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1 //===-- tsan_interceptors_posix.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 ThreadSanitizer (TSan), a race detector.
10 //
11 // FIXME: move as many interceptors as possible into
12 // sanitizer_common/sanitizer_common_interceptors.inc
13 //===----------------------------------------------------------------------===//
14 
15 #include "sanitizer_common/sanitizer_atomic.h"
16 #include "sanitizer_common/sanitizer_errno.h"
17 #include "sanitizer_common/sanitizer_libc.h"
18 #include "sanitizer_common/sanitizer_linux.h"
19 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
20 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
21 #include "sanitizer_common/sanitizer_placement_new.h"
22 #include "sanitizer_common/sanitizer_posix.h"
23 #include "sanitizer_common/sanitizer_stacktrace.h"
24 #include "sanitizer_common/sanitizer_tls_get_addr.h"
25 #include "interception/interception.h"
26 #include "tsan_interceptors.h"
27 #include "tsan_interface.h"
28 #include "tsan_platform.h"
29 #include "tsan_suppressions.h"
30 #include "tsan_rtl.h"
31 #include "tsan_mman.h"
32 #include "tsan_fd.h"
33 
34 #include <stdarg.h>
35 
36 using namespace __tsan;
37 
38 #if SANITIZER_FREEBSD || SANITIZER_MAC
39 #define stdout __stdoutp
40 #define stderr __stderrp
41 #endif
42 
43 #if SANITIZER_NETBSD
44 #define dirfd(dirp) (*(int *)(dirp))
45 #define fileno_unlocked(fp)              \
46   (((__sanitizer_FILE *)fp)->_file == -1 \
47        ? -1                              \
48        : (int)(unsigned short)(((__sanitizer_FILE *)fp)->_file))
49 
50 #define stdout ((__sanitizer_FILE*)&__sF[1])
51 #define stderr ((__sanitizer_FILE*)&__sF[2])
52 
53 #define nanosleep __nanosleep50
54 #define vfork __vfork14
55 #endif
56 
57 #if SANITIZER_ANDROID
58 #define mallopt(a, b)
59 #endif
60 
61 #ifdef __mips__
62 const int kSigCount = 129;
63 #else
64 const int kSigCount = 65;
65 #endif
66 
67 #ifdef __mips__
68 struct ucontext_t {
69   u64 opaque[768 / sizeof(u64) + 1];
70 };
71 #else
72 struct ucontext_t {
73   // The size is determined by looking at sizeof of real ucontext_t on linux.
74   u64 opaque[936 / sizeof(u64) + 1];
75 };
76 #endif
77 
78 #if defined(__x86_64__) || defined(__mips__) || SANITIZER_PPC64V1
79 #define PTHREAD_ABI_BASE  "GLIBC_2.3.2"
80 #elif defined(__aarch64__) || SANITIZER_PPC64V2
81 #define PTHREAD_ABI_BASE  "GLIBC_2.17"
82 #endif
83 
84 extern "C" int pthread_attr_init(void *attr);
85 extern "C" int pthread_attr_destroy(void *attr);
86 DECLARE_REAL(int, pthread_attr_getdetachstate, void *, void *)
87 extern "C" int pthread_attr_setstacksize(void *attr, uptr stacksize);
88 extern "C" int pthread_key_create(unsigned *key, void (*destructor)(void* v));
89 extern "C" int pthread_setspecific(unsigned key, const void *v);
90 DECLARE_REAL(int, pthread_mutexattr_gettype, void *, void *)
91 DECLARE_REAL(int, fflush, __sanitizer_FILE *fp)
92 DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr size)
93 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
94 extern "C" void *pthread_self();
95 extern "C" void _exit(int status);
96 #if !SANITIZER_NETBSD
97 extern "C" int fileno_unlocked(void *stream);
98 extern "C" int dirfd(void *dirp);
99 #endif
100 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_NETBSD
101 extern "C" int mallopt(int param, int value);
102 #endif
103 #if SANITIZER_NETBSD
104 extern __sanitizer_FILE __sF[];
105 #else
106 extern __sanitizer_FILE *stdout, *stderr;
107 #endif
108 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
109 const int PTHREAD_MUTEX_RECURSIVE = 1;
110 const int PTHREAD_MUTEX_RECURSIVE_NP = 1;
111 #else
112 const int PTHREAD_MUTEX_RECURSIVE = 2;
113 const int PTHREAD_MUTEX_RECURSIVE_NP = 2;
114 #endif
115 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
116 const int EPOLL_CTL_ADD = 1;
117 #endif
118 const int SIGILL = 4;
119 const int SIGTRAP = 5;
120 const int SIGABRT = 6;
121 const int SIGFPE = 8;
122 const int SIGSEGV = 11;
123 const int SIGPIPE = 13;
124 const int SIGTERM = 15;
125 #if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
126 const int SIGBUS = 10;
127 const int SIGSYS = 12;
128 #else
129 const int SIGBUS = 7;
130 const int SIGSYS = 31;
131 #endif
132 void *const MAP_FAILED = (void*)-1;
133 #if SANITIZER_NETBSD
134 const int PTHREAD_BARRIER_SERIAL_THREAD = 1234567;
135 #elif !SANITIZER_MAC
136 const int PTHREAD_BARRIER_SERIAL_THREAD = -1;
137 #endif
138 const int MAP_FIXED = 0x10;
139 typedef long long_t;
140 typedef __sanitizer::u16 mode_t;
141 
142 // From /usr/include/unistd.h
143 # define F_ULOCK 0      /* Unlock a previously locked region.  */
144 # define F_LOCK  1      /* Lock a region for exclusive use.  */
145 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
146 # define F_TEST  3      /* Test a region for other processes locks.  */
147 
148 #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
149 const int SA_SIGINFO = 0x40;
150 const int SIG_SETMASK = 3;
151 #elif defined(__mips__)
152 const int SA_SIGINFO = 8;
153 const int SIG_SETMASK = 3;
154 #else
155 const int SA_SIGINFO = 4;
156 const int SIG_SETMASK = 2;
157 #endif
158 
159 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \
160   (cur_thread_init(), !cur_thread()->is_inited)
161 
162 namespace __tsan {
163 struct SignalDesc {
164   bool armed;
165   bool sigaction;
166   __sanitizer_siginfo siginfo;
167   ucontext_t ctx;
168 };
169 
170 struct ThreadSignalContext {
171   int int_signal_send;
172   atomic_uintptr_t in_blocking_func;
173   atomic_uintptr_t have_pending_signals;
174   SignalDesc pending_signals[kSigCount];
175   // emptyset and oldset are too big for stack.
176   __sanitizer_sigset_t emptyset;
177   __sanitizer_sigset_t oldset;
178 };
179 
180 // The sole reason tsan wraps atexit callbacks is to establish synchronization
181 // between callback setup and callback execution.
182 struct AtExitCtx {
183   void (*f)();
184   void *arg;
185 };
186 
187 // InterceptorContext holds all global data required for interceptors.
188 // It's explicitly constructed in InitializeInterceptors with placement new
189 // and is never destroyed. This allows usage of members with non-trivial
190 // constructors and destructors.
191 struct InterceptorContext {
192   // The object is 64-byte aligned, because we want hot data to be located
193   // in a single cache line if possible (it's accessed in every interceptor).
194   ALIGNED(64) LibIgnore libignore;
195   __sanitizer_sigaction sigactions[kSigCount];
196 #if !SANITIZER_MAC && !SANITIZER_NETBSD
197   unsigned finalize_key;
198 #endif
199 
200   BlockingMutex atexit_mu;
201   Vector<struct AtExitCtx *> AtExitStack;
202 
InterceptorContext__tsan::InterceptorContext203   InterceptorContext()
204       : libignore(LINKER_INITIALIZED), AtExitStack() {
205   }
206 };
207 
208 static ALIGNED(64) char interceptor_placeholder[sizeof(InterceptorContext)];
interceptor_ctx()209 InterceptorContext *interceptor_ctx() {
210   return reinterpret_cast<InterceptorContext*>(&interceptor_placeholder[0]);
211 }
212 
libignore()213 LibIgnore *libignore() {
214   return &interceptor_ctx()->libignore;
215 }
216 
InitializeLibIgnore()217 void InitializeLibIgnore() {
218   const SuppressionContext &supp = *Suppressions();
219   const uptr n = supp.SuppressionCount();
220   for (uptr i = 0; i < n; i++) {
221     const Suppression *s = supp.SuppressionAt(i);
222     if (0 == internal_strcmp(s->type, kSuppressionLib))
223       libignore()->AddIgnoredLibrary(s->templ);
224   }
225   if (flags()->ignore_noninstrumented_modules)
226     libignore()->IgnoreNoninstrumentedModules(true);
227   libignore()->OnLibraryLoaded(0);
228 }
229 
230 // The following two hooks can be used by for cooperative scheduling when
231 // locking.
232 #ifdef TSAN_EXTERNAL_HOOKS
233 void OnPotentiallyBlockingRegionBegin();
234 void OnPotentiallyBlockingRegionEnd();
235 #else
OnPotentiallyBlockingRegionBegin()236 SANITIZER_WEAK_CXX_DEFAULT_IMPL void OnPotentiallyBlockingRegionBegin() {}
OnPotentiallyBlockingRegionEnd()237 SANITIZER_WEAK_CXX_DEFAULT_IMPL void OnPotentiallyBlockingRegionEnd() {}
238 #endif
239 
240 }  // namespace __tsan
241 
SigCtx(ThreadState * thr)242 static ThreadSignalContext *SigCtx(ThreadState *thr) {
243   ThreadSignalContext *ctx = (ThreadSignalContext*)thr->signal_ctx;
244   if (ctx == 0 && !thr->is_dead) {
245     ctx = (ThreadSignalContext*)MmapOrDie(sizeof(*ctx), "ThreadSignalContext");
246     MemoryResetRange(thr, (uptr)&SigCtx, (uptr)ctx, sizeof(*ctx));
247     thr->signal_ctx = ctx;
248   }
249   return ctx;
250 }
251 
ScopedInterceptor(ThreadState * thr,const char * fname,uptr pc)252 ScopedInterceptor::ScopedInterceptor(ThreadState *thr, const char *fname,
253                                      uptr pc)
254     : thr_(thr), pc_(pc), in_ignored_lib_(false), ignoring_(false) {
255   Initialize(thr);
256   if (!thr_->is_inited) return;
257   if (!thr_->ignore_interceptors) FuncEntry(thr, pc);
258   DPrintf("#%d: intercept %s()\n", thr_->tid, fname);
259   ignoring_ =
260       !thr_->in_ignored_lib && (flags()->ignore_interceptors_accesses ||
261                                 libignore()->IsIgnored(pc, &in_ignored_lib_));
262   EnableIgnores();
263 }
264 
~ScopedInterceptor()265 ScopedInterceptor::~ScopedInterceptor() {
266   if (!thr_->is_inited) return;
267   DisableIgnores();
268   if (!thr_->ignore_interceptors) {
269     ProcessPendingSignals(thr_);
270     FuncExit(thr_);
271     CheckNoLocks(thr_);
272   }
273 }
274 
EnableIgnores()275 void ScopedInterceptor::EnableIgnores() {
276   if (ignoring_) {
277     ThreadIgnoreBegin(thr_, pc_, /*save_stack=*/false);
278     if (flags()->ignore_noninstrumented_modules) thr_->suppress_reports++;
279     if (in_ignored_lib_) {
280       DCHECK(!thr_->in_ignored_lib);
281       thr_->in_ignored_lib = true;
282     }
283   }
284 }
285 
DisableIgnores()286 void ScopedInterceptor::DisableIgnores() {
287   if (ignoring_) {
288     ThreadIgnoreEnd(thr_, pc_);
289     if (flags()->ignore_noninstrumented_modules) thr_->suppress_reports--;
290     if (in_ignored_lib_) {
291       DCHECK(thr_->in_ignored_lib);
292       thr_->in_ignored_lib = false;
293     }
294   }
295 }
296 
297 #define TSAN_INTERCEPT(func) INTERCEPT_FUNCTION(func)
298 #if SANITIZER_FREEBSD
299 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func)
300 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(func)
301 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(func)
302 #elif SANITIZER_NETBSD
303 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func)
304 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(func) \
305          INTERCEPT_FUNCTION(__libc_##func)
306 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(func) \
307          INTERCEPT_FUNCTION(__libc_thr_##func)
308 #else
309 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION_VER(func, ver)
310 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(func)
311 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(func)
312 #endif
313 
314 #define READ_STRING_OF_LEN(thr, pc, s, len, n)                 \
315   MemoryAccessRange((thr), (pc), (uptr)(s),                         \
316     common_flags()->strict_string_checks ? (len) + 1 : (n), false)
317 
318 #define READ_STRING(thr, pc, s, n)                             \
319     READ_STRING_OF_LEN((thr), (pc), (s), internal_strlen(s), (n))
320 
321 #define BLOCK_REAL(name) (BlockingCall(thr), REAL(name))
322 
323 struct BlockingCall {
BlockingCallBlockingCall324   explicit BlockingCall(ThreadState *thr)
325       : thr(thr)
326       , ctx(SigCtx(thr)) {
327     for (;;) {
328       atomic_store(&ctx->in_blocking_func, 1, memory_order_relaxed);
329       if (atomic_load(&ctx->have_pending_signals, memory_order_relaxed) == 0)
330         break;
331       atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
332       ProcessPendingSignals(thr);
333     }
334     // When we are in a "blocking call", we process signals asynchronously
335     // (right when they arrive). In this context we do not expect to be
336     // executing any user/runtime code. The known interceptor sequence when
337     // this is not true is: pthread_join -> munmap(stack). It's fine
338     // to ignore munmap in this case -- we handle stack shadow separately.
339     thr->ignore_interceptors++;
340   }
341 
~BlockingCallBlockingCall342   ~BlockingCall() {
343     thr->ignore_interceptors--;
344     atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
345   }
346 
347   ThreadState *thr;
348   ThreadSignalContext *ctx;
349 };
350 
TSAN_INTERCEPTOR(unsigned,sleep,unsigned sec)351 TSAN_INTERCEPTOR(unsigned, sleep, unsigned sec) {
352   SCOPED_TSAN_INTERCEPTOR(sleep, sec);
353   unsigned res = BLOCK_REAL(sleep)(sec);
354   AfterSleep(thr, pc);
355   return res;
356 }
357 
TSAN_INTERCEPTOR(int,usleep,long_t usec)358 TSAN_INTERCEPTOR(int, usleep, long_t usec) {
359   SCOPED_TSAN_INTERCEPTOR(usleep, usec);
360   int res = BLOCK_REAL(usleep)(usec);
361   AfterSleep(thr, pc);
362   return res;
363 }
364 
TSAN_INTERCEPTOR(int,nanosleep,void * req,void * rem)365 TSAN_INTERCEPTOR(int, nanosleep, void *req, void *rem) {
366   SCOPED_TSAN_INTERCEPTOR(nanosleep, req, rem);
367   int res = BLOCK_REAL(nanosleep)(req, rem);
368   AfterSleep(thr, pc);
369   return res;
370 }
371 
TSAN_INTERCEPTOR(int,pause,int fake)372 TSAN_INTERCEPTOR(int, pause, int fake) {
373   SCOPED_TSAN_INTERCEPTOR(pause, fake);
374   return BLOCK_REAL(pause)(fake);
375 }
376 
at_exit_wrapper()377 static void at_exit_wrapper() {
378   AtExitCtx *ctx;
379   {
380     // Ensure thread-safety.
381     BlockingMutexLock l(&interceptor_ctx()->atexit_mu);
382 
383     // Pop AtExitCtx from the top of the stack of callback functions
384     uptr element = interceptor_ctx()->AtExitStack.Size() - 1;
385     ctx = interceptor_ctx()->AtExitStack[element];
386     interceptor_ctx()->AtExitStack.PopBack();
387   }
388 
389   Acquire(cur_thread(), (uptr)0, (uptr)ctx);
390   ((void(*)())ctx->f)();
391   InternalFree(ctx);
392 }
393 
cxa_at_exit_wrapper(void * arg)394 static void cxa_at_exit_wrapper(void *arg) {
395   Acquire(cur_thread(), 0, (uptr)arg);
396   AtExitCtx *ctx = (AtExitCtx*)arg;
397   ((void(*)(void *arg))ctx->f)(ctx->arg);
398   InternalFree(ctx);
399 }
400 
401 static int setup_at_exit_wrapper(ThreadState *thr, uptr pc, void(*f)(),
402       void *arg, void *dso);
403 
404 #if !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,atexit,void (* f)())405 TSAN_INTERCEPTOR(int, atexit, void (*f)()) {
406   if (in_symbolizer())
407     return 0;
408   // We want to setup the atexit callback even if we are in ignored lib
409   // or after fork.
