1 //===-- tsan_interceptors_posix.cpp ---------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of ThreadSanitizer (TSan), a race detector.
10 //
11 // FIXME: move as many interceptors as possible into
12 // sanitizer_common/sanitizer_common_interceptors.inc
13 //===----------------------------------------------------------------------===//
14 
15 #include "sanitizer_common/sanitizer_atomic.h"
16 #include "sanitizer_common/sanitizer_errno.h"
17 #include "sanitizer_common/sanitizer_libc.h"
18 #include "sanitizer_common/sanitizer_linux.h"
19 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
20 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
21 #include "sanitizer_common/sanitizer_placement_new.h"
22 #include "sanitizer_common/sanitizer_posix.h"
23 #include "sanitizer_common/sanitizer_stacktrace.h"
24 #include "sanitizer_common/sanitizer_tls_get_addr.h"
25 #include "interception/interception.h"
26 #include "tsan_interceptors.h"
27 #include "tsan_interface.h"
28 #include "tsan_platform.h"
29 #include "tsan_suppressions.h"
30 #include "tsan_rtl.h"
31 #include "tsan_mman.h"
32 #include "tsan_fd.h"
33 
34 #include <stdarg.h>
35 
36 using namespace __tsan;
37 
38 #if SANITIZER_FREEBSD || SANITIZER_MAC
39 #define stdout __stdoutp
40 #define stderr __stderrp
41 #endif
42 
43 #if SANITIZER_NETBSD
44 #define dirfd(dirp) (*(int *)(dirp))
45 #define fileno_unlocked(fp)              \
46   (((__sanitizer_FILE *)fp)->_file == -1 \
47        ? -1                              \
48        : (int)(unsigned short)(((__sanitizer_FILE *)fp)->_file))
49 
50 #define stdout ((__sanitizer_FILE*)&__sF[1])
51 #define stderr ((__sanitizer_FILE*)&__sF[2])
52 
53 #define nanosleep __nanosleep50
54 #define vfork __vfork14
55 #endif
56 
57 #ifdef __mips__
58 const int kSigCount = 129;
59 #else
60 const int kSigCount = 65;
61 #endif
62 
63 #ifdef __mips__
64 struct ucontext_t {
65   u64 opaque[768 / sizeof(u64) + 1];
66 };
67 #else
68 struct ucontext_t {
69   // The size is determined by looking at sizeof of real ucontext_t on linux.
70   u64 opaque[936 / sizeof(u64) + 1];
71 };
72 #endif
73 
74 #if defined(__x86_64__) || defined(__mips__) || SANITIZER_PPC64V1
75 #define PTHREAD_ABI_BASE  "GLIBC_2.3.2"
76 #elif defined(__aarch64__) || SANITIZER_PPC64V2
77 #define PTHREAD_ABI_BASE  "GLIBC_2.17"
78 #endif
79 
80 extern "C" int pthread_attr_init(void *attr);
81 extern "C" int pthread_attr_destroy(void *attr);
82 DECLARE_REAL(int, pthread_attr_getdetachstate, void *, void *)
83 extern "C" int pthread_attr_setstacksize(void *attr, uptr stacksize);
84 extern "C" int pthread_key_create(unsigned *key, void (*destructor)(void* v));
85 extern "C" int pthread_setspecific(unsigned key, const void *v);
86 DECLARE_REAL(int, pthread_mutexattr_gettype, void *, void *)
87 DECLARE_REAL(int, fflush, __sanitizer_FILE *fp)
88 DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr size)
89 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
90 extern "C" void *pthread_self();
91 extern "C" void _exit(int status);
92 #if !SANITIZER_NETBSD
93 extern "C" int fileno_unlocked(void *stream);
94 extern "C" int dirfd(void *dirp);
95 #endif
96 #if SANITIZER_GLIBC
97 extern "C" int mallopt(int param, int value);
98 #endif
99 #if SANITIZER_NETBSD
100 extern __sanitizer_FILE __sF[];
101 #else
102 extern __sanitizer_FILE *stdout, *stderr;
103 #endif
104 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
105 const int PTHREAD_MUTEX_RECURSIVE = 1;
106 const int PTHREAD_MUTEX_RECURSIVE_NP = 1;
107 #else
108 const int PTHREAD_MUTEX_RECURSIVE = 2;
109 const int PTHREAD_MUTEX_RECURSIVE_NP = 2;
110 #endif
111 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
112 const int EPOLL_CTL_ADD = 1;
113 #endif
114 const int SIGILL = 4;
115 const int SIGTRAP = 5;
116 const int SIGABRT = 6;
117 const int SIGFPE = 8;
