) {
715   ENSURE_MSAN_INITED();
716   int res = REAL(__fxstatat)(magic, fd, pathname, buf, flags);
717   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
718   return res;
719 }
720 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT MSAN_INTERCEPT_FUNC(__fxstatat)
721 #else
722 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT
723 #endif
724 
725 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,__fxstatat64,int magic,int fd,char * pathname,void * buf,int flags)726 INTERCEPTOR(int, __fxstatat64, int magic, int fd, char *pathname, void *buf,
727             int flags) {
728   ENSURE_MSAN_INITED();
729   int res = REAL(__fxstatat64)(magic, fd, pathname, buf, flags);
730   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
731   return res;
732 }
733 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64 MSAN_INTERCEPT_FUNC(__fxstatat64)
734 #else
735 #  define MSAN_MAYBE_INTERCEPT___FXSTATAT64
736 #endif
737 
INTERCEPTOR(int,pipe,int pipefd[2])738 INTERCEPTOR(int, pipe, int pipefd[2]) {
739   if (msan_init_is_running)
740     return REAL(pipe)(pipefd);
741   ENSURE_MSAN_INITED();
742   int res = REAL(pipe)(pipefd);
743   if (!res)
744     __msan_unpoison(pipefd, sizeof(int[2]));
745   return res;
746 }
747 
INTERCEPTOR(int,pipe2,int pipefd[2],int flags)748 INTERCEPTOR(int, pipe2, int pipefd[2], int flags) {
749   ENSURE_MSAN_INITED();
750   int res = REAL(pipe2)(pipefd, flags);
751   if (!res)
752     __msan_unpoison(pipefd, sizeof(int[2]));
753   return res;
754 }
755 
INTERCEPTOR(int,socketpair,int domain,int type,int protocol,int sv[2])756 INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int sv[2]) {
757   ENSURE_MSAN_INITED();
758   int res = REAL(socketpair)(domain, type, protocol, sv);
759   if (!res)
760     __msan_unpoison(sv, sizeof(int[2]));
761   return res;
762 }
763 
764 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(char *,fgets_unlocked,char * s,int size,void * stream)765 INTERCEPTOR(char *, fgets_unlocked, char *s, int size, void *stream) {
766   ENSURE_MSAN_INITED();
767   char *res = REAL(fgets_unlocked)(s, size, stream);
768   if (res)
769     __msan_unpoison(s, REAL(strlen)(s) + 1);
770   return res;
771 }
772 #define MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED INTERCEPT_FUNCTION(fgets_unlocked)
773 #else
774 #define MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED
775 #endif
776 
777 #define INTERCEPTOR_GETRLIMIT_BODY(func, resource, rlim)  \
778   if (msan_init_is_running)                               \
779     return REAL(getrlimit)(resource, rlim);               \
780   ENSURE_MSAN_INITED();                                   \
781   int res = REAL(func)(resource, rlim);                   \
782   if (!res)                                               \
783     __msan_unpoison(rlim, __sanitizer::struct_rlimit_sz); \
784   return res
785 
INTERCEPTOR(int,getrlimit,int resource,void * rlim)786 INTERCEPTOR(int, getrlimit, int resource, void *rlim) {
787   INTERCEPTOR_GETRLIMIT_BODY(getrlimit, resource, rlim);
788 }
789 
790 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,__getrlimit,int resource,void * rlim)791 INTERCEPTOR(int, __getrlimit, int resource, void *rlim) {
792   INTERCEPTOR_GETRLIMIT_BODY(__getrlimit, resource, rlim);
793 }
794 
INTERCEPTOR(int,getrlimit64,int resource,void * rlim)795 INTERCEPTOR(int, getrlimit64, int resource, void *rlim) {
796   if (msan_init_is_running) return REAL(getrlimit64)(resource, rlim);
797   ENSURE_MSAN_INITED();
798   int res = REAL(getrlimit64)(resource, rlim);
799   if (!res) __msan_unpoison(rlim, __sanitizer::struct_rlimit64_sz);
800   return res;
801 }
802 
INTERCEPTOR(int,prlimit,int pid,int resource,void * new_rlimit,void * old_rlimit)803 INTERCEPTOR(int, prlimit, int pid, int resource, void *new_rlimit,
804             void *old_rlimit) {
805   if (msan_init_is_running)
806     return REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
807   ENSURE_MSAN_INITED();
808   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit_sz);
809   int res = REAL(prlimit)(pid, resource, new_rlimit, old_rlimit);
810   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit_sz);
811   return res;
812 }
813 
INTERCEPTOR(int,prlimit64,int pid,int resource,void * new_rlimit,void * old_rlimit)814 INTERCEPTOR(int, prlimit64, int pid, int resource, void *new_rlimit,
815             void *old_rlimit) {
816   if (msan_init_is_running)
817     return REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
818   ENSURE_MSAN_INITED();
819   CHECK_UNPOISONED(new_rlimit, __sanitizer::struct_rlimit64_sz);
820   int res = REAL(prlimit64)(pid, resource, new_rlimit, old_rlimit);
821   if (!res) __msan_unpoison(old_rlimit, __sanitizer::struct_rlimit64_sz);
822   return res;
823 }
824 
825 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT INTERCEPT_FUNCTION(__getrlimit)
826 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64 INTERCEPT_FUNCTION(getrlimit64)
827 #define MSAN_MAYBE_INTERCEPT_PRLIMIT INTERCEPT_FUNCTION(prlimit)
828 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64 INTERCEPT_FUNCTION(prlimit64)
829 #else
830 #define MSAN_MAYBE_INTERCEPT___GETRLIMIT
831 #define MSAN_MAYBE_INTERCEPT_GETRLIMIT64
832 #define MSAN_MAYBE_INTERCEPT_PRLIMIT
833 #define MSAN_MAYBE_INTERCEPT_PRLIMIT64
834 #endif
835 
INTERCEPTOR(int,gethostname,char * name,SIZE_T len)836 INTERCEPTOR(int, gethostname, char *name, SIZE_T len) {
837   ENSURE_MSAN_INITED();
838   int res = REAL(gethostname)(name, len);
839   if (!res || (res == -1 && errno == errno_ENAMETOOLONG)) {
840     SIZE_T real_len = REAL(strnlen)(name, len);
841     if (real_len < len)