410   SCOPED_INTERCEPTOR_RAW(atexit, f);
411   return setup_at_exit_wrapper(thr, pc, (void(*)())f, 0, 0);
412 }
413 #endif
414 
TSAN_INTERCEPTOR(int,__cxa_atexit,void (* f)(void * a),void * arg,void * dso)415 TSAN_INTERCEPTOR(int, __cxa_atexit, void (*f)(void *a), void *arg, void *dso) {
416   if (in_symbolizer())
417     return 0;
418   SCOPED_TSAN_INTERCEPTOR(__cxa_atexit, f, arg, dso);
419   return setup_at_exit_wrapper(thr, pc, (void(*)())f, arg, dso);
420 }
421 
setup_at_exit_wrapper(ThreadState * thr,uptr pc,void (* f)(),void * arg,void * dso)422 static int setup_at_exit_wrapper(ThreadState *thr, uptr pc, void(*f)(),
423       void *arg, void *dso) {
424   AtExitCtx *ctx = (AtExitCtx*)InternalAlloc(sizeof(AtExitCtx));
425   ctx->f = f;
426   ctx->arg = arg;
427   Release(thr, pc, (uptr)ctx);
428   // Memory allocation in __cxa_atexit will race with free during exit,
429   // because we do not see synchronization around atexit callback list.
430   ThreadIgnoreBegin(thr, pc);
431   int res;
432   if (!dso) {
433     // NetBSD does not preserve the 2nd argument if dso is equal to 0
434     // Store ctx in a local stack-like structure
435 
436     // Ensure thread-safety.
437     BlockingMutexLock l(&interceptor_ctx()->atexit_mu);
438 
439     res = REAL(__cxa_atexit)((void (*)(void *a))at_exit_wrapper, 0, 0);
440     // Push AtExitCtx on the top of the stack of callback functions
441     if (!res) {
442       interceptor_ctx()->AtExitStack.PushBack(ctx);
443     }
444   } else {
445     res = REAL(__cxa_atexit)(cxa_at_exit_wrapper, ctx, dso);
446   }
447   ThreadIgnoreEnd(thr, pc);
448   return res;
449 }
450 
451 #if !SANITIZER_MAC && !SANITIZER_NETBSD
on_exit_wrapper(int status,void * arg)452 static void on_exit_wrapper(int status, void *arg) {
453   ThreadState *thr = cur_thread();
454   uptr pc = 0;
455   Acquire(thr, pc, (uptr)arg);
456   AtExitCtx *ctx = (AtExitCtx*)arg;
457   ((void(*)(int status, void *arg))ctx->f)(status, ctx->arg);
458   InternalFree(ctx);
459 }
460 
TSAN_INTERCEPTOR(int,on_exit,void (* f)(int,void *),void * arg)461 TSAN_INTERCEPTOR(int, on_exit, void(*f)(int, void*), void *arg) {
462   if (in_symbolizer())
463     return 0;
464   SCOPED_TSAN_INTERCEPTOR(on_exit, f, arg);
465   AtExitCtx *ctx = (AtExitCtx*)InternalAlloc(sizeof(AtExitCtx));
466   ctx->f = (void(*)())f;
467   ctx->arg = arg;
468   Release(thr, pc, (uptr)ctx);
469   // Memory allocation in __cxa_atexit will race with free during exit,
470   // because we do not see synchronization around atexit callback list.
471   ThreadIgnoreBegin(thr, pc);
472   int res = REAL(on_exit)(on_exit_wrapper, ctx);
473   ThreadIgnoreEnd(thr, pc);
474   return res;
475 }
476 #define TSAN_MAYBE_INTERCEPT_ON_EXIT TSAN_INTERCEPT(on_exit)
477 #else
478 #define TSAN_MAYBE_INTERCEPT_ON_EXIT
479 #endif
480 
481 // Cleanup old bufs.
JmpBufGarbageCollect(ThreadState * thr,uptr sp)482 static void JmpBufGarbageCollect(ThreadState *thr, uptr sp) {
483   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
484     JmpBuf *buf = &thr->jmp_bufs[i];
485     if (buf->sp <= sp) {
486       uptr sz = thr->jmp_bufs.Size();
487       internal_memcpy(buf, &thr->jmp_bufs[sz - 1], sizeof(*buf));
488       thr->jmp_bufs.PopBack();
489       i--;
490     }
491   }
492 }
493 
SetJmp(ThreadState * thr,uptr sp)494 static void SetJmp(ThreadState *thr, uptr sp) {
495   if (!thr->is_inited)  // called from libc guts during bootstrap
496     return;
497   // Cleanup old bufs.
498   JmpBufGarbageCollect(thr, sp);
499   // Remember the buf.
500   JmpBuf *buf = thr->jmp_bufs.PushBack();
501   buf->sp = sp;
502   buf->shadow_stack_pos = thr->shadow_stack_pos;
503   ThreadSignalContext *sctx = SigCtx(thr);
504   buf->int_signal_send = sctx ? sctx->int_signal_send : 0;
505   buf->in_blocking_func = sctx ?
506       atomic_load(&sctx->in_blocking_func, memory_order_relaxed) :
507       false;
508   buf->in_signal_handler = atomic_load(&thr->in_signal_handler,
509       memory_order_relaxed);
510 }
511 
LongJmp(ThreadState * thr,uptr * env)512 static void LongJmp(ThreadState *thr, uptr *env) {
513   uptr sp = ExtractLongJmpSp(env);
514   // Find the saved buf with matching sp.
515   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
516     JmpBuf *buf = &thr->jmp_bufs[i];
517     if (buf->sp == sp) {
518       CHECK_GE(thr->shadow_stack_pos, buf->shadow_stack_pos);
519       // Unwind the stack.
520       while (thr->shadow_stack_pos > buf->shadow_stack_pos)
521         FuncExit(thr);
522       ThreadSignalContext *sctx = SigCtx(thr);
523       if (sctx) {
524         sctx->int_signal_send = buf->int_signal_send;
525         atomic_store(&sctx->in_blocking_func, buf->in_blocking_func,
526             memory_order_relaxed);
527       }
528       atomic_store(&thr->in_signal_handler, buf->in_signal_handler,
529           memory_order_relaxed);
530       JmpBufGarbageCollect(thr, buf->sp - 1);  // do not collect buf->sp
531       return;
532     }
533   }
534   Printf("ThreadSanitizer: can't find longjmp buf\n");
535   CHECK(0);
536 }
537 
538 // FIXME: put everything below into a common extern "C" block?
__tsan_setjmp(uptr sp)539 extern "C" void __tsan_setjmp(uptr sp) {
540   cur_thread_init();
541   SetJmp(cur_thread(), sp);
542 }
543 
544 #if SANITIZER_MAC
545 TSAN_INTERCEPTOR(int, setjmp, void *env);
546 TSAN_INTERCEPTOR(int, _setjmp, void *env);
547 TSAN_INTERCEPTOR(int, sigsetjmp, void *env);
548 #else  // SANITIZER_MAC
549 
550 #if SANITIZER_NETBSD
551 #define setjmp_symname __setjmp14
552 #define sigsetjmp_symname __sigsetjmp14
553 #else
554 #define setjmp_symname setjmp
555 #define sigsetjmp_symname sigsetjmp
556 #endif
557 
558 #define TSAN_INTERCEPTOR_SETJMP_(x) __interceptor_ ## x
559 #define TSAN_INTERCEPTOR_SETJMP__(x) TSAN_INTERCEPTOR_SETJMP_(x)
560 #define TSAN_INTERCEPTOR_SETJMP TSAN_INTERCEPTOR_SETJMP__(setjmp_symname)
561 #define TSAN_INTERCEPTOR_SIGSETJMP TSAN_INTERCEPTOR_SETJMP__(sigsetjmp_symname)
562 
563 #define TSAN_STRING_SETJMP SANITIZER_STRINGIFY(setjmp_symname)
564 #define TSAN_STRING_SIGSETJMP SANITIZER_STRINGIFY(sigsetjmp_symname)
565 
566 // Not called.  Merely to satisfy TSAN_INTERCEPT().
567 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
568 int TSAN_INTERCEPTOR_SETJMP(void *env);
TSAN_INTERCEPTOR_SETJMP(void * env)569 extern "C" int TSAN_INTERCEPTOR_SETJMP(void *env) {
570   CHECK(0);
571   return 0;
572 }
573 
574 // FIXME: any reason to have a separate declaration?
575 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
576 int __interceptor__setjmp(void *env);
__interceptor__setjmp(void * env)577 extern "C" int __interceptor__setjmp(void *env) {
578   CHECK(0);
579   return 0;
580 }
581 
582 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
583 int TSAN_INTERCEPTOR_SIGSETJMP(void *env);
TSAN_INTERCEPTOR_SIGSETJMP(void * env)584 extern "C" int TSAN_INTERCEPTOR_SIGSETJMP(void *env) {
585   CHECK(0);
586   return 0;
587 }
588 
589 #if !SANITIZER_NETBSD
590 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
591 int __interceptor___sigsetjmp(void *env);
__interceptor___sigsetjmp(void * env)592 extern "C" int __interceptor___sigsetjmp(void *env) {
593   CHECK(0);
594   return 0;
595 }
596 #endif
597 
598 extern "C" int setjmp_symname(void *env);
599 extern "C" int _setjmp(void *env);
600 extern "C" int sigsetjmp_symname(void *env);
601 #if !SANITIZER_NETBSD
602 extern "C" int __sigsetjmp(void *env);
603 #endif
DEFINE_REAL(int,setjmp_symname,void * env)604 DEFINE_REAL(int, setjmp_symname, void *env)
605 DEFINE_REAL(int, _setjmp, void *env)
606 DEFINE_REAL(int, sigsetjmp_symname, void *env)
607 #if !SANITIZER_NETBSD
608 DEFINE_REAL(int, __sigsetjmp, void *env)
609 #endif
610 #endif  // SANITIZER_MAC
611 
612 #if SANITIZER_NETBSD
613 #define longjmp_symname __longjmp14
614 #define siglongjmp_symname __siglongjmp14
615 #else
616 #define longjmp_symname longjmp
617 #define siglongjmp_symname siglongjmp
618 #endif
619 
620 TSAN_INTERCEPTOR(void, longjmp_symname, uptr *env, int val) {
621   // Note: if we call REAL(longjmp) in the context of ScopedInterceptor,
622   // bad things will happen. We will jump over ScopedInterceptor dtor and can
623   // leave thr->in_ignored_lib set.
624   {
625     SCOPED_INTERCEPTOR_RAW(longjmp_symname, env, val);
626   }
627   LongJmp(cur_thread(), env);
628   REAL(longjmp_symname)(env, val);
629 }
630 
TSAN_INTERCEPTOR(void,siglongjmp_symname,uptr * env,int val)631 TSAN_INTERCEPTOR(void, siglongjmp_symname, uptr *env, int val) {
632   {
633     SCOPED_INTERCEPTOR_RAW(siglongjmp_symname, env, val);
634   }
635   LongJmp(cur_thread(), env);
636   REAL(siglongjmp_symname)(env, val);
637 }
638 
639 #if SANITIZER_NETBSD
TSAN_INTERCEPTOR(void,_longjmp,uptr * env,int val)640 TSAN_INTERCEPTOR(void, _longjmp, uptr *env, int val) {
641   {
642     SCOPED_INTERCEPTOR_RAW(_longjmp, env, val);
643   }
644   LongJmp(cur_thread(), env);
645   REAL(_longjmp)(env, val);
646 }
647 #endif
648 
649 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(void *,malloc,uptr size)650 TSAN_INTERCEPTOR(void*, malloc, uptr size) {
651   if (in_symbolizer())
652     return InternalAlloc(size);
653   void *p = 0;
654   {
655     SCOPED_INTERCEPTOR_RAW(malloc, size);
656     p = user_alloc(thr, pc, size);
657   }
658   invoke_malloc_hook(p, size);
659   return p;
660 }
661 
TSAN_INTERCEPTOR(void *,__libc_memalign,uptr align,uptr sz)662 TSAN_INTERCEPTOR(void*, __libc_memalign, uptr align, uptr sz) {
663   SCOPED_TSAN_INTERCEPTOR(__libc_memalign, align, sz);
664   return user_memalign(thr, pc, align, sz);
665 }
666 
TSAN_INTERCEPTOR(void *,calloc,uptr size,uptr n)667 TSAN_INTERCEPTOR(void*, calloc, uptr size, uptr n) {
668   if (in_symbolizer())
669     return InternalCalloc(size, n);
670   void *p = 0;
671   {
672     SCOPED_INTERCEPTOR_RAW(calloc, size, n);
673     p = user_calloc(thr, pc, size, n);
674   }
675   invoke_malloc_hook(p, n * size);
676   return p;
677 }
678 
TSAN_INTERCEPTOR(void *,realloc,void * p,uptr size)679 TSAN_INTERCEPTOR(void*, realloc, void *p, uptr size) {
680   if (in_symbolizer())
681     return InternalRealloc(p, size);
682   if (p)
683     invoke_free_hook(p);
684   {
685     SCOPED_INTERCEPTOR_RAW(realloc, p, size);
686     p = user_realloc(thr, pc, p, size);
687   }
688   invoke_malloc_hook(p, size);
689   return p;
690 }
691 
TSAN_INTERCEPTOR(void *,reallocarray,void * p,uptr size,uptr n)692 TSAN_INTERCEPTOR(void*, reallocarray, void *p, uptr size, uptr n) {
693   if (in_symbolizer())
694     return InternalReallocArray(p, size, n);
695   if (p)
696     invoke_free_hook(p);
697   {
698     SCOPED_INTERCEPTOR_RAW(reallocarray, p, size, n);
699     p = user_reallocarray(thr, pc, p, size, n);
700   }
701   invoke_malloc_hook(p, size);
702   return p;
703 }
704 
TSAN_INTERCEPTOR(void,free,void * p)705 TSAN_INTERCEPTOR(void, free, void *p) {
706   if (p == 0)
707     return;
708   if (in_symbolizer())
709     return InternalFree(p);
710   invoke_free_hook(p);
711   SCOPED_INTERCEPTOR_RAW(free, p);
712   user_free(thr, pc, p);
713 }
714 
TSAN_INTERCEPTOR(void,cfree,void * p)715 TSAN_INTERCEPTOR(void, cfree, void *p) {
716   if (p == 0)
717     return;
718   if (in_symbolizer())
719     return InternalFree(p);
720   invoke_free_hook(p);
721   SCOPED_INTERCEPTOR_RAW(cfree, p);
722   user_free(thr, pc, p);
723 }
724 
TSAN_INTERCEPTOR(uptr,malloc_usable_size,void * p)725 TSAN_INTERCEPTOR(uptr, malloc_usable_size, void *p) {
726   SCOPED_INTERCEPTOR_RAW(malloc_usable_size, p);
727   return user_alloc_usable_size(p);
728 }
729 #endif
730 
TSAN_INTERCEPTOR(char *,strcpy,char * dst,const char * src)731 TSAN_INTERCEPTOR(char *, strcpy, char *dst, const char *src) {
732   SCOPED_TSAN_INTERCEPTOR(strcpy, dst, src);
733   uptr srclen = internal_strlen(src);
734   MemoryAccessRange(thr, pc, (uptr)dst, srclen + 1, true);
735   MemoryAccessRange(thr, pc, (uptr)src, srclen + 1, false);
736   return REAL(strcpy)(dst, src);
737 }
738 
TSAN_INTERCEPTOR(char *,strncpy,char * dst,char * src,uptr n)739 TSAN_INTERCEPTOR(char*, strncpy, char *dst, char *src, uptr n) {
740   SCOPED_TSAN_INTERCEPTOR(strncpy, dst, src, n);
741   uptr srclen = internal_strnlen(src, n);
742   MemoryAccessRange(thr, pc, (uptr)dst, n, true);
743   MemoryAccessRange(thr, pc, (uptr)src, min(srclen + 1, n), false);
744   return REAL(strncpy)(dst, src, n);
745 }
746 
TSAN_INTERCEPTOR(char *,strdup,const char * str)747 TSAN_INTERCEPTOR(char*, strdup, const char *str) {
748   SCOPED_TSAN_INTERCEPTOR(strdup, str);
749   // strdup will call malloc, so no instrumentation is required here.