118 const int SIGSEGV = 11;
119 const int SIGPIPE = 13;
120 const int SIGTERM = 15;
121 #if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
122 const int SIGBUS = 10;
123 const int SIGSYS = 12;
124 #else
125 const int SIGBUS = 7;
126 const int SIGSYS = 31;
127 #endif
128 void *const MAP_FAILED = (void*)-1;
129 #if SANITIZER_NETBSD
130 const int PTHREAD_BARRIER_SERIAL_THREAD = 1234567;
131 #elif !SANITIZER_MAC
132 const int PTHREAD_BARRIER_SERIAL_THREAD = -1;
133 #endif
134 const int MAP_FIXED = 0x10;
135 typedef long long_t;
136 typedef __sanitizer::u16 mode_t;
137 
138 // From /usr/include/unistd.h
139 # define F_ULOCK 0      /* Unlock a previously locked region.  */
140 # define F_LOCK  1      /* Lock a region for exclusive use.  */
141 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
142 # define F_TEST  3      /* Test a region for other processes locks.  */
143 
144 #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
145 const int SA_SIGINFO = 0x40;
146 const int SIG_SETMASK = 3;
147 #elif defined(__mips__)
148 const int SA_SIGINFO = 8;
149 const int SIG_SETMASK = 3;
150 #else
151 const int SA_SIGINFO = 4;
152 const int SIG_SETMASK = 2;
153 #endif
154 
155 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \
156   (cur_thread_init(), !cur_thread()->is_inited)
157 
158 namespace __tsan {
159 struct SignalDesc {
160   bool armed;
161   bool sigaction;
162   __sanitizer_siginfo siginfo;
163   ucontext_t ctx;
164 };
165 
166 struct ThreadSignalContext {
167   int int_signal_send;
168   atomic_uintptr_t in_blocking_func;
169   atomic_uintptr_t have_pending_signals;
170   SignalDesc pending_signals[kSigCount];
171   // emptyset and oldset are too big for stack.
172   __sanitizer_sigset_t emptyset;
173   __sanitizer_sigset_t oldset;
174 };
175 
176 // The sole reason tsan wraps atexit callbacks is to establish synchronization
177 // between callback setup and callback execution.
178 struct AtExitCtx {
179   void (*f)();
180   void *arg;
181 };
182 
183 // InterceptorContext holds all global data required for interceptors.
184 // It's explicitly constructed in InitializeInterceptors with placement new
185 // and is never destroyed. This allows usage of members with non-trivial
186 // constructors and destructors.
187 struct InterceptorContext {
188   // The object is 64-byte aligned, because we want hot data to be located
189   // in a single cache line if possible (it's accessed in every interceptor).
190   ALIGNED(64) LibIgnore libignore;
191   __sanitizer_sigaction sigactions[kSigCount];
192 #if !SANITIZER_MAC && !SANITIZER_NETBSD
193   unsigned finalize_key;
194 #endif
195 
196   BlockingMutex atexit_mu;
197   Vector<struct AtExitCtx *> AtExitStack;
198 
InterceptorContext__tsan::InterceptorContext199   InterceptorContext()
200       : libignore(LINKER_INITIALIZED), AtExitStack() {
201   }
202 };
203 
204 static ALIGNED(64) char interceptor_placeholder[sizeof(InterceptorContext)];
interceptor_ctx()205 InterceptorContext *interceptor_ctx() {
206   return reinterpret_cast<InterceptorContext*>(&interceptor_placeholder[0]);
207 }
208 
libignore()209 LibIgnore *libignore() {
210   return &interceptor_ctx()->libignore;
211 }
212 
InitializeLibIgnore()213 void InitializeLibIgnore() {
214   const SuppressionContext &supp = *Suppressions();
215   const uptr n = supp.SuppressionCount();
216   for (uptr i = 0; i < n; i++) {
217     const Suppression *s = supp.SuppressionAt(i);
218     if (0 == internal_strcmp(s->type, kSuppressionLib))
219       libignore()->AddIgnoredLibrary(s->templ);
220   }
221   if (flags()->ignore_noninstrumented_modules)
222     libignore()->IgnoreNoninstrumentedModules(true);
223   libignore()->OnLibraryLoaded(0);
224 }
225 
226 // The following two hooks can be used by for cooperative scheduling when
227 // locking.