842       ++real_len;
843     __msan_unpoison(name, real_len);
844   }
845   return res;
846 }
847 
848 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,epoll_wait,int epfd,void * events,int maxevents,int timeout)849 INTERCEPTOR(int, epoll_wait, int epfd, void *events, int maxevents,
850     int timeout) {
851   ENSURE_MSAN_INITED();
852   int res = REAL(epoll_wait)(epfd, events, maxevents, timeout);
853   if (res > 0) {
854     __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
855   }
856   return res;
857 }
858 #define MSAN_MAYBE_INTERCEPT_EPOLL_WAIT INTERCEPT_FUNCTION(epoll_wait)
859 #else
860 #define MSAN_MAYBE_INTERCEPT_EPOLL_WAIT
861 #endif
862 
863 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
INTERCEPTOR(int,epoll_pwait,int epfd,void * events,int maxevents,int timeout,void * sigmask)864 INTERCEPTOR(int, epoll_pwait, int epfd, void *events, int maxevents,
865     int timeout, void *sigmask) {
866   ENSURE_MSAN_INITED();
867   int res = REAL(epoll_pwait)(epfd, events, maxevents, timeout, sigmask);
868   if (res > 0) {
869     __msan_unpoison(events, __sanitizer::struct_epoll_event_sz * res);
870   }
871   return res;
872 }
873 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT INTERCEPT_FUNCTION(epoll_pwait)
874 #else
875 #define MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT
876 #endif
877 
INTERCEPTOR(void *,calloc,SIZE_T nmemb,SIZE_T size)878 INTERCEPTOR(void *, calloc, SIZE_T nmemb, SIZE_T size) {
879   GET_MALLOC_STACK_TRACE;
880   if (UNLIKELY(!msan_inited))
881     // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
882     return AllocateFromLocalPool(nmemb * size);
883   return msan_calloc(nmemb, size, &stack);
884 }
885 
INTERCEPTOR(void *,realloc,void * ptr,SIZE_T size)886 INTERCEPTOR(void *, realloc, void *ptr, SIZE_T size) {
887   GET_MALLOC_STACK_TRACE;
888   if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
889     uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
890     uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
891     void *new_ptr;
892     if (UNLIKELY(!msan_inited)) {
893       new_ptr = AllocateFromLocalPool(copy_size);
894     } else {
895       copy_size = size;
896       new_ptr = msan_malloc(copy_size, &stack);
897     }
898     internal_memcpy(new_ptr, ptr, copy_size);
899     return new_ptr;
900   }
901   return msan_realloc(ptr, size, &stack);
902 }
903 
INTERCEPTOR(void *,reallocarray,void * ptr,SIZE_T nmemb,SIZE_T size)904 INTERCEPTOR(void *, reallocarray, void *ptr, SIZE_T nmemb, SIZE_T size) {
905   GET_MALLOC_STACK_TRACE;
906   return msan_reallocarray(ptr, nmemb, size, &stack);
907 }
908 
INTERCEPTOR(void *,malloc,SIZE_T size)909 INTERCEPTOR(void *, malloc, SIZE_T size) {
910   GET_MALLOC_STACK_TRACE;
911   if (UNLIKELY(!msan_inited))
912     // Hack: dlsym calls malloc before REAL(malloc) is retrieved from dlsym.
913     return AllocateFromLocalPool(size);
914   return msan_malloc(size, &stack);
915 }
916 
__msan_allocated_memory(const void * data,uptr size)917 void __msan_allocated_memory(const void *data, uptr size) {
918   GET_MALLOC_STACK_TRACE;
919   if (flags()->poison_in_malloc) {
920     stack.tag = STACK_TRACE_TAG_POISON;
921     PoisonMemory(data, size, &stack);
922   }
923 }
924 
__msan_copy_shadow(void * dest,const void * src,uptr n)925 void __msan_copy_shadow(void *dest, const void *src, uptr n) {
926   GET_STORE_STACK_TRACE;
927   MoveShadowAndOrigin(dest, src, n, &stack);
928 }
929 
__sanitizer_dtor_callback(const void * data,uptr size)930 void __sanitizer_dtor_callback(const void *data, uptr size) {
931   GET_MALLOC_STACK_TRACE;
932   if (flags()->poison_in_dtor) {
933     stack.tag = STACK_TRACE_TAG_POISON;
934     PoisonMemory(data, size, &stack);
935   }
936 }
937 
938 template <class Mmap>
mmap_interceptor(Mmap real_mmap,void * addr,SIZE_T length,int prot,int flags,int fd,OFF64_T offset)939 static void *mmap_interceptor(Mmap real_mmap, void *addr, SIZE_T length,
940                               int prot, int flags, int fd, OFF64_T offset) {
941   SIZE_T rounded_length = RoundUpTo(length, GetPageSize());
942   void *end_addr = (char *)addr + (rounded_length - 1);
943   if (addr && (!MEM_IS_APP(addr) || !MEM_IS_APP(end_addr))) {
944     if (flags & map_fixed) {
945       errno = errno_EINVAL;
946       return (void *)-1;
947     } else {
948       addr = nullptr;
949     }
950   }
951   void *res = real_mmap(addr, length, prot, flags, fd, offset);
952   if (res != (void *)-1) {
953     void *end_res = (char *)res + (rounded_length - 1);
954     if (MEM_IS_APP(res) && MEM_IS_APP(end_res)) {
955       __msan_unpoison(res, rounded_length);
956     } else {
957       // Application has attempted to map more memory than is supported by
958       // MSAN. Act as if we ran out of memory.
959       internal_munmap(res, length);
960       errno = errno_ENOMEM;
961       return (void *)-1;
962     }
963   }
964   return res;
965 }
966 
INTERCEPTOR(int,getrusage,int who,void * usage)967 INTERCEPTOR(int, getrusage, int who, void *usage) {
968   ENSURE_MSAN_INITED();
969   int res = REAL(getrusage)(who, usage);
970   if (res == 0) {
971     __msan_unpoison(usage, __sanitizer::struct_rusage_sz);
972   }
973   return res;
974 }
975 
976 class SignalHandlerScope {
977  public:
SignalHandlerScope()978   SignalHandlerScope() {
979     if (MsanThread *t = GetCurrentThread())
980       t->EnterSignalHandler();
981   }
~SignalHandlerScope()982   ~SignalHandlerScope() {
983     if (MsanThread *t = GetCurrentThread())
984       t->LeaveSignalHandler();
985   }
986 };
987 
988 // sigactions_mu guarantees atomicity of sigaction() and signal() calls.
