1 //===-- tsan_interceptors.cc ----------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of ThreadSanitizer (TSan), a race detector.
11 //
12 // FIXME: move as many interceptors as possible into
13 // sanitizer_common/sanitizer_common_interceptors.inc
14 //===----------------------------------------------------------------------===//
15 
16 #include "sanitizer_common/sanitizer_atomic.h"
17 #include "sanitizer_common/sanitizer_errno.h"
18 #include "sanitizer_common/sanitizer_libc.h"
19 #include "sanitizer_common/sanitizer_linux.h"
20 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
21 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
22 #include "sanitizer_common/sanitizer_placement_new.h"
23 #include "sanitizer_common/sanitizer_posix.h"
24 #include "sanitizer_common/sanitizer_stacktrace.h"
25 #include "sanitizer_common/sanitizer_tls_get_addr.h"
26 #include "interception/interception.h"
27 #include "tsan_interceptors.h"
28 #include "tsan_interface.h"
29 #include "tsan_platform.h"
30 #include "tsan_suppressions.h"
31 #include "tsan_rtl.h"
32 #include "tsan_mman.h"
33 #include "tsan_fd.h"
34 
35 
36 using namespace __tsan;  // NOLINT
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 ? -1 : \
47    (int)(unsigned short)(((__sanitizer_FILE*)fp)->_file))  // NOLINT
48 
49 #define stdout ((__sanitizer_FILE*)&__sF[1])
50 #define stderr ((__sanitizer_FILE*)&__sF[2])
51 
52 #define nanosleep __nanosleep50
53 #define vfork __vfork14
54 #endif
55 
56 #if SANITIZER_ANDROID
57 #define mallopt(a, b)
58 #endif
59 
60 #ifdef __mips__
61 const int kSigCount = 129;
62 #else
63 const int kSigCount = 65;
64 #endif
65 
66 #ifdef __mips__
67 struct ucontext_t {
68   u64 opaque[768 / sizeof(u64) + 1];
69 };
70 #else
71 struct ucontext_t {
72   // The size is determined by looking at sizeof of real ucontext_t on linux.
73   u64 opaque[936 / sizeof(u64) + 1];
74 };
75 #endif
76 
77 #if defined(__x86_64__) || defined(__mips__) || SANITIZER_PPC64V1
78 #define PTHREAD_ABI_BASE  "GLIBC_2.3.2"
79 #elif defined(__aarch64__) || SANITIZER_PPC64V2
80 #define PTHREAD_ABI_BASE  "GLIBC_2.17"
81 #endif
82 
83 extern "C" int pthread_attr_init(void *attr);
84 extern "C" int pthread_attr_destroy(void *attr);
85 DECLARE_REAL(int, pthread_attr_getdetachstate, void *, void *)
86 extern "C" int pthread_attr_setstacksize(void *attr, uptr stacksize);
87 extern "C" int pthread_key_create(unsigned *key, void (*destructor)(void* v));
88 extern "C" int pthread_setspecific(unsigned key, const void *v);
89 DECLARE_REAL(int, pthread_mutexattr_gettype, void *, void *)
90 DECLARE_REAL(int, fflush, __sanitizer_FILE *fp)
91 DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr size)
92 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
93 extern "C" void *pthread_self();
94 extern "C" void _exit(int status);
95 #if !SANITIZER_NETBSD
96 extern "C" int fileno_unlocked(void *stream);
97 extern "C" int dirfd(void *dirp);
98 #endif
99 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_NETBSD
100 extern "C" int mallopt(int param, int value);
101 #endif
102 #if SANITIZER_NETBSD
103 extern __sanitizer_FILE __sF[];
104 #else
105 extern __sanitizer_FILE *stdout, *stderr;
106 #endif
107 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
108 const int PTHREAD_MUTEX_RECURSIVE = 1;
109 const int PTHREAD_MUTEX_RECURSIVE_NP = 1;
110 #else
111 const int PTHREAD_MUTEX_RECURSIVE = 2;
112 const int PTHREAD_MUTEX_RECURSIVE_NP = 2;
113 #endif
114 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
115 const int EPOLL_CTL_ADD = 1;
116 #endif
117 const int SIGILL = 4;
118 const int SIGABRT = 6;
119 const int SIGFPE = 8;
120 const int SIGSEGV = 11;
121 const int SIGPIPE = 13;
122 const int SIGTERM = 15;
123 #if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
124 const int SIGBUS = 10;
125 const int SIGSYS = 12;
126 #else
127 const int SIGBUS = 7;
128 const int SIGSYS = 31;
129 #endif
130 void *const MAP_FAILED = (void*)-1;
131 #if SANITIZER_NETBSD
132 const int PTHREAD_BARRIER_SERIAL_THREAD = 1234567;
133 #elif !SANITIZER_MAC
134 const int PTHREAD_BARRIER_SERIAL_THREAD = -1;
135 #endif
136 const int MAP_FIXED = 0x10;
137 typedef long long_t;  // NOLINT
138 
139 // From /usr/include/unistd.h
140 # define F_ULOCK 0      /* Unlock a previously locked region.  */
141 # define F_LOCK  1      /* Lock a region for exclusive use.  */
142 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
143 # define F_TEST  3      /* Test a region for other processes locks.  */
144 
145 #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
146 const int SA_SIGINFO = 0x40;
147 const int SIG_SETMASK = 3;
148 #elif defined(__mips__)
149 const int SA_SIGINFO = 8;
150 const int SIG_SETMASK = 3;
151 #else
152 const int SA_SIGINFO = 4;
153 const int SIG_SETMASK = 2;
154 #endif
155 
156 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \
157   (!cur_thread()->is_inited)
158 
159 namespace __tsan {
160 struct SignalDesc {
161   bool armed;
162   bool sigaction;
163   __sanitizer_siginfo siginfo;
164   ucontext_t ctx;
165 };
166 
167 struct ThreadSignalContext {
168   int int_signal_send;
169   atomic_uintptr_t in_blocking_func;
170   atomic_uintptr_t have_pending_signals;
171   SignalDesc pending_signals[kSigCount];
172   // emptyset and oldset are too big for stack.
173   __sanitizer_sigset_t emptyset;
174   __sanitizer_sigset_t oldset;
175 };
176 
177 // The sole reason tsan wraps atexit callbacks is to establish synchronization
178 // between callback setup and callback execution.
179 struct AtExitCtx {
180   void (*f)();
181   void *arg;
182 };
183 
184 // InterceptorContext holds all global data required for interceptors.
185 // It's explicitly constructed in InitializeInterceptors with placement new
186 // and is never destroyed. This allows usage of members with non-trivial
187 // constructors and destructors.
188 struct InterceptorContext {
189   // The object is 64-byte aligned, because we want hot data to be located
190   // in a single cache line if possible (it's accessed in every interceptor).
191   ALIGNED(64) LibIgnore libignore;
192   __sanitizer_sigaction sigactions[kSigCount];
193 #if !SANITIZER_MAC && !SANITIZER_NETBSD
194   unsigned finalize_key;
195 #endif
196 
197   BlockingMutex atexit_mu;
198   Vector<struct AtExitCtx *> AtExitStack;
199 
InterceptorContext__tsan::InterceptorContext200   InterceptorContext()
201       : libignore(LINKER_INITIALIZED), AtExitStack() {
202   }
203 };
204 
205 static ALIGNED(64) char interceptor_placeholder[sizeof(InterceptorContext)];
interceptor_ctx()206 InterceptorContext *interceptor_ctx() {
207   return reinterpret_cast<InterceptorContext*>(&interceptor_placeholder[0]);
208 }
209 
libignore()210 LibIgnore *libignore() {
211   return &interceptor_ctx()->libignore;
212 }
213 
InitializeLibIgnore()214 void InitializeLibIgnore() {
215   const SuppressionContext &supp = *Suppressions();
216   const uptr n = supp.SuppressionCount();
217   for (uptr i = 0; i < n; i++) {
218     const Suppression *s = supp.SuppressionAt(i);
219     if (0 == internal_strcmp(s->type, kSuppressionLib))
220       libignore()->AddIgnoredLibrary(s->templ);
221   }
222   if (flags()->ignore_noninstrumented_modules)
223     libignore()->IgnoreNoninstrumentedModules(true);
224   libignore()->OnLibraryLoaded(0);
225 }
226 
227 // The following two hooks can be used by for cooperative scheduling when
228 // locking.
229 #ifdef TSAN_EXTERNAL_HOOKS
230 void OnPotentiallyBlockingRegionBegin();
231 void OnPotentiallyBlockingRegionEnd();
232 #else
OnPotentiallyBlockingRegionBegin()233 SANITIZER_WEAK_CXX_DEFAULT_IMPL void OnPotentiallyBlockingRegionBegin() {}
OnPotentiallyBlockingRegionEnd()234 SANITIZER_WEAK_CXX_DEFAULT_IMPL void OnPotentiallyBlockingRegionEnd() {}
235 #endif
236 
237 }  // namespace __tsan
238 
SigCtx(ThreadState * thr)239 static ThreadSignalContext *SigCtx(ThreadState *thr) {
240   ThreadSignalContext *ctx = (ThreadSignalContext*)thr->signal_ctx;
241   if (ctx == 0 && !thr->is_dead) {
242     ctx = (ThreadSignalContext*)MmapOrDie(sizeof(*ctx), "ThreadSignalContext");
243     MemoryResetRange(thr, (uptr)&SigCtx, (uptr)ctx, sizeof(*ctx));
244     thr->signal_ctx = ctx;
245   }
246   return ctx;
247 }
248 
ScopedInterceptor(ThreadState * thr,const char * fname,uptr pc)249 ScopedInterceptor::ScopedInterceptor(ThreadState *thr, const char *fname,
250                                      uptr pc)
251     : thr_(thr), pc_(pc), in_ignored_lib_(false), ignoring_(false) {
252   Initialize(thr);
253   if (!thr_->is_inited) return;
254   if (!thr_->ignore_interceptors) FuncEntry(thr, pc);
255   DPrintf("#%d: intercept %s()\n", thr_->tid, fname);
256   ignoring_ =
257       !thr_->in_ignored_lib && libignore()->IsIgnored(pc, &in_ignored_lib_);
258   EnableIgnores();
259 }
260 
~ScopedInterceptor()261 ScopedInterceptor::~ScopedInterceptor() {
262   if (!thr_->is_inited) return;
263   DisableIgnores();
264   if (!thr_->ignore_interceptors) {
265     ProcessPendingSignals(thr_);
266     FuncExit(thr_);
267     CheckNoLocks(thr_);
268   }
269 }
270 
EnableIgnores()271 void ScopedInterceptor::EnableIgnores() {
272   if (ignoring_) {
273     ThreadIgnoreBegin(thr_, pc_, /*save_stack=*/false);
274     if (flags()->ignore_noninstrumented_modules) thr_->suppress_reports++;
275     if (in_ignored_lib_) {
276       DCHECK(!thr_->in_ignored_lib);
277       thr_->in_ignored_lib = true;
278     }
279   }
280 }
281 
DisableIgnores()282 void ScopedInterceptor::DisableIgnores() {
283   if (ignoring_) {
284     ThreadIgnoreEnd(thr_, pc_);
285     if (flags()->ignore_noninstrumented_modules) thr_->suppress_reports--;
286     if (in_ignored_lib_) {
287       DCHECK(thr_->in_ignored_lib);
288       thr_->in_ignored_lib = false;
289     }
290   }
291 }
292 
293 #define TSAN_INTERCEPT(func) INTERCEPT_FUNCTION(func)
294 #if SANITIZER_FREEBSD
295 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func)
296 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(func)
297 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(func)
298 #elif SANITIZER_NETBSD
299 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func)
300 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(func) \
301          INTERCEPT_FUNCTION(__libc_##func)
302 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(func) \
303          INTERCEPT_FUNCTION(__libc_thr_##func)
304 #else
305 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION_VER(func, ver)
306 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(func)
307 # define TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(func)
308 #endif
309 
310 #define READ_STRING_OF_LEN(thr, pc, s, len, n)                 \
311   MemoryAccessRange((thr), (pc), (uptr)(s),                         \
312     common_flags()->strict_string_checks ? (len) + 1 : (n), false)
313 
314 #define READ_STRING(thr, pc, s, n)                             \
315     READ_STRING_OF_LEN((thr), (pc), (s), internal_strlen(s), (n))
316 
317 #define BLOCK_REAL(name) (BlockingCall(thr), REAL(name))
318 
319 struct BlockingCall {
BlockingCallBlockingCall320   explicit BlockingCall(ThreadState *thr)
321       : thr(thr)
322       , ctx(SigCtx(thr)) {
323     for (;;) {
324       atomic_store(&ctx->in_blocking_func, 1, memory_order_relaxed);
325       if (atomic_load(&ctx->have_pending_signals, memory_order_relaxed) == 0)
326         break;
327       atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
328       ProcessPendingSignals(thr);
329     }
330     // When we are in a "blocking call", we process signals asynchronously
331     // (right when they arrive). In this context we do not expect to be
332     // executing any user/runtime code. The known interceptor sequence when
333     // this is not true is: pthread_join -> munmap(stack). It's fine
334     // to ignore munmap in this case -- we handle stack shadow separately.
335     thr->ignore_interceptors++;
336   }
337 
~BlockingCallBlockingCall338   ~BlockingCall() {
339     thr->ignore_interceptors--;
340     atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
341   }
342 
343   ThreadState *thr;
344   ThreadSignalContext *ctx;
345 };
346 
TSAN_INTERCEPTOR(unsigned,sleep,unsigned sec)347 TSAN_INTERCEPTOR(unsigned, sleep, unsigned sec) {
348   SCOPED_TSAN_INTERCEPTOR(sleep, sec);
349   unsigned res = BLOCK_REAL(sleep)(sec);
350   AfterSleep(thr, pc);
351   return res;
352 }
353 
TSAN_INTERCEPTOR(int,usleep,long_t usec)354 TSAN_INTERCEPTOR(int, usleep, long_t usec) {
355   SCOPED_TSAN_INTERCEPTOR(usleep, usec);
356   int res = BLOCK_REAL(usleep)(usec);
357   AfterSleep(thr, pc);
358   return res;
359 }
360 
TSAN_INTERCEPTOR(int,nanosleep,void * req,void * rem)361 TSAN_INTERCEPTOR(int, nanosleep, void *req, void *rem) {
362   SCOPED_TSAN_INTERCEPTOR(nanosleep, req, rem);
363   int res = BLOCK_REAL(nanosleep)(req, rem);
364   AfterSleep(thr, pc);
365   return res;
366 }
367 
TSAN_INTERCEPTOR(int,pause,int fake)368 TSAN_INTERCEPTOR(int, pause, int fake) {
369   SCOPED_TSAN_INTERCEPTOR(pause, fake);
370   return BLOCK_REAL(pause)(fake);
371 }
372 
at_exit_wrapper()373 static void at_exit_wrapper() {
374   AtExitCtx *ctx;
375   {
376     // Ensure thread-safety.
377     BlockingMutexLock l(&interceptor_ctx()->atexit_mu);
378 
379     // Pop AtExitCtx from the top of the stack of callback functions
380     uptr element = interceptor_ctx()->AtExitStack.Size() - 1;
381     ctx = interceptor_ctx()->AtExitStack[element];
382     interceptor_ctx()->AtExitStack.PopBack();
383   }
384 
385   Acquire(cur_thread(), (uptr)0, (uptr)ctx);
386   ((void(*)())ctx->f)();
387   InternalFree(ctx);
388 }
389 
cxa_at_exit_wrapper(void * arg)390 static void cxa_at_exit_wrapper(void *arg) {
391   Acquire(cur_thread(), 0, (uptr)arg);
392   AtExitCtx *ctx = (AtExitCtx*)arg;
393   ((void(*)(void *arg))ctx->f)(ctx->arg);
394   InternalFree(ctx);
395 }
396 
397 static int setup_at_exit_wrapper(ThreadState *thr, uptr pc, void(*f)(),
398       void *arg, void *dso);
399 
400 #if !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,atexit,void (* f)())401 TSAN_INTERCEPTOR(int, atexit, void (*f)()) {
402   if (UNLIKELY(cur_thread()->in_symbolizer))
403     return 0;
404   // We want to setup the atexit callback even if we are in ignored lib
405   // or after fork.
406   SCOPED_INTERCEPTOR_RAW(atexit, f);
407   return setup_at_exit_wrapper(thr, pc, (void(*)())f, 0, 0);
408 }
409 #endif
410 
TSAN_INTERCEPTOR(int,__cxa_atexit,void (* f)(void * a),void * arg,void * dso)411 TSAN_INTERCEPTOR(int, __cxa_atexit, void (*f)(void *a), void *arg, void *dso) {
412   if (UNLIKELY(cur_thread()->in_symbolizer))
413     return 0;
414   SCOPED_TSAN_INTERCEPTOR(__cxa_atexit, f, arg, dso);
415   return setup_at_exit_wrapper(thr, pc, (void(*)())f, arg, dso);
416 }
417 
setup_at_exit_wrapper(ThreadState * thr,uptr pc,void (* f)(),void * arg,void * dso)418 static int setup_at_exit_wrapper(ThreadState *thr, uptr pc, void(*f)(),
419       void *arg, void *dso) {
420   AtExitCtx *ctx = (AtExitCtx*)InternalAlloc(sizeof(AtExitCtx));
421   ctx->f = f;
422   ctx->arg = arg;
423   Release(thr, pc, (uptr)ctx);
424   // Memory allocation in __cxa_atexit will race with free during exit,
425   // because we do not see synchronization around atexit callback list.