228 #ifdef TSAN_EXTERNAL_HOOKS
229 void OnPotentiallyBlockingRegionBegin();
230 void OnPotentiallyBlockingRegionEnd();
231 #else
OnPotentiallyBlockingRegionBegin()232 SANITIZER_WEAK_CXX_DEFAULT_IMPL void OnPotentiallyBlockingRegionBegin() {}
OnPotentiallyBlockingRegionEnd()233 SANITIZER_WEAK_CXX_DEFAULT_IMPL void OnPotentiallyBlockingRegionEnd() {}
234 #endif
235 
236 }  // namespace __tsan
237 
SigCtx(ThreadState * thr)238 static ThreadSignalContext *SigCtx(ThreadState *thr) {
239   ThreadSignalContext *ctx = (ThreadSignalContext*)thr->signal_ctx;
240   if (ctx == 0 && !thr->is_dead) {
241     ctx = (ThreadSignalContext*)MmapOrDie(sizeof(*ctx), "ThreadSignalContext");
242     MemoryResetRange(thr, (uptr)&SigCtx, (uptr)ctx, sizeof(*ctx));
243     thr->signal_ctx = ctx;
244   }
245   return ctx;
246 }
247 
ScopedInterceptor(ThreadState * thr,const char * fname,uptr pc)248 ScopedInterceptor::ScopedInterceptor(ThreadState *thr, const char *fname,
249                                      uptr pc)
250     : thr_(thr), pc_(pc), in_ignored_lib_(false), ignoring_(false) {
251   Initialize(thr);
252   if (!thr_->is_inited) return;
253   if (!thr_->ignore_interceptors) FuncEntry(thr, pc);
254   DPrintf("#%d: intercept %s()\n", thr_->tid, fname);
255   ignoring_ =
256       !thr_->in_ignored_lib && (flags()->ignore_interceptors_accesses ||
257                                 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 (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 (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 (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)490 static void SetJmp(ThreadState *thr, uptr 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->shadow_stack_pos = thr->shadow_stack_pos;
499   ThreadSignalContext *sctx = SigCtx(thr);
500   buf->int_signal_send = sctx ? sctx->int_signal_send : 0;
501   buf->in_blocking_func = sctx ?
502       atomic_load(&sctx->in_blocking_func, memory_order_relaxed) :
503       false;
504   buf->in_signal_handler = atomic_load(&thr->in_signal_handler,
505       memory_order_relaxed);
506 }
507 
LongJmp(ThreadState * thr,uptr * env)508 static void LongJmp(ThreadState *thr, uptr *env) {
509   uptr sp = ExtractLongJmpSp(env);
510   // Find the saved buf with matching sp.
511   for (uptr i = 0; i < thr->jmp_bufs.Size(); i++) {
512     JmpBuf *buf = &thr->jmp_bufs[i];
513     if (buf->sp == sp) {
514       CHECK_GE(thr->shadow_stack_pos, buf->shadow_stack_pos);
515       // Unwind the stack.
516       while (thr->shadow_stack_pos > buf->shadow_stack_pos)
517         FuncExit(thr);
518       ThreadSignalContext *sctx = SigCtx(thr);
519       if (sctx) {
520         sctx->int_signal_send = buf->int_signal_send;
521         atomic_store(&sctx->in_blocking_func, buf->in_blocking_func,
522             memory_order_relaxed);
523       }
524       atomic_store(&thr->in_signal_handler, buf->in_signal_handler,
525           memory_order_relaxed);
526       JmpBufGarbageCollect(thr, buf->sp - 1);  // do not collect buf->sp
527       return;
528     }
529   }
530   Printf("ThreadSanitizer: can't find longjmp buf\n");
531   CHECK(0);
532 }
533 
534 // FIXME: put everything below into a common extern "C" block?