750   return REAL(strdup)(str);
751 }
752 
753 // Zero out addr if it points into shadow memory and was provided as a hint
754 // only, i.e., MAP_FIXED is not set.
fix_mmap_addr(void ** addr,long_t sz,int flags)755 static bool fix_mmap_addr(void **addr, long_t sz, int flags) {
756   if (*addr) {
757     if (!IsAppMem((uptr)*addr) || !IsAppMem((uptr)*addr + sz - 1)) {
758       if (flags & MAP_FIXED) {
759         errno = errno_EINVAL;
760         return false;
761       } else {
762         *addr = 0;
763       }
764     }
765   }
766   return true;
767 }
768 
769 template <class Mmap>
mmap_interceptor(ThreadState * thr,uptr pc,Mmap real_mmap,void * addr,SIZE_T sz,int prot,int flags,int fd,OFF64_T off)770 static void *mmap_interceptor(ThreadState *thr, uptr pc, Mmap real_mmap,
771                               void *addr, SIZE_T sz, int prot, int flags,
772                               int fd, OFF64_T off) {
773   if (!fix_mmap_addr(&addr, sz, flags)) return MAP_FAILED;
774   void *res = real_mmap(addr, sz, prot, flags, fd, off);
775   if (res != MAP_FAILED) {
776     if (fd > 0) FdAccess(thr, pc, fd);
777     MemoryRangeImitateWriteOrResetRange(thr, pc, (uptr)res, sz);
778   }
779   return res;
780 }
781 
TSAN_INTERCEPTOR(int,munmap,void * addr,long_t sz)782 TSAN_INTERCEPTOR(int, munmap, void *addr, long_t sz) {
783   SCOPED_TSAN_INTERCEPTOR(munmap, addr, sz);
784   UnmapShadow(thr, (uptr)addr, sz);
785   int res = REAL(munmap)(addr, sz);
786   return res;
787 }
788 
789 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,memalign,uptr align,uptr sz)790 TSAN_INTERCEPTOR(void*, memalign, uptr align, uptr sz) {
791   SCOPED_INTERCEPTOR_RAW(memalign, align, sz);
792   return user_memalign(thr, pc, align, sz);
793 }
794 #define TSAN_MAYBE_INTERCEPT_MEMALIGN TSAN_INTERCEPT(memalign)
795 #else
796 #define TSAN_MAYBE_INTERCEPT_MEMALIGN
797 #endif
798 
799 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(void *,aligned_alloc,uptr align,uptr sz)800 TSAN_INTERCEPTOR(void*, aligned_alloc, uptr align, uptr sz) {
801   if (in_symbolizer())
802     return InternalAlloc(sz, nullptr, align);
803   SCOPED_INTERCEPTOR_RAW(aligned_alloc, align, sz);
804   return user_aligned_alloc(thr, pc, align, sz);
805 }
806 
TSAN_INTERCEPTOR(void *,valloc,uptr sz)807 TSAN_INTERCEPTOR(void*, valloc, uptr sz) {
808   if (in_symbolizer())
809     return InternalAlloc(sz, nullptr, GetPageSizeCached());
810   SCOPED_INTERCEPTOR_RAW(valloc, sz);
811   return user_valloc(thr, pc, sz);
812 }
813 #endif
814 
815 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,pvalloc,uptr sz)816 TSAN_INTERCEPTOR(void*, pvalloc, uptr sz) {
817   if (in_symbolizer()) {
818     uptr PageSize = GetPageSizeCached();
819     sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
820     return InternalAlloc(sz, nullptr, PageSize);
821   }
822   SCOPED_INTERCEPTOR_RAW(pvalloc, sz);
823   return user_pvalloc(thr, pc, sz);
824 }
825 #define TSAN_MAYBE_INTERCEPT_PVALLOC TSAN_INTERCEPT(pvalloc)
826 #else
827 #define TSAN_MAYBE_INTERCEPT_PVALLOC
828 #endif
829 
830 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,posix_memalign,void ** memptr,uptr align,uptr sz)831 TSAN_INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr sz) {
832   if (in_symbolizer()) {
833     void *p = InternalAlloc(sz, nullptr, align);
834     if (!p)
835       return errno_ENOMEM;
836     *memptr = p;
837     return 0;
838   }
839   SCOPED_INTERCEPTOR_RAW(posix_memalign, memptr, align, sz);
840   return user_posix_memalign(thr, pc, memptr, align, sz);
841 }
842 #endif
843 
844 // __cxa_guard_acquire and friends need to be intercepted in a special way -
845 // regular interceptors will break statically-linked libstdc++. Linux
846 // interceptors are especially defined as weak functions (so that they don't
847 // cause link errors when user defines them as well). So they silently
848 // auto-disable themselves when such symbol is already present in the binary. If
849 // we link libstdc++ statically, it will bring own __cxa_guard_acquire which
850 // will silently replace our interceptor.  That's why on Linux we simply export
851 // these interceptors with INTERFACE_ATTRIBUTE.
852 // On OS X, we don't support statically linking, so we just use a regular
853 // interceptor.
854 #if SANITIZER_MAC
855 #define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR
856 #else
857 #define STDCXX_INTERCEPTOR(rettype, name, ...) \
858   extern "C" rettype INTERFACE_ATTRIBUTE name(__VA_ARGS__)
859 #endif
860 
861 // Used in thread-safe function static initialization.
STDCXX_INTERCEPTOR(int,__cxa_guard_acquire,atomic_uint32_t * g)862 STDCXX_INTERCEPTOR(int, __cxa_guard_acquire, atomic_uint32_t *g) {
863   SCOPED_INTERCEPTOR_RAW(__cxa_guard_acquire, g);
864   OnPotentiallyBlockingRegionBegin();
865   auto on_exit = at_scope_exit(&OnPotentiallyBlockingRegionEnd);
866   for (;;) {
867     u32 cmp = atomic_load(g, memory_order_acquire);
868     if (cmp == 0) {
869       if (atomic_compare_exchange_strong(g, &cmp, 1<<16, memory_order_relaxed))
870         return 1;
871     } else if (cmp == 1) {
872       Acquire(thr, pc, (uptr)g);
873       return 0;
874     } else {
875       internal_sched_yield();
876     }
877   }
878 }
879 
STDCXX_INTERCEPTOR(void,__cxa_guard_release,atomic_uint32_t * g)880 STDCXX_INTERCEPTOR(void, __cxa_guard_release, atomic_uint32_t *g) {
881   SCOPED_INTERCEPTOR_RAW(__cxa_guard_release, g);
882   Release(thr, pc, (uptr)g);
883   atomic_store(g, 1, memory_order_release);
884 }
885 
STDCXX_INTERCEPTOR(void,__cxa_guard_abort,atomic_uint32_t * g)886 STDCXX_INTERCEPTOR(void, __cxa_guard_abort, atomic_uint32_t *g) {
887   SCOPED_INTERCEPTOR_RAW(__cxa_guard_abort, g);
888   atomic_store(g, 0, memory_order_relaxed);
889 }
890 
891 namespace __tsan {
DestroyThreadState()892 void DestroyThreadState() {
893   ThreadState *thr = cur_thread();
894   Processor *proc = thr->proc();
895   ThreadFinish(thr);
896   ProcUnwire(proc, thr);
897   ProcDestroy(proc);
898   DTLS_Destroy();
899   cur_thread_finalize();
900 }
901 
PlatformCleanUpThreadState(ThreadState * thr)902 void PlatformCleanUpThreadState(ThreadState *thr) {
903   ThreadSignalContext *sctx = thr->signal_ctx;
904   if (sctx) {
905     thr->signal_ctx = 0;
906     UnmapOrDie(sctx, sizeof(*sctx));
907   }
908 }
909 }  // namespace __tsan
910 
911 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
thread_finalize(void * v)912 static void thread_finalize(void *v) {
913   uptr iter = (uptr)v;
914   if (iter > 1) {
915     if (pthread_setspecific(interceptor_ctx()->finalize_key,
916         (void*)(iter - 1))) {
917       Printf("ThreadSanitizer: failed to set thread key\n");
918       Die();
919     }
920     return;
921   }
922   DestroyThreadState();
923 }
924 #endif
925 
926 
927 struct ThreadParam {
928   void* (*callback)(void *arg);
929   void *param;
930   atomic_uintptr_t tid;
931 };
932 
__tsan_thread_start_func(void * arg)933 extern "C" void *__tsan_thread_start_func(void *arg) {
934   ThreadParam *p = (ThreadParam*)arg;
935   void* (*callback)(void *arg) = p->callback;
936   void *param = p->param;
937   int tid = 0;
938   {
939     cur_thread_init();
940     ThreadState *thr = cur_thread();
941     // Thread-local state is not initialized yet.
942     ScopedIgnoreInterceptors ignore;
943 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
944     ThreadIgnoreBegin(thr, 0);
945     if (pthread_setspecific(interceptor_ctx()->finalize_key,
946                             (void *)GetPthreadDestructorIterations())) {
947       Printf("ThreadSanitizer: failed to set thread key\n");
948       Die();
949     }
950     ThreadIgnoreEnd(thr, 0);
951 #endif
952     while ((tid = atomic_load(&p->tid, memory_order_acquire)) == 0)
953       internal_sched_yield();
954     Processor *proc = ProcCreate();
955     ProcWire(proc, thr);
956     ThreadStart(thr, tid, GetTid(), ThreadType::Regular);
957     atomic_store(&p->tid, 0, memory_order_release);
958   }
959   void *res = callback(param);
960   // Prevent the callback from being tail called,
961   // it mixes up stack traces.
962   volatile int foo = 42;
963   foo++;
964   return res;
965 }
966 
TSAN_INTERCEPTOR(int,pthread_create,void * th,void * attr,void * (* callback)(void *),void * param)967 TSAN_INTERCEPTOR(int, pthread_create,
968     void *th, void *attr, void *(*callback)(void*), void * param) {
969   SCOPED_INTERCEPTOR_RAW(pthread_create, th, attr, callback, param);
970 
971   MaybeSpawnBackgroundThread();
972 
973   if (ctx->after_multithreaded_fork) {
974     if (flags()->die_after_fork) {
975       Report("ThreadSanitizer: starting new threads after multi-threaded "
976           "fork is not supported. Dying (set die_after_fork=0 to override)\n");
977       Die();
978     } else {
979       VPrintf(1, "ThreadSanitizer: starting new threads after multi-threaded "
980           "fork is not supported (pid %d). Continuing because of "
981           "die_after_fork=0, but you are on your own\n", internal_getpid());
982     }
983   }
984   __sanitizer_pthread_attr_t myattr;
985   if (attr == 0) {
986     pthread_attr_init(&myattr);
987     attr = &myattr;
988   }
989   int detached = 0;
990   REAL(pthread_attr_getdetachstate)(attr, &detached);
991   AdjustStackSize(attr);
992 
993   ThreadParam p;
994   p.callback = callback;
995   p.param = param;
996   atomic_store(&p.tid, 0, memory_order_relaxed);
997   int res = -1;
998   {
999     // Otherwise we see false positives in pthread stack manipulation.
1000     ScopedIgnoreInterceptors ignore;
1001     ThreadIgnoreBegin(thr, pc);
1002     res = REAL(pthread_create)(th, attr, __tsan_thread_start_func, &p);
1003     ThreadIgnoreEnd(thr, pc);
1004   }
1005   if (res == 0) {
1006     int tid = ThreadCreate(thr, pc, *(uptr*)th, IsStateDetached(detached));
1007     CHECK_NE(tid, 0);
1008     // Synchronization on p.tid serves two purposes:
1009     // 1. ThreadCreate must finish before the new thread starts.
1010     //    Otherwise the new thread can call pthread_detach, but the pthread_t
1011     //    identifier is not yet registered in ThreadRegistry by ThreadCreate.
1012     // 2. ThreadStart must finish before this thread continues.
1013     //    Otherwise, this thread can call pthread_detach and reset thr->sync
1014     //    before the new thread got a chance to acquire from it in ThreadStart.
1015     atomic_store(&p.tid, tid, memory_order_release);
1016     while (atomic_load(&p.tid, memory_order_acquire) != 0)
1017       internal_sched_yield();
1018   }
1019   if (attr == &myattr)
1020     pthread_attr_destroy(&myattr);
1021   return res;
1022 }
1023 
TSAN_INTERCEPTOR(int,pthread_join,void * th,void ** ret)1024 TSAN_INTERCEPTOR(int, pthread_join, void *th, void **ret) {
1025   SCOPED_INTERCEPTOR_RAW(pthread_join, th, ret);
1026   int tid = ThreadConsumeTid(thr, pc, (uptr)th);
1027   ThreadIgnoreBegin(thr, pc);
1028   int res = BLOCK_REAL(pthread_join)(th, ret);
1029   ThreadIgnoreEnd(thr, pc);
1030   if (res == 0) {
1031     ThreadJoin(thr, pc, tid);
1032   }
1033   return res;
1034 }
1035 
1036 DEFINE_REAL_PTHREAD_FUNCTIONS
1037 
TSAN_INTERCEPTOR(int,pthread_detach,void * th)1038 TSAN_INTERCEPTOR(int, pthread_detach, void *th) {
1039   SCOPED_INTERCEPTOR_RAW(pthread_detach, th);
1040   int tid = ThreadConsumeTid(thr, pc, (uptr)th);
1041   int res = REAL(pthread_detach)(th);
1042   if (res == 0) {
1043     ThreadDetach(thr, pc, tid);
1044   }
1045   return res;
1046 }
1047 
TSAN_INTERCEPTOR(void,pthread_exit,void * retval)1048 TSAN_INTERCEPTOR(void, pthread_exit, void *retval) {
1049   {
1050     SCOPED_INTERCEPTOR_RAW(pthread_exit, retval);
1051 #if !SANITIZER_MAC && !SANITIZER_ANDROID
1052     CHECK_EQ(thr, &cur_thread_placeholder);
1053 #endif
1054   }
1055   REAL(pthread_exit)(retval);
1056 }
1057 
1058 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,pthread_tryjoin_np,void * th,void ** ret)1059 TSAN_INTERCEPTOR(int, pthread_tryjoin_np, void *th, void **ret) {
1060   SCOPED_INTERCEPTOR_RAW(pthread_tryjoin_np, th, ret);
1061   int tid = ThreadConsumeTid(thr, pc, (uptr)th);
1062   ThreadIgnoreBegin(thr, pc);
1063   int res = REAL(pthread_tryjoin_np)(th, ret);
1064   ThreadIgnoreEnd(thr, pc);
1065   if (res == 0)
1066     ThreadJoin(thr, pc, tid);
1067   else
1068     ThreadNotJoined(thr, pc, tid, (uptr)th);
1069   return res;
1070 }
1071 
TSAN_INTERCEPTOR(int,pthread_timedjoin_np,void * th,void ** ret,const struct timespec * abstime)1072 TSAN_INTERCEPTOR(int, pthread_timedjoin_np, void *th, void **ret,
1073                  const struct timespec *abstime) {
1074   SCOPED_INTERCEPTOR_RAW(pthread_timedjoin_np, th, ret, abstime);
1075   int tid = ThreadConsumeTid(thr, pc, (uptr)th);
1076   ThreadIgnoreBegin(thr, pc);
1077   int res = BLOCK_REAL(pthread_timedjoin_np)(th, ret, abstime);
1078   ThreadIgnoreEnd(thr, pc);
1079   if (res == 0)
1080     ThreadJoin(thr, pc, tid);
1081   else
1082     ThreadNotJoined(thr, pc, tid, (uptr)th);
1083   return res;
1084 }
1085 #endif
1086 
1087 // Problem:
1088 // NPTL implementation of pthread_cond has 2 versions (2.2.5 and 2.3.2).
1089 // pthread_cond_t has different size in the different versions.
1090 // If call new REAL functions for old pthread_cond_t, they will corrupt memory
1091 // after pthread_cond_t (old cond is smaller).
1092 // If we call old REAL functions for new pthread_cond_t, we will lose  some
1093 // functionality (e.g. old functions do not support waiting against
1094 // CLOCK_REALTIME).
1095 // Proper handling would require to have 2 versions of interceptors as well.
1096 // But this is messy, in particular requires linker scripts when sanitizer
1097 // runtime is linked into a shared library.
1098 // Instead we assume we don't have dynamic libraries built against old
1099 // pthread (2.2.5 is dated by 2002). And provide legacy_pthread_cond flag
1100 // that allows to work with old libraries (but this mode does not support
1101 // some features, e.g. pthread_condattr_getpshared).
init_cond(void * c,bool force=false)1102 static void *init_cond(void *c, bool force = false) {
1103   // sizeof(pthread_cond_t) >= sizeof(uptr) in both versions.
1104   // So we allocate additional memory on the side large enough to hold
1105   // any pthread_cond_t object. Always call new REAL functions, but pass
1106   // the aux object to them.
1107   // Note: the code assumes that PTHREAD_COND_INITIALIZER initializes
1108   // first word of pthread_cond_t to zero.
1109   // It's all relevant only for linux.
1110   if (!common_flags()->legacy_pthread_cond)
1111     return c;
1112   atomic_uintptr_t *p = (atomic_uintptr_t*)c;
1113   uptr cond = atomic_load(p, memory_order_acquire);
1114   if (!force && cond != 0)
1115     return (void*)cond;
1116   void *newcond = WRAP(malloc)(pthread_cond_t_sz);
1117   internal_memset(newcond, 0, pthread_cond_t_sz);
1118   if (atomic_compare_exchange_strong(p, &cond, (uptr)newcond,
1119       memory_order_acq_rel))
1120     return newcond;
1121   WRAP(free)(newcond);
1122   return (void*)cond;
1123 }
1124 
1125 namespace {
1126 
1127 template <class Fn>
1128 struct CondMutexUnlockCtx {
1129   ScopedInterceptor *si;
1130   ThreadState *thr;
1131   uptr pc;
1132   void *m;
1133   void *c;
1134   const Fn &fn;
1135 
Cancel__anon4024eda90111::CondMutexUnlockCtx1136   int Cancel() const { return fn(); }
1137   void Unlock() const;
1138 };
1139 
1140 template <class Fn>
Unlock() const1141 void CondMutexUnlockCtx<Fn>::Unlock() const {
1142   // pthread_cond_wait interceptor has enabled async signal delivery
1143   // (see BlockingCall below). Disable async signals since we are running
1144   // tsan code. Also ScopedInterceptor and BlockingCall destructors won't run
1145   // since the thread is cancelled, so we have to manually execute them
1146   // (the thread still can run some user code due to pthread_cleanup_push).