426   ThreadIgnoreBegin(thr, pc);
427   int res;
428   if (!dso) {
429     // NetBSD does not preserve the 2nd argument if dso is equal to 0
430     // Store ctx in a local stack-like structure
431 
432     // Ensure thread-safety.
433     BlockingMutexLock l(&interceptor_ctx()->atexit_mu);
434 
435     res = REAL(__cxa_atexit)((void (*)(void *a))at_exit_wrapper, 0, 0);
436     // Push AtExitCtx on the top of the stack of callback functions
437     if (!res) {
438       interceptor_ctx()->AtExitStack.PushBack(ctx);
439     }
440   } else {
441     res = REAL(__cxa_atexit)(cxa_at_exit_wrapper, ctx, dso);
442   }
443   ThreadIgnoreEnd(thr, pc);
444   return res;
445 }
446 
447 #if !SANITIZER_MAC && !SANITIZER_NETBSD
on_exit_wrapper(int status,void * arg)448 static void on_exit_wrapper(int status, void *arg) {
449   ThreadState *thr = cur_thread();
450   uptr pc = 0;
451   Acquire(thr, pc, (uptr)arg);
452   AtExitCtx *ctx = (AtExitCtx*)arg;
453   ((void(*)(int status, void *arg))ctx->f)(status, ctx->arg);
454   InternalFree(ctx);
455 }
456 
TSAN_INTERCEPTOR(int,on_exit,void (* f)(int,void *),void * arg)457 TSAN_INTERCEPTOR(int, on_exit, void(*f)(int, void*), void *arg) {
458   if (UNLIKELY(cur_thread()->in_symbolizer))
459     return 0;
460   SCOPED_TSAN_INTERCEPTOR(on_exit, f, arg);
461   AtExitCtx *ctx = (AtExitCtx*)InternalAlloc(sizeof(AtExitCtx));
462   ctx->f = (void(*)())f;
463   ctx->arg = arg;
464   Release(thr, pc, (uptr)ctx);
465   // Memory allocation in __cxa_atexit will race with free during exit,
466   // because we do not see synchronization around atexit callback list.
467   ThreadIgnoreBegin(thr, pc);
468   int res = REAL(on_exit)(on_exit_wrapper, ctx);
469   ThreadIgnoreEnd(thr, pc);
470   return res;
471 }
472 #define TSAN_MAYBE_INTERCEPT_ON_EXIT TSAN_INTERCEPT(on_exit)
473 #else
474 #define TSAN_MAYBE_INTERCEPT_ON_EXIT
475 #endif
476 
477 // Cleanup old bufs.
JmpBufGarbageCollect(ThreadState * thr,uptr sp)478 static void JmpBufGarbageCollect(ThreadState *thr, uptr sp) {
479   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
480     JmpBuf *buf = &thr->jmp_bufs[i];
481     if (buf->sp <= sp) {
482       uptr sz = thr->jmp_bufs.Size();
483       internal_memcpy(buf, &thr->jmp_bufs[sz - 1], sizeof(*buf));
484       thr->jmp_bufs.PopBack();
485       i--;
486     }
487   }
488 }
489 
SetJmp(ThreadState * thr,uptr sp,uptr mangled_sp)490 static void SetJmp(ThreadState *thr, uptr sp, uptr mangled_sp) {
491   if (!thr->is_inited)  // called from libc guts during bootstrap
492     return;
493   // Cleanup old bufs.
494   JmpBufGarbageCollect(thr, sp);
495   // Remember the buf.
496   JmpBuf *buf = thr->jmp_bufs.PushBack();
497   buf->sp = sp;
498   buf->mangled_sp = mangled_sp;
499   buf->shadow_stack_pos = thr->shadow_stack_pos;
500   ThreadSignalContext *sctx = SigCtx(thr);
501   buf->int_signal_send = sctx ? sctx->int_signal_send : 0;
502   buf->in_blocking_func = sctx ?
503       atomic_load(&sctx->in_blocking_func, memory_order_relaxed) :
504       false;
505   buf->in_signal_handler = atomic_load(&thr->in_signal_handler,
506       memory_order_relaxed);
507 }
508 
LongJmp(ThreadState * thr,uptr * env)509 static void LongJmp(ThreadState *thr, uptr *env) {
510 #ifdef __powerpc__
511   uptr mangled_sp = env[0];
512 #elif SANITIZER_FREEBSD
513   uptr mangled_sp = env[2];
514 #elif SANITIZER_NETBSD
515   uptr mangled_sp = env[6];
516 #elif SANITIZER_MAC
517 # ifdef __aarch64__
518   uptr mangled_sp =
519       (GetMacosVersion() >= MACOS_VERSION_MOJAVE) ? env[12] : env[13];
520 # else
521     uptr mangled_sp = env[2];
522 # endif
523 #elif SANITIZER_LINUX
524 # ifdef __aarch64__
525   uptr mangled_sp = env[13];
526 # elif defined(__mips64)
527   uptr mangled_sp = env[1];
528 # else
529   uptr mangled_sp = env[6];
530 # endif
531 #endif
532   // Find the saved buf by mangled_sp.
533   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
534     JmpBuf *buf = &thr->jmp_bufs[i];
535     if (buf->mangled_sp == mangled_sp) {
536       CHECK_GE(thr->shadow_stack_pos, buf->shadow_stack_pos);
537       // Unwind the stack.
538       while (thr->shadow_stack_pos > buf->shadow_stack_pos)
539         FuncExit(thr);
540       ThreadSignalContext *sctx = SigCtx(thr);
541       if (sctx) {
542         sctx->int_signal_send = buf->int_signal_send;
543         atomic_store(&sctx->in_blocking_func, buf->in_blocking_func,
544             memory_order_relaxed);
545       }
546       atomic_store(&thr->in_signal_handler, buf->in_signal_handler,
547           memory_order_relaxed);
548       JmpBufGarbageCollect(thr, buf->sp - 1);  // do not collect buf->sp
549       return;
550     }
551   }
552   Printf("ThreadSanitizer: can't find longjmp buf\n");
553   CHECK(0);
554 }
555 
556 // FIXME: put everything below into a common extern "C" block?
__tsan_setjmp(uptr sp,uptr mangled_sp)557 extern "C" void __tsan_setjmp(uptr sp, uptr mangled_sp) {
558   SetJmp(cur_thread(), sp, mangled_sp);
559 }
560 
561 #if SANITIZER_MAC
562 TSAN_INTERCEPTOR(int, setjmp, void *env);
563 TSAN_INTERCEPTOR(int, _setjmp, void *env);
564 TSAN_INTERCEPTOR(int, sigsetjmp, void *env);
565 #else  // SANITIZER_MAC
566 
567 #if SANITIZER_NETBSD
568 #define setjmp_symname __setjmp14
569 #define sigsetjmp_symname __sigsetjmp14
570 #else
571 #define setjmp_symname setjmp
572 #define sigsetjmp_symname sigsetjmp
573 #endif
574 
575 #define TSAN_INTERCEPTOR_SETJMP_(x) __interceptor_ ## x
576 #define TSAN_INTERCEPTOR_SETJMP__(x) TSAN_INTERCEPTOR_SETJMP_(x)
577 #define TSAN_INTERCEPTOR_SETJMP TSAN_INTERCEPTOR_SETJMP__(setjmp_symname)
578 #define TSAN_INTERCEPTOR_SIGSETJMP TSAN_INTERCEPTOR_SETJMP__(sigsetjmp_symname)
579 
580 #define TSAN_STRING_SETJMP SANITIZER_STRINGIFY(setjmp_symname)
581 #define TSAN_STRING_SIGSETJMP SANITIZER_STRINGIFY(sigsetjmp_symname)
582 
583 // Not called.  Merely to satisfy TSAN_INTERCEPT().
584 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
585 int TSAN_INTERCEPTOR_SETJMP(void *env);
TSAN_INTERCEPTOR_SETJMP(void * env)586 extern "C" int TSAN_INTERCEPTOR_SETJMP(void *env) {
587   CHECK(0);
588   return 0;
589 }
590 
591 // FIXME: any reason to have a separate declaration?
592 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
593 int __interceptor__setjmp(void *env);
__interceptor__setjmp(void * env)594 extern "C" int __interceptor__setjmp(void *env) {
595   CHECK(0);
596   return 0;
597 }
598 
599 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
600 int TSAN_INTERCEPTOR_SIGSETJMP(void *env);
TSAN_INTERCEPTOR_SIGSETJMP(void * env)601 extern "C" int TSAN_INTERCEPTOR_SIGSETJMP(void *env) {
602   CHECK(0);
603   return 0;
604 }
605 
606 #if !SANITIZER_NETBSD
607 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
608 int __interceptor___sigsetjmp(void *env);
__interceptor___sigsetjmp(void * env)609 extern "C" int __interceptor___sigsetjmp(void *env) {
610   CHECK(0);
611   return 0;
612 }
613 #endif
614 
615 extern "C" int setjmp_symname(void *env);
616 extern "C" int _setjmp(void *env);
617 extern "C" int sigsetjmp_symname(void *env);
618 #if !SANITIZER_NETBSD
619 extern "C" int __sigsetjmp(void *env);
620 #endif
DEFINE_REAL(int,setjmp_symname,void * env)621 DEFINE_REAL(int, setjmp_symname, void *env)
622 DEFINE_REAL(int, _setjmp, void *env)
623 DEFINE_REAL(int, sigsetjmp_symname, void *env)
624 #if !SANITIZER_NETBSD
625 DEFINE_REAL(int, __sigsetjmp, void *env)
626 #endif
627 #endif  // SANITIZER_MAC
628 
629 #if SANITIZER_NETBSD
630 #define longjmp_symname __longjmp14
631 #define siglongjmp_symname __siglongjmp14
632 #else
633 #define longjmp_symname longjmp
634 #define siglongjmp_symname siglongjmp
635 #endif
636 
637 TSAN_INTERCEPTOR(void, longjmp_symname, uptr *env, int val) {
638   // Note: if we call REAL(longjmp) in the context of ScopedInterceptor,
639   // bad things will happen. We will jump over ScopedInterceptor dtor and can
640   // leave thr->in_ignored_lib set.
641   {
642     SCOPED_INTERCEPTOR_RAW(longjmp_symname, env, val);
643   }
644   LongJmp(cur_thread(), env);
645   REAL(longjmp_symname)(env, val);
646 }
647 
TSAN_INTERCEPTOR(void,siglongjmp_symname,uptr * env,int val)648 TSAN_INTERCEPTOR(void, siglongjmp_symname, uptr *env, int val) {
649   {
650     SCOPED_INTERCEPTOR_RAW(siglongjmp_symname, env, val);
651   }
652   LongJmp(cur_thread(), env);
653   REAL(siglongjmp_symname)(env, val);
654 }
655 
656 #if SANITIZER_NETBSD
TSAN_INTERCEPTOR(void,_longjmp,uptr * env,int val)657 TSAN_INTERCEPTOR(void, _longjmp, uptr *env, int val) {
658   {
659     SCOPED_INTERCEPTOR_RAW(_longjmp, env, val);
660   }
661   LongJmp(cur_thread(), env);
662   REAL(_longjmp)(env, val);
663 }
664 #endif
665 
666 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(void *,malloc,uptr size)667 TSAN_INTERCEPTOR(void*, malloc, uptr size) {
668   if (UNLIKELY(cur_thread()->in_symbolizer))
669     return InternalAlloc(size);
670   void *p = 0;
671   {
672     SCOPED_INTERCEPTOR_RAW(malloc, size);
673     p = user_alloc(thr, pc, size);
674   }
675   invoke_malloc_hook(p, size);
676   return p;
677 }
678 
TSAN_INTERCEPTOR(void *,__libc_memalign,uptr align,uptr sz)679 TSAN_INTERCEPTOR(void*, __libc_memalign, uptr align, uptr sz) {
680   SCOPED_TSAN_INTERCEPTOR(__libc_memalign, align, sz);
681   return user_memalign(thr, pc, align, sz);
682 }
683 
TSAN_INTERCEPTOR(void *,calloc,uptr size,uptr n)684 TSAN_INTERCEPTOR(void*, calloc, uptr size, uptr n) {
685   if (UNLIKELY(cur_thread()->in_symbolizer))
686     return InternalCalloc(size, n);
687   void *p = 0;
688   {
689     SCOPED_INTERCEPTOR_RAW(calloc, size, n);
690     p = user_calloc(thr, pc, size, n);
691   }
692   invoke_malloc_hook(p, n * size);
693   return p;
694 }
695 
TSAN_INTERCEPTOR(void *,realloc,void * p,uptr size)696 TSAN_INTERCEPTOR(void*, realloc, void *p, uptr size) {
697   if (UNLIKELY(cur_thread()->in_symbolizer))
698     return InternalRealloc(p, size);
699   if (p)
700     invoke_free_hook(p);
701   {
702     SCOPED_INTERCEPTOR_RAW(realloc, p, size);
703     p = user_realloc(thr, pc, p, size);
704   }
705   invoke_malloc_hook(p, size);
706   return p;
707 }
708 
TSAN_INTERCEPTOR(void,free,void * p)709 TSAN_INTERCEPTOR(void, free, void *p) {
710   if (p == 0)
711     return;
712   if (UNLIKELY(cur_thread()->in_symbolizer))
713     return InternalFree(p);
714   invoke_free_hook(p);
715   SCOPED_INTERCEPTOR_RAW(free, p);
716   user_free(thr, pc, p);
717 }
718 
TSAN_INTERCEPTOR(void,cfree,void * p)719 TSAN_INTERCEPTOR(void, cfree, void *p) {
720   if (p == 0)
721     return;
722   if (UNLIKELY(cur_thread()->in_symbolizer))
723     return InternalFree(p);
724   invoke_free_hook(p);
725   SCOPED_INTERCEPTOR_RAW(cfree, p);
726   user_free(thr, pc, p);
727 }
728 
TSAN_INTERCEPTOR(uptr,malloc_usable_size,void * p)729 TSAN_INTERCEPTOR(uptr, malloc_usable_size, void *p) {
730   SCOPED_INTERCEPTOR_RAW(malloc_usable_size, p);
731   return user_alloc_usable_size(p);
732 }
733 #endif
734 
TSAN_INTERCEPTOR(char *,strcpy,char * dst,const char * src)735 TSAN_INTERCEPTOR(char*, strcpy, char *dst, const char *src) {  // NOLINT
736   SCOPED_TSAN_INTERCEPTOR(strcpy, dst, src);  // NOLINT
737   uptr srclen = internal_strlen(src);
738   MemoryAccessRange(thr, pc, (uptr)dst, srclen + 1, true);
739   MemoryAccessRange(thr, pc, (uptr)src, srclen + 1, false);
740   return REAL(strcpy)(dst, src);  // NOLINT
741 }
742 
TSAN_INTERCEPTOR(char *,strncpy,char * dst,char * src,uptr n)743 TSAN_INTERCEPTOR(char*, strncpy, char *dst, char *src, uptr n) {
744   SCOPED_TSAN_INTERCEPTOR(strncpy, dst, src, n);
745   uptr srclen = internal_strnlen(src, n);
746   MemoryAccessRange(thr, pc, (uptr)dst, n, true);
747   MemoryAccessRange(thr, pc, (uptr)src, min(srclen + 1, n), false);
748   return REAL(strncpy)(dst, src, n);
749 }
750 
TSAN_INTERCEPTOR(char *,strdup,const char * str)751 TSAN_INTERCEPTOR(char*, strdup, const char *str) {
752   SCOPED_TSAN_INTERCEPTOR(strdup, str);
753   // strdup will call malloc, so no instrumentation is required here.