__tsan_setjmp(uptr sp)535 extern "C" void __tsan_setjmp(uptr sp) {
536   cur_thread_init();
537   SetJmp(cur_thread(), sp);
538 }
539 
540 #if SANITIZER_MAC
541 TSAN_INTERCEPTOR(int, setjmp, void *env);
542 TSAN_INTERCEPTOR(int, _setjmp, void *env);
543 TSAN_INTERCEPTOR(int, sigsetjmp, void *env);
544 #else  // SANITIZER_MAC
545 
546 #if SANITIZER_NETBSD
547 #define setjmp_symname __setjmp14
548 #define sigsetjmp_symname __sigsetjmp14
549 #else
550 #define setjmp_symname setjmp
551 #define sigsetjmp_symname sigsetjmp
552 #endif
553 
554 #define TSAN_INTERCEPTOR_SETJMP_(x) __interceptor_ ## x
555 #define TSAN_INTERCEPTOR_SETJMP__(x) TSAN_INTERCEPTOR_SETJMP_(x)
556 #define TSAN_INTERCEPTOR_SETJMP TSAN_INTERCEPTOR_SETJMP__(setjmp_symname)
557 #define TSAN_INTERCEPTOR_SIGSETJMP TSAN_INTERCEPTOR_SETJMP__(sigsetjmp_symname)
558 
559 #define TSAN_STRING_SETJMP SANITIZER_STRINGIFY(setjmp_symname)
560 #define TSAN_STRING_SIGSETJMP SANITIZER_STRINGIFY(sigsetjmp_symname)
561 
562 // Not called.  Merely to satisfy TSAN_INTERCEPT().
563 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
564 int TSAN_INTERCEPTOR_SETJMP(void *env);
TSAN_INTERCEPTOR_SETJMP(void * env)565 extern "C" int TSAN_INTERCEPTOR_SETJMP(void *env) {
566   CHECK(0);
567   return 0;
568 }
569 
570 // FIXME: any reason to have a separate declaration?
571 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
572 int __interceptor__setjmp(void *env);
__interceptor__setjmp(void * env)573 extern "C" int __interceptor__setjmp(void *env) {
574   CHECK(0);
575   return 0;
576 }
577 
578 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
579 int TSAN_INTERCEPTOR_SIGSETJMP(void *env);
TSAN_INTERCEPTOR_SIGSETJMP(void * env)580 extern "C" int TSAN_INTERCEPTOR_SIGSETJMP(void *env) {
581   CHECK(0);
582   return 0;
583 }
584 
585 #if !SANITIZER_NETBSD
586 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
587 int __interceptor___sigsetjmp(void *env);
__interceptor___sigsetjmp(void * env)588 extern "C" int __interceptor___sigsetjmp(void *env) {
589   CHECK(0);
590   return 0;
591 }
592 #endif
593 
594 extern "C" int setjmp_symname(void *env);
595 extern "C" int _setjmp(void *env);
596 extern "C" int sigsetjmp_symname(void *env);
597 #if !SANITIZER_NETBSD
598 extern "C" int __sigsetjmp(void *env);
599 #endif
DEFINE_REAL(int,setjmp_symname,void * env)600 DEFINE_REAL(int, setjmp_symname, void *env)
601 DEFINE_REAL(int, _setjmp, void *env)
602 DEFINE_REAL(int, sigsetjmp_symname, void *env)
603 #if !SANITIZER_NETBSD
604 DEFINE_REAL(int, __sigsetjmp, void *env)
605 #endif
606 #endif  // SANITIZER_MAC
607 
608 #if SANITIZER_NETBSD
609 #define longjmp_symname __longjmp14
610 #define siglongjmp_symname __siglongjmp14
611 #else
612 #define longjmp_symname longjmp
613 #define siglongjmp_symname siglongjmp
614 #endif
615 
616 TSAN_INTERCEPTOR(void, longjmp_symname, uptr *env, int val) {
617   // Note: if we call REAL(longjmp) in the context of ScopedInterceptor,
618   // bad things will happen. We will jump over ScopedInterceptor dtor and can
619   // leave thr->in_ignored_lib set.