989 // Access to sigactions[] is gone with relaxed atomics to avoid data race with
990 // the signal handler.
991 const int kMaxSignals = 1024;
992 static atomic_uintptr_t sigactions[kMaxSignals];
993 static StaticSpinMutex sigactions_mu;
994 
SignalHandler(int signo)995 static void SignalHandler(int signo) {
996   SignalHandlerScope signal_handler_scope;
997   ScopedThreadLocalStateBackup stlsb;
998   UnpoisonParam(1);
999 
1000   typedef void (*signal_cb)(int x);
1001   signal_cb cb =
1002       (signal_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
1003   cb(signo);
1004 }
1005 
SignalAction(int signo,void * si,void * uc)1006 static void SignalAction(int signo, void *si, void *uc) {
1007   SignalHandlerScope signal_handler_scope;
1008   ScopedThreadLocalStateBackup stlsb;
1009   UnpoisonParam(3);
1010   __msan_unpoison(si, sizeof(__sanitizer_sigaction));
1011   __msan_unpoison(uc, __sanitizer::ucontext_t_sz);
1012 
1013   typedef void (*sigaction_cb)(int, void *, void *);
1014   sigaction_cb cb =
1015       (sigaction_cb)atomic_load(&sigactions[signo], memory_order_relaxed);
1016   cb(signo, si, uc);
1017 }
1018 
read_sigaction(const __sanitizer_sigaction * act)1019 static void read_sigaction(const __sanitizer_sigaction *act) {
1020   CHECK_UNPOISONED(&act->sa_flags, sizeof(act->sa_flags));
1021   if (act->sa_flags & __sanitizer::sa_siginfo)
1022     CHECK_UNPOISONED(&act->sigaction, sizeof(act->sigaction));
1023   else
1024     CHECK_UNPOISONED(&act->handler, sizeof(act->handler));
1025   CHECK_UNPOISONED(&act->sa_mask, sizeof(act->sa_mask));
1026 }
1027 
1028 extern "C" int pthread_attr_init(void *attr);
1029 extern "C" int pthread_attr_destroy(void *attr);
1030 
MsanThreadStartFunc(void * arg)1031 static void *MsanThreadStartFunc(void *arg) {
1032   MsanThread *t = (MsanThread *)arg;
1033   SetCurrentThread(t);
1034   return t->ThreadStart();
1035 }
1036 
INTERCEPTOR(int,pthread_create,void * th,void * attr,void * (* callback)(void *),void * param)1037 INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*),
1038             void * param) {
1039   ENSURE_MSAN_INITED(); // for GetTlsSize()
1040   __sanitizer_pthread_attr_t myattr;
1041   if (!attr) {
1042     pthread_attr_init(&myattr);
1043     attr = &myattr;
1044   }
1045 
1046   AdjustStackSize(attr);
1047 
1048   MsanThread *t = MsanThread::Create(callback, param);
1049 
1050   int res = REAL(pthread_create)(th, attr, MsanThreadStartFunc, t);
1051 
1052   if (attr == &myattr)
1053     pthread_attr_destroy(&myattr);
1054   if (!res) {
1055     __msan_unpoison(th, __sanitizer::pthread_t_sz);
1056   }
1057   return res;
1058 }
1059 
INTERCEPTOR(int,pthread_key_create,__sanitizer_pthread_key_t * key,void (* dtor)(void * value))1060 INTERCEPTOR(int, pthread_key_create, __sanitizer_pthread_key_t *key,
1061             void (*dtor)(void *value)) {
1062   if (msan_init_is_running) return REAL(pthread_key_create)(key, dtor);
1063   ENSURE_MSAN_INITED();
1064   int res = REAL(pthread_key_create)(key, dtor);
1065   if (!res && key)
1066     __msan_unpoison(key, sizeof(*key));
1067   return res;
1068 }
1069 
1070 #if SANITIZER_NETBSD
1071 INTERCEPTOR(int, __libc_thr_keycreate, __sanitizer_pthread_key_t *m,
1072             void (*dtor)(void *value))
1073 ALIAS(WRAPPER_NAME(pthread_key_create));
1074 #endif
1075 
INTERCEPTOR(int,pthread_join,void * th,void ** retval)1076 INTERCEPTOR(int, pthread_join, void *th, void **retval) {
1077   ENSURE_MSAN_INITED();
1078   int res = REAL(pthread_join)(th, retval);
1079   if (!res && retval)
1080     __msan_unpoison(retval, sizeof(*retval));
1081   return res;
1082 }
1083 
1084 extern char *tzname[2];
1085 
INTERCEPTOR(void,tzset,int fake)1086 INTERCEPTOR(void, tzset, int fake) {
1087   ENSURE_MSAN_INITED();
1088   InterceptorScope interceptor_scope;
1089   REAL(tzset)(fake);
1090   if (tzname[0])
1091     __msan_unpoison(tzname[0], REAL(strlen)(tzname[0]) + 1);
1092   if (tzname[1])
1093     __msan_unpoison(tzname[1], REAL(strlen)(tzname[1]) + 1);
1094   return;
1095 }
1096 
1097 struct MSanAtExitRecord {
1098   void (*func)(void *arg);
1099   void *arg;
1100 };
1101 
1102 struct InterceptorContext {
1103   BlockingMutex atexit_mu;
1104   Vector<struct MSanAtExitRecord *> AtExitStack;
1105 
InterceptorContextInterceptorContext1106   InterceptorContext()
1107       : AtExitStack() {
1108   }
1109 };
1110 
1111 static ALIGNED(64) char interceptor_placeholder[sizeof(InterceptorContext)];
interceptor_ctx()1112 InterceptorContext *interceptor_ctx() {
1113   return reinterpret_cast<InterceptorContext*>(&interceptor_placeholder[0]);
1114 }
1115 
MSanAtExitWrapper()1116 void MSanAtExitWrapper() {
1117   MSanAtExitRecord *r;
1118   {
1119     BlockingMutexLock l(&interceptor_ctx()->atexit_mu);
1120 
1121     uptr element = interceptor_ctx()->AtExitStack.Size() - 1;
1122     r = interceptor_ctx()->AtExitStack[element];
1123     interceptor_ctx()->AtExitStack.PopBack();
1124   }
1125 
1126   UnpoisonParam(1);
1127   ((void(*)())r->func)();
1128   InternalFree(r);
1129 }
1130 
MSanCxaAtExitWrapper(void * arg)1131 void MSanCxaAtExitWrapper(void *arg) {
1132   UnpoisonParam(1);
1133   MSanAtExitRecord *r = (MSanAtExitRecord *)arg;
1134   // libc before 2.27 had race which caused occasional double handler execution
1135   // https://sourceware.org/ml/libc-alpha/2017-08/msg01204.html
1136   if (!r->func)
1137     return;
1138   r->func(r->arg);
1139   r->func = nullptr;
1140 }
1141 
1142 static int setup_at_exit_wrapper(void(*f)(), void *arg, void *dso);
1143 
1144 // Unpoison argument shadow for C++ module destructors.