754   return REAL(strdup)(str);
755 }
756 
fix_mmap_addr(void ** addr,long_t sz,int flags)757 static bool fix_mmap_addr(void **addr, long_t sz, int flags) {
758   if (*addr) {
759     if (!IsAppMem((uptr)*addr) || !IsAppMem((uptr)*addr + sz - 1)) {
760       if (flags & MAP_FIXED) {
761         errno = errno_EINVAL;
762         return false;
763       } else {
764         *addr = 0;
765       }
766     }
767   }
768   return true;
769 }
770 
771 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)772 static void *mmap_interceptor(ThreadState *thr, uptr pc, Mmap real_mmap,
773                               void *addr, SIZE_T sz, int prot, int flags,
774                               int fd, OFF64_T off) {
775   if (!fix_mmap_addr(&addr, sz, flags)) return MAP_FAILED;
776   void *res = real_mmap(addr, sz, prot, flags, fd, off);
777   if (res != MAP_FAILED) {
778     if (fd > 0) FdAccess(thr, pc, fd);
779     if (thr->ignore_reads_and_writes == 0)
780       MemoryRangeImitateWrite(thr, pc, (uptr)res, sz);
781     else
782       MemoryResetRange(thr, pc, (uptr)res, sz);
783   }
784   return res;
785 }
786 
TSAN_INTERCEPTOR(int,munmap,void * addr,long_t sz)787 TSAN_INTERCEPTOR(int, munmap, void *addr, long_t sz) {
788   SCOPED_TSAN_INTERCEPTOR(munmap, addr, sz);
789   if (sz != 0) {
790     // If sz == 0, munmap will return EINVAL and don't unmap any memory.
791     DontNeedShadowFor((uptr)addr, sz);
792     ScopedGlobalProcessor sgp;
793     ctx->metamap.ResetRange(thr->proc(), (uptr)addr, (uptr)sz);
794   }
795   int res = REAL(munmap)(addr, sz);
796   return res;
797 }
798 
799 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,memalign,uptr align,uptr sz)800 TSAN_INTERCEPTOR(void*, memalign, uptr align, uptr sz) {
801   SCOPED_INTERCEPTOR_RAW(memalign, align, sz);
802   return user_memalign(thr, pc, align, sz);
803 }
804 #define TSAN_MAYBE_INTERCEPT_MEMALIGN TSAN_INTERCEPT(memalign)
805 #else
806 #define TSAN_MAYBE_INTERCEPT_MEMALIGN
807 #endif
808 
809 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(void *,aligned_alloc,uptr align,uptr sz)810 TSAN_INTERCEPTOR(void*, aligned_alloc, uptr align, uptr sz) {
811   if (UNLIKELY(cur_thread()->in_symbolizer))
812     return InternalAlloc(sz, nullptr, align);
813   SCOPED_INTERCEPTOR_RAW(aligned_alloc, align, sz);
814   return user_aligned_alloc(thr, pc, align, sz);
815 }
816 
TSAN_INTERCEPTOR(void *,valloc,uptr sz)817 TSAN_INTERCEPTOR(void*, valloc, uptr sz) {
818   if (UNLIKELY(cur_thread()->in_symbolizer))
819     return InternalAlloc(sz, nullptr, GetPageSizeCached());
820   SCOPED_INTERCEPTOR_RAW(valloc, sz);
821   return user_valloc(thr, pc, sz);
822 }
823 #endif
824 
825 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,pvalloc,uptr sz)826 TSAN_INTERCEPTOR(void*, pvalloc, uptr sz) {
827   if (UNLIKELY(cur_thread()->in_symbolizer)) {
828     uptr PageSize = GetPageSizeCached();
829     sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
830     return InternalAlloc(sz, nullptr, PageSize);
831   }
832   SCOPED_INTERCEPTOR_RAW(pvalloc, sz);
833   return user_pvalloc(thr, pc, sz);
834 }
835 #define TSAN_MAYBE_INTERCEPT_PVALLOC TSAN_INTERCEPT(pvalloc)
836 #else
837 #define TSAN_MAYBE_INTERCEPT_PVALLOC
838 #endif
839 
840 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,posix_memalign,void ** memptr,uptr align,uptr sz)841 TSAN_INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr sz) {
842   if (UNLIKELY(cur_thread()->in_symbolizer)) {
843     void *p = InternalAlloc(sz, nullptr, align);
844     if (!p)
845       return errno_ENOMEM;
846     *memptr = p;
847     return 0;
848   }
849   SCOPED_INTERCEPTOR_RAW(posix_memalign, memptr, align, sz);
850   return user_posix_memalign(thr, pc, memptr, align, sz);
851 }
852 #endif
853 
854 // __cxa_guard_acquire and friends need to be intercepted in a special way -
855 // regular interceptors will break statically-linked libstdc++. Linux
856 // interceptors are especially defined as weak functions (so that they don't
857 // cause link errors when user defines them as well). So they silently
858 // auto-disable themselves when such symbol is already present in the binary. If
859 // we link libstdc++ statically, it will bring own __cxa_guard_acquire which
860 // will silently replace our interceptor.  That's why on Linux we simply export
861 // these interceptors with INTERFACE_ATTRIBUTE.
862 // On OS X, we don't support statically linking, so we just use a regular
863 // interceptor.
864 #if SANITIZER_MAC
865 #define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR
866 #else
867 #define STDCXX_INTERCEPTOR(rettype, name, ...) \
868   extern "C" rettype INTERFACE_ATTRIBUTE name(__VA_ARGS__)
869 #endif
870 
871 // Used in thread-safe function static initialization.
STDCXX_INTERCEPTOR(int,__cxa_guard_acquire,atomic_uint32_t * g)872 STDCXX_INTERCEPTOR(int, __cxa_guard_acquire, atomic_uint32_t *g) {
873   SCOPED_INTERCEPTOR_RAW(__cxa_guard_acquire, g);
874   OnPotentiallyBlockingRegionBegin();
875   auto on_exit = at_scope_exit(&OnPotentiallyBlockingRegionEnd);
876   for (;;) {
877     u32 cmp = atomic_load(g, memory_order_acquire);
878     if (cmp == 0) {
879       if (atomic_compare_exchange_strong(g, &cmp, 1<<16, memory_order_relaxed))
880         return 1;
881     } else if (cmp == 1) {
882       Acquire(thr, pc, (uptr)g);
883       return 0;
884     } else {
885       internal_sched_yield();
886     }
887   }
888 }
889 
STDCXX_INTERCEPTOR(void,__cxa_guard_release,atomic_uint32_t * g)890 STDCXX_INTERCEPTOR(void, __cxa_guard_release, atomic_uint32_t *g) {
891   SCOPED_INTERCEPTOR_RAW(__cxa_guard_release, g);
892   Release(thr, pc, (uptr)g);
893   atomic_store(g, 1, memory_order_release);
894 }
895 
STDCXX_INTERCEPTOR(void,__cxa_guard_abort,atomic_uint32_t * g)896 STDCXX_INTERCEPTOR(void, __cxa_guard_abort, atomic_uint32_t *g) {
897   SCOPED_INTERCEPTOR_RAW(__cxa_guard_abort, g);
898   atomic_store(g, 0, memory_order_relaxed);
899 }
900 
901 namespace __tsan {
DestroyThreadState()902 void DestroyThreadState() {
903   ThreadState *thr = cur_thread();
904   Processor *proc = thr->proc();
905   ThreadFinish(thr);
906   ProcUnwire(proc, thr);
907   ProcDestroy(proc);
908   ThreadSignalContext *sctx = thr->signal_ctx;
909   if (sctx) {
910     thr->signal_ctx = 0;
911     UnmapOrDie(sctx, sizeof(*sctx));
912   }
913   DTLS_Destroy();
914   cur_thread_finalize();
915 }
916 }  // namespace __tsan
917 
918 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
thread_finalize(void * v)919 static void thread_finalize(void *v) {
920   uptr iter = (uptr)v;
921   if (iter > 1) {
922     if (pthread_setspecific(interceptor_ctx()->finalize_key,
923         (void*)(iter - 1))) {
924       Printf("ThreadSanitizer: failed to set thread key\n");
925       Die();
926     }
927     return;
928   }
929   DestroyThreadState();
930 }
931 #endif
932 
933 
934 struct ThreadParam {
935   void* (*callback)(void *arg);
936   void *param;
937   atomic_uintptr_t tid;
938 };
939 
__tsan_thread_start_func(void * arg)940 extern "C" void *__tsan_thread_start_func(void *arg) {
941   ThreadParam *p = (ThreadParam*)arg;
942   void* (*callback)(void *arg) = p->callback;
943   void *param = p->param;
944   int tid = 0;
945   {
946     ThreadState *thr = cur_thread();
947     // Thread-local state is not initialized yet.
948     ScopedIgnoreInterceptors ignore;
949 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
950     ThreadIgnoreBegin(thr, 0);
951     if (pthread_setspecific(interceptor_ctx()->finalize_key,
952                             (void *)GetPthreadDestructorIterations())) {
953       Printf("ThreadSanitizer: failed to set thread key\n");
954       Die();
955     }
956     ThreadIgnoreEnd(thr, 0);
957 #endif
958     while ((tid = atomic_load(&p->tid, memory_order_acquire)) == 0)
959       internal_sched_yield();
960     Processor *proc = ProcCreate();
961     ProcWire(proc, thr);
962     ThreadStart(thr, tid, GetTid(), /*workerthread*/ false);
963     atomic_store(&p->tid, 0, memory_order_release);
964   }
965   void *res = callback(param);
966   // Prevent the callback from being tail called,
967   // it mixes up stack traces.
968   volatile int foo = 42;
969   foo++;
970   return res;
971 }
972 
TSAN_INTERCEPTOR(int,pthread_create,void * th,void * attr,void * (* callback)(void *),void * param)973 TSAN_INTERCEPTOR(int, pthread_create,
974     void *th, void *attr, void *(*callback)(void*), void * param) {
975   SCOPED_INTERCEPTOR_RAW(pthread_create, th, attr, callback, param);
976 
977   MaybeSpawnBackgroundThread();
978 
979   if (ctx->after_multithreaded_fork) {
980     if (flags()->die_after_fork) {
981       Report("ThreadSanitizer: starting new threads after multi-threaded "
982           "fork is not supported. Dying (set die_after_fork=0 to override)\n");
983       Die();
984     } else {
985       VPrintf(1, "ThreadSanitizer: starting new threads after multi-threaded "
986           "fork is not supported (pid %d). Continuing because of "
987           "die_after_fork=0, but you are on your own\n", internal_getpid());
988     }
989   }
990   __sanitizer_pthread_attr_t myattr;
991   if (attr == 0) {
992     pthread_attr_init(&myattr);
993     attr = &myattr;
994   }
995   int detached = 0;
996   REAL(pthread_attr_getdetachstate)(attr, &detached);
997   AdjustStackSize(attr);
998 
999   ThreadParam p;
1000   p.callback = callback;
1001   p.param = param;
1002   atomic_store(&p.tid, 0, memory_order_relaxed);
1003   int res = -1;
1004   {
1005     // Otherwise we see false positives in pthread stack manipulation.
1006     ScopedIgnoreInterceptors ignore;
1007     ThreadIgnoreBegin(thr, pc);
1008     res = REAL(pthread_create)(th, attr, __tsan_thread_start_func, &p);
1009     ThreadIgnoreEnd(thr, pc);
1010   }
1011   if (res == 0) {
1012     int tid = ThreadCreate(thr, pc, *(uptr*)th, IsStateDetached(detached));
1013     CHECK_NE(tid, 0);
1014     // Synchronization on p.tid serves two purposes:
1015     // 1. ThreadCreate must finish before the new thread starts.
1016     //    Otherwise the new thread can call pthread_detach, but the pthread_t
1017     //    identifier is not yet registered in ThreadRegistry by ThreadCreate.
1018     // 2. ThreadStart must finish before this thread continues.
1019     //    Otherwise, this thread can call pthread_detach and reset thr->sync
1020     //    before the new thread got a chance to acquire from it in ThreadStart.
1021     atomic_store(&p.tid, tid, memory_order_release);
1022     while (atomic_load(&p.tid, memory_order_acquire) != 0)
1023       internal_sched_yield();
1024   }
1025   if (attr == &myattr)
1026     pthread_attr_destroy(&myattr);
1027   return res;
1028 }
1029 
TSAN_INTERCEPTOR(int,pthread_join,void * th,void ** ret)1030 TSAN_INTERCEPTOR(int, pthread_join, void *th, void **ret) {
1031   SCOPED_INTERCEPTOR_RAW(pthread_join, th, ret);
1032   int tid = ThreadTid(thr, pc, (uptr)th);
1033   ThreadIgnoreBegin(thr, pc);
1034   int res = BLOCK_REAL(pthread_join)(th, ret);
1035   ThreadIgnoreEnd(thr, pc);
1036   if (res == 0) {
1037     ThreadJoin(thr, pc, tid);
1038   }
1039   return res;
1040 }
1041 
1042 DEFINE_REAL_PTHREAD_FUNCTIONS
1043 
TSAN_INTERCEPTOR(int,pthread_detach,void * th)1044 TSAN_INTERCEPTOR(int, pthread_detach, void *th) {
1045   SCOPED_TSAN_INTERCEPTOR(pthread_detach, th);
1046   int tid = ThreadTid(thr, pc, (uptr)th);
1047   int res = REAL(pthread_detach)(th);
1048   if (res == 0) {
1049     ThreadDetach(thr, pc, tid);
1050   }
1051   return res;
1052 }
1053 
1054 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,pthread_tryjoin_np,void * th,void ** ret)1055 TSAN_INTERCEPTOR(int, pthread_tryjoin_np, void *th, void **ret) {
1056   SCOPED_TSAN_INTERCEPTOR(pthread_tryjoin_np, th, ret);
1057   int tid = ThreadTid(thr, pc, (uptr)th);
1058   ThreadIgnoreBegin(thr, pc);
1059   int res = REAL(pthread_tryjoin_np)(th, ret);
1060   ThreadIgnoreEnd(thr, pc);
1061   if (res == 0)
1062     ThreadJoin(thr, pc, tid);
1063   else
1064     ThreadNotJoined(thr, pc, tid, (uptr)th);
1065   return res;
1066 }
1067 
TSAN_INTERCEPTOR(int,pthread_timedjoin_np,void * th,void ** ret,const struct timespec * abstime)1068 TSAN_INTERCEPTOR(int, pthread_timedjoin_np, void *th, void **ret,
1069                  const struct timespec *abstime) {
1070   SCOPED_TSAN_INTERCEPTOR(pthread_timedjoin_np, th, ret, abstime);
1071   int tid = ThreadTid(thr, pc, (uptr)th);
1072   ThreadIgnoreBegin(thr, pc);
1073   int res = BLOCK_REAL(pthread_timedjoin_np)(th, ret, abstime);
1074   ThreadIgnoreEnd(thr, pc);
1075   if (res == 0)
1076     ThreadJoin(thr, pc, tid);
1077   else
1078     ThreadNotJoined(thr, pc, tid, (uptr)th);
1079   return res;
1080 }
1081 #endif
1082 
1083 // Problem:
1084 // NPTL implementation of pthread_cond has 2 versions (2.2.5 and 2.3.2).
1085 // pthread_cond_t has different size in the different versions.
1086 // If call new REAL functions for old pthread_cond_t, they will corrupt memory
1087 // after pthread_cond_t (old cond is smaller).
1088 // If we call old REAL functions for new pthread_cond_t, we will lose  some
1089 // functionality (e.g. old functions do not support waiting against
1090 // CLOCK_REALTIME).
1091 // Proper handling would require to have 2 versions of interceptors as well.
1092 // But this is messy, in particular requires linker scripts when sanitizer
1093 // runtime is linked into a shared library.
1094 // Instead we assume we don't have dynamic libraries built against old
1095 // pthread (2.2.5 is dated by 2002). And provide legacy_pthread_cond flag
1096 // that allows to work with old libraries (but this mode does not support
1097 // some features, e.g. pthread_condattr_getpshared).
init_cond(void * c,bool force=false)1098 static void *init_cond(void *c, bool force = false) {
1099   // sizeof(pthread_cond_t) >= sizeof(uptr) in both versions.
1100   // So we allocate additional memory on the side large enough to hold
1101   // any pthread_cond_t object. Always call new REAL functions, but pass
1102   // the aux object to them.
1103   // Note: the code assumes that PTHREAD_COND_INITIALIZER initializes
1104   // first word of pthread_cond_t to zero.
1105   // It's all relevant only for linux.
1106   if (!common_flags()->legacy_pthread_cond)
1107     return c;
1108   atomic_uintptr_t *p = (atomic_uintptr_t*)c;
1109   uptr cond = atomic_load(p, memory_order_acquire);
1110   if (!force && cond != 0)
1111     return (void*)cond;
1112   void *newcond = WRAP(malloc)(pthread_cond_t_sz);
1113   internal_memset(newcond, 0, pthread_cond_t_sz);
1114   if (atomic_compare_exchange_strong(p, &cond, (uptr)newcond,
1115       memory_order_acq_rel))
1116     return newcond;
1117   WRAP(free)(newcond);
1118   return (void*)cond;
1119 }
1120 
1121 struct CondMutexUnlockCtx {
1122   ScopedInterceptor *si;
1123   ThreadState *thr;
1124   uptr pc;
1125   void *m;
1126 };
1127 
cond_mutex_unlock(CondMutexUnlockCtx * arg)1128 static void cond_mutex_unlock(CondMutexUnlockCtx *arg) {
1129   // pthread_cond_wait interceptor has enabled async signal delivery
1130   // (see BlockingCall below). Disable async signals since we are running
1131   // tsan code. Also ScopedInterceptor and BlockingCall destructors won't run
1132   // since the thread is cancelled, so we have to manually execute them
1133   // (the thread still can run some user code due to pthread_cleanup_push).