620   {
621     SCOPED_INTERCEPTOR_RAW(longjmp_symname, env, val);
622   }
623   LongJmp(cur_thread(), env);
624   REAL(longjmp_symname)(env, val);
625 }
626 
TSAN_INTERCEPTOR(void,siglongjmp_symname,uptr * env,int val)627 TSAN_INTERCEPTOR(void, siglongjmp_symname, uptr *env, int val) {
628   {
629     SCOPED_INTERCEPTOR_RAW(siglongjmp_symname, env, val);
630   }
631   LongJmp(cur_thread(), env);
632   REAL(siglongjmp_symname)(env, val);
633 }
634 
635 #if SANITIZER_NETBSD
TSAN_INTERCEPTOR(void,_longjmp,uptr * env,int val)636 TSAN_INTERCEPTOR(void, _longjmp, uptr *env, int val) {
637   {
638     SCOPED_INTERCEPTOR_RAW(_longjmp, env, val);
639   }
640   LongJmp(cur_thread(), env);
641   REAL(_longjmp)(env, val);
642 }
643 #endif
644 
645 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(void *,malloc,uptr size)646 TSAN_INTERCEPTOR(void*, malloc, uptr size) {
647   if (in_symbolizer())
648     return InternalAlloc(size);
649   void *p = 0;
650   {
651     SCOPED_INTERCEPTOR_RAW(malloc, size);
652     p = user_alloc(thr, pc, size);
653   }
654   invoke_malloc_hook(p, size);
655   return p;
656 }
657 
TSAN_INTERCEPTOR(void *,__libc_memalign,uptr align,uptr sz)658 TSAN_INTERCEPTOR(void*, __libc_memalign, uptr align, uptr sz) {
659   SCOPED_TSAN_INTERCEPTOR(__libc_memalign, align, sz);
660   return user_memalign(thr, pc, align, sz);
661 }
662 
TSAN_INTERCEPTOR(void *,calloc,uptr size,uptr n)663 TSAN_INTERCEPTOR(void*, calloc, uptr size, uptr n) {
664   if (in_symbolizer())
665     return InternalCalloc(size, n);
666   void *p = 0;
667   {
668     SCOPED_INTERCEPTOR_RAW(calloc, size, n);
669     p = user_calloc(thr, pc, size, n);
670   }
671   invoke_malloc_hook(p, n * size);
672   return p;
673 }
674 
TSAN_INTERCEPTOR(void *,realloc,void * p,uptr size)675 TSAN_INTERCEPTOR(void*, realloc, void *p, uptr size) {
676   if (in_symbolizer())
677     return InternalRealloc(p, size);
678   if (p)
679     invoke_free_hook(p);
680   {
681     SCOPED_INTERCEPTOR_RAW(realloc, p, size);
682     p = user_realloc(thr, pc, p, size);
683   }
684   invoke_malloc_hook(p, size);
685   return p;
686 }
687 
TSAN_INTERCEPTOR(void *,reallocarray,void * p,uptr size,uptr n)688 TSAN_INTERCEPTOR(void*, reallocarray, void *p, uptr size, uptr n) {
689   if (in_symbolizer())
690     return InternalReallocArray(p, size, n);
691   if (p)
692     invoke_free_hook(p);
693   {
694     SCOPED_INTERCEPTOR_RAW(reallocarray, p, size, n);
695     p = user_reallocarray(thr, pc, p, size, n);
696   }
697   invoke_malloc_hook(p, size);
698   return p;
699 }
700 
TSAN_INTERCEPTOR(void,free,void * p)701 TSAN_INTERCEPTOR(void, free, void *p) {
702   if (p == 0)
703     return;
704   if (in_symbolizer())
705     return InternalFree(p);
706   invoke_free_hook(p);
707   SCOPED_INTERCEPTOR_RAW(free, p);
708   user_free(thr, pc, p);
709 }
710 
TSAN_INTERCEPTOR(void,cfree,void * p)711 TSAN_INTERCEPTOR(void, cfree, void *p) {
712   if (p == 0)