INTERCEPTOR(int,__cxa_atexit,void (* func)(void *),void * arg,void * dso_handle)1145 INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
1146             void *dso_handle) {
1147   if (msan_init_is_running) return REAL(__cxa_atexit)(func, arg, dso_handle);
1148   return setup_at_exit_wrapper((void(*)())func, arg, dso_handle);
1149 }
1150 
1151 // Unpoison argument shadow for C++ module destructors.
INTERCEPTOR(int,atexit,void (* func)())1152 INTERCEPTOR(int, atexit, void (*func)()) {
1153   // Avoid calling real atexit as it is unrechable on at least on Linux.
1154   if (msan_init_is_running)
1155     return REAL(__cxa_atexit)((void (*)(void *a))func, 0, 0);
1156   return setup_at_exit_wrapper((void(*)())func, 0, 0);
1157 }
1158 
setup_at_exit_wrapper(void (* f)(),void * arg,void * dso)1159 static int setup_at_exit_wrapper(void(*f)(), void *arg, void *dso) {
1160   ENSURE_MSAN_INITED();
1161   MSanAtExitRecord *r =
1162       (MSanAtExitRecord *)InternalAlloc(sizeof(MSanAtExitRecord));
1163   r->func = (void(*)(void *a))f;
1164   r->arg = arg;
1165   int res;
1166   if (!dso) {
1167     // NetBSD does not preserve the 2nd argument if dso is equal to 0
1168     // Store ctx in a local stack-like structure
1169 
1170     BlockingMutexLock l(&interceptor_ctx()->atexit_mu);
1171 
1172     res = REAL(__cxa_atexit)((void (*)(void *a))MSanAtExitWrapper, 0, 0);
1173     if (!res) {
1174       interceptor_ctx()->AtExitStack.PushBack(r);
1175     }
1176   } else {
1177     res = REAL(__cxa_atexit)(MSanCxaAtExitWrapper, r, dso);
1178   }
1179   return res;
1180 }
1181 
BeforeFork()1182 static void BeforeFork() {
1183   StackDepotLockAll();
1184   ChainedOriginDepotLockAll();
1185 }
1186 
AfterFork()1187 static void AfterFork() {
1188   ChainedOriginDepotUnlockAll();
1189   StackDepotUnlockAll();
1190 }
1191 
INTERCEPTOR(int,fork,void)1192 INTERCEPTOR(int, fork, void) {
1193   ENSURE_MSAN_INITED();
1194   BeforeFork();
1195   int pid = REAL(fork)();
1196   AfterFork();
1197   return pid;
1198 }
1199 
1200 // NetBSD ships with openpty(3) in -lutil, that needs to be prebuilt explicitly
1201 // with MSan.
1202 #if SANITIZER_LINUX
INTERCEPTOR(int,openpty,int * aparent,int * aworker,char * name,const void * termp,const void * winp)1203 INTERCEPTOR(int, openpty, int *aparent, int *aworker, char *name,
1204             const void *termp, const void *winp) {
1205   ENSURE_MSAN_INITED();
1206   InterceptorScope interceptor_scope;
1207   int res = REAL(openpty)(aparent, aworker, name, termp, winp);
1208   if (!res) {
1209     __msan_unpoison(aparent, sizeof(*aparent));
1210     __msan_unpoison(aworker, sizeof(*aworker));
1211   }
1212   return res;
1213 }
1214 #define MSAN_MAYBE_INTERCEPT_OPENPTY INTERCEPT_FUNCTION(openpty)
1215 #else
1216 #define MSAN_MAYBE_INTERCEPT_OPENPTY
1217 #endif
1218 
1219 // NetBSD ships with forkpty(3) in -lutil, that needs to be prebuilt explicitly
1220 // with MSan.
1221 #if SANITIZER_LINUX
INTERCEPTOR(int,forkpty,int * aparent,char * name,const void * termp,const void * winp)1222 INTERCEPTOR(int, forkpty, int *aparent, char *name, const void *termp,
1223             const void *winp) {
1224   ENSURE_MSAN_INITED();
1225   InterceptorScope interceptor_scope;
1226   int res = REAL(forkpty)(aparent, name, termp, winp);
1227   if (res != -1)
1228     __msan_unpoison(aparent, sizeof(*aparent));
1229   return res;
1230 }
1231 #define MSAN_MAYBE_INTERCEPT_FORKPTY INTERCEPT_FUNCTION(forkpty)
1232 #else
1233 #define MSAN_MAYBE_INTERCEPT_FORKPTY
1234 #endif
1235 
1236 struct MSanInterceptorContext {
1237   bool in_interceptor_scope;
1238 };
1239 
1240 namespace __msan {
1241 
OnExit()1242 int OnExit() {
1243   // FIXME: ask frontend whether we need to return failure.
1244   return 0;
1245 }
1246 
1247 } // namespace __msan
1248 
1249 // A version of CHECK_UNPOISONED using a saved scope value. Used in common
1250 // interceptors.