1134   ThreadSignalContext *ctx = SigCtx(arg->thr);
1135   CHECK_EQ(atomic_load(&ctx->in_blocking_func, memory_order_relaxed), 1);
1136   atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
1137   MutexPostLock(arg->thr, arg->pc, (uptr)arg->m, MutexFlagDoPreLockOnPostLock);
1138   // Undo BlockingCall ctor effects.
1139   arg->thr->ignore_interceptors--;
1140   arg->si->~ScopedInterceptor();
1141 }
1142 
INTERCEPTOR(int,pthread_cond_init,void * c,void * a)1143 INTERCEPTOR(int, pthread_cond_init, void *c, void *a) {
1144   void *cond = init_cond(c, true);
1145   SCOPED_TSAN_INTERCEPTOR(pthread_cond_init, cond, a);
1146   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true);
1147   return REAL(pthread_cond_init)(cond, a);
1148 }
1149 
cond_wait(ThreadState * thr,uptr pc,ScopedInterceptor * si,int (* fn)(void * c,void * m,void * abstime),void * c,void * m,void * t)1150 static int cond_wait(ThreadState *thr, uptr pc, ScopedInterceptor *si,
1151                      int (*fn)(void *c, void *m, void *abstime), void *c,
1152                      void *m, void *t) {
1153   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1154   MutexUnlock(thr, pc, (uptr)m);
1155   CondMutexUnlockCtx arg = {si, thr, pc, m};
1156   int res = 0;
1157   // This ensures that we handle mutex lock even in case of pthread_cancel.
1158   // See test/tsan/cond_cancel.cc.
1159   {
1160     // Enable signal delivery while the thread is blocked.
1161     BlockingCall bc(thr);
1162     res = call_pthread_cancel_with_cleanup(
1163         fn, c, m, t, (void (*)(void *arg))cond_mutex_unlock, &arg);
1164   }
1165   if (res == errno_EOWNERDEAD) MutexRepair(thr, pc, (uptr)m);
1166   MutexPostLock(thr, pc, (uptr)m, MutexFlagDoPreLockOnPostLock);
1167   return res;
1168 }
1169 
INTERCEPTOR(int,pthread_cond_wait,void * c,void * m)1170 INTERCEPTOR(int, pthread_cond_wait, void *c, void *m) {
1171   void *cond = init_cond(c);
1172   SCOPED_TSAN_INTERCEPTOR(pthread_cond_wait, cond, m);
1173   return cond_wait(thr, pc, &si, (int (*)(void *c, void *m, void *abstime))REAL(
1174                                      pthread_cond_wait),
1175                    cond, m, 0);
1176 }
1177 
INTERCEPTOR(int,pthread_cond_timedwait,void * c,void * m,void * abstime)1178 INTERCEPTOR(int, pthread_cond_timedwait, void *c, void *m, void *abstime) {
1179   void *cond = init_cond(c);
1180   SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait, cond, m, abstime);
1181   return cond_wait(thr, pc, &si, REAL(pthread_cond_timedwait), cond, m,
1182                    abstime);
1183 }
1184 
1185 #if SANITIZER_MAC
INTERCEPTOR(int,pthread_cond_timedwait_relative_np,void * c,void * m,void * reltime)1186 INTERCEPTOR(int, pthread_cond_timedwait_relative_np, void *c, void *m,
1187             void *reltime) {
1188   void *cond = init_cond(c);
1189   SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait_relative_np, cond, m, reltime);
1190   return cond_wait(thr, pc, &si, REAL(pthread_cond_timedwait_relative_np), cond,
1191                    m, reltime);
1192 }
1193 #endif
1194 
INTERCEPTOR(int,pthread_cond_signal,void * c)1195 INTERCEPTOR(int, pthread_cond_signal, void *c) {
1196   void *cond = init_cond(c);
1197   SCOPED_TSAN_INTERCEPTOR(pthread_cond_signal, cond);
1198   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1199   return REAL(pthread_cond_signal)(cond);
1200 }
1201 
INTERCEPTOR(int,pthread_cond_broadcast,void * c)1202 INTERCEPTOR(int, pthread_cond_broadcast, void *c) {
1203   void *cond = init_cond(c);
1204   SCOPED_TSAN_INTERCEPTOR(pthread_cond_broadcast, cond);
1205   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1206   return REAL(pthread_cond_broadcast)(cond);
1207 }
1208 
INTERCEPTOR(int,pthread_cond_destroy,void * c)1209 INTERCEPTOR(int, pthread_cond_destroy, void *c) {
1210   void *cond = init_cond(c);
1211   SCOPED_TSAN_INTERCEPTOR(pthread_cond_destroy, cond);
1212   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true);
1213   int res = REAL(pthread_cond_destroy)(cond);
1214   if (common_flags()->legacy_pthread_cond) {
1215     // Free our aux cond and zero the pointer to not leave dangling pointers.
1216     WRAP(free)(cond);
1217     atomic_store((atomic_uintptr_t*)c, 0, memory_order_relaxed);
1218   }
1219   return res;
1220 }
1221 
TSAN_INTERCEPTOR(int,pthread_mutex_init,void * m,void * a)1222 TSAN_INTERCEPTOR(int, pthread_mutex_init, void *m, void *a) {
1223   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_init, m, a);
1224   int res = REAL(pthread_mutex_init)(m, a);
1225   if (res == 0) {
1226     u32 flagz = 0;
1227     if (a) {
1228       int type = 0;
1229       if (REAL(pthread_mutexattr_gettype)(a, &type) == 0)
1230         if (type == PTHREAD_MUTEX_RECURSIVE ||
1231             type == PTHREAD_MUTEX_RECURSIVE_NP)
1232           flagz |= MutexFlagWriteReentrant;
1233     }
1234     MutexCreate(thr, pc, (uptr)m, flagz);
1235   }
1236   return res;
1237 }
1238 
TSAN_INTERCEPTOR(int,pthread_mutex_destroy,void * m)1239 TSAN_INTERCEPTOR(int, pthread_mutex_destroy, void *m) {
1240   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_destroy, m);
1241   int res = REAL(pthread_mutex_destroy)(m);
1242   if (res == 0 || res == errno_EBUSY) {
1243     MutexDestroy(thr, pc, (uptr)m);
1244   }
1245   return res;
1246 }
1247 
TSAN_INTERCEPTOR(int,pthread_mutex_trylock,void * m)1248 TSAN_INTERCEPTOR(int, pthread_mutex_trylock, void *m) {
1249   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_trylock, m);
1250   int res = REAL(pthread_mutex_trylock)(m);
1251   if (res == errno_EOWNERDEAD)
1252     MutexRepair(thr, pc, (uptr)m);
1253   if (res == 0 || res == errno_EOWNERDEAD)
1254     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1255   return res;
1256 }
1257 
1258 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_mutex_timedlock,void * m,void * abstime)1259 TSAN_INTERCEPTOR(int, pthread_mutex_timedlock, void *m, void *abstime) {
1260   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_timedlock, m, abstime);
1261   int res = REAL(pthread_mutex_timedlock)(m, abstime);
1262   if (res == 0) {
1263     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1264   }
1265   return res;
1266 }
1267 #endif
1268 
1269 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_spin_init,void * m,int pshared)1270 TSAN_INTERCEPTOR(int, pthread_spin_init, void *m, int pshared) {
1271   SCOPED_TSAN_INTERCEPTOR(pthread_spin_init, m, pshared);
1272   int res = REAL(pthread_spin_init)(m, pshared);
1273   if (res == 0) {
1274     MutexCreate(thr, pc, (uptr)m);
1275   }
1276   return res;
1277 }
1278 
TSAN_INTERCEPTOR(int,pthread_spin_destroy,void * m)1279 TSAN_INTERCEPTOR(int, pthread_spin_destroy, void *m) {
1280   SCOPED_TSAN_INTERCEPTOR(pthread_spin_destroy, m);
1281   int res = REAL(pthread_spin_destroy)(m);
1282   if (res == 0) {
1283     MutexDestroy(thr, pc, (uptr)m);
1284   }
1285   return res;
1286 }
1287 
TSAN_INTERCEPTOR(int,pthread_spin_lock,void * m)1288 TSAN_INTERCEPTOR(int, pthread_spin_lock, void *m) {
1289   SCOPED_TSAN_INTERCEPTOR(pthread_spin_lock, m);
1290   MutexPreLock(thr, pc, (uptr)m);
1291   int res = REAL(pthread_spin_lock)(m);
1292   if (res == 0) {
1293     MutexPostLock(thr, pc, (uptr)m);
1294   }
1295   return res;
1296 }
1297 
TSAN_INTERCEPTOR(int,pthread_spin_trylock,void * m)1298 TSAN_INTERCEPTOR(int, pthread_spin_trylock, void *m) {
1299   SCOPED_TSAN_INTERCEPTOR(pthread_spin_trylock, m);
1300   int res = REAL(pthread_spin_trylock)(m);
1301   if (res == 0) {
1302     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1303   }
1304   return res;
1305 }
1306 
TSAN_INTERCEPTOR(int,pthread_spin_unlock,void * m)1307 TSAN_INTERCEPTOR(int, pthread_spin_unlock, void *m) {
1308   SCOPED_TSAN_INTERCEPTOR(pthread_spin_unlock, m);
1309   MutexUnlock(thr, pc, (uptr)m);
1310   int res = REAL(pthread_spin_unlock)(m);
1311   return res;
1312 }
1313 #endif
1314 
TSAN_INTERCEPTOR(int,pthread_rwlock_init,void * m,void * a)1315 TSAN_INTERCEPTOR(int, pthread_rwlock_init, void *m, void *a) {
1316   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_init, m, a);
1317   int res = REAL(pthread_rwlock_init)(m, a);
1318   if (res == 0) {
1319     MutexCreate(thr, pc, (uptr)m);
1320   }
1321   return res;
1322 }
1323 
TSAN_INTERCEPTOR(int,pthread_rwlock_destroy,void * m)1324 TSAN_INTERCEPTOR(int, pthread_rwlock_destroy, void *m) {
1325   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_destroy, m);
1326   int res = REAL(pthread_rwlock_destroy)(m);
1327   if (res == 0) {
1328     MutexDestroy(thr, pc, (uptr)m);
1329   }
1330   return res;
1331 }
1332 
TSAN_INTERCEPTOR(int,pthread_rwlock_rdlock,void * m)1333 TSAN_INTERCEPTOR(int, pthread_rwlock_rdlock, void *m) {
1334   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_rdlock, m);
1335   MutexPreReadLock(thr, pc, (uptr)m);
1336   int res = REAL(pthread_rwlock_rdlock)(m);
1337   if (res == 0) {
1338     MutexPostReadLock(thr, pc, (uptr)m);
1339   }
1340   return res;
1341 }
1342 
TSAN_INTERCEPTOR(int,pthread_rwlock_tryrdlock,void * m)1343 TSAN_INTERCEPTOR(int, pthread_rwlock_tryrdlock, void *m) {
1344   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_tryrdlock, m);
1345   int res = REAL(pthread_rwlock_tryrdlock)(m);
1346   if (res == 0) {
1347     MutexPostReadLock(thr, pc, (uptr)m, MutexFlagTryLock);
1348   }
1349   return res;
1350 }
1351 
1352 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_rwlock_timedrdlock,void * m,void * abstime)1353 TSAN_INTERCEPTOR(int, pthread_rwlock_timedrdlock, void *m, void *abstime) {
1354   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedrdlock, m, abstime);
1355   int res = REAL(pthread_rwlock_timedrdlock)(m, abstime);
1356   if (res == 0) {
1357     MutexPostReadLock(thr, pc, (uptr)m);
1358   }
1359   return res;
1360 }
1361 #endif
1362 
TSAN_INTERCEPTOR(int,pthread_rwlock_wrlock,void * m)1363 TSAN_INTERCEPTOR(int, pthread_rwlock_wrlock, void *m) {
1364   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_wrlock, m);
1365   MutexPreLock(thr, pc, (uptr)m);
1366   int res = REAL(pthread_rwlock_wrlock)(m);
1367   if (res == 0) {
1368     MutexPostLock(thr, pc, (uptr)m);
1369   }
1370   return res;
1371 }
1372 
TSAN_INTERCEPTOR(int,pthread_rwlock_trywrlock,void * m)1373 TSAN_INTERCEPTOR(int, pthread_rwlock_trywrlock, void *m) {
1374   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_trywrlock, m);
1375   int res = REAL(pthread_rwlock_trywrlock)(m);
1376   if (res == 0) {
1377     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1378   }
1379   return res;
1380 }
1381 
1382 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_rwlock_timedwrlock,void * m,void * abstime)1383 TSAN_INTERCEPTOR(int, pthread_rwlock_timedwrlock, void *m, void *abstime) {
1384   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedwrlock, m, abstime);
1385   int res = REAL(pthread_rwlock_timedwrlock)(m, abstime);
1386   if (res == 0) {
1387     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1388   }
1389   return res;
1390 }
1391 #endif
1392 
TSAN_INTERCEPTOR(int,pthread_rwlock_unlock,void * m)1393 TSAN_INTERCEPTOR(int, pthread_rwlock_unlock, void *m) {
1394   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_unlock, m);
1395   MutexReadOrWriteUnlock(thr, pc, (uptr)m);
1396   int res = REAL(pthread_rwlock_unlock)(m);
1397   return res;
1398 }
1399 
1400 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_barrier_init,void * b,void * a,unsigned count)1401 TSAN_INTERCEPTOR(int, pthread_barrier_init, void *b, void *a, unsigned count) {
1402   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_init, b, a, count);
1403   MemoryWrite(thr, pc, (uptr)b, kSizeLog1);
1404   int res = REAL(pthread_barrier_init)(b, a, count);
1405   return res;
1406 }
1407 
TSAN_INTERCEPTOR(int,pthread_barrier_destroy,void * b)1408 TSAN_INTERCEPTOR(int, pthread_barrier_destroy, void *b) {
1409   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_destroy, b);
1410   MemoryWrite(thr, pc, (uptr)b, kSizeLog1);
1411   int res = REAL(pthread_barrier_destroy)(b);
1412   return res;
1413 }
1414 
TSAN_INTERCEPTOR(int,pthread_barrier_wait,void * b)1415 TSAN_INTERCEPTOR(int, pthread_barrier_wait, void *b) {
1416   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_wait, b);
1417   Release(thr, pc, (uptr)b);
1418   MemoryRead(thr, pc, (uptr)b, kSizeLog1);
1419   int res = REAL(pthread_barrier_wait)(b);
1420   MemoryRead(thr, pc, (uptr)b, kSizeLog1);
1421   if (res == 0 || res == PTHREAD_BARRIER_SERIAL_THREAD) {
1422     Acquire(thr, pc, (uptr)b);
1423   }
1424   return res;
1425 }
1426 #endif
1427 
TSAN_INTERCEPTOR(int,pthread_once,void * o,void (* f)())1428 TSAN_INTERCEPTOR(int, pthread_once, void *o, void (*f)()) {
1429   SCOPED_INTERCEPTOR_RAW(pthread_once, o, f);
1430   if (o == 0 || f == 0)