1147   ThreadSignalContext *ctx = SigCtx(thr);
1148   CHECK_EQ(atomic_load(&ctx->in_blocking_func, memory_order_relaxed), 1);
1149   atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
1150   MutexPostLock(thr, pc, (uptr)m, MutexFlagDoPreLockOnPostLock);
1151   // Undo BlockingCall ctor effects.
1152   thr->ignore_interceptors--;
1153   si->~ScopedInterceptor();
1154 }
1155 }  // namespace
1156 
INTERCEPTOR(int,pthread_cond_init,void * c,void * a)1157 INTERCEPTOR(int, pthread_cond_init, void *c, void *a) {
1158   void *cond = init_cond(c, true);
1159   SCOPED_TSAN_INTERCEPTOR(pthread_cond_init, cond, a);
1160   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true);
1161   return REAL(pthread_cond_init)(cond, a);
1162 }
1163 
1164 template <class Fn>
cond_wait(ThreadState * thr,uptr pc,ScopedInterceptor * si,const Fn & fn,void * c,void * m)1165 int cond_wait(ThreadState *thr, uptr pc, ScopedInterceptor *si, const Fn &fn,
1166               void *c, void *m) {
1167   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1168   MutexUnlock(thr, pc, (uptr)m);
1169   int res = 0;
1170   // This ensures that we handle mutex lock even in case of pthread_cancel.
1171   // See test/tsan/cond_cancel.cpp.
1172   {
1173     // Enable signal delivery while the thread is blocked.
1174     BlockingCall bc(thr);
1175     CondMutexUnlockCtx<Fn> arg = {si, thr, pc, m, c, fn};
1176     res = call_pthread_cancel_with_cleanup(
1177         [](void *arg) -> int {
1178           return ((const CondMutexUnlockCtx<Fn> *)arg)->Cancel();
1179         },
1180         [](void *arg) { ((const CondMutexUnlockCtx<Fn> *)arg)->Unlock(); },
1181         &arg);
1182   }
1183   if (res == errno_EOWNERDEAD) MutexRepair(thr, pc, (uptr)m);
1184   MutexPostLock(thr, pc, (uptr)m, MutexFlagDoPreLockOnPostLock);
1185   return res;
1186 }
1187 
INTERCEPTOR(int,pthread_cond_wait,void * c,void * m)1188 INTERCEPTOR(int, pthread_cond_wait, void *c, void *m) {
1189   void *cond = init_cond(c);
1190   SCOPED_TSAN_INTERCEPTOR(pthread_cond_wait, cond, m);
1191   return cond_wait(
1192       thr, pc, &si, [=]() { return REAL(pthread_cond_wait)(cond, m); }, cond,
1193       m);
1194 }
1195 
INTERCEPTOR(int,pthread_cond_timedwait,void * c,void * m,void * abstime)1196 INTERCEPTOR(int, pthread_cond_timedwait, void *c, void *m, void *abstime) {
1197   void *cond = init_cond(c);
1198   SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait, cond, m, abstime);
1199   return cond_wait(
1200       thr, pc, &si,
1201       [=]() { return REAL(pthread_cond_timedwait)(cond, m, abstime); }, cond,
1202       m);
1203 }
1204 
1205 #if SANITIZER_LINUX
INTERCEPTOR(int,pthread_cond_clockwait,void * c,void * m,__sanitizer_clockid_t clock,void * abstime)1206 INTERCEPTOR(int, pthread_cond_clockwait, void *c, void *m,
1207             __sanitizer_clockid_t clock, void *abstime) {
1208   void *cond = init_cond(c);
1209   SCOPED_TSAN_INTERCEPTOR(pthread_cond_clockwait, cond, m, clock, abstime);
1210   return cond_wait(
1211       thr, pc, &si,
1212       [=]() { return REAL(pthread_cond_clockwait)(cond, m, clock, abstime); },
1213       cond, m);
1214 }
1215 #define TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT TSAN_INTERCEPT(pthread_cond_clockwait)
1216 #else
1217 #define TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT
1218 #endif
1219 
1220 #if SANITIZER_MAC
INTERCEPTOR(int,pthread_cond_timedwait_relative_np,void * c,void * m,void * reltime)1221 INTERCEPTOR(int, pthread_cond_timedwait_relative_np, void *c, void *m,
1222             void *reltime) {
1223   void *cond = init_cond(c);
1224   SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait_relative_np, cond, m, reltime);
1225   return cond_wait(
1226       thr, pc, &si,
1227       [=]() {
1228         return REAL(pthread_cond_timedwait_relative_np)(cond, m, reltime);
1229       },
1230       cond, m);
1231 }
1232 #endif
1233 
INTERCEPTOR(int,pthread_cond_signal,void * c)1234 INTERCEPTOR(int, pthread_cond_signal, void *c) {
1235   void *cond = init_cond(c);
1236   SCOPED_TSAN_INTERCEPTOR(pthread_cond_signal, cond);
1237   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1238   return REAL(pthread_cond_signal)(cond);
1239 }
1240 
INTERCEPTOR(int,pthread_cond_broadcast,void * c)1241 INTERCEPTOR(int, pthread_cond_broadcast, void *c) {
1242   void *cond = init_cond(c);
1243   SCOPED_TSAN_INTERCEPTOR(pthread_cond_broadcast, cond);
1244   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1245   return REAL(pthread_cond_broadcast)(cond);
1246 }
1247 
INTERCEPTOR(int,pthread_cond_destroy,void * c)1248 INTERCEPTOR(int, pthread_cond_destroy, void *c) {
1249   void *cond = init_cond(c);
1250   SCOPED_TSAN_INTERCEPTOR(pthread_cond_destroy, cond);
1251   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true);
1252   int res = REAL(pthread_cond_destroy)(cond);
1253   if (common_flags()->legacy_pthread_cond) {
1254     // Free our aux cond and zero the pointer to not leave dangling pointers.
1255     WRAP(free)(cond);
1256     atomic_store((atomic_uintptr_t*)c, 0, memory_order_relaxed);
1257   }
1258   return res;
1259 }
1260 
TSAN_INTERCEPTOR(int,pthread_mutex_init,void * m,void * a)1261 TSAN_INTERCEPTOR(int, pthread_mutex_init, void *m, void *a) {
1262   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_init, m, a);
1263   int res = REAL(pthread_mutex_init)(m, a);
1264   if (res == 0) {
1265     u32 flagz = 0;
1266     if (a) {
1267       int type = 0;
1268       if (REAL(pthread_mutexattr_gettype)(a, &type) == 0)
1269         if (type == PTHREAD_MUTEX_RECURSIVE ||
1270             type == PTHREAD_MUTEX_RECURSIVE_NP)
1271           flagz |= MutexFlagWriteReentrant;
1272     }
1273     MutexCreate(thr, pc, (uptr)m, flagz);
1274   }
1275   return res;
1276 }
1277 
TSAN_INTERCEPTOR(int,pthread_mutex_destroy,void * m)1278 TSAN_INTERCEPTOR(int, pthread_mutex_destroy, void *m) {
1279   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_destroy, m);
1280   int res = REAL(pthread_mutex_destroy)(m);
1281   if (res == 0 || res == errno_EBUSY) {
1282     MutexDestroy(thr, pc, (uptr)m);
1283   }
1284   return res;
1285 }
1286 
TSAN_INTERCEPTOR(int,pthread_mutex_trylock,void * m)1287 TSAN_INTERCEPTOR(int, pthread_mutex_trylock, void *m) {
1288   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_trylock, m);
1289   int res = REAL(pthread_mutex_trylock)(m);
1290   if (res == errno_EOWNERDEAD)
1291     MutexRepair(thr, pc, (uptr)m);
1292   if (res == 0 || res == errno_EOWNERDEAD)
1293     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1294   return res;
1295 }
1296 
1297 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_mutex_timedlock,void * m,void * abstime)1298 TSAN_INTERCEPTOR(int, pthread_mutex_timedlock, void *m, void *abstime) {
1299   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_timedlock, m, abstime);
1300   int res = REAL(pthread_mutex_timedlock)(m, abstime);
1301   if (res == 0) {
1302     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1303   }
1304   return res;
1305 }
1306 #endif
1307 
1308 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_spin_init,void * m,int pshared)1309 TSAN_INTERCEPTOR(int, pthread_spin_init, void *m, int pshared) {
1310   SCOPED_TSAN_INTERCEPTOR(pthread_spin_init, m, pshared);
1311   int res = REAL(pthread_spin_init)(m, pshared);
1312   if (res == 0) {
1313     MutexCreate(thr, pc, (uptr)m);
1314   }
1315   return res;
1316 }
1317 
TSAN_INTERCEPTOR(int,pthread_spin_destroy,void * m)1318 TSAN_INTERCEPTOR(int, pthread_spin_destroy, void *m) {
1319   SCOPED_TSAN_INTERCEPTOR(pthread_spin_destroy, m);
1320   int res = REAL(pthread_spin_destroy)(m);
1321   if (res == 0) {
1322     MutexDestroy(thr, pc, (uptr)m);
1323   }
1324   return res;
1325 }
1326 
TSAN_INTERCEPTOR(int,pthread_spin_lock,void * m)1327 TSAN_INTERCEPTOR(int, pthread_spin_lock, void *m) {
1328   SCOPED_TSAN_INTERCEPTOR(pthread_spin_lock, m);
1329   MutexPreLock(thr, pc, (uptr)m);
1330   int res = REAL(pthread_spin_lock)(m);
1331   if (res == 0) {
1332     MutexPostLock(thr, pc, (uptr)m);
1333   }
1334   return res;
1335 }
1336 
TSAN_INTERCEPTOR(int,pthread_spin_trylock,void * m)1337 TSAN_INTERCEPTOR(int, pthread_spin_trylock, void *m) {
1338   SCOPED_TSAN_INTERCEPTOR(pthread_spin_trylock, m);
1339   int res = REAL(pthread_spin_trylock)(m);
1340   if (res == 0) {
1341     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1342   }
1343   return res;
1344 }
1345 
TSAN_INTERCEPTOR(int,pthread_spin_unlock,void * m)1346 TSAN_INTERCEPTOR(int, pthread_spin_unlock, void *m) {
1347   SCOPED_TSAN_INTERCEPTOR(pthread_spin_unlock, m);
1348   MutexUnlock(thr, pc, (uptr)m);
1349   int res = REAL(pthread_spin_unlock)(m);
1350   return res;
1351 }
1352 #endif
1353 
TSAN_INTERCEPTOR(int,pthread_rwlock_init,void * m,void * a)1354 TSAN_INTERCEPTOR(int, pthread_rwlock_init, void *m, void *a) {
1355   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_init, m, a);
1356   int res = REAL(pthread_rwlock_init)(m, a);
1357   if (res == 0) {
1358     MutexCreate(thr, pc, (uptr)m);
1359   }
1360   return res;
1361 }
1362 
TSAN_INTERCEPTOR(int,pthread_rwlock_destroy,void * m)1363 TSAN_INTERCEPTOR(int, pthread_rwlock_destroy, void *m) {
1364   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_destroy, m);
1365   int res = REAL(pthread_rwlock_destroy)(m);
1366   if (res == 0) {
1367     MutexDestroy(thr, pc, (uptr)m);
1368   }
1369   return res;
1370 }
1371 
TSAN_INTERCEPTOR(int,pthread_rwlock_rdlock,void * m)1372 TSAN_INTERCEPTOR(int, pthread_rwlock_rdlock, void *m) {
1373   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_rdlock, m);
1374   MutexPreReadLock(thr, pc, (uptr)m);
1375   int res = REAL(pthread_rwlock_rdlock)(m);
1376   if (res == 0) {
1377     MutexPostReadLock(thr, pc, (uptr)m);
1378   }
1379   return res;
1380 }
1381 
TSAN_INTERCEPTOR(int,pthread_rwlock_tryrdlock,void * m)1382 TSAN_INTERCEPTOR(int, pthread_rwlock_tryrdlock, void *m) {
1383   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_tryrdlock, m);
1384   int res = REAL(pthread_rwlock_tryrdlock)(m);
1385   if (res == 0) {
1386     MutexPostReadLock(thr, pc, (uptr)m, MutexFlagTryLock);
1387   }
1388   return res;
1389 }
1390 
1391 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_rwlock_timedrdlock,void * m,void * abstime)1392 TSAN_INTERCEPTOR(int, pthread_rwlock_timedrdlock, void *m, void *abstime) {
1393   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedrdlock, m, abstime);
1394   int res = REAL(pthread_rwlock_timedrdlock)(m, abstime);
1395   if (res == 0) {
1396     MutexPostReadLock(thr, pc, (uptr)m);
1397   }
1398   return res;
1399 }
1400 #endif
1401 
TSAN_INTERCEPTOR(int,pthread_rwlock_wrlock,void * m)1402 TSAN_INTERCEPTOR(int, pthread_rwlock_wrlock, void *m) {
1403   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_wrlock, m);
1404   MutexPreLock(thr, pc, (uptr)m);
1405   int res = REAL(pthread_rwlock_wrlock)(m);
1406   if (res == 0) {
1407     MutexPostLock(thr, pc, (uptr)m);
1408   }
1409   return res;
1410 }
1411 
TSAN_INTERCEPTOR(int,pthread_rwlock_trywrlock,void * m)1412 TSAN_INTERCEPTOR(int, pthread_rwlock_trywrlock, void *m) {
1413   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_trywrlock, m);
1414   int res = REAL(pthread_rwlock_trywrlock)(m);
1415   if (res == 0) {
1416     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1417   }
1418   return res;
1419 }
1420 
1421 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_rwlock_timedwrlock,void * m,void * abstime)1422 TSAN_INTERCEPTOR(int, pthread_rwlock_timedwrlock, void *m, void *abstime) {
1423   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedwrlock, m, abstime);
1424   int res = REAL(pthread_rwlock_timedwrlock)(m, abstime);
1425   if (res == 0) {
1426     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1427   }
1428   return res;
1429 }
1430 #endif
1431 
TSAN_INTERCEPTOR(int,pthread_rwlock_unlock,void * m)1432 TSAN_INTERCEPTOR(int, pthread_rwlock_unlock, void *m) {
1433   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_unlock, m);
1434   MutexReadOrWriteUnlock(thr, pc, (uptr)m);
1435   int res = REAL(pthread_rwlock_unlock)(m);
1436   return res;
1437 }
1438 
1439 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_barrier_init,void * b,void * a,unsigned count)1440 TSAN_INTERCEPTOR(int, pthread_barrier_init, void *b, void *a, unsigned count) {
1441   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_init, b, a, count);
1442   MemoryWrite(thr, pc, (uptr)b, kSizeLog1);
1443   int res = REAL(pthread_barrier_init)(b, a, count);
1444   return res;
1445 }
1446 
TSAN_INTERCEPTOR(int,pthread_barrier_destroy,void * b)1447 TSAN_INTERCEPTOR(int, pthread_barrier_destroy, void *b) {
1448   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_destroy, b);
1449   MemoryWrite(thr, pc, (uptr)b, kSizeLog1);
1450   int res = REAL(pthread_barrier_destroy)(b);
1451   return res;
1452 }
1453 
TSAN_INTERCEPTOR(int,pthread_barrier_wait,void * b)1454 TSAN_INTERCEPTOR(int, pthread_barrier_wait, void *b) {
1455   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_wait, b);
1456   Release(thr, pc, (uptr)b);
1457   MemoryRead(thr, pc, (uptr)b, kSizeLog1);
1458   int res = REAL(pthread_barrier_wait)(b);
1459   MemoryRead(thr, pc, (uptr)b, kSizeLog1);
1460   if (res == 0 || res == PTHREAD_BARRIER_SERIAL_THREAD) {