1251 #define CHECK_UNPOISONED_CTX(ctx, x, n)                         \
1252   do {                                                          \
1253     if (!((MSanInterceptorContext *)ctx)->in_interceptor_scope) \
1254       CHECK_UNPOISONED_0(x, n);                                 \
1255   } while (0)
1256 
1257 #define MSAN_INTERCEPT_FUNC(name)                                       \
1258   do {                                                                  \
1259     if (!INTERCEPT_FUNCTION(name))                                      \
1260       VReport(1, "MemorySanitizer: failed to intercept '%s'\n", #name); \
1261   } while (0)
1262 
1263 #define MSAN_INTERCEPT_FUNC_VER(name, ver)                                 \
1264   do {                                                                     \
1265     if (!INTERCEPT_FUNCTION_VER(name, ver))                                \
1266       VReport(1, "MemorySanitizer: failed to intercept '%s@@%s'\n", #name, \
1267               #ver);                                                       \
1268   } while (0)
1269 #define MSAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)             \
1270   do {                                                                      \
1271     if (!INTERCEPT_FUNCTION_VER(name, ver) && !INTERCEPT_FUNCTION(name))    \
1272       VReport(1, "MemorySanitizer: failed to intercept '%s@@%s' or '%s'\n", \
1273               #name, #ver, #name);                                          \
1274   } while (0)
1275 
1276 #define COMMON_INTERCEPT_FUNCTION(name) MSAN_INTERCEPT_FUNC(name)
1277 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver) \
1278   MSAN_INTERCEPT_FUNC_VER(name, ver)
1279 #define COMMON_INTERCEPT_FUNCTION_VER_UNVERSIONED_FALLBACK(name, ver) \
1280   MSAN_INTERCEPT_FUNC_VER_UNVERSIONED_FALLBACK(name, ver)
1281 #define COMMON_INTERCEPTOR_UNPOISON_PARAM(count)  \
1282   UnpoisonParam(count)
1283 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
1284   __msan_unpoison(ptr, size)
1285 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
1286   CHECK_UNPOISONED_CTX(ctx, ptr, size)
1287 #define COMMON_INTERCEPTOR_INITIALIZE_RANGE(ptr, size) \
1288   __msan_unpoison(ptr, size)
1289 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)                  \
1290   if (msan_init_is_running) return REAL(func)(__VA_ARGS__);       \
1291   ENSURE_MSAN_INITED();                                           \
1292   MSanInterceptorContext msan_ctx = {IsInInterceptorScope()};     \
1293   ctx = (void *)&msan_ctx;                                        \
1294   (void)ctx;                                                      \
1295   InterceptorScope interceptor_scope;                             \
1296   __msan_unpoison(__errno_location(), sizeof(int)); /* NOLINT */
1297 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
1298   do {                                            \
1299   } while (false)
1300 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
1301   do {                                         \
1302   } while (false)
1303 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
1304   do {                                         \
1305   } while (false)
1306 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
1307   do {                                                      \
1308   } while (false)
1309 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
1310   do {                                                \
1311   } while (false)  // FIXME
1312 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
1313   do {                                                         \
1314   } while (false)  // FIXME
1315 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
1316 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
1317 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)                    \
1318   do {                                                                         \
1319     link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE((handle));                   \
1320     if (filename && map)                                                       \
1321       ForEachMappedRegion(map, __msan_unpoison);                               \
1322   } while (false)
1323 
1324 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!msan_inited)
1325 
1326 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
1327   if (MsanThread *t = GetCurrentThread()) {                                    \
1328     *begin = t->tls_begin();                                                   \
1329     *end = t->tls_end();                                                       \
1330   } else {                                                                     \
1331     *begin = *end = 0;                                                         \
1332   }
1333 
1334 #define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size) \
1335   {                                                         \
1336     (void)ctx;                                              \
1337     return __msan_memset(block, c, size);                   \
1338   }
1339 #define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size) \
1340   {                                                          \
1341     (void)ctx;                                               \
1342     return __msan_memmove(to, from, size);                   \
1343   }
1344 #define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size) \
1345   {                                                         \
1346     (void)ctx;                                              \
1347     return __msan_memcpy(to, from, size);                   \
1348   }
1349 
1350 #define COMMON_INTERCEPTOR_COPY_STRING(ctx, to, from, size) \
1351   do {                                                      \
1352     GET_STORE_STACK_TRACE;                                  \
1353     CopyShadowAndOrigin(to, from, size, &stack);            \
1354     __msan_unpoison(to + size, 1);                          \
1355   } while (false)
1356 
1357 #define COMMON_INTERCEPTOR_MMAP_IMPL(ctx, mmap, addr, length, prot, flags, fd, \
1358                                      offset)                                   \
1359   do {                                                                         \
1360     return mmap_interceptor(REAL(mmap), addr, sz, prot, flags, fd, off);       \
1361   } while (false)
1362 
1363 #include "sanitizer_common/sanitizer_platform_interceptors.h"
1364 #include "sanitizer_common/sanitizer_common_interceptors.inc"
1365 
1366 static uptr signal_impl(int signo, uptr cb);
1367 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
1368                           __sanitizer_sigaction *oldact);
1369 
1370 #define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
1371   { return sigaction_impl(signo, act, oldact); }
1372 
1373 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
1374   {                                                          \
1375     handler = signal_impl(signo, handler);                   \
1376     InterceptorScope interceptor_scope;                      \
1377     return REAL(func)(signo, handler);                       \