1431     return errno_EINVAL;
1432   atomic_uint32_t *a;
1433 
1434   if (SANITIZER_MAC)
1435     a = static_cast<atomic_uint32_t*>((void *)((char *)o + sizeof(long_t)));
1436   else if (SANITIZER_NETBSD)
1437     a = static_cast<atomic_uint32_t*>
1438           ((void *)((char *)o + __sanitizer::pthread_mutex_t_sz));
1439   else
1440     a = static_cast<atomic_uint32_t*>(o);
1441 
1442   u32 v = atomic_load(a, memory_order_acquire);
1443   if (v == 0 && atomic_compare_exchange_strong(a, &v, 1,
1444                                                memory_order_relaxed)) {
1445     (*f)();
1446     if (!thr->in_ignored_lib)
1447       Release(thr, pc, (uptr)o);
1448     atomic_store(a, 2, memory_order_release);
1449   } else {
1450     while (v != 2) {
1451       internal_sched_yield();
1452       v = atomic_load(a, memory_order_acquire);
1453     }
1454     if (!thr->in_ignored_lib)
1455       Acquire(thr, pc, (uptr)o);
1456   }
1457   return 0;
1458 }
1459 
1460 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,__fxstat,int version,int fd,void * buf)1461 TSAN_INTERCEPTOR(int, __fxstat, int version, int fd, void *buf) {
1462   SCOPED_TSAN_INTERCEPTOR(__fxstat, version, fd, buf);
1463   if (fd > 0)
1464     FdAccess(thr, pc, fd);
1465   return REAL(__fxstat)(version, fd, buf);
1466 }
1467 #define TSAN_MAYBE_INTERCEPT___FXSTAT TSAN_INTERCEPT(__fxstat)
1468 #else
1469 #define TSAN_MAYBE_INTERCEPT___FXSTAT
1470 #endif
1471 
TSAN_INTERCEPTOR(int,fstat,int fd,void * buf)1472 TSAN_INTERCEPTOR(int, fstat, int fd, void *buf) {
1473 #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_ANDROID || SANITIZER_NETBSD
1474   SCOPED_TSAN_INTERCEPTOR(fstat, fd, buf);
1475   if (fd > 0)
1476     FdAccess(thr, pc, fd);
1477   return REAL(fstat)(fd, buf);
1478 #else
1479   SCOPED_TSAN_INTERCEPTOR(__fxstat, 0, fd, buf);
1480   if (fd > 0)
1481     FdAccess(thr, pc, fd);
1482   return REAL(__fxstat)(0, fd, buf);
1483 #endif
1484 }
1485 
1486 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,__fxstat64,int version,int fd,void * buf)1487 TSAN_INTERCEPTOR(int, __fxstat64, int version, int fd, void *buf) {
1488   SCOPED_TSAN_INTERCEPTOR(__fxstat64, version, fd, buf);
1489   if (fd > 0)
1490     FdAccess(thr, pc, fd);
1491   return REAL(__fxstat64)(version, fd, buf);
1492 }
1493 #define TSAN_MAYBE_INTERCEPT___FXSTAT64 TSAN_INTERCEPT(__fxstat64)
1494 #else
1495 #define TSAN_MAYBE_INTERCEPT___FXSTAT64
1496 #endif
1497 
1498 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,fstat64,int fd,void * buf)1499 TSAN_INTERCEPTOR(int, fstat64, int fd, void *buf) {
1500   SCOPED_TSAN_INTERCEPTOR(__fxstat64, 0, fd, buf);
1501   if (fd > 0)
1502     FdAccess(thr, pc, fd);
1503   return REAL(__fxstat64)(0, fd, buf);
1504 }
1505 #define TSAN_MAYBE_INTERCEPT_FSTAT64 TSAN_INTERCEPT(fstat64)
1506 #else
1507 #define TSAN_MAYBE_INTERCEPT_FSTAT64
1508 #endif
1509 
TSAN_INTERCEPTOR(int,open,const char * name,int flags,int mode)1510 TSAN_INTERCEPTOR(int, open, const char *name, int flags, int mode) {
1511   SCOPED_TSAN_INTERCEPTOR(open, name, flags, mode);
1512   READ_STRING(thr, pc, name, 0);
1513   int fd = REAL(open)(name, flags, mode);
1514   if (fd >= 0)
1515     FdFileCreate(thr, pc, fd);
1516   return fd;
1517 }
1518 
1519 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,open64,const char * name,int flags,int mode)1520 TSAN_INTERCEPTOR(int, open64, const char *name, int flags, int mode) {
1521   SCOPED_TSAN_INTERCEPTOR(open64, name, flags, mode);
1522   READ_STRING(thr, pc, name, 0);
1523   int fd = REAL(open64)(name, flags, mode);
1524   if (fd >= 0)
1525     FdFileCreate(thr, pc, fd);
1526   return fd;
1527 }
1528 #define TSAN_MAYBE_INTERCEPT_OPEN64 TSAN_INTERCEPT(open64)
1529 #else
1530 #define TSAN_MAYBE_INTERCEPT_OPEN64
1531 #endif
1532 
TSAN_INTERCEPTOR(int,creat,const char * name,int mode)1533 TSAN_INTERCEPTOR(int, creat, const char *name, int mode) {
1534   SCOPED_TSAN_INTERCEPTOR(creat, name, mode);
1535   READ_STRING(thr, pc, name, 0);
1536   int fd = REAL(creat)(name, mode);
1537   if (fd >= 0)
1538     FdFileCreate(thr, pc, fd);
1539   return fd;
1540 }
1541 
1542 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,creat64,const char * name,int mode)1543 TSAN_INTERCEPTOR(int, creat64, const char *name, int mode) {
1544   SCOPED_TSAN_INTERCEPTOR(creat64, name, mode);
1545   READ_STRING(thr, pc, name, 0);
1546   int fd = REAL(creat64)(name, mode);
1547   if (fd >= 0)
1548     FdFileCreate(thr, pc, fd);
1549   return fd;
1550 }
1551 #define TSAN_MAYBE_INTERCEPT_CREAT64 TSAN_INTERCEPT(creat64)
1552 #else
1553 #define TSAN_MAYBE_INTERCEPT_CREAT64
1554 #endif
1555 
TSAN_INTERCEPTOR(int,dup,int oldfd)1556 TSAN_INTERCEPTOR(int, dup, int oldfd) {
1557   SCOPED_TSAN_INTERCEPTOR(dup, oldfd);
1558   int newfd = REAL(dup)(oldfd);
1559   if (oldfd >= 0 && newfd >= 0 && newfd != oldfd)
1560     FdDup(thr, pc, oldfd, newfd, true);
1561   return newfd;
1562 }
1563 
TSAN_INTERCEPTOR(int,dup2,int oldfd,int newfd)1564 TSAN_INTERCEPTOR(int, dup2, int oldfd, int newfd) {
1565   SCOPED_TSAN_INTERCEPTOR(dup2, oldfd, newfd);
1566   int newfd2 = REAL(dup2)(oldfd, newfd);
1567   if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd)
1568     FdDup(thr, pc, oldfd, newfd2, false);
1569   return newfd2;
1570 }
1571 
1572 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,dup3,int oldfd,int newfd,int flags)1573 TSAN_INTERCEPTOR(int, dup3, int oldfd, int newfd, int flags) {
1574   SCOPED_TSAN_INTERCEPTOR(dup3, oldfd, newfd, flags);
1575   int newfd2 = REAL(dup3)(oldfd, newfd, flags);
1576   if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd)
1577     FdDup(thr, pc, oldfd, newfd2, false);
1578   return newfd2;
1579 }
1580 #endif
1581 
1582 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,eventfd,unsigned initval,int flags)1583 TSAN_INTERCEPTOR(int, eventfd, unsigned initval, int flags) {
1584   SCOPED_TSAN_INTERCEPTOR(eventfd, initval, flags);
1585   int fd = REAL(eventfd)(initval, flags);
1586   if (fd >= 0)
1587     FdEventCreate(thr, pc, fd);
1588   return fd;
1589 }
1590 #define TSAN_MAYBE_INTERCEPT_EVENTFD TSAN_INTERCEPT(eventfd)
1591 #else
1592 #define TSAN_MAYBE_INTERCEPT_EVENTFD
1593 #endif
1594 
1595 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,signalfd,int fd,void * mask,int flags)1596 TSAN_INTERCEPTOR(int, signalfd, int fd, void *mask, int flags) {
1597   SCOPED_TSAN_INTERCEPTOR(signalfd, fd, mask, flags);
1598   if (fd >= 0)
1599     FdClose(thr, pc, fd);
1600   fd = REAL(signalfd)(fd, mask, flags);
1601   if (fd >= 0)
1602     FdSignalCreate(thr, pc, fd);
1603   return fd;
1604 }
1605 #define TSAN_MAYBE_INTERCEPT_SIGNALFD TSAN_INTERCEPT(signalfd)
1606 #else
1607 #define TSAN_MAYBE_INTERCEPT_SIGNALFD
1608 #endif
1609 
1610 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,inotify_init,int fake)1611 TSAN_INTERCEPTOR(int, inotify_init, int fake) {
1612   SCOPED_TSAN_INTERCEPTOR(inotify_init, fake);
1613   int fd = REAL(inotify_init)(fake);
1614   if (fd >= 0)
1615     FdInotifyCreate(thr, pc, fd);
1616   return fd;
1617 }
1618 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT TSAN_INTERCEPT(inotify_init)
1619 #else
1620 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT
1621 #endif
1622 
1623 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,inotify_init1,int flags)1624 TSAN_INTERCEPTOR(int, inotify_init1, int flags) {
1625   SCOPED_TSAN_INTERCEPTOR(inotify_init1, flags);
1626   int fd = REAL(inotify_init1)(flags);
1627   if (fd >= 0)
1628     FdInotifyCreate(thr, pc, fd);
1629   return fd;
1630 }
1631 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1 TSAN_INTERCEPT(inotify_init1)
1632 #else
1633 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1
1634 #endif
1635 
TSAN_INTERCEPTOR(int,socket,int domain,int type,int protocol)1636 TSAN_INTERCEPTOR(int, socket, int domain, int type, int protocol) {
1637   SCOPED_TSAN_INTERCEPTOR(socket, domain, type, protocol);
1638   int fd = REAL(socket)(domain, type, protocol);
1639   if (fd >= 0)
1640     FdSocketCreate(thr, pc, fd);
1641   return fd;
1642 }
1643 
TSAN_INTERCEPTOR(int,socketpair,int domain,int type,int protocol,int * fd)1644 TSAN_INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int *fd) {
1645   SCOPED_TSAN_INTERCEPTOR(socketpair, domain, type, protocol, fd);
1646   int res = REAL(socketpair)(domain, type, protocol, fd);
1647   if (res == 0 && fd[0] >= 0 && fd[1] >= 0)
1648     FdPipeCreate(thr, pc, fd[0], fd[1]);
1649   return res;
1650 }
1651 
TSAN_INTERCEPTOR(int,connect,int fd,void * addr,unsigned addrlen)1652 TSAN_INTERCEPTOR(int, connect, int fd, void *addr, unsigned addrlen) {
1653   SCOPED_TSAN_INTERCEPTOR(connect, fd, addr, addrlen);
1654   FdSocketConnecting(thr, pc, fd);
1655   int res = REAL(connect)(fd, addr, addrlen);
1656   if (res == 0 && fd >= 0)
1657     FdSocketConnect(thr, pc, fd);
1658   return res;
1659 }
1660 
TSAN_INTERCEPTOR(int,bind,int fd,void * addr,unsigned addrlen)1661 TSAN_INTERCEPTOR(int, bind, int fd, void *addr, unsigned addrlen) {
1662   SCOPED_TSAN_INTERCEPTOR(bind, fd, addr, addrlen);
1663   int res = REAL(bind)(fd, addr, addrlen);
1664   if (fd > 0 && res == 0)
1665     FdAccess(thr, pc, fd);
1666   return res;
1667 }
1668 
TSAN_INTERCEPTOR(int,listen,int fd,int backlog)1669 TSAN_INTERCEPTOR(int, listen, int fd, int backlog) {
1670   SCOPED_TSAN_INTERCEPTOR(listen, fd, backlog);
1671   int res = REAL(listen)(fd, backlog);
1672   if (fd > 0 && res == 0)
1673     FdAccess(thr, pc, fd);
1674   return res;
1675 }
1676 
TSAN_INTERCEPTOR(int,close,int fd)1677 TSAN_INTERCEPTOR(int, close, int fd) {
1678   SCOPED_TSAN_INTERCEPTOR(close, fd);
1679   if (fd >= 0)
1680     FdClose(thr, pc, fd);
1681   return REAL(close)(fd);
1682 }
1683 
1684 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,__close,int fd)1685 TSAN_INTERCEPTOR(int, __close, int fd) {
1686   SCOPED_TSAN_INTERCEPTOR(__close, fd);
1687   if (fd >= 0)
1688     FdClose(thr, pc, fd);
1689   return REAL(__close)(fd);
1690 }
1691 #define TSAN_MAYBE_INTERCEPT___CLOSE TSAN_INTERCEPT(__close)
1692 #else
1693 #define TSAN_MAYBE_INTERCEPT___CLOSE
1694 #endif
1695 
1696 // glibc guts
1697 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(void,__res_iclose,void * state,bool free_addr)1698 TSAN_INTERCEPTOR(void, __res_iclose, void *state, bool free_addr) {
1699   SCOPED_TSAN_INTERCEPTOR(__res_iclose, state, free_addr);
1700   int fds[64];
1701   int cnt = ExtractResolvFDs(state, fds, ARRAY_SIZE(fds));
1702   for (int i = 0; i < cnt; i++) {
1703     if (fds[i] > 0)
1704       FdClose(thr, pc, fds[i]);
1705   }
1706   REAL(__res_iclose)(state, free_addr);
1707 }
1708 #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE TSAN_INTERCEPT(__res_iclose)
1709 #else
1710 #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE
1711 #endif
1712 
TSAN_INTERCEPTOR(int,pipe,int * pipefd)1713 TSAN_INTERCEPTOR(int, pipe, int *pipefd) {
1714   SCOPED_TSAN_INTERCEPTOR(pipe, pipefd);
1715   int res = REAL(pipe)(pipefd);
1716   if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0)
1717     FdPipeCreate(thr, pc, pipefd[0], pipefd[1]);
1718   return res;
1719 }
1720 
1721 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pipe2,int * pipefd,int flags)1722 TSAN_INTERCEPTOR(int, pipe2, int *pipefd, int flags) {
1723   SCOPED_TSAN_INTERCEPTOR(pipe2, pipefd, flags);
1724   int res = REAL(pipe2)(pipefd, flags);
1725   if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0)
1726     FdPipeCreate(thr, pc, pipefd[0], pipefd[1]);
1727   return res;
1728 }
1729 #endif
1730 
TSAN_INTERCEPTOR(int,unlink,char * path)1731 TSAN_INTERCEPTOR(int, unlink, char *path) {
1732   SCOPED_TSAN_INTERCEPTOR(unlink, path);
1733   Release(thr, pc, File2addr(path));
1734   int res = REAL(unlink)(path);
1735   return res;
1736 }
1737 
TSAN_INTERCEPTOR(void *,tmpfile,int fake)1738 TSAN_INTERCEPTOR(void*, tmpfile, int fake) {
1739   SCOPED_TSAN_INTERCEPTOR(tmpfile, fake);
1740   void *res = REAL(tmpfile)(fake);
1741   if (res) {
1742     int fd = fileno_unlocked(res);
1743     if (fd >= 0)
1744       FdFileCreate(thr, pc, fd);
1745   }
1746   return res;
1747 }
1748 
1749 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,tmpfile64,int fake)1750 TSAN_INTERCEPTOR(void*, tmpfile64, int fake) {
1751   SCOPED_TSAN_INTERCEPTOR(tmpfile64, fake);
1752   void *res = REAL(tmpfile64)(fake);
1753   if (res) {
1754     int fd = fileno_unlocked(res);
1755     if (fd >= 0)
1756       FdFileCreate(thr, pc, fd);
1757   }
1758   return res;
1759 }
1760 #define TSAN_MAYBE_INTERCEPT_TMPFILE64 TSAN_INTERCEPT(tmpfile64)
1761 #else
1762 #define TSAN_MAYBE_INTERCEPT_TMPFILE64
1763 #endif
1764 
FlushStreams()1765 static void FlushStreams() {
1766   // Flushing all the streams here may freeze the process if a child thread is
1767   // performing file stream operations at the same time.