713     return;
714   if (in_symbolizer())
715     return InternalFree(p);
716   invoke_free_hook(p);
717   SCOPED_INTERCEPTOR_RAW(cfree, p);
718   user_free(thr, pc, p);
719 }
720 
TSAN_INTERCEPTOR(uptr,malloc_usable_size,void * p)721 TSAN_INTERCEPTOR(uptr, malloc_usable_size, void *p) {
722   SCOPED_INTERCEPTOR_RAW(malloc_usable_size, p);
723   return user_alloc_usable_size(p);
724 }
725 #endif
726 
TSAN_INTERCEPTOR(char *,strcpy,char * dst,const char * src)727 TSAN_INTERCEPTOR(char *, strcpy, char *dst, const char *src) {
728   SCOPED_TSAN_INTERCEPTOR(strcpy, dst, src);
729   uptr srclen = internal_strlen(src);
730   MemoryAccessRange(thr, pc, (uptr)dst, srclen + 1, true);
731   MemoryAccessRange(thr, pc, (uptr)src, srclen + 1, false);
732   return REAL(strcpy)(dst, src);
733 }
734 
TSAN_INTERCEPTOR(char *,strncpy,char * dst,char * src,uptr n)735 TSAN_INTERCEPTOR(char*, strncpy, char *dst, char *src, uptr n) {
736   SCOPED_TSAN_INTERCEPTOR(strncpy, dst, src, n);
737   uptr srclen = internal_strnlen(src, n);
738   MemoryAccessRange(thr, pc, (uptr)dst, n, true);
739   MemoryAccessRange(thr, pc, (uptr)src, min(srclen + 1, n), false);
740   return REAL(strncpy)(dst, src, n);
741 }
742 
TSAN_INTERCEPTOR(char *,strdup,const char * str)743 TSAN_INTERCEPTOR(char*, strdup, const char *str) {
744   SCOPED_TSAN_INTERCEPTOR(strdup, str);
745   // strdup will call malloc, so no instrumentation is required here.
746   return REAL(strdup)(str);
747 }
748 
749 // Zero out addr if it points into shadow memory and was provided as a hint
750 // only, i.e., MAP_FIXED is not set.
fix_mmap_addr(void ** addr,long_t sz,int flags)751 static bool fix_mmap_addr(void **addr, long_t sz, int flags) {
752   if (*addr) {
753     if (!IsAppMem((uptr)*addr) || !IsAppMem((uptr)*addr + sz - 1)) {
754       if (flags & MAP_FIXED) {
755         errno = errno_EINVAL;
756         return false;
757       } else {
758         *addr = 0;
759       }
760     }
761   }
762   return true;
763 }
764 
765 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)766 static void *mmap_interceptor(ThreadState *thr, uptr pc, Mmap real_mmap,
767                               void *addr, SIZE_T sz, int prot, int flags,
768                               int fd, OFF64_T off) {
769   if (!fix_mmap_addr(&addr, sz, flags)) return MAP_FAILED;
770   void *res = real_mmap(addr, sz, prot, flags, fd, off);
771   if (res != MAP_FAILED) {
772     if (fd > 0) FdAccess(thr, pc, fd);
773     MemoryRangeImitateWriteOrResetRange(thr, pc, (uptr)res, sz);
774   }
775   return res;
776 }
777 
TSAN_INTERCEPTOR(int,munmap,void * addr,long_t sz)778 TSAN_INTERCEPTOR(int, munmap, void *addr, long_t sz) {
779   SCOPED_TSAN_INTERCEPTOR(munmap, addr, sz);
780   UnmapShadow(thr, (uptr)addr, sz);
781   int res = REAL(munmap)(addr, sz);
782   return res;
783 }
784 
785 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,memalign,uptr align,uptr sz)786 TSAN_INTERCEPTOR(void*, memalign, uptr align, uptr sz) {