1378   }
1379 
1380 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
1381 
sigaction_impl(int signo,const __sanitizer_sigaction * act,__sanitizer_sigaction * oldact)1382 static int sigaction_impl(int signo, const __sanitizer_sigaction *act,
1383                           __sanitizer_sigaction *oldact) {
1384   ENSURE_MSAN_INITED();
1385   if (signo <= 0 || signo >= kMaxSignals) {
1386     errno = errno_EINVAL;
1387     return -1;
1388   }
1389   if (act) read_sigaction(act);
1390   int res;
1391   if (flags()->wrap_signals) {
1392     SpinMutexLock lock(&sigactions_mu);
1393     uptr old_cb = atomic_load(&sigactions[signo], memory_order_relaxed);
1394     __sanitizer_sigaction new_act;
1395     __sanitizer_sigaction *pnew_act = act ? &new_act : nullptr;
1396     if (act) {
1397       REAL(memcpy)(pnew_act, act, sizeof(__sanitizer_sigaction));
1398       uptr cb = (uptr)pnew_act->sigaction;
1399       uptr new_cb = (pnew_act->sa_flags & __sanitizer::sa_siginfo)
1400                         ? (uptr)SignalAction
1401                         : (uptr)SignalHandler;
1402       if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1403         atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1404         pnew_act->sigaction = (decltype(pnew_act->sigaction))new_cb;
1405       }
1406     }
1407     res = REAL(SIGACTION_SYMNAME)(signo, pnew_act, oldact);
1408     if (res == 0 && oldact) {
1409       uptr cb = (uptr)oldact->sigaction;
1410       if (cb == (uptr)SignalAction || cb == (uptr)SignalHandler) {
1411         oldact->sigaction = (decltype(oldact->sigaction))old_cb;
1412       }
1413     }
1414   } else {
1415     res = REAL(SIGACTION_SYMNAME)(signo, act, oldact);
1416   }
1417 
1418   if (res == 0 && oldact) {
1419     __msan_unpoison(oldact, sizeof(__sanitizer_sigaction));
1420   }
1421   return res;
1422 }
1423 
signal_impl(int signo,uptr cb)1424 static uptr signal_impl(int signo, uptr cb) {
1425   ENSURE_MSAN_INITED();
1426   if (signo <= 0 || signo >= kMaxSignals) {
1427     errno = errno_EINVAL;
1428     return -1;
1429   }
1430   if (flags()->wrap_signals) {
1431     SpinMutexLock lock(&sigactions_mu);
1432     if (cb != __sanitizer::sig_ign && cb != __sanitizer::sig_dfl) {
1433       atomic_store(&sigactions[signo], cb, memory_order_relaxed);
1434       cb = (uptr)&SignalHandler;
1435     }
1436   }
1437   return cb;
1438 }
1439 
1440 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) CHECK_UNPOISONED(p, s)
1441 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
1442   do {                                       \
1443   } while (false)
1444 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
1445   do {                                       \
1446   } while (false)
1447 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) __msan_unpoison(p, s)
1448 #include "sanitizer_common/sanitizer_common_syscalls.inc"
1449 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
1450 
1451 struct dlinfo {
1452   char *dli_fname;
1453   void *dli_fbase;
1454   char *dli_sname;
1455   void *dli_saddr;
1456 };
1457 
INTERCEPTOR(int,dladdr,void * addr,dlinfo * info)1458 INTERCEPTOR(int, dladdr, void *addr, dlinfo *info) {
1459   void *ctx;
1460   COMMON_INTERCEPTOR_ENTER(ctx, dladdr, addr, info);
1461   int res = REAL(dladdr)(addr, info);
1462   if (res != 0) {
1463     __msan_unpoison(info, sizeof(*info));
1464     if (info->dli_fname)
1465       __msan_unpoison(info->dli_fname, REAL(strlen)(info->dli_fname) + 1);
1466     if (info->dli_sname)
1467       __msan_unpoison(info->dli_sname, REAL(strlen)(info->dli_sname) + 1);
1468   }
1469   return res;
1470 }
1471 
INTERCEPTOR(char *,dlerror,int fake)1472 INTERCEPTOR(char *, dlerror, int fake) {
1473   void *ctx;
1474   COMMON_INTERCEPTOR_ENTER(ctx, dlerror, fake);
1475   char *res = REAL(dlerror)(fake);
1476   if (res) __msan_unpoison(res, REAL(strlen)(res) + 1);
1477   return res;
1478 }
1479 
1480 typedef int (*dl_iterate_phdr_cb)(__sanitizer_dl_phdr_info *info, SIZE_T size,
1481                                   void *data);
1482 struct dl_iterate_phdr_data {
1483   dl_iterate_phdr_cb callback;
1484   void *data;
1485 };
1486 
msan_dl_iterate_phdr_cb(__sanitizer_dl_phdr_info * info,SIZE_T size,void * data)1487 static int msan_dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
1488                                    void *data) {
1489   if (info) {
1490     __msan_unpoison(info, size);
1491     if (info->dlpi_phdr && info->dlpi_phnum)
1492       __msan_unpoison(info->dlpi_phdr, struct_ElfW_Phdr_sz * info->dlpi_phnum);
1493     if (info->dlpi_name)
1494       __msan_unpoison(info->dlpi_name, REAL(strlen)(info->dlpi_name) + 1);
1495   }
1496   dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
1497   UnpoisonParam(3);
1498   return cbdata->callback(info, size, cbdata->data);
1499 }
1500 
INTERCEPTOR(void *,shmat,int shmid,const void * shmaddr,int shmflg)1501 INTERCEPTOR(void *, shmat, int shmid, const void *shmaddr, int shmflg) {
1502   ENSURE_MSAN_INITED();
1503   void *p = REAL(shmat)(shmid, shmaddr, shmflg);
1504   if (p != (void *)-1) {
1505     __sanitizer_shmid_ds ds;
1506     int res = REAL(shmctl)(shmid, shmctl_ipc_stat, &ds);
1507     if (!res) {
1508       __msan_unpoison(p, ds.shm_segsz);
1509     }
1510   }
1511   return p;
1512 }
1513 
INTERCEPTOR(int,dl_iterate_phdr,dl_iterate_phdr_cb callback,void * data)1514 INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb callback, void *data) {
1515   void *ctx;
1516   COMMON_INTERCEPTOR_ENTER(ctx, dl_iterate_phdr, callback, data);
1517   dl_iterate_phdr_data cbdata;
1518   cbdata.callback = callback;
1519   cbdata.data = data;
1520   int res = REAL(dl_iterate_phdr)(msan_dl_iterate_phdr_cb, (void *)&cbdata);
1521   return res;
1522 }
1523 
1524 // wchar_t *wcschr(const wchar_t *wcs, wchar_t wc);
INTERCEPTOR(wchar_t *,wcschr,void * s,wchar_t wc,void * ps)1525 INTERCEPTOR(wchar_t *, wcschr, void *s, wchar_t wc, void *ps) {
1526   ENSURE_MSAN_INITED();
1527   wchar_t *res = REAL(wcschr)(s, wc, ps);
1528   return res;
1529 }
1530 
1531 // wchar_t *wcscpy(wchar_t *dest, const wchar_t *src);
INTERCEPTOR(wchar_t *,wcscpy,wchar_t * dest,const wchar_t * src)1532 INTERCEPTOR(wchar_t *, wcscpy, wchar_t *dest, const wchar_t *src) {
1533   ENSURE_MSAN_INITED();
1534   GET_STORE_STACK_TRACE;
1535   wchar_t *res = REAL(wcscpy)(dest, src);
1536   CopyShadowAndOrigin(dest, src, sizeof(wchar_t) * (REAL(wcslen)(src) + 1),
1537                       &stack);
1538   return res;
1539 }
1540 
INTERCEPTOR(wchar_t *,wcsncpy,wchar_t * dest,const wchar_t * src,SIZE_T n)1541 INTERCEPTOR(wchar_t *, wcsncpy, wchar_t *dest, const wchar_t *src, SIZE_T n) {
1542   ENSURE_MSAN_INITED();
1543   GET_STORE_STACK_TRACE;
1544   SIZE_T copy_size = REAL(wcsnlen)(src, n);
1545   if (copy_size < n) copy_size++;           // trailing \0
1546   wchar_t *res = REAL(wcsncpy)(dest, src, n);
1547   CopyShadowAndOrigin(dest, src, copy_size * sizeof(wchar_t), &stack);
1548   __msan_unpoison(dest + copy_size, (n - copy_size) * sizeof(wchar_t));
1549   return res;
1550 }
1551 
1552 // These interface functions reside here so that they can use
1553 // REAL(memset), etc.