1461     Acquire(thr, pc, (uptr)b);
1462   }
1463   return res;
1464 }
1465 #endif
1466 
TSAN_INTERCEPTOR(int,pthread_once,void * o,void (* f)())1467 TSAN_INTERCEPTOR(int, pthread_once, void *o, void (*f)()) {
1468   SCOPED_INTERCEPTOR_RAW(pthread_once, o, f);
1469   if (o == 0 || f == 0)
1470     return errno_EINVAL;
1471   atomic_uint32_t *a;
1472 
1473   if (SANITIZER_MAC)
1474     a = static_cast<atomic_uint32_t*>((void *)((char *)o + sizeof(long_t)));
1475   else if (SANITIZER_NETBSD)
1476     a = static_cast<atomic_uint32_t*>
1477           ((void *)((char *)o + __sanitizer::pthread_mutex_t_sz));
1478   else
1479     a = static_cast<atomic_uint32_t*>(o);
1480 
1481   u32 v = atomic_load(a, memory_order_acquire);
1482   if (v == 0 && atomic_compare_exchange_strong(a, &v, 1,
1483                                                memory_order_relaxed)) {
1484     (*f)();
1485     if (!thr->in_ignored_lib)
1486       Release(thr, pc, (uptr)o);
1487     atomic_store(a, 2, memory_order_release);
1488   } else {
1489     while (v != 2) {
1490       internal_sched_yield();
1491       v = atomic_load(a, memory_order_acquire);
1492     }
1493     if (!thr->in_ignored_lib)
1494       Acquire(thr, pc, (uptr)o);
1495   }
1496   return 0;
1497 }
1498 
1499 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,__fxstat,int version,int fd,void * buf)1500 TSAN_INTERCEPTOR(int, __fxstat, int version, int fd, void *buf) {
1501   SCOPED_TSAN_INTERCEPTOR(__fxstat, version, fd, buf);
1502   if (fd > 0)
1503     FdAccess(thr, pc, fd);
1504   return REAL(__fxstat)(version, fd, buf);
1505 }
1506 #define TSAN_MAYBE_INTERCEPT___FXSTAT TSAN_INTERCEPT(__fxstat)
1507 #else
1508 #define TSAN_MAYBE_INTERCEPT___FXSTAT
1509 #endif
1510 
TSAN_INTERCEPTOR(int,fstat,int fd,void * buf)1511 TSAN_INTERCEPTOR(int, fstat, int fd, void *buf) {
1512 #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_ANDROID || SANITIZER_NETBSD
1513   SCOPED_TSAN_INTERCEPTOR(fstat, fd, buf);
1514   if (fd > 0)
1515     FdAccess(thr, pc, fd);
1516   return REAL(fstat)(fd, buf);
1517 #else
1518   SCOPED_TSAN_INTERCEPTOR(__fxstat, 0, fd, buf);
1519   if (fd > 0)
1520     FdAccess(thr, pc, fd);
1521   return REAL(__fxstat)(0, fd, buf);
1522 #endif
1523 }
1524 
1525 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,__fxstat64,int version,int fd,void * buf)1526 TSAN_INTERCEPTOR(int, __fxstat64, int version, int fd, void *buf) {
1527   SCOPED_TSAN_INTERCEPTOR(__fxstat64, version, fd, buf);
1528   if (fd > 0)
1529     FdAccess(thr, pc, fd);
1530   return REAL(__fxstat64)(version, fd, buf);
1531 }
1532 #define TSAN_MAYBE_INTERCEPT___FXSTAT64 TSAN_INTERCEPT(__fxstat64)
1533 #else
1534 #define TSAN_MAYBE_INTERCEPT___FXSTAT64
1535 #endif
1536 
1537 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,fstat64,int fd,void * buf)1538 TSAN_INTERCEPTOR(int, fstat64, int fd, void *buf) {
1539   SCOPED_TSAN_INTERCEPTOR(__fxstat64, 0, fd, buf);
1540   if (fd > 0)
1541     FdAccess(thr, pc, fd);
1542   return REAL(__fxstat64)(0, fd, buf);
1543 }
1544 #define TSAN_MAYBE_INTERCEPT_FSTAT64 TSAN_INTERCEPT(fstat64)
1545 #else
1546 #define TSAN_MAYBE_INTERCEPT_FSTAT64
1547 #endif
1548 
TSAN_INTERCEPTOR(int,open,const char * name,int oflag,...)1549 TSAN_INTERCEPTOR(int, open, const char *name, int oflag, ...) {
1550   va_list ap;
1551   va_start(ap, oflag);
1552   mode_t mode = va_arg(ap, int);
1553   va_end(ap);
1554   SCOPED_TSAN_INTERCEPTOR(open, name, oflag, mode);
1555   READ_STRING(thr, pc, name, 0);
1556   int fd = REAL(open)(name, oflag, mode);
1557   if (fd >= 0)
1558     FdFileCreate(thr, pc, fd);
1559   return fd;
1560 }
1561 
1562 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,open64,const char * name,int oflag,...)1563 TSAN_INTERCEPTOR(int, open64, const char *name, int oflag, ...) {
1564   va_list ap;
1565   va_start(ap, oflag);
1566   mode_t mode = va_arg(ap, int);
1567   va_end(ap);
1568   SCOPED_TSAN_INTERCEPTOR(open64, name, oflag, mode);
1569   READ_STRING(thr, pc, name, 0);
1570   int fd = REAL(open64)(name, oflag, mode);
1571   if (fd >= 0)
1572     FdFileCreate(thr, pc, fd);
1573   return fd;
1574 }
1575 #define TSAN_MAYBE_INTERCEPT_OPEN64 TSAN_INTERCEPT(open64)
1576 #else
1577 #define TSAN_MAYBE_INTERCEPT_OPEN64
1578 #endif
1579 
TSAN_INTERCEPTOR(int,creat,const char * name,int mode)1580 TSAN_INTERCEPTOR(int, creat, const char *name, int mode) {
1581   SCOPED_TSAN_INTERCEPTOR(creat, name, mode);
1582   READ_STRING(thr, pc, name, 0);
1583   int fd = REAL(creat)(name, mode);
1584   if (fd >= 0)
1585     FdFileCreate(thr, pc, fd);
1586   return fd;
1587 }
1588 
1589 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,creat64,const char * name,int mode)1590 TSAN_INTERCEPTOR(int, creat64, const char *name, int mode) {
1591   SCOPED_TSAN_INTERCEPTOR(creat64, name, mode);
1592   READ_STRING(thr, pc, name, 0);
1593   int fd = REAL(creat64)(name, mode);
1594   if (fd >= 0)
1595     FdFileCreate(thr, pc, fd);
1596   return fd;
1597 }
1598 #define TSAN_MAYBE_INTERCEPT_CREAT64 TSAN_INTERCEPT(creat64)
1599 #else
1600 #define TSAN_MAYBE_INTERCEPT_CREAT64
1601 #endif
1602 
TSAN_INTERCEPTOR(int,dup,int oldfd)1603 TSAN_INTERCEPTOR(int, dup, int oldfd) {
1604   SCOPED_TSAN_INTERCEPTOR(dup, oldfd);
1605   int newfd = REAL(dup)(oldfd);
1606   if (oldfd >= 0 && newfd >= 0 && newfd != oldfd)
1607     FdDup(thr, pc, oldfd, newfd, true);
1608   return newfd;
1609 }
1610 
TSAN_INTERCEPTOR(int,dup2,int oldfd,int newfd)1611 TSAN_INTERCEPTOR(int, dup2, int oldfd, int newfd) {
1612   SCOPED_TSAN_INTERCEPTOR(dup2, oldfd, newfd);
1613   int newfd2 = REAL(dup2)(oldfd, newfd);
1614   if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd)
1615     FdDup(thr, pc, oldfd, newfd2, false);
1616   return newfd2;
1617 }
1618 
1619 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,dup3,int oldfd,int newfd,int flags)1620 TSAN_INTERCEPTOR(int, dup3, int oldfd, int newfd, int flags) {
1621   SCOPED_TSAN_INTERCEPTOR(dup3, oldfd, newfd, flags);
1622   int newfd2 = REAL(dup3)(oldfd, newfd, flags);
1623   if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd)
1624     FdDup(thr, pc, oldfd, newfd2, false);
1625   return newfd2;
1626 }
1627 #endif
1628 
1629 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,eventfd,unsigned initval,int flags)1630 TSAN_INTERCEPTOR(int, eventfd, unsigned initval, int flags) {
1631   SCOPED_TSAN_INTERCEPTOR(eventfd, initval, flags);
1632   int fd = REAL(eventfd)(initval, flags);
1633   if (fd >= 0)
1634     FdEventCreate(thr, pc, fd);
1635   return fd;
1636 }
1637 #define TSAN_MAYBE_INTERCEPT_EVENTFD TSAN_INTERCEPT(eventfd)
1638 #else
1639 #define TSAN_MAYBE_INTERCEPT_EVENTFD
1640 #endif
1641 
1642 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,signalfd,int fd,void * mask,int flags)1643 TSAN_INTERCEPTOR(int, signalfd, int fd, void *mask, int flags) {
1644   SCOPED_TSAN_INTERCEPTOR(signalfd, fd, mask, flags);
1645   if (fd >= 0)
1646     FdClose(thr, pc, fd);
1647   fd = REAL(signalfd)(fd, mask, flags);
1648   if (fd >= 0)
1649     FdSignalCreate(thr, pc, fd);
1650   return fd;
1651 }
1652 #define TSAN_MAYBE_INTERCEPT_SIGNALFD TSAN_INTERCEPT(signalfd)
1653 #else
1654 #define TSAN_MAYBE_INTERCEPT_SIGNALFD
1655 #endif
1656 
1657 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,inotify_init,int fake)1658 TSAN_INTERCEPTOR(int, inotify_init, int fake) {
1659   SCOPED_TSAN_INTERCEPTOR(inotify_init, fake);
1660   int fd = REAL(inotify_init)(fake);
1661   if (fd >= 0)
1662     FdInotifyCreate(thr, pc, fd);
1663   return fd;
1664 }
1665 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT TSAN_INTERCEPT(inotify_init)
1666 #else
1667 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT
1668 #endif
1669 
1670 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,inotify_init1,int flags)1671 TSAN_INTERCEPTOR(int, inotify_init1, int flags) {
1672   SCOPED_TSAN_INTERCEPTOR(inotify_init1, flags);
1673   int fd = REAL(inotify_init1)(flags);
1674   if (fd >= 0)
1675     FdInotifyCreate(thr, pc, fd);
1676   return fd;
1677 }
1678 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1 TSAN_INTERCEPT(inotify_init1)
1679 #else
1680 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1
1681 #endif
1682 
TSAN_INTERCEPTOR(int,socket,int domain,int type,int protocol)1683 TSAN_INTERCEPTOR(int, socket, int domain, int type, int protocol) {
1684   SCOPED_TSAN_INTERCEPTOR(socket, domain, type, protocol);
1685   int fd = REAL(socket)(domain, type, protocol);
1686   if (fd >= 0)
1687     FdSocketCreate(thr, pc, fd);
1688   return fd;
1689 }
1690 
TSAN_INTERCEPTOR(int,socketpair,int domain,int type,int protocol,int * fd)1691 TSAN_INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int *fd) {
1692   SCOPED_TSAN_INTERCEPTOR(socketpair, domain, type, protocol, fd);
1693   int res = REAL(socketpair)(domain, type, protocol, fd);
1694   if (res == 0 && fd[0] >= 0 && fd[1] >= 0)
1695     FdPipeCreate(thr, pc, fd[0], fd[1]);
1696   return res;
1697 }
1698 
TSAN_INTERCEPTOR(int,connect,int fd,void * addr,unsigned addrlen)1699 TSAN_INTERCEPTOR(int, connect, int fd, void *addr, unsigned addrlen) {
1700   SCOPED_TSAN_INTERCEPTOR(connect, fd, addr, addrlen);
1701   FdSocketConnecting(thr, pc, fd);
1702   int res = REAL(connect)(fd, addr, addrlen);
1703   if (res == 0 && fd >= 0)
1704     FdSocketConnect(thr, pc, fd);
1705   return res;
1706 }
1707 
TSAN_INTERCEPTOR(int,bind,int fd,void * addr,unsigned addrlen)1708 TSAN_INTERCEPTOR(int, bind, int fd, void *addr, unsigned addrlen) {
1709   SCOPED_TSAN_INTERCEPTOR(bind, fd, addr, addrlen);
1710   int res = REAL(bind)(fd, addr, addrlen);
1711   if (fd > 0 && res == 0)
1712     FdAccess(thr, pc, fd);
1713   return res;
1714 }
1715 
TSAN_INTERCEPTOR(int,listen,int fd,int backlog)1716 TSAN_INTERCEPTOR(int, listen, int fd, int backlog) {
1717   SCOPED_TSAN_INTERCEPTOR(listen, fd, backlog);
1718   int res = REAL(listen)(fd, backlog);
1719   if (fd > 0 && res == 0)
1720     FdAccess(thr, pc, fd);
1721   return res;
1722 }
1723 
TSAN_INTERCEPTOR(int,close,int fd)1724 TSAN_INTERCEPTOR(int, close, int fd) {
1725   SCOPED_TSAN_INTERCEPTOR(close, fd);
1726   if (fd >= 0)
1727     FdClose(thr, pc, fd);
1728   return REAL(close)(fd);
1729 }
1730 
1731 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,__close,int fd)1732 TSAN_INTERCEPTOR(int, __close, int fd) {
1733   SCOPED_TSAN_INTERCEPTOR(__close, fd);
1734   if (fd >= 0)
1735     FdClose(thr, pc, fd);
1736   return REAL(__close)(fd);
1737 }
1738 #define TSAN_MAYBE_INTERCEPT___CLOSE TSAN_INTERCEPT(__close)
1739 #else
1740 #define TSAN_MAYBE_INTERCEPT___CLOSE
1741 #endif
1742 
1743 // glibc guts
1744 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(void,__res_iclose,void * state,bool free_addr)1745 TSAN_INTERCEPTOR(void, __res_iclose, void *state, bool free_addr) {
1746   SCOPED_TSAN_INTERCEPTOR(__res_iclose, state, free_addr);
1747   int fds[64];
1748   int cnt = ExtractResolvFDs(state, fds, ARRAY_SIZE(fds));
1749   for (int i = 0; i < cnt; i++) {
1750     if (fds[i] > 0)
1751       FdClose(thr, pc, fds[i]);
1752   }
1753   REAL(__res_iclose)(state, free_addr);
1754 }
1755 #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE TSAN_INTERCEPT(__res_iclose)
1756 #else
1757 #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE
1758 #endif
1759 
TSAN_INTERCEPTOR(int,pipe,int * pipefd)1760 TSAN_INTERCEPTOR(int, pipe, int *pipefd) {
1761   SCOPED_TSAN_INTERCEPTOR(pipe, pipefd);
1762   int res = REAL(pipe)(pipefd);
1763   if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0)
1764     FdPipeCreate(thr, pc, pipefd[0], pipefd[1]);
1765   return res;
1766 }
1767 
1768 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pipe2,int * pipefd,int flags)1769 TSAN_INTERCEPTOR(int, pipe2, int *pipefd, int flags) {
1770   SCOPED_TSAN_INTERCEPTOR(pipe2, pipefd, flags);
1771   int res = REAL(pipe2)(pipefd, flags);
1772   if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0)
1773     FdPipeCreate(thr, pc, pipefd[0], pipefd[1]);
1774   return res;
1775 }
1776 #endif
1777 
TSAN_INTERCEPTOR(int,unlink,char * path)1778 TSAN_INTERCEPTOR(int, unlink, char *path) {
1779   SCOPED_TSAN_INTERCEPTOR(unlink, path);
1780   Release(thr, pc, File2addr(path));
1781   int res = REAL(unlink)(path);
1782   return res;
1783 }
1784 
TSAN_INTERCEPTOR(void *,tmpfile,int fake)1785 TSAN_INTERCEPTOR(void*, tmpfile, int fake) {
1786   SCOPED_TSAN_INTERCEPTOR(tmpfile, fake);
1787   void *res = REAL(tmpfile)(fake);
1788   if (res) {
1789     int fd = fileno_unlocked(res);
1790     if (fd >= 0)
1791       FdFileCreate(thr, pc, fd);
1792   }
1793   return res;
1794 }
1795 
1796 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,tmpfile64,int fake)1797 TSAN_INTERCEPTOR(void*, tmpfile64, int fake) {
1798   SCOPED_TSAN_INTERCEPTOR(tmpfile64, fake);
1799   void *res = REAL(tmpfile64)(fake);
1800   if (res) {
1801     int fd = fileno_unlocked(res);
1802     if (fd >= 0)
1803       FdFileCreate(thr, pc, fd);
1804   }
1805   return res;
1806 }
1807 #define TSAN_MAYBE_INTERCEPT_TMPFILE64 TSAN_INTERCEPT(tmpfile64)
1808 #else
1809 #define TSAN_MAYBE_INTERCEPT_TMPFILE64
1810 #endif
1811 
FlushStreams()1812 static void FlushStreams() {
1813   // Flushing all the streams here may freeze the process if a child thread is
1814   // performing file stream operations at the same time.