1768   REAL(fflush)(stdout);
1769   REAL(fflush)(stderr);
1770 }
1771 
TSAN_INTERCEPTOR(void,abort,int fake)1772 TSAN_INTERCEPTOR(void, abort, int fake) {
1773   SCOPED_TSAN_INTERCEPTOR(abort, fake);
1774   FlushStreams();
1775   REAL(abort)(fake);
1776 }
1777 
TSAN_INTERCEPTOR(int,rmdir,char * path)1778 TSAN_INTERCEPTOR(int, rmdir, char *path) {
1779   SCOPED_TSAN_INTERCEPTOR(rmdir, path);
1780   Release(thr, pc, Dir2addr(path));
1781   int res = REAL(rmdir)(path);
1782   return res;
1783 }
1784 
TSAN_INTERCEPTOR(int,closedir,void * dirp)1785 TSAN_INTERCEPTOR(int, closedir, void *dirp) {
1786   SCOPED_TSAN_INTERCEPTOR(closedir, dirp);
1787   if (dirp) {
1788     int fd = dirfd(dirp);
1789     FdClose(thr, pc, fd);
1790   }
1791   return REAL(closedir)(dirp);
1792 }
1793 
1794 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,epoll_create,int size)1795 TSAN_INTERCEPTOR(int, epoll_create, int size) {
1796   SCOPED_TSAN_INTERCEPTOR(epoll_create, size);
1797   int fd = REAL(epoll_create)(size);
1798   if (fd >= 0)
1799     FdPollCreate(thr, pc, fd);
1800   return fd;
1801 }
1802 
TSAN_INTERCEPTOR(int,epoll_create1,int flags)1803 TSAN_INTERCEPTOR(int, epoll_create1, int flags) {
1804   SCOPED_TSAN_INTERCEPTOR(epoll_create1, flags);
1805   int fd = REAL(epoll_create1)(flags);
1806   if (fd >= 0)
1807     FdPollCreate(thr, pc, fd);
1808   return fd;
1809 }
1810 
TSAN_INTERCEPTOR(int,epoll_ctl,int epfd,int op,int fd,void * ev)1811 TSAN_INTERCEPTOR(int, epoll_ctl, int epfd, int op, int fd, void *ev) {
1812   SCOPED_TSAN_INTERCEPTOR(epoll_ctl, epfd, op, fd, ev);
1813   if (epfd >= 0)
1814     FdAccess(thr, pc, epfd);
1815   if (epfd >= 0 && fd >= 0)
1816     FdAccess(thr, pc, fd);
1817   if (op == EPOLL_CTL_ADD && epfd >= 0)
1818     FdRelease(thr, pc, epfd);
1819   int res = REAL(epoll_ctl)(epfd, op, fd, ev);
1820   return res;
1821 }
1822 
TSAN_INTERCEPTOR(int,epoll_wait,int epfd,void * ev,int cnt,int timeout)1823 TSAN_INTERCEPTOR(int, epoll_wait, int epfd, void *ev, int cnt, int timeout) {
1824   SCOPED_TSAN_INTERCEPTOR(epoll_wait, epfd, ev, cnt, timeout);
1825   if (epfd >= 0)
1826     FdAccess(thr, pc, epfd);
1827   int res = BLOCK_REAL(epoll_wait)(epfd, ev, cnt, timeout);
1828   if (res > 0 && epfd >= 0)
1829     FdAcquire(thr, pc, epfd);
1830   return res;
1831 }
1832 
TSAN_INTERCEPTOR(int,epoll_pwait,int epfd,void * ev,int cnt,int timeout,void * sigmask)1833 TSAN_INTERCEPTOR(int, epoll_pwait, int epfd, void *ev, int cnt, int timeout,
1834                  void *sigmask) {
1835   SCOPED_TSAN_INTERCEPTOR(epoll_pwait, epfd, ev, cnt, timeout, sigmask);
1836   if (epfd >= 0)
1837     FdAccess(thr, pc, epfd);
1838   int res = BLOCK_REAL(epoll_pwait)(epfd, ev, cnt, timeout, sigmask);
1839   if (res > 0 && epfd >= 0)
1840     FdAcquire(thr, pc, epfd);
1841   return res;
1842 }
1843 
1844 #define TSAN_MAYBE_INTERCEPT_EPOLL \
1845     TSAN_INTERCEPT(epoll_create); \
1846     TSAN_INTERCEPT(epoll_create1); \
1847     TSAN_INTERCEPT(epoll_ctl); \
1848     TSAN_INTERCEPT(epoll_wait); \
1849     TSAN_INTERCEPT(epoll_pwait)
1850 #else
1851 #define TSAN_MAYBE_INTERCEPT_EPOLL
1852 #endif
1853 
1854 // The following functions are intercepted merely to process pending signals.
1855 // If program blocks signal X, we must deliver the signal before the function
1856 // returns. Similarly, if program unblocks a signal (or returns from sigsuspend)
1857 // it's better to deliver the signal straight away.
TSAN_INTERCEPTOR(int,sigsuspend,const __sanitizer_sigset_t * mask)1858 TSAN_INTERCEPTOR(int, sigsuspend, const __sanitizer_sigset_t *mask) {
1859   SCOPED_TSAN_INTERCEPTOR(sigsuspend, mask);
1860   return REAL(sigsuspend)(mask);
1861 }
1862 
TSAN_INTERCEPTOR(int,sigblock,int mask)1863 TSAN_INTERCEPTOR(int, sigblock, int mask) {
1864   SCOPED_TSAN_INTERCEPTOR(sigblock, mask);
1865   return REAL(sigblock)(mask);
1866 }
1867 
TSAN_INTERCEPTOR(int,sigsetmask,int mask)1868 TSAN_INTERCEPTOR(int, sigsetmask, int mask) {
1869   SCOPED_TSAN_INTERCEPTOR(sigsetmask, mask);
1870   return REAL(sigsetmask)(mask);
1871 }
1872 
TSAN_INTERCEPTOR(int,pthread_sigmask,int how,const __sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)1873 TSAN_INTERCEPTOR(int, pthread_sigmask, int how, const __sanitizer_sigset_t *set,
1874     __sanitizer_sigset_t *oldset) {
1875   SCOPED_TSAN_INTERCEPTOR(pthread_sigmask, how, set, oldset);
1876   return REAL(pthread_sigmask)(how, set, oldset);
1877 }
1878 
1879 namespace __tsan {
1880 
CallUserSignalHandler(ThreadState * thr,bool sync,bool acquire,bool sigact,int sig,__sanitizer_siginfo * info,void * uctx)1881 static void CallUserSignalHandler(ThreadState *thr, bool sync, bool acquire,
1882                                   bool sigact, int sig,
1883                                   __sanitizer_siginfo *info, void *uctx) {
1884   __sanitizer_sigaction *sigactions = interceptor_ctx()->sigactions;
1885   if (acquire)
1886     Acquire(thr, 0, (uptr)&sigactions[sig]);
1887   // Signals are generally asynchronous, so if we receive a signals when
1888   // ignores are enabled we should disable ignores. This is critical for sync
1889   // and interceptors, because otherwise we can miss syncronization and report
1890   // false races.
1891   int ignore_reads_and_writes = thr->ignore_reads_and_writes;
1892   int ignore_interceptors = thr->ignore_interceptors;
1893   int ignore_sync = thr->ignore_sync;
1894   if (!ctx->after_multithreaded_fork) {
1895     thr->ignore_reads_and_writes = 0;
1896     thr->fast_state.ClearIgnoreBit();
1897     thr->ignore_interceptors = 0;
1898     thr->ignore_sync = 0;
1899   }
1900   // Ensure that the handler does not spoil errno.
1901   const int saved_errno = errno;
1902   errno = 99;
1903   // This code races with sigaction. Be careful to not read sa_sigaction twice.
1904   // Also need to remember pc for reporting before the call,
1905   // because the handler can reset it.
1906   volatile uptr pc =
1907       sigact ? (uptr)sigactions[sig].sigaction : (uptr)sigactions[sig].handler;
1908   if (pc != sig_dfl && pc != sig_ign) {
1909     if (sigact)
1910       ((__sanitizer_sigactionhandler_ptr)pc)(sig, info, uctx);
1911     else
1912       ((__sanitizer_sighandler_ptr)pc)(sig);
1913   }
1914   if (!ctx->after_multithreaded_fork) {
1915     thr->ignore_reads_and_writes = ignore_reads_and_writes;
1916     if (ignore_reads_and_writes)
1917       thr->fast_state.SetIgnoreBit();
1918     thr->ignore_interceptors = ignore_interceptors;
1919     thr->ignore_sync = ignore_sync;
1920   }
1921   // We do not detect errno spoiling for SIGTERM,
1922   // because some SIGTERM handlers do spoil errno but reraise SIGTERM,
1923   // tsan reports false positive in such case.
1924   // It's difficult to properly detect this situation (reraise),
1925   // because in async signal processing case (when handler is called directly
1926   // from rtl_generic_sighandler) we have not yet received the reraised
1927   // signal; and it looks too fragile to intercept all ways to reraise a signal.
1928   if (flags()->report_bugs && !sync && sig != SIGTERM && errno != 99) {
1929     VarSizeStackTrace stack;
1930     // StackTrace::GetNestInstructionPc(pc) is used because return address is
1931     // expected, OutputReport() will undo this.
1932     ObtainCurrentStack(thr, StackTrace::GetNextInstructionPc(pc), &stack);
1933     ThreadRegistryLock l(ctx->thread_registry);
1934     ScopedReport rep(ReportTypeErrnoInSignal);
1935     if (!IsFiredSuppression(ctx, ReportTypeErrnoInSignal, stack)) {
1936       rep.AddStack(stack, true);
1937       OutputReport(thr, rep);
1938     }
1939   }
1940   errno = saved_errno;
1941 }
1942 
ProcessPendingSignals(ThreadState * thr)1943 void ProcessPendingSignals(ThreadState *thr) {
1944   ThreadSignalContext *sctx = SigCtx(thr);
1945   if (sctx == 0 ||
1946       atomic_load(&sctx->have_pending_signals, memory_order_relaxed) == 0)
1947     return;
1948   atomic_store(&sctx->have_pending_signals, 0, memory_order_relaxed);
1949   atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed);
1950   internal_sigfillset(&sctx->emptyset);
1951   int res = REAL(pthread_sigmask)(SIG_SETMASK, &sctx->emptyset, &sctx->oldset);
1952   CHECK_EQ(res, 0);
1953   for (int sig = 0; sig < kSigCount; sig++) {
1954     SignalDesc *signal = &sctx->pending_signals[sig];
1955     if (signal->armed) {
1956       signal->armed = false;
1957       CallUserSignalHandler(thr, false, true, signal->sigaction, sig,
1958           &signal->siginfo, &signal->ctx);
1959     }
1960   }
1961   res = REAL(pthread_sigmask)(SIG_SETMASK, &sctx->oldset, 0);
1962   CHECK_EQ(res, 0);
1963   atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed);
1964 }
1965 
1966 }  // namespace __tsan
1967 
is_sync_signal(ThreadSignalContext * sctx,int sig)1968 static bool is_sync_signal(ThreadSignalContext *sctx, int sig) {
1969   return sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1970       sig == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS ||
1971       // If we are sending signal to ourselves, we must process it now.
1972       (sctx && sig == sctx->int_signal_send);
1973 }
1974 
rtl_generic_sighandler(bool sigact,int sig,__sanitizer_siginfo * info,void * ctx)1975 void ALWAYS_INLINE rtl_generic_sighandler(bool sigact, int sig,
1976                                           __sanitizer_siginfo *info,
1977                                           void *ctx) {
1978   ThreadState *thr = cur_thread();
1979   ThreadSignalContext *sctx = SigCtx(thr);
1980   if (sig < 0 || sig >= kSigCount) {
1981     VPrintf(1, "ThreadSanitizer: ignoring signal %d\n", sig);
1982     return;
1983   }
1984   // Don't mess with synchronous signals.
1985   const bool sync = is_sync_signal(sctx, sig);
1986   if (sync ||
1987       // If we are in blocking function, we can safely process it now
1988       // (but check if we are in a recursive interceptor,
1989       // i.e. pthread_join()->munmap()).
1990       (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed))) {
1991     atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed);
1992     if (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed)) {
1993       atomic_store(&sctx->in_blocking_func, 0, memory_order_relaxed);
1994       CallUserSignalHandler(thr, sync, true, sigact, sig, info, ctx);
1995       atomic_store(&sctx->in_blocking_func, 1, memory_order_relaxed);
1996     } else {
1997       // Be very conservative with when we do acquire in this case.
1998       // It's unsafe to do acquire in async handlers, because ThreadState
1999       // can be in inconsistent state.
2000       // SIGSYS looks relatively safe -- it's synchronous and can actually
2001       // need some global state.
2002       bool acq = (sig == SIGSYS);
2003       CallUserSignalHandler(thr, sync, acq, sigact, sig, info, ctx);
2004     }
2005     atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed);
2006     return;
2007   }
2008 
2009   if (sctx == 0)
2010     return;
2011   SignalDesc *signal = &sctx->pending_signals[sig];
2012   if (signal->armed == false) {
2013     signal->armed = true;
2014     signal->sigaction = sigact;
2015     if (info)
2016       internal_memcpy(&signal->siginfo, info, sizeof(*info));
2017     if (ctx)
2018       internal_memcpy(&signal->ctx, ctx, sizeof(signal->ctx));
2019     atomic_store(&sctx->have_pending_signals, 1, memory_order_relaxed);
2020   }
2021 }
2022 
rtl_sighandler(int sig)2023 static void rtl_sighandler(int sig) {
2024   rtl_generic_sighandler(false, sig, 0, 0);
2025 }
2026 
rtl_sigaction(int sig,__sanitizer_siginfo * info,void * ctx)2027 static void rtl_sigaction(int sig, __sanitizer_siginfo *info, void *ctx) {
2028   rtl_generic_sighandler(true, sig, info, ctx);
2029 }
2030 
TSAN_INTERCEPTOR(int,raise,int sig)2031 TSAN_INTERCEPTOR(int, raise, int sig) {
2032   SCOPED_TSAN_INTERCEPTOR(raise, sig);
2033   ThreadSignalContext *sctx = SigCtx(thr);
2034   CHECK_NE(sctx, 0);
2035   int prev = sctx->int_signal_send;
2036   sctx->int_signal_send = sig;
2037   int res = REAL(raise)(sig);
2038   CHECK_EQ(sctx->int_signal_send, sig);
2039   sctx->int_signal_send = prev;
2040   return res;
2041 }
2042 
TSAN_INTERCEPTOR(int,kill,int pid,int sig)2043 TSAN_INTERCEPTOR(int, kill, int pid, int sig) {
2044   SCOPED_TSAN_INTERCEPTOR(kill, pid, sig);
2045   ThreadSignalContext *sctx = SigCtx(thr);
2046   CHECK_NE(sctx, 0);
2047   int prev = sctx->int_signal_send;
2048   if (pid == (int)internal_getpid()) {
2049     sctx->int_signal_send = sig;
2050   }
2051   int res = REAL(kill)(pid, sig);
2052   if (pid == (int)internal_getpid()) {
2053     CHECK_EQ(sctx->int_signal_send, sig);
2054     sctx->int_signal_send = prev;
2055   }
2056   return res;
2057 }
2058 
TSAN_INTERCEPTOR(int,pthread_kill,void * tid,int sig)2059 TSAN_INTERCEPTOR(int, pthread_kill, void *tid, int sig) {
2060   SCOPED_TSAN_INTERCEPTOR(pthread_kill, tid, sig);
2061   ThreadSignalContext *sctx = SigCtx(thr);
2062   CHECK_NE(sctx, 0);
2063   int prev = sctx->int_signal_send;
2064   if (tid == pthread_self()) {
2065     sctx->int_signal_send = sig;
2066   }
2067   int res = REAL(pthread_kill)(tid, sig);
2068   if (tid == pthread_self()) {
2069     CHECK_EQ(sctx->int_signal_send, sig);
2070     sctx->int_signal_send = prev;
2071   }
2072   return res;
2073 }
2074 
TSAN_INTERCEPTOR(int,gettimeofday,void * tv,void * tz)2075 TSAN_INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
2076   SCOPED_TSAN_INTERCEPTOR(gettimeofday, tv, tz);
2077   // It's intercepted merely to process pending signals.
2078   return REAL(gettimeofday)(tv, tz);
2079 }
2080 
TSAN_INTERCEPTOR(int,getaddrinfo,void * node,void * service,void * hints,void * rv)2081 TSAN_INTERCEPTOR(int, getaddrinfo, void *node, void *service,
2082     void *hints, void *rv) {
2083   SCOPED_TSAN_INTERCEPTOR(getaddrinfo, node, service, hints, rv);
2084   // We miss atomic synchronization in getaddrinfo,
2085   // and can report false race between malloc and free
2086   // inside of getaddrinfo. So ignore memory accesses.
2087   ThreadIgnoreBegin(thr, pc);
2088   int res = REAL(getaddrinfo)(node, service, hints, rv);
2089   ThreadIgnoreEnd(thr, pc);
2090   return res;
2091 }
2092 
TSAN_INTERCEPTOR(int,fork,int fake)2093 TSAN_INTERCEPTOR(int, fork, int fake) {
2094   if (UNLIKELY(cur_thread()->in_symbolizer))
2095     return REAL(fork)(fake);
2096   SCOPED_INTERCEPTOR_RAW(fork, fake);
2097   ForkBefore(thr, pc);
2098   int pid;
2099   {
2100     // On OS X, REAL(fork) can call intercepted functions (OSSpinLockLock), and
2101     // we'll assert in CheckNoLocks() unless we ignore interceptors.
2102     ScopedIgnoreInterceptors ignore;
2103     pid = REAL(fork)(fake);
2104   }
2105   if (pid == 0) {
2106     // child
2107     ForkChildAfter(thr, pc);
2108     FdOnFork(thr, pc);
2109   } else if (pid > 0) {
2110     // parent
2111     ForkParentAfter(thr, pc);
2112   } else {
2113     // error
2114     ForkParentAfter(thr, pc);
2115   }
2116   return pid;
2117 }
2118 
TSAN_INTERCEPTOR(int,vfork,int fake)2119 TSAN_INTERCEPTOR(int, vfork, int fake) {
2120   // Some programs (e.g. openjdk) call close for all file descriptors
2121   // in the child process. Under tsan it leads to false positives, because
2122   // address space is shared, so the parent process also thinks that
2123   // the descriptors are closed (while they are actually not).
2124   // This leads to false positives due to missed synchronization.
2125   // Strictly saying this is undefined behavior, because vfork child is not
2126   // allowed to call any functions other than exec/exit. But this is what
2127   // openjdk does, so we want to handle it.
2128   // We could disable interceptors in the child process. But it's not possible
2129   // to simply intercept and wrap vfork, because vfork child is not allowed
2130   // to return from the function that calls vfork, and that's exactly what
2131   // we would do. So this would require some assembly trickery as well.