__msan_unpoison(const void * a,uptr size)1554 void __msan_unpoison(const void *a, uptr size) {
1555   if (!MEM_IS_APP(a)) return;
1556   SetShadow(a, size, 0);
1557 }
1558 
__msan_poison(const void * a,uptr size)1559 void __msan_poison(const void *a, uptr size) {
1560   if (!MEM_IS_APP(a)) return;
1561   SetShadow(a, size, __msan::flags()->poison_heap_with_zeroes ? 0 : -1);
1562 }
1563 
__msan_poison_stack(void * a,uptr size)1564 void __msan_poison_stack(void *a, uptr size) {
1565   if (!MEM_IS_APP(a)) return;
1566   SetShadow(a, size, __msan::flags()->poison_stack_with_zeroes ? 0 : -1);
1567 }
1568 
__msan_unpoison_param(uptr n)1569 void __msan_unpoison_param(uptr n) { UnpoisonParam(n); }
1570 
__msan_clear_and_unpoison(void * a,uptr size)1571 void __msan_clear_and_unpoison(void *a, uptr size) {
1572   REAL(memset)(a, 0, size);
1573   SetShadow(a, size, 0);
1574 }
1575 
__msan_memcpy(void * dest,const void * src,SIZE_T n)1576 void *__msan_memcpy(void *dest, const void *src, SIZE_T n) {
1577   if (!msan_inited) return internal_memcpy(dest, src, n);
1578   if (msan_init_is_running || __msan::IsInSymbolizer())
1579     return REAL(memcpy)(dest, src, n);
1580   ENSURE_MSAN_INITED();
1581   GET_STORE_STACK_TRACE;
1582   void *res = REAL(memcpy)(dest, src, n);
1583   CopyShadowAndOrigin(dest, src, n, &stack);
1584   return res;
1585 }
1586 
__msan_memset(void * s,int c,SIZE_T n)1587 void *__msan_memset(void *s, int c, SIZE_T n) {
1588   if (!msan_inited) return internal_memset(s, c, n);
1589   if (msan_init_is_running) return REAL(memset)(s, c, n);
1590   ENSURE_MSAN_INITED();
1591   void *res = REAL(memset)(s, c, n);
1592   __msan_unpoison(s, n);
1593   return res;
1594 }
1595 
__msan_memmove(void * dest,const void * src,SIZE_T n)1596 void *__msan_memmove(void *dest, const void *src, SIZE_T n) {
1597   if (!msan_inited) return internal_memmove(dest, src, n);
1598   if (msan_init_is_running) return REAL(memmove)(dest, src, n);
1599   ENSURE_MSAN_INITED();
1600   GET_STORE_STACK_TRACE;
1601   void *res = REAL(memmove)(dest, src, n);
1602   MoveShadowAndOrigin(dest, src, n, &stack);
1603   return res;
1604 }
1605 
__msan_unpoison_string(const char * s)1606 void __msan_unpoison_string(const char* s) {
1607   if (!MEM_IS_APP(s)) return;
1608   __msan_unpoison(s, REAL(strlen)(s) + 1);
1609 }
1610 
1611 namespace __msan {
1612 
InitializeInterceptors()1613 void InitializeInterceptors() {
1614   static int inited = 0;
1615   CHECK_EQ(inited, 0);
1616 
1617   new(interceptor_ctx()) InterceptorContext();
1618 
1619   InitializeCommonInterceptors();
1620   InitializeSignalInterceptors();
1621 
1622   INTERCEPT_FUNCTION(posix_memalign);
1623   MSAN_MAYBE_INTERCEPT_MEMALIGN;
1624   MSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN;
1625   INTERCEPT_FUNCTION(valloc);
1626   MSAN_MAYBE_INTERCEPT_PVALLOC;
1627   INTERCEPT_FUNCTION(malloc);
1628   INTERCEPT_FUNCTION(calloc);
1629   INTERCEPT_FUNCTION(realloc);
1630   INTERCEPT_FUNCTION(reallocarray);
1631   INTERCEPT_FUNCTION(free);
1632   MSAN_MAYBE_INTERCEPT_CFREE;
1633   MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE;
1634   MSAN_MAYBE_INTERCEPT_MALLINFO;
1635   MSAN_MAYBE_INTERCEPT_MALLOPT;
1636   MSAN_MAYBE_INTERCEPT_MALLOC_STATS;
1637   INTERCEPT_FUNCTION(fread);
1638   MSAN_MAYBE_INTERCEPT_FREAD_UNLOCKED;
1639   INTERCEPT_FUNCTION(memccpy);
1640   MSAN_MAYBE_INTERCEPT_MEMPCPY;
1641   INTERCEPT_FUNCTION(bcopy);