1815   REAL(fflush)(stdout);
1816   REAL(fflush)(stderr);
1817 }
1818 
TSAN_INTERCEPTOR(void,abort,int fake)1819 TSAN_INTERCEPTOR(void, abort, int fake) {
1820   SCOPED_TSAN_INTERCEPTOR(abort, fake);
1821   FlushStreams();
1822   REAL(abort)(fake);
1823 }
1824 
TSAN_INTERCEPTOR(int,rmdir,char * path)1825 TSAN_INTERCEPTOR(int, rmdir, char *path) {
1826   SCOPED_TSAN_INTERCEPTOR(rmdir, path);
1827   Release(thr, pc, Dir2addr(path));
1828   int res = REAL(rmdir)(path);
1829   return res;
1830 }
1831 
TSAN_INTERCEPTOR(int,closedir,void * dirp)1832 TSAN_INTERCEPTOR(int, closedir, void *dirp) {
1833   SCOPED_TSAN_INTERCEPTOR(closedir, dirp);
1834   if (dirp) {
1835     int fd = dirfd(dirp);
1836     FdClose(thr, pc, fd);
1837   }
1838   return REAL(closedir)(dirp);
1839 }
1840 
1841 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,epoll_create,int size)1842 TSAN_INTERCEPTOR(int, epoll_create, int size) {
1843   SCOPED_TSAN_INTERCEPTOR(epoll_create, size);
1844   int fd = REAL(epoll_create)(size);
1845   if (fd >= 0)
1846     FdPollCreate(thr, pc, fd);
1847   return fd;
1848 }
1849 
TSAN_INTERCEPTOR(int,epoll_create1,int flags)1850 TSAN_INTERCEPTOR(int, epoll_create1, int flags) {
1851   SCOPED_TSAN_INTERCEPTOR(epoll_create1, flags);
1852   int fd = REAL(epoll_create1)(flags);
1853   if (fd >= 0)
1854     FdPollCreate(thr, pc, fd);
1855   return fd;
1856 }
1857 
TSAN_INTERCEPTOR(int,epoll_ctl,int epfd,int op,int fd,void * ev)1858 TSAN_INTERCEPTOR(int, epoll_ctl, int epfd, int op, int fd, void *ev) {
1859   SCOPED_TSAN_INTERCEPTOR(epoll_ctl, epfd, op, fd, ev);
1860   if (epfd >= 0)
1861     FdAccess(thr, pc, epfd);
1862   if (epfd >= 0 && fd >= 0)
1863     FdAccess(thr, pc, fd);
1864   if (op == EPOLL_CTL_ADD && epfd >= 0)
1865     FdRelease(thr, pc, epfd);
1866   int res = REAL(epoll_ctl)(epfd, op, fd, ev);
1867   return res;
1868 }
1869 
TSAN_INTERCEPTOR(int,epoll_wait,int epfd,void * ev,int cnt,int timeout)1870 TSAN_INTERCEPTOR(int, epoll_wait, int epfd, void *ev, int cnt, int timeout) {
1871   SCOPED_TSAN_INTERCEPTOR(epoll_wait, epfd, ev, cnt, timeout);
1872   if (epfd >= 0)
1873     FdAccess(thr, pc, epfd);
1874   int res = BLOCK_REAL(epoll_wait)(epfd, ev, cnt, timeout);
1875   if (res > 0 && epfd >= 0)
1876     FdAcquire(thr, pc, epfd);
1877   return res;
1878 }
1879 
TSAN_INTERCEPTOR(int,epoll_pwait,int epfd,void * ev,int cnt,int timeout,void * sigmask)1880 TSAN_INTERCEPTOR(int, epoll_pwait, int epfd, void *ev, int cnt, int timeout,
1881                  void *sigmask) {
1882   SCOPED_TSAN_INTERCEPTOR(epoll_pwait, epfd, ev, cnt, timeout, sigmask);
1883   if (epfd >= 0)
1884     FdAccess(thr, pc, epfd);
1885   int res = BLOCK_REAL(epoll_pwait)(epfd, ev, cnt, timeout, sigmask);
1886   if (res > 0 && epfd >= 0)
1887     FdAcquire(thr, pc, epfd);
1888   return res;
1889 }
1890 
1891 #define TSAN_MAYBE_INTERCEPT_EPOLL \
1892     TSAN_INTERCEPT(epoll_create); \
1893     TSAN_INTERCEPT(epoll_create1); \
1894     TSAN_INTERCEPT(epoll_ctl); \
1895     TSAN_INTERCEPT(epoll_wait); \
1896     TSAN_INTERCEPT(epoll_pwait)
1897 #else
1898 #define TSAN_MAYBE_INTERCEPT_EPOLL
1899 #endif
1900 
1901 // The following functions are intercepted merely to process pending signals.
1902 // If program blocks signal X, we must deliver the signal before the function
1903 // returns. Similarly, if program unblocks a signal (or returns from sigsuspend)
1904 // it's better to deliver the signal straight away.
TSAN_INTERCEPTOR(int,sigsuspend,const __sanitizer_sigset_t * mask)1905 TSAN_INTERCEPTOR(int, sigsuspend, const __sanitizer_sigset_t *mask) {
1906   SCOPED_TSAN_INTERCEPTOR(sigsuspend, mask);
1907   return REAL(sigsuspend)(mask);
1908 }
1909 
TSAN_INTERCEPTOR(int,sigblock,int mask)1910 TSAN_INTERCEPTOR(int, sigblock, int mask) {
1911   SCOPED_TSAN_INTERCEPTOR(sigblock, mask);
1912   return REAL(sigblock)(mask);
1913 }
1914 
TSAN_INTERCEPTOR(int,sigsetmask,int mask)1915 TSAN_INTERCEPTOR(int, sigsetmask, int mask) {
1916   SCOPED_TSAN_INTERCEPTOR(sigsetmask, mask);
1917   return REAL(sigsetmask)(mask);
1918 }
1919 
TSAN_INTERCEPTOR(int,pthread_sigmask,int how,const __sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)1920 TSAN_INTERCEPTOR(int, pthread_sigmask, int how, const __sanitizer_sigset_t *set,
1921     __sanitizer_sigset_t *oldset) {
1922   SCOPED_TSAN_INTERCEPTOR(pthread_sigmask, how, set, oldset);
1923   return REAL(pthread_sigmask)(how, set, oldset);
1924 }
1925 
1926 namespace __tsan {
1927 
CallUserSignalHandler(ThreadState * thr,bool sync,bool acquire,bool sigact,int sig,__sanitizer_siginfo * info,void * uctx)1928 static void CallUserSignalHandler(ThreadState *thr, bool sync, bool acquire,
1929                                   bool sigact, int sig,
1930                                   __sanitizer_siginfo *info, void *uctx) {
1931   __sanitizer_sigaction *sigactions = interceptor_ctx()->sigactions;
1932   if (acquire)
1933     Acquire(thr, 0, (uptr)&sigactions[sig]);
1934   // Signals are generally asynchronous, so if we receive a signals when
1935   // ignores are enabled we should disable ignores. This is critical for sync
1936   // and interceptors, because otherwise we can miss syncronization and report
1937   // false races.
1938   int ignore_reads_and_writes = thr->ignore_reads_and_writes;
1939   int ignore_interceptors = thr->ignore_interceptors;
1940   int ignore_sync = thr->ignore_sync;
1941   if (!ctx->after_multithreaded_fork) {
1942     thr->ignore_reads_and_writes = 0;
1943     thr->fast_state.ClearIgnoreBit();
1944     thr->ignore_interceptors = 0;
1945     thr->ignore_sync = 0;
1946   }
1947   // Ensure that the handler does not spoil errno.
1948   const int saved_errno = errno;
1949   errno = 99;
1950   // This code races with sigaction. Be careful to not read sa_sigaction twice.
1951   // Also need to remember pc for reporting before the call,
1952   // because the handler can reset it.
1953   volatile uptr pc =
1954       sigact ? (uptr)sigactions[sig].sigaction : (uptr)sigactions[sig].handler;
1955   if (pc != sig_dfl && pc != sig_ign) {
1956     if (sigact)
1957       ((__sanitizer_sigactionhandler_ptr)pc)(sig, info, uctx);
1958     else
1959       ((__sanitizer_sighandler_ptr)pc)(sig);
1960   }
1961   if (!ctx->after_multithreaded_fork) {
1962     thr->ignore_reads_and_writes = ignore_reads_and_writes;
1963     if (ignore_reads_and_writes)
1964       thr->fast_state.SetIgnoreBit();
1965     thr->ignore_interceptors = ignore_interceptors;
1966     thr->ignore_sync = ignore_sync;
1967   }
1968   // We do not detect errno spoiling for SIGTERM,
1969   // because some SIGTERM handlers do spoil errno but reraise SIGTERM,
1970   // tsan reports false positive in such case.
1971   // It's difficult to properly detect this situation (reraise),
1972   // because in async signal processing case (when handler is called directly
1973   // from rtl_generic_sighandler) we have not yet received the reraised
1974   // signal; and it looks too fragile to intercept all ways to reraise a signal.
1975   if (flags()->report_bugs && !sync && sig != SIGTERM && errno != 99) {
1976     VarSizeStackTrace stack;
1977     // StackTrace::GetNestInstructionPc(pc) is used because return address is
1978     // expected, OutputReport() will undo this.
1979     ObtainCurrentStack(thr, StackTrace::GetNextInstructionPc(pc), &stack);
1980     ThreadRegistryLock l(ctx->thread_registry);
1981     ScopedReport rep(ReportTypeErrnoInSignal);
1982     if (!IsFiredSuppression(ctx, ReportTypeErrnoInSignal, stack)) {
1983       rep.AddStack(stack, true);
1984       OutputReport(thr, rep);
1985     }
1986   }
1987   errno = saved_errno;
1988 }
1989 
ProcessPendingSignals(ThreadState * thr)1990 void ProcessPendingSignals(ThreadState *thr) {
1991   ThreadSignalContext *sctx = SigCtx(thr);
1992   if (sctx == 0 ||
1993       atomic_load(&sctx->have_pending_signals, memory_order_relaxed) == 0)
1994     return;
1995   atomic_store(&sctx->have_pending_signals, 0, memory_order_relaxed);
1996   atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed);
1997   internal_sigfillset(&sctx->emptyset);
1998   int res = REAL(pthread_sigmask)(SIG_SETMASK, &sctx->emptyset, &sctx->oldset);
1999   CHECK_EQ(res, 0);
2000   for (int sig = 0; sig < kSigCount; sig++) {
2001     SignalDesc *signal = &sctx->pending_signals[sig];
2002     if (signal->armed) {
2003       signal->armed = false;
2004       CallUserSignalHandler(thr, false, true, signal->sigaction, sig,
2005           &signal->siginfo, &signal->ctx);
2006     }
2007   }
2008   res = REAL(pthread_sigmask)(SIG_SETMASK, &sctx->oldset, 0);
2009   CHECK_EQ(res, 0);
2010   atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed);
2011 }
2012 
2013 }  // namespace __tsan
2014 
is_sync_signal(ThreadSignalContext * sctx,int sig)2015 static bool is_sync_signal(ThreadSignalContext *sctx, int sig) {
2016   return sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || sig == SIGTRAP ||
2017          sig == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS ||
2018          // If we are sending signal to ourselves, we must process it now.
2019          (sctx && sig == sctx->int_signal_send);
2020 }
2021 
rtl_generic_sighandler(bool sigact,int sig,__sanitizer_siginfo * info,void * ctx)2022 void ALWAYS_INLINE rtl_generic_sighandler(bool sigact, int sig,
2023                                           __sanitizer_siginfo *info,
2024                                           void *ctx) {
2025   cur_thread_init();
2026   ThreadState *thr = cur_thread();
2027   ThreadSignalContext *sctx = SigCtx(thr);
2028   if (sig < 0 || sig >= kSigCount) {
2029     VPrintf(1, "ThreadSanitizer: ignoring signal %d\n", sig);
2030     return;
2031   }
2032   // Don't mess with synchronous signals.
2033   const bool sync = is_sync_signal(sctx, sig);
2034   if (sync ||
2035       // If we are in blocking function, we can safely process it now
2036       // (but check if we are in a recursive interceptor,
2037       // i.e. pthread_join()->munmap()).
2038       (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed))) {
2039     atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed);
2040     if (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed)) {
2041       atomic_store(&sctx->in_blocking_func, 0, memory_order_relaxed);
2042       CallUserSignalHandler(thr, sync, true, sigact, sig, info, ctx);
2043       atomic_store(&sctx->in_blocking_func, 1, memory_order_relaxed);
2044     } else {
2045       // Be very conservative with when we do acquire in this case.
2046       // It's unsafe to do acquire in async handlers, because ThreadState
2047       // can be in inconsistent state.
2048       // SIGSYS looks relatively safe -- it's synchronous and can actually
2049       // need some global state.
2050       bool acq = (sig == SIGSYS);
2051       CallUserSignalHandler(thr, sync, acq, sigact, sig, info, ctx);
2052     }
2053     atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed);
2054     return;
2055   }
2056 
2057   if (sctx == 0)
2058     return;
2059   SignalDesc *signal = &sctx->pending_signals[sig];
2060   if (signal->armed == false) {
2061     signal->armed = true;
2062     signal->sigaction = sigact;
2063     if (info)
2064       internal_memcpy(&signal->siginfo, info, sizeof(*info));
2065     if (ctx)
2066       internal_memcpy(&signal->ctx, ctx, sizeof(signal->ctx));
2067     atomic_store(&sctx->have_pending_signals, 1, memory_order_relaxed);
2068   }
2069 }
2070 
rtl_sighandler(int sig)2071 static void rtl_sighandler(int sig) {
2072   rtl_generic_sighandler(false, sig, 0, 0);
2073 }
2074 
rtl_sigaction(int sig,__sanitizer_siginfo * info,void * ctx)2075 static void rtl_sigaction(int sig, __sanitizer_siginfo *info, void *ctx) {
2076   rtl_generic_sighandler(true, sig, info, ctx);
2077 }
2078 
TSAN_INTERCEPTOR(int,raise,int sig)2079 TSAN_INTERCEPTOR(int, raise, int sig) {
2080   SCOPED_TSAN_INTERCEPTOR(raise, sig);
2081   ThreadSignalContext *sctx = SigCtx(thr);
2082   CHECK_NE(sctx, 0);
2083   int prev = sctx->int_signal_send;
2084   sctx->int_signal_send = sig;
2085   int res = REAL(raise)(sig);
2086   CHECK_EQ(sctx->int_signal_send, sig);
2087   sctx->int_signal_send = prev;
2088   return res;
2089 }
2090 
TSAN_INTERCEPTOR(int,kill,int pid,int sig)2091 TSAN_INTERCEPTOR(int, kill, int pid, int sig) {
2092   SCOPED_TSAN_INTERCEPTOR(kill, pid, sig);
2093   ThreadSignalContext *sctx = SigCtx(thr);
2094   CHECK_NE(sctx, 0);
2095   int prev = sctx->int_signal_send;
2096   if (pid == (int)internal_getpid()) {
2097     sctx->int_signal_send = sig;
2098   }
2099   int res = REAL(kill)(pid, sig);
2100   if (pid == (int)internal_getpid()) {
2101     CHECK_EQ(sctx->int_signal_send, sig);
2102     sctx->int_signal_send = prev;
2103   }
2104   return res;
2105 }
2106 
TSAN_INTERCEPTOR(int,pthread_kill,void * tid,int sig)2107 TSAN_INTERCEPTOR(int, pthread_kill, void *tid, int sig) {
2108   SCOPED_TSAN_INTERCEPTOR(pthread_kill, tid, sig);
2109   ThreadSignalContext *sctx = SigCtx(thr);
2110   CHECK_NE(sctx, 0);
2111   int prev = sctx->int_signal_send;
2112   if (tid == pthread_self()) {
2113     sctx->int_signal_send = sig;
2114   }
2115   int res = REAL(pthread_kill)(tid, sig);
2116   if (tid == pthread_self()) {
2117     CHECK_EQ(sctx->int_signal_send, sig);
2118     sctx->int_signal_send = prev;
2119   }
2120   return res;
2121 }
2122 
TSAN_INTERCEPTOR(int,gettimeofday,void * tv,void * tz)2123 TSAN_INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
2124   SCOPED_TSAN_INTERCEPTOR(gettimeofday, tv, tz);
2125   // It's intercepted merely to process pending signals.
2126   return REAL(gettimeofday)(tv, tz);
2127 }
2128 
TSAN_INTERCEPTOR(int,getaddrinfo,void * node,void * service,void * hints,void * rv)2129 TSAN_INTERCEPTOR(int, getaddrinfo, void *node, void *service,
2130     void *hints, void *rv) {
2131   SCOPED_TSAN_INTERCEPTOR(getaddrinfo, node, service, hints, rv);
2132   // We miss atomic synchronization in getaddrinfo,
2133   // and can report false race between malloc and free
2134   // inside of getaddrinfo. So ignore memory accesses.
2135   ThreadIgnoreBegin(thr, pc);
2136   int res = REAL(getaddrinfo)(node, service, hints, rv);
2137   ThreadIgnoreEnd(thr, pc);
2138   return res;
2139 }
2140 
TSAN_INTERCEPTOR(int,fork,int fake)2141 TSAN_INTERCEPTOR(int, fork, int fake) {
2142   if (in_symbolizer())
2143     return REAL(fork)(fake);
2144   SCOPED_INTERCEPTOR_RAW(fork, fake);
2145   ForkBefore(thr, pc);
2146   int pid;
2147   {
2148     // On OS X, REAL(fork) can call intercepted functions (OSSpinLockLock), and
2149     // we'll assert in CheckNoLocks() unless we ignore interceptors.
2150     ScopedIgnoreInterceptors ignore;
2151     pid = REAL(fork)(fake);
2152   }
2153   if (pid == 0) {
2154     // child
2155     ForkChildAfter(thr, pc);
2156     FdOnFork(thr, pc);
2157   } else if (pid > 0) {
2158     // parent
2159     ForkParentAfter(thr, pc);
2160   } else {
2161     // error
2162     ForkParentAfter(thr, pc);
2163   }
2164   return pid;
2165 }
2166 
TSAN_INTERCEPTOR(int,vfork,int fake)2167 TSAN_INTERCEPTOR(int, vfork, int fake) {
2168   // Some programs (e.g. openjdk) call close for all file descriptors
2169   // in the child process. Under tsan it leads to false positives, because
2170   // address space is shared, so the parent process also thinks that
2171   // the descriptors are closed (while they are actually not).