787   SCOPED_INTERCEPTOR_RAW(memalign, align, sz);
788   return user_memalign(thr, pc, align, sz);
789 }
790 #define TSAN_MAYBE_INTERCEPT_MEMALIGN TSAN_INTERCEPT(memalign)
791 #else
792 #define TSAN_MAYBE_INTERCEPT_MEMALIGN
793 #endif
794 
795 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(void *,aligned_alloc,uptr align,uptr sz)796 TSAN_INTERCEPTOR(void*, aligned_alloc, uptr align, uptr sz) {
797   if (in_symbolizer())
798     return InternalAlloc(sz, nullptr, align);
799   SCOPED_INTERCEPTOR_RAW(aligned_alloc, align, sz);
800   return user_aligned_alloc(thr, pc, align, sz);
801 }
802 
TSAN_INTERCEPTOR(void *,valloc,uptr sz)803 TSAN_INTERCEPTOR(void*, valloc, uptr sz) {
804   if (in_symbolizer())
805     return InternalAlloc(sz, nullptr, GetPageSizeCached());
806   SCOPED_INTERCEPTOR_RAW(valloc, sz);
807   return user_valloc(thr, pc, sz);
808 }
809 #endif
810 
811 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,pvalloc,uptr sz)812 TSAN_INTERCEPTOR(void*, pvalloc, uptr sz) {
813   if (in_symbolizer()) {
814     uptr PageSize = GetPageSizeCached();
815     sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
816     return InternalAlloc(sz, nullptr, PageSize);
817   }
818   SCOPED_INTERCEPTOR_RAW(pvalloc, sz);
819   return user_pvalloc(thr, pc, sz);
820 }
821 #define TSAN_MAYBE_INTERCEPT_PVALLOC TSAN_INTERCEPT(pvalloc)
822 #else
823 #define TSAN_MAYBE_INTERCEPT_PVALLOC
824 #endif
825 
826 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,posix_memalign,void ** memptr,uptr align,uptr sz)827 TSAN_INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr sz) {
828   if (in_symbolizer()) {
829     void *p = InternalAlloc(sz, nullptr, align);
830     if (!p)
831       return errno_ENOMEM;
832     *memptr = p;
833     return 0;
834   }
835   SCOPED_INTERCEPTOR_RAW(posix_memalign, memptr, align, sz);
836   return user_posix_memalign(thr, pc, memptr, align, sz);
837 }
838 #endif
839 
840 // __cxa_guard_acquire and friends need to be intercepted in a special way -
841 // regular interceptors will break statically-linked libstdc++. Linux
842 // interceptors are especially defined as weak functions (so that they don't
843 // cause link errors when user defines them as well). So they silently
844 // auto-disable themselves when such symbol is already present in the binary. If
845 // we link libstdc++ statically, it will bring own __cxa_guard_acquire which
846 // will silently replace our interceptor.  That's why on Linux we simply export
847 // these interceptors with INTERFACE_ATTRIBUTE.
848 // On OS X, we don't support statically linking, so we just use a regular
849 // interceptor.
850 #if SANITIZER_MAC
851 #define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR
852 #else
853 #define STDCXX_INTERCEPTOR(rettype, name, ...) \
854   extern "C" rettype INTERFACE_ATTRIBUTE name(__VA_ARGS__)
855 #endif
856 
857 // Used in thread-safe function static initialization.