1642   INTERCEPT_FUNCTION(wmemset);
1643   INTERCEPT_FUNCTION(wmemcpy);
1644   MSAN_MAYBE_INTERCEPT_WMEMPCPY;
1645   INTERCEPT_FUNCTION(wmemmove);
1646   INTERCEPT_FUNCTION(strcpy);
1647   MSAN_MAYBE_INTERCEPT_STPCPY;
1648   INTERCEPT_FUNCTION(strdup);
1649   MSAN_MAYBE_INTERCEPT___STRDUP;
1650   INTERCEPT_FUNCTION(strncpy);
1651   MSAN_MAYBE_INTERCEPT_GCVT;
1652   INTERCEPT_FUNCTION(strcat);
1653   INTERCEPT_FUNCTION(strncat);
1654   INTERCEPT_STRTO(strtod);
1655   INTERCEPT_STRTO(strtof);
1656   INTERCEPT_STRTO(strtold);
1657   INTERCEPT_STRTO(strtol);
1658   INTERCEPT_STRTO(strtoul);
1659   INTERCEPT_STRTO(strtoll);
1660   INTERCEPT_STRTO(strtoull);
1661   INTERCEPT_STRTO(strtouq);
1662   INTERCEPT_STRTO(wcstod);
1663   INTERCEPT_STRTO(wcstof);
1664   INTERCEPT_STRTO(wcstold);
1665   INTERCEPT_STRTO(wcstol);
1666   INTERCEPT_STRTO(wcstoul);
1667   INTERCEPT_STRTO(wcstoll);
1668   INTERCEPT_STRTO(wcstoull);
1669 #ifdef SANITIZER_NLDBL_VERSION
1670   INTERCEPT_FUNCTION_VER(vswprintf, SANITIZER_NLDBL_VERSION);
1671   INTERCEPT_FUNCTION_VER(swprintf, SANITIZER_NLDBL_VERSION);
1672 #else
1673   INTERCEPT_FUNCTION(vswprintf);
1674   INTERCEPT_FUNCTION(swprintf);
1675 #endif
1676   INTERCEPT_FUNCTION(strftime);
1677   INTERCEPT_FUNCTION(strftime_l);
1678   MSAN_MAYBE_INTERCEPT___STRFTIME_L;
1679   INTERCEPT_FUNCTION(wcsftime);
1680   INTERCEPT_FUNCTION(wcsftime_l);
1681   MSAN_MAYBE_INTERCEPT___WCSFTIME_L;
1682   INTERCEPT_FUNCTION(mbtowc);
1683   INTERCEPT_FUNCTION(mbrtowc);
1684   INTERCEPT_FUNCTION(wcslen);
1685   INTERCEPT_FUNCTION(wcsnlen);
1686   INTERCEPT_FUNCTION(wcschr);
1687   INTERCEPT_FUNCTION(wcscpy);
1688   INTERCEPT_FUNCTION(wcsncpy);
1689   INTERCEPT_FUNCTION(wcscmp);
1690   INTERCEPT_FUNCTION(getenv);
1691   INTERCEPT_FUNCTION(setenv);
1692   INTERCEPT_FUNCTION(putenv);
1693   INTERCEPT_FUNCTION(gettimeofday);
1694   MSAN_MAYBE_INTERCEPT_FCVT;
1695   MSAN_MAYBE_INTERCEPT_FSTAT;
1696   MSAN_MAYBE_INTERCEPT___FXSTAT;
1697   MSAN_MAYBE_INTERCEPT_FSTATAT;
1698   MSAN_MAYBE_INTERCEPT___FXSTATAT;
1699   MSAN_MAYBE_INTERCEPT___FXSTAT64;
1700   MSAN_MAYBE_INTERCEPT___FXSTATAT64;
1701   INTERCEPT_FUNCTION(pipe);
1702   INTERCEPT_FUNCTION(pipe2);
1703   INTERCEPT_FUNCTION(socketpair);
1704   MSAN_MAYBE_INTERCEPT_FGETS_UNLOCKED;
1705   INTERCEPT_FUNCTION(getrlimit);
1706   MSAN_MAYBE_INTERCEPT___GETRLIMIT;
1707   MSAN_MAYBE_INTERCEPT_GETRLIMIT64;
1708   MSAN_MAYBE_INTERCEPT_PRLIMIT;
1709   MSAN_MAYBE_INTERCEPT_PRLIMIT64;
1710   INTERCEPT_FUNCTION(gethostname);
1711   MSAN_MAYBE_INTERCEPT_EPOLL_WAIT;
1712   MSAN_MAYBE_INTERCEPT_EPOLL_PWAIT;
1713   INTERCEPT_FUNCTION(dladdr);
1714   INTERCEPT_FUNCTION(dlerror);
1715   INTERCEPT_FUNCTION(dl_iterate_phdr);
1716   INTERCEPT_FUNCTION(getrusage);
1717 #if defined(__mips__)
1718   INTERCEPT_FUNCTION_VER(pthread_create, "GLIBC_2.2");
1719 #else
1720   INTERCEPT_FUNCTION(pthread_create);
1721 #endif
1722   INTERCEPT_FUNCTION(pthread_key_create);
1723 
1724 #if SANITIZER_NETBSD
1725   INTERCEPT_FUNCTION(__libc_thr_keycreate);
1726 #endif
1727 
1728   INTERCEPT_FUNCTION(pthread_join);
1729   INTERCEPT_FUNCTION(tzset);
1730   INTERCEPT_FUNCTION(atexit);
1731   INTERCEPT_FUNCTION(__cxa_atexit);
1732   INTERCEPT_FUNCTION(shmat);
1733   INTERCEPT_FUNCTION(fork);
1734   MSAN_MAYBE_INTERCEPT_OPENPTY;
1735   MSAN_MAYBE_INTERCEPT_FORKPTY;
1736 
1737   inited = 1;
1738 }
1739 } // namespace __msan
1740