2172   // This leads to false positives due to missed synchronization.
2173   // Strictly saying this is undefined behavior, because vfork child is not
2174   // allowed to call any functions other than exec/exit. But this is what
2175   // openjdk does, so we want to handle it.
2176   // We could disable interceptors in the child process. But it's not possible
2177   // to simply intercept and wrap vfork, because vfork child is not allowed
2178   // to return from the function that calls vfork, and that's exactly what
2179   // we would do. So this would require some assembly trickery as well.
2180   // Instead we simply turn vfork into fork.
2181   return WRAP(fork)(fake);
2182 }
2183 
2184 #if !SANITIZER_MAC && !SANITIZER_ANDROID
2185 typedef int (*dl_iterate_phdr_cb_t)(__sanitizer_dl_phdr_info *info, SIZE_T size,
2186                                     void *data);
2187 struct dl_iterate_phdr_data {
2188   ThreadState *thr;
2189   uptr pc;
2190   dl_iterate_phdr_cb_t cb;
2191   void *data;
2192 };
2193 
IsAppNotRodata(uptr addr)2194 static bool IsAppNotRodata(uptr addr) {
2195   return IsAppMem(addr) && *(u64*)MemToShadow(addr) != kShadowRodata;
2196 }
2197 
dl_iterate_phdr_cb(__sanitizer_dl_phdr_info * info,SIZE_T size,void * data)2198 static int dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
2199                               void *data) {
2200   dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
2201   // dlopen/dlclose allocate/free dynamic-linker-internal memory, which is later
2202   // accessible in dl_iterate_phdr callback. But we don't see synchronization
2203   // inside of dynamic linker, so we "unpoison" it here in order to not
2204   // produce false reports. Ignoring malloc/free in dlopen/dlclose is not enough
2205   // because some libc functions call __libc_dlopen.
2206   if (info && IsAppNotRodata((uptr)info->dlpi_name))
2207     MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name,
2208                      internal_strlen(info->dlpi_name));
2209   int res = cbdata->cb(info, size, cbdata->data);
2210   // Perform the check one more time in case info->dlpi_name was overwritten
2211   // by user callback.
2212   if (info && IsAppNotRodata((uptr)info->dlpi_name))
2213     MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name,
2214                      internal_strlen(info->dlpi_name));
2215   return res;
2216 }
2217 
TSAN_INTERCEPTOR(int,dl_iterate_phdr,dl_iterate_phdr_cb_t cb,void * data)2218 TSAN_INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb_t cb, void *data) {
2219   SCOPED_TSAN_INTERCEPTOR(dl_iterate_phdr, cb, data);
2220   dl_iterate_phdr_data cbdata;
2221   cbdata.thr = thr;
2222   cbdata.pc = pc;
2223   cbdata.cb = cb;
2224   cbdata.data = data;
2225   int res = REAL(dl_iterate_phdr)(dl_iterate_phdr_cb, &cbdata);
2226   return res;
2227 }
2228 #endif
2229 
OnExit(ThreadState * thr)2230 static int OnExit(ThreadState *thr) {
2231   int status = Finalize(thr);
2232   FlushStreams();
2233   return status;
2234 }
2235 
2236 struct TsanInterceptorContext {
2237   ThreadState *thr;
2238   const uptr caller_pc;
2239   const uptr pc;
2240 };
2241 
2242 #if !SANITIZER_MAC
HandleRecvmsg(ThreadState * thr,uptr pc,__sanitizer_msghdr * msg)2243 static void HandleRecvmsg(ThreadState *thr, uptr pc,
2244     __sanitizer_msghdr *msg) {
2245   int fds[64];
2246   int cnt = ExtractRecvmsgFDs(msg, fds, ARRAY_SIZE(fds));
2247   for (int i = 0; i < cnt; i++)
2248     FdEventCreate(thr, pc, fds[i]);
2249 }
2250 #endif
2251 
2252 #include "sanitizer_common/sanitizer_platform_interceptors.h"
2253 // Causes interceptor recursion (getaddrinfo() and fopen())
2254 #undef SANITIZER_INTERCEPT_GETADDRINFO
2255 // We define our own.
2256 #if SANITIZER_INTERCEPT_TLS_GET_ADDR
2257 #define NEED_TLS_GET_ADDR
2258 #endif
2259 #undef SANITIZER_INTERCEPT_TLS_GET_ADDR
2260 #undef SANITIZER_INTERCEPT_PTHREAD_SIGMASK
2261 
2262 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
2263 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver)                          \
2264   INTERCEPT_FUNCTION_VER(name, ver)
2265 
2266 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size)                    \
2267   MemoryAccessRange(((TsanInterceptorContext *)ctx)->thr,                 \
2268                     ((TsanInterceptorContext *)ctx)->pc, (uptr)ptr, size, \
2269                     true)
2270 
2271 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size)                       \
2272   MemoryAccessRange(((TsanInterceptorContext *) ctx)->thr,                  \
2273                     ((TsanInterceptorContext *) ctx)->pc, (uptr) ptr, size, \
2274                     false)
2275 
2276 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)      \
2277   SCOPED_TSAN_INTERCEPTOR(func, __VA_ARGS__);         \
2278   TsanInterceptorContext _ctx = {thr, caller_pc, pc}; \
2279   ctx = (void *)&_ctx;                                \
2280   (void) ctx;
2281 
2282 #define COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, func, ...) \
2283   SCOPED_INTERCEPTOR_RAW(func, __VA_ARGS__);              \
2284   TsanInterceptorContext _ctx = {thr, caller_pc, pc};     \
2285   ctx = (void *)&_ctx;                                    \
2286   (void) ctx;
2287 
2288 #define COMMON_INTERCEPTOR_FILE_OPEN(ctx, file, path) \
2289   if (path)                                           \
2290     Acquire(thr, pc, File2addr(path));                \
2291   if (file) {                                         \
2292     int fd = fileno_unlocked(file);                   \
2293     if (fd >= 0) FdFileCreate(thr, pc, fd);           \
2294   }
2295 
2296 #define COMMON_INTERCEPTOR_FILE_CLOSE(ctx, file) \
2297   if (file) {                                    \
2298     int fd = fileno_unlocked(file);              \
2299     if (fd >= 0) FdClose(thr, pc, fd);           \
2300   }
2301 
2302 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
2303   libignore()->OnLibraryLoaded(filename)
2304 
2305 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() \
2306   libignore()->OnLibraryUnloaded()
2307 
2308 #define COMMON_INTERCEPTOR_ACQUIRE(ctx, u) \
2309   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, u)
2310 
2311 #define COMMON_INTERCEPTOR_RELEASE(ctx, u) \
2312   Release(((TsanInterceptorContext *) ctx)->thr, pc, u)
2313 
2314 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
2315   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, Dir2addr(path))
2316 
2317 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
2318   FdAcquire(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2319 
2320 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
2321   FdRelease(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2322 
2323 #define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) \
2324   FdAccess(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2325 
2326 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
2327   FdSocketAccept(((TsanInterceptorContext *) ctx)->thr, pc, fd, newfd)
2328 
2329 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
2330   ThreadSetName(((TsanInterceptorContext *) ctx)->thr, name)
2331 
2332 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
2333   __tsan::ctx->thread_registry->SetThreadNameByUserId(thread, name)
2334 
2335 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) BLOCK_REAL(name)
2336 
2337 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) \
2338   OnExit(((TsanInterceptorContext *) ctx)->thr)
2339 
2340 #define COMMON_INTERCEPTOR_MUTEX_PRE_LOCK(ctx, m) \
2341   MutexPreLock(((TsanInterceptorContext *)ctx)->thr, \
2342             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2343 
2344 #define COMMON_INTERCEPTOR_MUTEX_POST_LOCK(ctx, m) \
2345   MutexPostLock(((TsanInterceptorContext *)ctx)->thr, \
2346             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2347 
2348 #define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) \
2349   MutexUnlock(((TsanInterceptorContext *)ctx)->thr, \
2350             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2351 
2352 #define COMMON_INTERCEPTOR_MUTEX_REPAIR(ctx, m) \
2353   MutexRepair(((TsanInterceptorContext *)ctx)->thr, \
2354             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2355 
2356 #define COMMON_INTERCEPTOR_MUTEX_INVALID(ctx, m) \
2357   MutexInvalidAccess(((TsanInterceptorContext *)ctx)->thr, \
2358                      ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2359 
2360 #define COMMON_INTERCEPTOR_MMAP_IMPL(ctx, mmap, addr, sz, prot, flags, fd,  \
2361                                      off)                                   \
2362   do {                                                                      \
2363     return mmap_interceptor(thr, pc, REAL(mmap), addr, sz, prot, flags, fd, \
2364                             off);                                           \
2365   } while (false)
2366 
2367 #if !SANITIZER_MAC
2368 #define COMMON_INTERCEPTOR_HANDLE_RECVMSG(ctx, msg) \
2369   HandleRecvmsg(((TsanInterceptorContext *)ctx)->thr, \
2370       ((TsanInterceptorContext *)ctx)->pc, msg)
2371 #endif
2372 
2373 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
2374   if (TsanThread *t = GetCurrentThread()) {                                    \
2375     *begin = t->tls_begin();                                                   \
2376     *end = t->tls_end();                                                       \
2377   } else {                                                                     \
2378     *begin = *end = 0;                                                         \
2379   }
2380 
2381 #define COMMON_INTERCEPTOR_USER_CALLBACK_START() \
2382   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START()
2383 
2384 #define COMMON_INTERCEPTOR_USER_CALLBACK_END() \
2385   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END()
2386 
2387 #include "sanitizer_common/sanitizer_common_interceptors.inc"
2388 
2389 static int sigaction_impl(int sig, const __sanitizer_sigaction *act,
2390                           __sanitizer_sigaction *old);
2391 static __sanitizer_sighandler_ptr signal_impl(int sig,
2392                                               __sanitizer_sighandler_ptr h);
2393 
2394 #define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
2395   { return sigaction_impl(signo, act, oldact); }
2396 
2397 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
2398   { return (uptr)signal_impl(signo, (__sanitizer_sighandler_ptr)handler); }
2399 
2400 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
2401 
sigaction_impl(int sig,const __sanitizer_sigaction * act,__sanitizer_sigaction * old)2402 int sigaction_impl(int sig, const __sanitizer_sigaction *act,
2403                    __sanitizer_sigaction *old) {
2404   // Note: if we call REAL(sigaction) directly for any reason without proxying
2405   // the signal handler through rtl_sigaction, very bad things will happen.
2406   // The handler will run synchronously and corrupt tsan per-thread state.
2407   SCOPED_INTERCEPTOR_RAW(sigaction, sig, act, old);
2408   __sanitizer_sigaction *sigactions = interceptor_ctx()->sigactions;
2409   __sanitizer_sigaction old_stored;
2410   if (old) internal_memcpy(&old_stored, &sigactions[sig], sizeof(old_stored));
2411   __sanitizer_sigaction newact;
2412   if (act) {
2413     // Copy act into sigactions[sig].
2414     // Can't use struct copy, because compiler can emit call to memcpy.
2415     // Can't use internal_memcpy, because it copies byte-by-byte,
2416     // and signal handler reads the handler concurrently. It it can read
2417     // some bytes from old value and some bytes from new value.
2418     // Use volatile to prevent insertion of memcpy.
2419     sigactions[sig].handler =
2420         *(volatile __sanitizer_sighandler_ptr const *)&act->handler;
2421     sigactions[sig].sa_flags = *(volatile int const *)&act->sa_flags;
2422     internal_memcpy(&sigactions[sig].sa_mask, &act->sa_mask,
2423                     sizeof(sigactions[sig].sa_mask));
2424 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
2425     sigactions[sig].sa_restorer = act->sa_restorer;
2426 #endif
2427     internal_memcpy(&newact, act, sizeof(newact));
2428     internal_sigfillset(&newact.sa_mask);
2429     if ((uptr)act->handler != sig_ign && (uptr)act->handler != sig_dfl) {
2430       if (newact.sa_flags & SA_SIGINFO)
2431         newact.sigaction = rtl_sigaction;
2432       else
2433         newact.handler = rtl_sighandler;
2434     }
2435     ReleaseStore(thr, pc, (uptr)&sigactions[sig]);
2436     act = &newact;
2437   }
2438   int res = REAL(sigaction)(sig, act, old);
2439   if (res == 0 && old) {
2440     uptr cb = (uptr)old->sigaction;
2441     if (cb == (uptr)rtl_sigaction || cb == (uptr)rtl_sighandler) {
2442       internal_memcpy(old, &old_stored, sizeof(*old));
2443     }
2444   }
2445   return res;
2446 }
2447 
signal_impl(int sig,__sanitizer_sighandler_ptr h)2448 static __sanitizer_sighandler_ptr signal_impl(int sig,
2449                                               __sanitizer_sighandler_ptr h) {
2450   __sanitizer_sigaction act;
2451   act.handler = h;
2452   internal_memset(&act.sa_mask, -1, sizeof(act.sa_mask));
2453   act.sa_flags = 0;
2454   __sanitizer_sigaction old;
2455   int res = sigaction_symname(sig, &act, &old);
2456   if (res) return (__sanitizer_sighandler_ptr)sig_err;
2457   return old.handler;
2458 }
2459 
2460 #define TSAN_SYSCALL() \
2461   ThreadState *thr = cur_thread(); \
2462   if (thr->ignore_interceptors) \
2463     return; \
2464   ScopedSyscall scoped_syscall(thr) \
2465 /**/
2466 
2467 struct ScopedSyscall {
2468   ThreadState *thr;
2469 
ScopedSyscallScopedSyscall2470   explicit ScopedSyscall(ThreadState *thr)
2471       : thr(thr) {
2472     Initialize(thr);
2473   }
2474 
~ScopedSyscallScopedSyscall2475   ~ScopedSyscall() {
2476     ProcessPendingSignals(thr);
2477   }
2478 };
2479 
2480 #if !SANITIZER_FREEBSD && !SANITIZER_MAC
syscall_access_range(uptr pc,uptr p,uptr s,bool write)2481 static void syscall_access_range(uptr pc, uptr p, uptr s, bool write) {
2482   TSAN_SYSCALL();
2483   MemoryAccessRange(thr, pc, p, s, write);
2484 }
2485 
syscall_acquire(uptr pc,uptr addr)2486 static USED void syscall_acquire(uptr pc, uptr addr) {
2487   TSAN_SYSCALL();
2488   Acquire(thr, pc, addr);
2489   DPrintf("syscall_acquire(%p)\n", addr);
2490 }
2491 
syscall_release(uptr pc,uptr addr)2492 static USED void syscall_release(uptr pc, uptr addr) {
2493   TSAN_SYSCALL();
2494   DPrintf("syscall_release(%p)\n", addr);
2495   Release(thr, pc, addr);
2496 }
2497 
syscall_fd_close(uptr pc,int fd)2498 static void syscall_fd_close(uptr pc, int fd) {
2499   TSAN_SYSCALL();
2500   FdClose(thr, pc, fd);
2501 }
2502 
syscall_fd_acquire(uptr pc,int fd)2503 static USED void syscall_fd_acquire(uptr pc, int fd) {
2504   TSAN_SYSCALL();
2505   FdAcquire(thr, pc, fd);
2506   DPrintf("syscall_fd_acquire(%p)\n", fd);
2507 }
2508 
syscall_fd_release(uptr pc,int fd)2509 static USED void syscall_fd_release(uptr pc, int fd) {
2510   TSAN_SYSCALL();
2511   DPrintf("syscall_fd_release(%p)\n", fd);
2512   FdRelease(thr, pc, fd);
2513 }
2514 
syscall_pre_fork(uptr pc)2515 static void syscall_pre_fork(uptr pc) {
2516   TSAN_SYSCALL();
2517   ForkBefore(thr, pc);
2518 }
2519 
syscall_post_fork(uptr pc,int pid)2520 static void syscall_post_fork(uptr pc, int pid) {
2521   TSAN_SYSCALL();
2522   if (pid == 0) {
2523     // child
2524     ForkChildAfter(thr, pc);
2525     FdOnFork(thr, pc);
2526   } else if (pid > 0) {
2527     // parent
2528     ForkParentAfter(thr, pc);
2529   } else {
2530     // error
2531     ForkParentAfter(thr, pc);
2532   }
2533 }
2534 #endif
2535 
2536 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) \
2537   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), false)
2538 
2539 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
2540   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), true)
2541 
2542 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
2543   do {                                       \
2544     (void)(p);                               \
2545     (void)(s);                               \
2546   } while (false)
2547 
2548 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
2549   do {                                        \
2550     (void)(p);                                \
2551     (void)(s);                                \
2552   } while (false)
2553 
2554 #define COMMON_SYSCALL_ACQUIRE(addr) \
2555     syscall_acquire(GET_CALLER_PC(), (uptr)(addr))
2556 
2557 #define COMMON_SYSCALL_RELEASE(addr) \
2558     syscall_release(GET_CALLER_PC(), (uptr)(addr))
2559 
2560 #define COMMON_SYSCALL_FD_CLOSE(fd) syscall_fd_close(GET_CALLER_PC(), fd)
2561 
2562 #define COMMON_SYSCALL_FD_ACQUIRE(fd) syscall_fd_acquire(GET_CALLER_PC(), fd)
2563 
2564 #define COMMON_SYSCALL_FD_RELEASE(fd) syscall_fd_release(GET_CALLER_PC(), fd)
2565 
2566 #define COMMON_SYSCALL_PRE_FORK() \
2567   syscall_pre_fork(GET_CALLER_PC())
2568 
2569 #define COMMON_SYSCALL_POST_FORK(res) \
2570   syscall_post_fork(GET_CALLER_PC(), res)
2571 
2572 #include "sanitizer_common/sanitizer_common_syscalls.inc"
2573 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
2574 
2575 #ifdef NEED_TLS_GET_ADDR
2576 // Define own interceptor instead of sanitizer_common's for three reasons:
2577 // 1. It must not process pending signals.