2132   // Instead we simply turn vfork into fork.
2133   return WRAP(fork)(fake);
2134 }
2135 
2136 #if !SANITIZER_MAC && !SANITIZER_ANDROID
2137 typedef int (*dl_iterate_phdr_cb_t)(__sanitizer_dl_phdr_info *info, SIZE_T size,
2138                                     void *data);
2139 struct dl_iterate_phdr_data {
2140   ThreadState *thr;
2141   uptr pc;
2142   dl_iterate_phdr_cb_t cb;
2143   void *data;
2144 };
2145 
IsAppNotRodata(uptr addr)2146 static bool IsAppNotRodata(uptr addr) {
2147   return IsAppMem(addr) && *(u64*)MemToShadow(addr) != kShadowRodata;
2148 }
2149 
dl_iterate_phdr_cb(__sanitizer_dl_phdr_info * info,SIZE_T size,void * data)2150 static int dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
2151                               void *data) {
2152   dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
2153   // dlopen/dlclose allocate/free dynamic-linker-internal memory, which is later
2154   // accessible in dl_iterate_phdr callback. But we don't see synchronization
2155   // inside of dynamic linker, so we "unpoison" it here in order to not
2156   // produce false reports. Ignoring malloc/free in dlopen/dlclose is not enough
2157   // because some libc functions call __libc_dlopen.
2158   if (info && IsAppNotRodata((uptr)info->dlpi_name))
2159     MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name,
2160                      internal_strlen(info->dlpi_name));
2161   int res = cbdata->cb(info, size, cbdata->data);
2162   // Perform the check one more time in case info->dlpi_name was overwritten
2163   // by user callback.
2164   if (info && IsAppNotRodata((uptr)info->dlpi_name))
2165     MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name,
2166                      internal_strlen(info->dlpi_name));
2167   return res;
2168 }
2169 
TSAN_INTERCEPTOR(int,dl_iterate_phdr,dl_iterate_phdr_cb_t cb,void * data)2170 TSAN_INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb_t cb, void *data) {
2171   SCOPED_TSAN_INTERCEPTOR(dl_iterate_phdr, cb, data);
2172   dl_iterate_phdr_data cbdata;
2173   cbdata.thr = thr;
2174   cbdata.pc = pc;
2175   cbdata.cb = cb;
2176   cbdata.data = data;
2177   int res = REAL(dl_iterate_phdr)(dl_iterate_phdr_cb, &cbdata);
2178   return res;
2179 }
2180 #endif
2181 
OnExit(ThreadState * thr)2182 static int OnExit(ThreadState *thr) {
2183   int status = Finalize(thr);
2184   FlushStreams();
2185   return status;
2186 }
2187 
2188 struct TsanInterceptorContext {
2189   ThreadState *thr;
2190   const uptr caller_pc;
2191   const uptr pc;
2192 };
2193 
2194 #if !SANITIZER_MAC
HandleRecvmsg(ThreadState * thr,uptr pc,__sanitizer_msghdr * msg)2195 static void HandleRecvmsg(ThreadState *thr, uptr pc,
2196     __sanitizer_msghdr *msg) {
2197   int fds[64];
2198   int cnt = ExtractRecvmsgFDs(msg, fds, ARRAY_SIZE(fds));
2199   for (int i = 0; i < cnt; i++)
2200     FdEventCreate(thr, pc, fds[i]);
2201 }
2202 #endif
2203 
2204 #include "sanitizer_common/sanitizer_platform_interceptors.h"
2205 // Causes interceptor recursion (getaddrinfo() and fopen())
2206 #undef SANITIZER_INTERCEPT_GETADDRINFO
2207 // There interceptors do not seem to be strictly necessary for tsan.
2208 // But we see cases where the interceptors consume 70% of execution time.
2209 // Memory blocks passed to fgetgrent_r are "written to" by tsan several times.
2210 // First, there is some recursion (getgrnam_r calls fgetgrent_r), and each
2211 // function "writes to" the buffer. Then, the same memory is "written to"
2212 // twice, first as buf and then as pwbufp (both of them refer to the same
2213 // addresses).
2214 #undef SANITIZER_INTERCEPT_GETPWENT
2215 #undef SANITIZER_INTERCEPT_GETPWENT_R
2216 #undef SANITIZER_INTERCEPT_FGETPWENT
2217 #undef SANITIZER_INTERCEPT_GETPWNAM_AND_FRIENDS
2218 #undef SANITIZER_INTERCEPT_GETPWNAM_R_AND_FRIENDS
2219 // We define our own.
2220 #if SANITIZER_INTERCEPT_TLS_GET_ADDR
2221 #define NEED_TLS_GET_ADDR
2222 #endif
2223 #undef SANITIZER_INTERCEPT_TLS_GET_ADDR
2224 
2225 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
2226 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver)                          \
2227   INTERCEPT_FUNCTION_VER(name, ver)
2228 
2229 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size)                    \
2230   MemoryAccessRange(((TsanInterceptorContext *)ctx)->thr,                 \
2231                     ((TsanInterceptorContext *)ctx)->pc, (uptr)ptr, size, \
2232                     true)
2233 
2234 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size)                       \
2235   MemoryAccessRange(((TsanInterceptorContext *) ctx)->thr,                  \
2236                     ((TsanInterceptorContext *) ctx)->pc, (uptr) ptr, size, \
2237                     false)
2238 
2239 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)      \
2240   SCOPED_TSAN_INTERCEPTOR(func, __VA_ARGS__);         \
2241   TsanInterceptorContext _ctx = {thr, caller_pc, pc}; \
2242   ctx = (void *)&_ctx;                                \
2243   (void) ctx;
2244 
2245 #define COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, func, ...) \
2246   SCOPED_INTERCEPTOR_RAW(func, __VA_ARGS__);              \
2247   TsanInterceptorContext _ctx = {thr, caller_pc, pc};     \
2248   ctx = (void *)&_ctx;                                    \
2249   (void) ctx;
2250 
2251 #define COMMON_INTERCEPTOR_FILE_OPEN(ctx, file, path) \
2252   if (path)                                           \
2253     Acquire(thr, pc, File2addr(path));                \
2254   if (file) {                                         \
2255     int fd = fileno_unlocked(file);                   \
2256     if (fd >= 0) FdFileCreate(thr, pc, fd);           \
2257   }
2258 
2259 #define COMMON_INTERCEPTOR_FILE_CLOSE(ctx, file) \
2260   if (file) {                                    \
2261     int fd = fileno_unlocked(file);              \
2262     if (fd >= 0) FdClose(thr, pc, fd);           \
2263   }
2264 
2265 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
2266   libignore()->OnLibraryLoaded(filename)
2267 
2268 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() \
2269   libignore()->OnLibraryUnloaded()
2270 
2271 #define COMMON_INTERCEPTOR_ACQUIRE(ctx, u) \
2272   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, u)
2273 
2274 #define COMMON_INTERCEPTOR_RELEASE(ctx, u) \
2275   Release(((TsanInterceptorContext *) ctx)->thr, pc, u)
2276 
2277 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
2278   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, Dir2addr(path))
2279 
2280 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
2281   FdAcquire(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2282 
2283 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
2284   FdRelease(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2285 
2286 #define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) \
2287   FdAccess(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2288 
2289 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
2290   FdSocketAccept(((TsanInterceptorContext *) ctx)->thr, pc, fd, newfd)
2291 
2292 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
2293   ThreadSetName(((TsanInterceptorContext *) ctx)->thr, name)
2294 
2295 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
2296   __tsan::ctx->thread_registry->SetThreadNameByUserId(thread, name)
2297 
2298 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) BLOCK_REAL(name)
2299 
2300 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) \
2301   OnExit(((TsanInterceptorContext *) ctx)->thr)
2302 
2303 #define COMMON_INTERCEPTOR_MUTEX_PRE_LOCK(ctx, m) \
2304   MutexPreLock(((TsanInterceptorContext *)ctx)->thr, \
2305             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2306 
2307 #define COMMON_INTERCEPTOR_MUTEX_POST_LOCK(ctx, m) \
2308   MutexPostLock(((TsanInterceptorContext *)ctx)->thr, \
2309             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2310 
2311 #define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) \
2312   MutexUnlock(((TsanInterceptorContext *)ctx)->thr, \
2313             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2314 
2315 #define COMMON_INTERCEPTOR_MUTEX_REPAIR(ctx, m) \
2316   MutexRepair(((TsanInterceptorContext *)ctx)->thr, \
2317             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2318 
2319 #define COMMON_INTERCEPTOR_MUTEX_INVALID(ctx, m) \
2320   MutexInvalidAccess(((TsanInterceptorContext *)ctx)->thr, \
2321                      ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2322 
2323 #define COMMON_INTERCEPTOR_MMAP_IMPL(ctx, mmap, addr, sz, prot, flags, fd,  \
2324                                      off)                                   \
2325   do {                                                                      \
2326     return mmap_interceptor(thr, pc, REAL(mmap), addr, sz, prot, flags, fd, \
2327                             off);                                           \
2328   } while (false)
2329 
2330 #if !SANITIZER_MAC
2331 #define COMMON_INTERCEPTOR_HANDLE_RECVMSG(ctx, msg) \
2332   HandleRecvmsg(((TsanInterceptorContext *)ctx)->thr, \
2333       ((TsanInterceptorContext *)ctx)->pc, msg)
2334 #endif
2335 
2336 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
2337   if (TsanThread *t = GetCurrentThread()) {                                    \
2338     *begin = t->tls_begin();                                                   \
2339     *end = t->tls_end();                                                       \
2340   } else {                                                                     \
2341     *begin = *end = 0;                                                         \
2342   }
2343 
2344 #define COMMON_INTERCEPTOR_USER_CALLBACK_START() \
2345   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START()
2346 
2347 #define COMMON_INTERCEPTOR_USER_CALLBACK_END() \
2348   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END()
2349 
2350 #include "sanitizer_common/sanitizer_common_interceptors.inc"
2351 
2352 static int sigaction_impl(int sig, const __sanitizer_sigaction *act,
2353                           __sanitizer_sigaction *old);
2354 static __sanitizer_sighandler_ptr signal_impl(int sig,
2355                                               __sanitizer_sighandler_ptr h);
2356 
2357 #define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
2358   { return sigaction_impl(signo, act, oldact); }
2359 
2360 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
2361   { return (uptr)signal_impl(signo, (__sanitizer_sighandler_ptr)handler); }
2362 
2363 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
2364 
sigaction_impl(int sig,const __sanitizer_sigaction * act,__sanitizer_sigaction * old)2365 int sigaction_impl(int sig, const __sanitizer_sigaction *act,
2366                    __sanitizer_sigaction *old) {
2367   // Note: if we call REAL(sigaction) directly for any reason without proxying
2368   // the signal handler through rtl_sigaction, very bad things will happen.
2369   // The handler will run synchronously and corrupt tsan per-thread state.
2370   SCOPED_INTERCEPTOR_RAW(sigaction, sig, act, old);
2371   __sanitizer_sigaction *sigactions = interceptor_ctx()->sigactions;
2372   __sanitizer_sigaction old_stored;
2373   if (old) internal_memcpy(&old_stored, &sigactions[sig], sizeof(old_stored));
2374   __sanitizer_sigaction newact;
2375   if (act) {
2376     // Copy act into sigactions[sig].
2377     // Can't use struct copy, because compiler can emit call to memcpy.
2378     // Can't use internal_memcpy, because it copies byte-by-byte,
2379     // and signal handler reads the handler concurrently. It it can read
2380     // some bytes from old value and some bytes from new value.
2381     // Use volatile to prevent insertion of memcpy.
2382     sigactions[sig].handler =
2383         *(volatile __sanitizer_sighandler_ptr const *)&act->handler;
2384     sigactions[sig].sa_flags = *(volatile int const *)&act->sa_flags;
2385     internal_memcpy(&sigactions[sig].sa_mask, &act->sa_mask,
2386                     sizeof(sigactions[sig].sa_mask));
2387 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
2388     sigactions[sig].sa_restorer = act->sa_restorer;
2389 #endif
2390     internal_memcpy(&newact, act, sizeof(newact));
2391     internal_sigfillset(&newact.sa_mask);
2392     if ((uptr)act->handler != sig_ign && (uptr)act->handler != sig_dfl) {
2393       if (newact.sa_flags & SA_SIGINFO)
2394         newact.sigaction = rtl_sigaction;
2395       else
2396         newact.handler = rtl_sighandler;
2397     }
2398     ReleaseStore(thr, pc, (uptr)&sigactions[sig]);
2399     act = &newact;
2400   }
2401   int res = REAL(sigaction)(sig, act, old);
2402   if (res == 0 && old) {
2403     uptr cb = (uptr)old->sigaction;
2404     if (cb == (uptr)rtl_sigaction || cb == (uptr)rtl_sighandler) {
2405       internal_memcpy(old, &old_stored, sizeof(*old));
2406     }
2407   }
2408   return res;
2409 }
2410 
signal_impl(int sig,__sanitizer_sighandler_ptr h)2411 static __sanitizer_sighandler_ptr signal_impl(int sig,
2412                                               __sanitizer_sighandler_ptr h) {
2413   __sanitizer_sigaction act;
2414   act.handler = h;
2415   internal_memset(&act.sa_mask, -1, sizeof(act.sa_mask));
2416   act.sa_flags = 0;
2417   __sanitizer_sigaction old;
2418   int res = sigaction_symname(sig, &act, &old);
2419   if (res) return (__sanitizer_sighandler_ptr)sig_err;
2420   return old.handler;
2421 }
2422 
2423 #define TSAN_SYSCALL() \
2424   ThreadState *thr = cur_thread(); \
2425   if (thr->ignore_interceptors) \
2426     return; \
2427   ScopedSyscall scoped_syscall(thr) \
2428 /**/
2429 
2430 struct ScopedSyscall {
2431   ThreadState *thr;
2432 
ScopedSyscallScopedSyscall2433   explicit ScopedSyscall(ThreadState *thr)
2434       : thr(thr) {
2435     Initialize(thr);
2436   }
2437 
~ScopedSyscallScopedSyscall2438   ~ScopedSyscall() {
2439     ProcessPendingSignals(thr);
2440   }
2441 };
2442 
2443 #if !SANITIZER_FREEBSD && !SANITIZER_MAC
syscall_access_range(uptr pc,uptr p,uptr s,bool write)2444 static void syscall_access_range(uptr pc, uptr p, uptr s, bool write) {
2445   TSAN_SYSCALL();
2446   MemoryAccessRange(thr, pc, p, s, write);
2447 }
2448 
syscall_acquire(uptr pc,uptr addr)2449 static void syscall_acquire(uptr pc, uptr addr) {
2450   TSAN_SYSCALL();
2451   Acquire(thr, pc, addr);
2452   DPrintf("syscall_acquire(%p)\n", addr);
2453 }
2454 
syscall_release(uptr pc,uptr addr)2455 static void syscall_release(uptr pc, uptr addr) {
2456   TSAN_SYSCALL();
2457   DPrintf("syscall_release(%p)\n", addr);
2458   Release(thr, pc, addr);
2459 }
2460 
syscall_fd_close(uptr pc,int fd)2461 static void syscall_fd_close(uptr pc, int fd) {
2462   TSAN_SYSCALL();
2463   FdClose(thr, pc, fd);
2464 }
2465 
syscall_fd_acquire(uptr pc,int fd)2466 static USED void syscall_fd_acquire(uptr pc, int fd) {
2467   TSAN_SYSCALL();
2468   FdAcquire(thr, pc, fd);
2469   DPrintf("syscall_fd_acquire(%p)\n", fd);
2470 }
2471 
syscall_fd_release(uptr pc,int fd)2472 static USED void syscall_fd_release(uptr pc, int fd) {
2473   TSAN_SYSCALL();
2474   DPrintf("syscall_fd_release(%p)\n", fd);
2475   FdRelease(thr, pc, fd);
2476 }
2477 
syscall_pre_fork(uptr pc)2478 static void syscall_pre_fork(uptr pc) {
2479   TSAN_SYSCALL();
2480   ForkBefore(thr, pc);
2481 }
2482 
syscall_post_fork(uptr pc,int pid)2483 static void syscall_post_fork(uptr pc, int pid) {
2484   TSAN_SYSCALL();
2485   if (pid == 0) {
2486     // child
2487     ForkChildAfter(thr, pc);
2488     FdOnFork(thr, pc);
2489   } else if (pid > 0) {
2490     // parent
2491     ForkParentAfter(thr, pc);
2492   } else {
2493     // error
2494     ForkParentAfter(thr, pc);
2495   }
2496 }
2497 #endif
2498 
2499 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) \
2500   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), false)
2501 
2502 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
2503   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), true)
2504 
2505 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
2506   do {                                       \
2507     (void)(p);                               \
2508     (void)(s);                               \
2509   } while (false)
2510 
2511 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
2512   do {                                        \
2513     (void)(p);                                \
2514     (void)(s);                                \
2515   } while (false)
2516 
2517 #define COMMON_SYSCALL_ACQUIRE(addr) \
2518     syscall_acquire(GET_CALLER_PC(), (uptr)(addr))
2519 
2520 #define COMMON_SYSCALL_RELEASE(addr) \
2521     syscall_release(GET_CALLER_PC(), (uptr)(addr))
2522 
2523 #define COMMON_SYSCALL_FD_CLOSE(fd) syscall_fd_close(GET_CALLER_PC(), fd)
2524 
2525 #define COMMON_SYSCALL_FD_ACQUIRE(fd) syscall_fd_acquire(GET_CALLER_PC(), fd)
2526 
2527 #define COMMON_SYSCALL_FD_RELEASE(fd) syscall_fd_release(GET_CALLER_PC(), fd)
2528 
2529 #define COMMON_SYSCALL_PRE_FORK() \
2530   syscall_pre_fork(GET_CALLER_PC())
2531 
2532 #define COMMON_SYSCALL_POST_FORK(res) \
2533   syscall_post_fork(GET_CALLER_PC(), res)
2534 
2535 #include "sanitizer_common/sanitizer_common_syscalls.inc"
2536 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
2537 
2538 #ifdef NEED_TLS_GET_ADDR
2539 // Define own interceptor instead of sanitizer_common's for three reasons:
2540 // 1. It must not process pending signals.