2578 //    Signal handlers may contain MOVDQA instruction (see below).
2579 // 2. It must be as simple as possible to not contain MOVDQA.
2580 // 3. Sanitizer_common version uses COMMON_INTERCEPTOR_INITIALIZE_RANGE which
2581 //    is empty for tsan (meant only for msan).
2582 // Note: __tls_get_addr can be called with mis-aligned stack due to:
2583 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
2584 // So the interceptor must work with mis-aligned stack, in particular, does not
2585 // execute MOVDQA with stack addresses.
TSAN_INTERCEPTOR(void *,__tls_get_addr,void * arg)2586 TSAN_INTERCEPTOR(void *, __tls_get_addr, void *arg) {
2587   void *res = REAL(__tls_get_addr)(arg);
2588   ThreadState *thr = cur_thread();
2589   if (!thr)
2590     return res;
2591   DTLS::DTV *dtv = DTLS_on_tls_get_addr(arg, res, thr->tls_addr,
2592                                         thr->tls_addr + thr->tls_size);
2593   if (!dtv)
2594     return res;
2595   // New DTLS block has been allocated.
2596   MemoryResetRange(thr, 0, dtv->beg, dtv->size);
2597   return res;
2598 }
2599 #endif
2600 
2601 #if SANITIZER_NETBSD
TSAN_INTERCEPTOR(void,_lwp_exit)2602 TSAN_INTERCEPTOR(void, _lwp_exit) {
2603   SCOPED_TSAN_INTERCEPTOR(_lwp_exit);
2604   DestroyThreadState();
2605   REAL(_lwp_exit)();
2606 }
2607 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT TSAN_INTERCEPT(_lwp_exit)
2608 #else
2609 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT
2610 #endif
2611 
2612 #if SANITIZER_FREEBSD
TSAN_INTERCEPTOR(void,thr_exit,tid_t * state)2613 TSAN_INTERCEPTOR(void, thr_exit, tid_t *state) {
2614   SCOPED_TSAN_INTERCEPTOR(thr_exit, state);
2615   DestroyThreadState();
2616   REAL(thr_exit(state));
2617 }
2618 #define TSAN_MAYBE_INTERCEPT_THR_EXIT TSAN_INTERCEPT(thr_exit)
2619 #else
2620 #define TSAN_MAYBE_INTERCEPT_THR_EXIT
2621 #endif
2622 
2623 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_init, void *c, void *a)
2624 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_signal, void *c)
2625 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_broadcast, void *c)
2626 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_wait, void *c, void *m)
2627 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_destroy, void *c)
2628 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_init, void *m, void *a)
2629 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_destroy, void *m)
2630 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_trylock, void *m)
2631 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_init, void *m, void *a)
2632 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_destroy, void *m)
2633 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_rdlock, void *m)
2634 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_tryrdlock, void *m)
2635 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_wrlock, void *m)
2636 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_trywrlock, void *m)
2637 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_unlock, void *m)
2638 TSAN_INTERCEPTOR_NETBSD_ALIAS_THR(int, once, void *o, void (*f)())
2639 TSAN_INTERCEPTOR_NETBSD_ALIAS_THR2(int, sigsetmask, sigmask, int a, void *b,
2640   void *c)
2641 
2642 namespace __tsan {
2643 
finalize(void * arg)2644 static void finalize(void *arg) {
2645   ThreadState *thr = cur_thread();
2646   int status = Finalize(thr);
2647   // Make sure the output is not lost.
2648   FlushStreams();
2649   if (status)
2650     Die();
2651 }
2652 
2653 #if !SANITIZER_MAC && !SANITIZER_ANDROID
unreachable()2654 static void unreachable() {
2655   Report("FATAL: ThreadSanitizer: unreachable called\n");
2656   Die();
2657 }
2658 #endif
2659 
2660 // Define default implementation since interception of libdispatch  is optional.
InitializeLibdispatchInterceptors()2661 SANITIZER_WEAK_ATTRIBUTE void InitializeLibdispatchInterceptors() {}
2662 
InitializeInterceptors()2663 void InitializeInterceptors() {
2664 #if !SANITIZER_MAC
2665   // We need to setup it early, because functions like dlsym() can call it.
2666   REAL(memset) = internal_memset;
2667   REAL(memcpy) = internal_memcpy;
2668 #endif
2669 
2670   // Instruct libc malloc to consume less memory.
2671 #if SANITIZER_LINUX
2672   mallopt(1, 0);  // M_MXFAST
2673   mallopt(-3, 32*1024);  // M_MMAP_THRESHOLD
2674 #endif
2675 
2676   new(interceptor_ctx()) InterceptorContext();
2677 
2678   InitializeCommonInterceptors();
2679   InitializeSignalInterceptors();
2680   InitializeLibdispatchInterceptors();
2681 
2682 #if !SANITIZER_MAC
2683   // We can not use TSAN_INTERCEPT to get setjmp addr,
2684   // because it does &setjmp and setjmp is not present in some versions of libc.
2685   using __interception::InterceptFunction;
2686   InterceptFunction(TSAN_STRING_SETJMP, (uptr*)&REAL(setjmp_symname), 0, 0);
2687   InterceptFunction("_setjmp", (uptr*)&REAL(_setjmp), 0, 0);
2688   InterceptFunction(TSAN_STRING_SIGSETJMP, (uptr*)&REAL(sigsetjmp_symname), 0,
2689                     0);
2690 #if !SANITIZER_NETBSD
2691   InterceptFunction("__sigsetjmp", (uptr*)&REAL(__sigsetjmp), 0, 0);
2692 #endif
2693 #endif
2694 
2695   TSAN_INTERCEPT(longjmp_symname);
2696   TSAN_INTERCEPT(siglongjmp_symname);
2697 #if SANITIZER_NETBSD
2698   TSAN_INTERCEPT(_longjmp);
2699 #endif
2700 
2701   TSAN_INTERCEPT(malloc);
2702   TSAN_INTERCEPT(__libc_memalign);
2703   TSAN_INTERCEPT(calloc);
2704   TSAN_INTERCEPT(realloc);
2705   TSAN_INTERCEPT(reallocarray);
2706   TSAN_INTERCEPT(free);
2707   TSAN_INTERCEPT(cfree);
2708   TSAN_INTERCEPT(munmap);
2709   TSAN_MAYBE_INTERCEPT_MEMALIGN;
2710   TSAN_INTERCEPT(valloc);
2711   TSAN_MAYBE_INTERCEPT_PVALLOC;
2712   TSAN_INTERCEPT(posix_memalign);
2713 
2714   TSAN_INTERCEPT(strcpy);
2715   TSAN_INTERCEPT(strncpy);
2716   TSAN_INTERCEPT(strdup);
2717 
2718   TSAN_INTERCEPT(pthread_create);
2719   TSAN_INTERCEPT(pthread_join);
2720   TSAN_INTERCEPT(pthread_detach);
2721   TSAN_INTERCEPT(pthread_exit);
2722   #if SANITIZER_LINUX
2723   TSAN_INTERCEPT(pthread_tryjoin_np);
2724   TSAN_INTERCEPT(pthread_timedjoin_np);
2725   #endif
2726 
2727   TSAN_INTERCEPT_VER(pthread_cond_init, PTHREAD_ABI_BASE);
2728   TSAN_INTERCEPT_VER(pthread_cond_signal, PTHREAD_ABI_BASE);
2729   TSAN_INTERCEPT_VER(pthread_cond_broadcast, PTHREAD_ABI_BASE);
2730   TSAN_INTERCEPT_VER(pthread_cond_wait, PTHREAD_ABI_BASE);
2731   TSAN_INTERCEPT_VER(pthread_cond_timedwait, PTHREAD_ABI_BASE);
2732   TSAN_INTERCEPT_VER(pthread_cond_destroy, PTHREAD_ABI_BASE);
2733 
2734   TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT;
2735 
2736   TSAN_INTERCEPT(pthread_mutex_init);
2737   TSAN_INTERCEPT(pthread_mutex_destroy);
2738   TSAN_INTERCEPT(pthread_mutex_trylock);
2739   TSAN_INTERCEPT(pthread_mutex_timedlock);
2740 
2741   TSAN_INTERCEPT(pthread_spin_init);
2742   TSAN_INTERCEPT(pthread_spin_destroy);
2743   TSAN_INTERCEPT(pthread_spin_lock);
2744   TSAN_INTERCEPT(pthread_spin_trylock);
2745   TSAN_INTERCEPT(pthread_spin_unlock);
2746 
2747   TSAN_INTERCEPT(pthread_rwlock_init);
2748   TSAN_INTERCEPT(pthread_rwlock_destroy);
2749   TSAN_INTERCEPT(pthread_rwlock_rdlock);
2750   TSAN_INTERCEPT(pthread_rwlock_tryrdlock);
2751   TSAN_INTERCEPT(pthread_rwlock_timedrdlock);
2752   TSAN_INTERCEPT(pthread_rwlock_wrlock);
2753   TSAN_INTERCEPT(pthread_rwlock_trywrlock);
2754   TSAN_INTERCEPT(pthread_rwlock_timedwrlock);
2755   TSAN_INTERCEPT(pthread_rwlock_unlock);
2756 
2757   TSAN_INTERCEPT(pthread_barrier_init);
2758   TSAN_INTERCEPT(pthread_barrier_destroy);
2759   TSAN_INTERCEPT(pthread_barrier_wait);
2760 
2761   TSAN_INTERCEPT(pthread_once);
2762 
2763   TSAN_INTERCEPT(fstat);
2764   TSAN_MAYBE_INTERCEPT___FXSTAT;
2765   TSAN_MAYBE_INTERCEPT_FSTAT64;
2766   TSAN_MAYBE_INTERCEPT___FXSTAT64;
2767   TSAN_INTERCEPT(open);
2768   TSAN_MAYBE_INTERCEPT_OPEN64;
2769   TSAN_INTERCEPT(creat);
2770   TSAN_MAYBE_INTERCEPT_CREAT64;
2771   TSAN_INTERCEPT(dup);
2772   TSAN_INTERCEPT(dup2);
2773   TSAN_INTERCEPT(dup3);
2774   TSAN_MAYBE_INTERCEPT_EVENTFD;
2775   TSAN_MAYBE_INTERCEPT_SIGNALFD;
2776   TSAN_MAYBE_INTERCEPT_INOTIFY_INIT;
2777   TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1;
2778   TSAN_INTERCEPT(socket);
2779   TSAN_INTERCEPT(socketpair);
2780   TSAN_INTERCEPT(connect);
2781   TSAN_INTERCEPT(bind);
2782   TSAN_INTERCEPT(listen);
2783   TSAN_MAYBE_INTERCEPT_EPOLL;
2784   TSAN_INTERCEPT(close);
2785   TSAN_MAYBE_INTERCEPT___CLOSE;
2786   TSAN_MAYBE_INTERCEPT___RES_ICLOSE;
2787   TSAN_INTERCEPT(pipe);
2788   TSAN_INTERCEPT(pipe2);
2789 
2790   TSAN_INTERCEPT(unlink);
2791   TSAN_INTERCEPT(tmpfile);
2792   TSAN_MAYBE_INTERCEPT_TMPFILE64;
2793   TSAN_INTERCEPT(abort);
2794   TSAN_INTERCEPT(rmdir);
2795   TSAN_INTERCEPT(closedir);
2796 
2797   TSAN_INTERCEPT(sigsuspend);
2798   TSAN_INTERCEPT(sigblock);
2799   TSAN_INTERCEPT(sigsetmask);
2800   TSAN_INTERCEPT(pthread_sigmask);
2801   TSAN_INTERCEPT(raise);
2802   TSAN_INTERCEPT(kill);
2803   TSAN_INTERCEPT(pthread_kill);
2804   TSAN_INTERCEPT(sleep);
2805   TSAN_INTERCEPT(usleep);
2806   TSAN_INTERCEPT(nanosleep);
2807   TSAN_INTERCEPT(pause);
2808   TSAN_INTERCEPT(gettimeofday);
2809   TSAN_INTERCEPT(getaddrinfo);
2810 
2811   TSAN_INTERCEPT(fork);
2812   TSAN_INTERCEPT(vfork);
2813 #if !SANITIZER_ANDROID
2814   TSAN_INTERCEPT(dl_iterate_phdr);
2815 #endif
2816   TSAN_MAYBE_INTERCEPT_ON_EXIT;
2817   TSAN_INTERCEPT(__cxa_atexit);
2818   TSAN_INTERCEPT(_exit);
2819 
2820 #ifdef NEED_TLS_GET_ADDR
2821   TSAN_INTERCEPT(__tls_get_addr);
2822 #endif
2823 
2824   TSAN_MAYBE_INTERCEPT__LWP_EXIT;
2825   TSAN_MAYBE_INTERCEPT_THR_EXIT;
2826 
2827 #if !SANITIZER_MAC && !SANITIZER_ANDROID
2828   // Need to setup it, because interceptors check that the function is resolved.
2829   // But atexit is emitted directly into the module, so can't be resolved.
2830   REAL(atexit) = (int(*)(void(*)()))unreachable;
2831 #endif
2832 
2833   if (REAL(__cxa_atexit)(&finalize, 0, 0)) {
2834     Printf("ThreadSanitizer: failed to setup atexit callback\n");
2835     Die();
2836   }
2837 
2838 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
2839   if (pthread_key_create(&interceptor_ctx()->finalize_key, &thread_finalize)) {
2840     Printf("ThreadSanitizer: failed to create thread key\n");
2841     Die();
2842   }
2843 #endif
2844 
2845   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_init);
2846   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_signal);
2847   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_broadcast);
2848   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_wait);
2849   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_destroy);
2850   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_init);
2851   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_destroy);
2852   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_trylock);
2853   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_init);
2854   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_destroy);
2855   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_rdlock);
2856   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_tryrdlock);
2857   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_wrlock);
2858   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_trywrlock);
2859   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_unlock);
2860   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(once);
2861   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(sigsetmask);
2862 
2863   FdInit();
2864 }
2865 
2866 }  // namespace __tsan
2867 
2868 // Invisible barrier for tests.
2869 // There were several unsuccessful iterations for this functionality:
2870 // 1. Initially it was implemented in user code using
2871 //    REAL(pthread_barrier_wait). But pthread_barrier_wait is not supported on
2872 //    MacOS. Futexes are linux-specific for this matter.
2873 // 2. Then we switched to atomics+usleep(10). But usleep produced parasitic
2874 //    "as-if synchronized via sleep" messages in reports which failed some
2875 //    output tests.
2876 // 3. Then we switched to atomics+sched_yield. But this produced tons of tsan-
2877 //    visible events, which lead to "failed to restore stack trace" failures.
2878 // Note that no_sanitize_thread attribute does not turn off atomic interception
2879 // so attaching it to the function defined in user code does not help.
2880 // That's why we now have what we have.
2881 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
__tsan_testonly_barrier_init(u64 * barrier,u32 count)2882 void __tsan_testonly_barrier_init(u64 *barrier, u32 count) {
2883   if (count >= (1 << 8)) {
2884       Printf("barrier_init: count is too large (%d)\n", count);
2885       Die();
2886   }
2887   // 8 lsb is thread count, the remaining are count of entered threads.
2888   *barrier = count;
2889 }
2890 
2891 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
__tsan_testonly_barrier_wait(u64 * barrier)2892 void __tsan_testonly_barrier_wait(u64 *barrier) {
2893   unsigned old = __atomic_fetch_add(barrier, 1 << 8, __ATOMIC_RELAXED);
2894   unsigned old_epoch = (old >> 8) / (old & 0xff);
2895   for (;;) {
2896     unsigned cur = __atomic_load_n(barrier, __ATOMIC_RELAXED);
2897     unsigned cur_epoch = (cur >> 8) / (cur & 0xff);
2898     if (cur_epoch != old_epoch)
2899       return;
2900     internal_sched_yield();
2901   }
2902 }
2903