2541 //    Signal handlers may contain MOVDQA instruction (see below).
2542 // 2. It must be as simple as possible to not contain MOVDQA.
2543 // 3. Sanitizer_common version uses COMMON_INTERCEPTOR_INITIALIZE_RANGE which
2544 //    is empty for tsan (meant only for msan).
2545 // Note: __tls_get_addr can be called with mis-aligned stack due to:
2546 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
2547 // So the interceptor must work with mis-aligned stack, in particular, does not
2548 // execute MOVDQA with stack addresses.
TSAN_INTERCEPTOR(void *,__tls_get_addr,void * arg)2549 TSAN_INTERCEPTOR(void *, __tls_get_addr, void *arg) {
2550   void *res = REAL(__tls_get_addr)(arg);
2551   ThreadState *thr = cur_thread();
2552   if (!thr)
2553     return res;
2554   DTLS::DTV *dtv = DTLS_on_tls_get_addr(arg, res, thr->tls_addr,
2555                                         thr->tls_addr + thr->tls_size);
2556   if (!dtv)
2557     return res;
2558   // New DTLS block has been allocated.
2559   MemoryResetRange(thr, 0, dtv->beg, dtv->size);
2560   return res;
2561 }
2562 #endif
2563 
2564 #if SANITIZER_NETBSD
TSAN_INTERCEPTOR(void,_lwp_exit)2565 TSAN_INTERCEPTOR(void, _lwp_exit) {
2566   SCOPED_TSAN_INTERCEPTOR(_lwp_exit);
2567   DestroyThreadState();
2568   REAL(_lwp_exit)();
2569 }
2570 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT TSAN_INTERCEPT(_lwp_exit)
2571 #else
2572 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT
2573 #endif
2574 
2575 #if SANITIZER_FREEBSD
TSAN_INTERCEPTOR(void,thr_exit,tid_t * state)2576 TSAN_INTERCEPTOR(void, thr_exit, tid_t *state) {
2577   SCOPED_TSAN_INTERCEPTOR(thr_exit, state);
2578   DestroyThreadState();
2579   REAL(thr_exit(state));
2580 }
2581 #define TSAN_MAYBE_INTERCEPT_THR_EXIT TSAN_INTERCEPT(thr_exit)
2582 #else
2583 #define TSAN_MAYBE_INTERCEPT_THR_EXIT
2584 #endif
2585 
2586 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_init, void *c, void *a)
2587 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_signal, void *c)
2588 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_broadcast, void *c)
2589 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_wait, void *c, void *m)
2590 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_destroy, void *c)
2591 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_init, void *m, void *a)
2592 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_destroy, void *m)
2593 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_trylock, void *m)
2594 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_init, void *m, void *a)
2595 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_destroy, void *m)
2596 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_rdlock, void *m)
2597 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_tryrdlock, void *m)
2598 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_wrlock, void *m)
2599 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_trywrlock, void *m)
2600 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_unlock, void *m)
2601 TSAN_INTERCEPTOR_NETBSD_ALIAS_THR(int, once, void *o, void (*f)())
2602 TSAN_INTERCEPTOR_NETBSD_ALIAS_THR2(int, sigsetmask, sigmask, int a, void *b,
2603   void *c)
2604 
2605 namespace __tsan {
2606 
finalize(void * arg)2607 static void finalize(void *arg) {
2608   ThreadState *thr = cur_thread();
2609   int status = Finalize(thr);
2610   // Make sure the output is not lost.
2611   FlushStreams();
2612   if (status)
2613     Die();
2614 }
2615 
2616 #if !SANITIZER_MAC && !SANITIZER_ANDROID
unreachable()2617 static void unreachable() {
2618   Report("FATAL: ThreadSanitizer: unreachable called\n");
2619   Die();
2620 }
2621 #endif
2622 
InitializeInterceptors()2623 void InitializeInterceptors() {
2624 #if !SANITIZER_MAC
2625   // We need to setup it early, because functions like dlsym() can call it.
2626   REAL(memset) = internal_memset;
2627   REAL(memcpy) = internal_memcpy;
2628 #endif
2629 
2630   // Instruct libc malloc to consume less memory.
2631 #if SANITIZER_LINUX
2632   mallopt(1, 0);  // M_MXFAST
2633   mallopt(-3, 32*1024);  // M_MMAP_THRESHOLD
2634 #endif
2635 
2636   new(interceptor_ctx()) InterceptorContext();
2637 
2638   InitializeCommonInterceptors();
2639   InitializeSignalInterceptors();
2640 
2641 #if !SANITIZER_MAC
2642   // We can not use TSAN_INTERCEPT to get setjmp addr,
2643   // because it does &setjmp and setjmp is not present in some versions of libc.
2644   using __interception::GetRealFunctionAddress;
2645   GetRealFunctionAddress(TSAN_STRING_SETJMP,
2646                          (uptr*)&REAL(setjmp_symname), 0, 0);
2647   GetRealFunctionAddress("_setjmp", (uptr*)&REAL(_setjmp), 0, 0);
2648   GetRealFunctionAddress(TSAN_STRING_SIGSETJMP,
2649                          (uptr*)&REAL(sigsetjmp_symname), 0, 0);
2650 #if !SANITIZER_NETBSD
2651   GetRealFunctionAddress("__sigsetjmp", (uptr*)&REAL(__sigsetjmp), 0, 0);
2652 #endif
2653 #endif
2654 
2655   TSAN_INTERCEPT(longjmp_symname);
2656   TSAN_INTERCEPT(siglongjmp_symname);
2657 #if SANITIZER_NETBSD
2658   TSAN_INTERCEPT(_longjmp);
2659 #endif
2660 
2661   TSAN_INTERCEPT(malloc);
2662   TSAN_INTERCEPT(__libc_memalign);
2663   TSAN_INTERCEPT(calloc);
2664   TSAN_INTERCEPT(realloc);
2665   TSAN_INTERCEPT(free);
2666   TSAN_INTERCEPT(cfree);
2667   TSAN_INTERCEPT(munmap);
2668   TSAN_MAYBE_INTERCEPT_MEMALIGN;
2669   TSAN_INTERCEPT(valloc);
2670   TSAN_MAYBE_INTERCEPT_PVALLOC;
2671   TSAN_INTERCEPT(posix_memalign);
2672 
2673   TSAN_INTERCEPT(strcpy);  // NOLINT
2674   TSAN_INTERCEPT(strncpy);
2675   TSAN_INTERCEPT(strdup);
2676 
2677   TSAN_INTERCEPT(pthread_create);
2678   TSAN_INTERCEPT(pthread_join);
2679   TSAN_INTERCEPT(pthread_detach);
2680   #if SANITIZER_LINUX
2681   TSAN_INTERCEPT(pthread_tryjoin_np);
2682   TSAN_INTERCEPT(pthread_timedjoin_np);
2683   #endif
2684 
2685   TSAN_INTERCEPT_VER(pthread_cond_init, PTHREAD_ABI_BASE);
2686   TSAN_INTERCEPT_VER(pthread_cond_signal, PTHREAD_ABI_BASE);
2687   TSAN_INTERCEPT_VER(pthread_cond_broadcast, PTHREAD_ABI_BASE);
2688   TSAN_INTERCEPT_VER(pthread_cond_wait, PTHREAD_ABI_BASE);
2689   TSAN_INTERCEPT_VER(pthread_cond_timedwait, PTHREAD_ABI_BASE);
2690   TSAN_INTERCEPT_VER(pthread_cond_destroy, PTHREAD_ABI_BASE);
2691 
2692   TSAN_INTERCEPT(pthread_mutex_init);
2693   TSAN_INTERCEPT(pthread_mutex_destroy);
2694   TSAN_INTERCEPT(pthread_mutex_trylock);
2695   TSAN_INTERCEPT(pthread_mutex_timedlock);
2696 
2697   TSAN_INTERCEPT(pthread_spin_init);
2698   TSAN_INTERCEPT(pthread_spin_destroy);
2699   TSAN_INTERCEPT(pthread_spin_lock);
2700   TSAN_INTERCEPT(pthread_spin_trylock);
2701   TSAN_INTERCEPT(pthread_spin_unlock);
2702 
2703   TSAN_INTERCEPT(pthread_rwlock_init);
2704   TSAN_INTERCEPT(pthread_rwlock_destroy);
2705   TSAN_INTERCEPT(pthread_rwlock_rdlock);
2706   TSAN_INTERCEPT(pthread_rwlock_tryrdlock);
2707   TSAN_INTERCEPT(pthread_rwlock_timedrdlock);
2708   TSAN_INTERCEPT(pthread_rwlock_wrlock);
2709   TSAN_INTERCEPT(pthread_rwlock_trywrlock);
2710   TSAN_INTERCEPT(pthread_rwlock_timedwrlock);
2711   TSAN_INTERCEPT(pthread_rwlock_unlock);
2712 
2713   TSAN_INTERCEPT(pthread_barrier_init);
2714   TSAN_INTERCEPT(pthread_barrier_destroy);
2715   TSAN_INTERCEPT(pthread_barrier_wait);
2716 
2717   TSAN_INTERCEPT(pthread_once);
2718 
2719   TSAN_INTERCEPT(fstat);
2720   TSAN_MAYBE_INTERCEPT___FXSTAT;
2721   TSAN_MAYBE_INTERCEPT_FSTAT64;
2722   TSAN_MAYBE_INTERCEPT___FXSTAT64;
2723   TSAN_INTERCEPT(open);
2724   TSAN_MAYBE_INTERCEPT_OPEN64;
2725   TSAN_INTERCEPT(creat);
2726   TSAN_MAYBE_INTERCEPT_CREAT64;
2727   TSAN_INTERCEPT(dup);
2728   TSAN_INTERCEPT(dup2);
2729   TSAN_INTERCEPT(dup3);
2730   TSAN_MAYBE_INTERCEPT_EVENTFD;
2731   TSAN_MAYBE_INTERCEPT_SIGNALFD;
2732   TSAN_MAYBE_INTERCEPT_INOTIFY_INIT;
2733   TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1;
2734   TSAN_INTERCEPT(socket);
2735   TSAN_INTERCEPT(socketpair);
2736   TSAN_INTERCEPT(connect);
2737   TSAN_INTERCEPT(bind);
2738   TSAN_INTERCEPT(listen);
2739   TSAN_MAYBE_INTERCEPT_EPOLL;
2740   TSAN_INTERCEPT(close);
2741   TSAN_MAYBE_INTERCEPT___CLOSE;
2742   TSAN_MAYBE_INTERCEPT___RES_ICLOSE;
2743   TSAN_INTERCEPT(pipe);
2744   TSAN_INTERCEPT(pipe2);
2745 
2746   TSAN_INTERCEPT(unlink);
2747   TSAN_INTERCEPT(tmpfile);
2748   TSAN_MAYBE_INTERCEPT_TMPFILE64;
2749   TSAN_INTERCEPT(abort);
2750   TSAN_INTERCEPT(rmdir);
2751   TSAN_INTERCEPT(closedir);
2752 
2753   TSAN_INTERCEPT(sigsuspend);
2754   TSAN_INTERCEPT(sigblock);
2755   TSAN_INTERCEPT(sigsetmask);
2756   TSAN_INTERCEPT(pthread_sigmask);
2757   TSAN_INTERCEPT(raise);
2758   TSAN_INTERCEPT(kill);
2759   TSAN_INTERCEPT(pthread_kill);
2760   TSAN_INTERCEPT(sleep);
2761   TSAN_INTERCEPT(usleep);
2762   TSAN_INTERCEPT(nanosleep);
2763   TSAN_INTERCEPT(pause);
2764   TSAN_INTERCEPT(gettimeofday);
2765   TSAN_INTERCEPT(getaddrinfo);
2766 
2767   TSAN_INTERCEPT(fork);
2768   TSAN_INTERCEPT(vfork);
2769 #if !SANITIZER_ANDROID
2770   TSAN_INTERCEPT(dl_iterate_phdr);
2771 #endif
2772   TSAN_MAYBE_INTERCEPT_ON_EXIT;
2773   TSAN_INTERCEPT(__cxa_atexit);
2774   TSAN_INTERCEPT(_exit);
2775 
2776 #ifdef NEED_TLS_GET_ADDR
2777   TSAN_INTERCEPT(__tls_get_addr);
2778 #endif
2779 
2780   TSAN_MAYBE_INTERCEPT__LWP_EXIT;
2781   TSAN_MAYBE_INTERCEPT_THR_EXIT;
2782 
2783 #if !SANITIZER_MAC && !SANITIZER_ANDROID
2784   // Need to setup it, because interceptors check that the function is resolved.
2785   // But atexit is emitted directly into the module, so can't be resolved.
2786   REAL(atexit) = (int(*)(void(*)()))unreachable;
2787 #endif
2788 
2789   if (REAL(__cxa_atexit)(&finalize, 0, 0)) {
2790     Printf("ThreadSanitizer: failed to setup atexit callback\n");
2791     Die();
2792   }
2793 
2794 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
2795   if (pthread_key_create(&interceptor_ctx()->finalize_key, &thread_finalize)) {
2796     Printf("ThreadSanitizer: failed to create thread key\n");
2797     Die();
2798   }
2799 #endif
2800 
2801   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_init);
2802   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_signal);
2803   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_broadcast);
2804   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_wait);
2805   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_destroy);
2806   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_init);
2807   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_destroy);
2808   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_trylock);
2809   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_init);
2810   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_destroy);
2811   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_rdlock);
2812   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_tryrdlock);
2813   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_wrlock);
2814   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_trywrlock);
2815   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_unlock);
2816   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(once);
2817   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(sigsetmask);
2818 
2819   FdInit();
2820 }
2821 
2822 }  // namespace __tsan
2823 
2824 // Invisible barrier for tests.
2825 // There were several unsuccessful iterations for this functionality:
2826 // 1. Initially it was implemented in user code using
2827 //    REAL(pthread_barrier_wait). But pthread_barrier_wait is not supported on
2828 //    MacOS. Futexes are linux-specific for this matter.
2829 // 2. Then we switched to atomics+usleep(10). But usleep produced parasitic
2830 //    "as-if synchronized via sleep" messages in reports which failed some
2831 //    output tests.
2832 // 3. Then we switched to atomics+sched_yield. But this produced tons of tsan-
2833 //    visible events, which lead to "failed to restore stack trace" failures.
2834 // Note that no_sanitize_thread attribute does not turn off atomic interception
2835 // so attaching it to the function defined in user code does not help.
2836 // That's why we now have what we have.
2837 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
__tsan_testonly_barrier_init(u64 * barrier,u32 count)2838 void __tsan_testonly_barrier_init(u64 *barrier, u32 count) {
2839   if (count >= (1 << 8)) {
2840       Printf("barrier_init: count is too large (%d)\n", count);
2841       Die();
2842   }
2843   // 8 lsb is thread count, the remaining are count of entered threads.
2844   *barrier = count;
2845 }
2846 
2847 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
__tsan_testonly_barrier_wait(u64 * barrier)2848 void __tsan_testonly_barrier_wait(u64 *barrier) {
2849   unsigned old = __atomic_fetch_add(barrier, 1 << 8, __ATOMIC_RELAXED);
2850   unsigned old_epoch = (old >> 8) / (old & 0xff);
2851   for (;;) {
2852     unsigned cur = __atomic_load_n(barrier, __ATOMIC_RELAXED);
2853     unsigned cur_epoch = (cur >> 8) / (cur & 0xff);
2854     if (cur_epoch != old_epoch)
2855       return;
2856     internal_sched_yield();
2857   }
2858 }
2859