STDCXX_INTERCEPTOR(int,__cxa_guard_acquire,atomic_uint32_t * g)858 STDCXX_INTERCEPTOR(int, __cxa_guard_acquire, atomic_uint32_t *g) {
859   SCOPED_INTERCEPTOR_RAW(__cxa_guard_acquire, g);
860   OnPotentiallyBlockingRegionBegin();
861   auto on_exit = at_scope_exit(&OnPotentiallyBlockingRegionEnd);
862   for (;;) {
863     u32 cmp = atomic_load(g, memory_order_acquire);
864     if (cmp == 0) {
865       if (atomic_compare_exchange_strong(g, &cmp, 1<<16, memory_order_relaxed))
866         return 1;
867     } else if (cmp == 1) {
868       Acquire(thr, pc, (uptr)g);
869       return 0;
870     } else {
871       internal_sched_yield();
872     }
873   }
874 }
875 
STDCXX_INTERCEPTOR(void,__cxa_guard_release,atomic_uint32_t * g)876 STDCXX_INTERCEPTOR(void, __cxa_guard_release, atomic_uint32_t *g) {
877   SCOPED_INTERCEPTOR_RAW(__cxa_guard_release, g);
878   Release(thr, pc, (uptr)g);
879   atomic_store(g, 1, memory_order_release);
880 }
881 
STDCXX_INTERCEPTOR(void,__cxa_guard_abort,atomic_uint32_t * g)882 STDCXX_INTERCEPTOR(void, __cxa_guard_abort, atomic_uint32_t *g) {
883   SCOPED_INTERCEPTOR_RAW(__cxa_guard_abort, g);
884   atomic_store(g, 0, memory_order_relaxed);
885 }
886 
887 namespace __tsan {
DestroyThreadState()888 void DestroyThreadState() {
889   ThreadState *thr = cur_thread();
890   Processor *proc = thr->proc();
891   ThreadFinish(thr);
892   ProcUnwire(proc, thr);
893   ProcDestroy(proc);
894   DTLS_Destroy();
895   cur_thread_finalize();
896 }
897 
PlatformCleanUpThreadState(ThreadState * thr)898 void PlatformCleanUpThreadState(ThreadState *thr) {
899   ThreadSignalContext *sctx = thr->signal_ctx;
900   if (sctx) {
901     thr->signal_ctx = 0;
902     UnmapOrDie(sctx, sizeof(*sctx));
903   }
904 }
905 }  // namespace __tsan
906 
907 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
thread_finalize(void * v)908 static void thread_finalize(void *v) {
909   uptr iter = (uptr)v;
910   if (iter > 1) {
911     if (pthread_setspecific(interceptor_ctx()->finalize_key,
912         (void*)(iter - 1))) {
913       Printf("ThreadSanitizer: failed to set thread key\n");
914       Die();
915     }
916     return;
917   }
918   DestroyThreadState();
919 }
920 #endif
921 
922 
923 struct ThreadParam {
924   void* (*callback)(void *arg);
925   void *param;
926   atomic_uintptr_t tid;
927 };
928 
__tsan_thread_start_func(void * arg)929 extern "C" void *__tsan_thread_start_func(void *arg) {
930   ThreadParam *p = (ThreadParam*)arg;
931   void* (*callback)(void *arg) = p->callback;
932   void *param = p->param;
933   int tid = 0;
934   {
935     cur_thread_init();
936     ThreadState *thr = cur_thread();
937     // Thread-local state is not initialized yet.
938     ScopedIgnoreInterceptors ignore;
939 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
940     ThreadIgnoreBegin(thr, 0);
941     if (pthread_setspecific(interceptor_ctx()->finalize_key,
942                             (void *)GetPthreadDestructorIterations())) {
943       Printf("ThreadSanitizer: failed to set thread key\n");
944       Die();
945     }
946     ThreadIgnoreEnd(thr, 0);
947 #endif
948     while ((tid = atomic_load(&p->tid, memory_order_acquire)) == 0)
949       internal_sched_yield();
950     Processor *proc = ProcCreate();
951     ProcWire(proc, thr);
952     ThreadStart(thr, tid, GetTid(), ThreadType::Regular);
953     atomic_store(&p->tid, 0, memory_order_release);
954   }
955   void *res = callback(param);
956   // Prevent the callback from being tail called,
957   // it mixes up stack traces.
958   volatile int foo = 42;
959   foo++;
960   return res;
961 }
962 
TSAN_INTERCEPTOR(int,pthread_create,void * th,void * attr,void * (* callback)(void *),void * param)963 TSAN_INTERCEPTOR(int, pthread_create,
964     void *th, void *attr, void *(*callback)(void*), void * param) {
965   SCOPED_INTERCEPTOR_RAW(pthread_create, th, attr, callback, param);
966 
967   MaybeSpawnBackgroundThread();
968 
969   if (ctx->after_multithreaded_fork) {
970     if (flags()->die_after_fork) {
971       Report("ThreadSanitizer: starting new threads after multi-threaded "
972           "fork is not supported. Dying (set die_after_fork=0 to override)\n");
973       Die();
974     } else {
975       VPrintf(1, "ThreadSanitizer: starting new threads after multi-threaded "
976           "fork is not supported (pid %d). Continuing because of "
977           "die_after_fork=0, but you are on your own\n", internal_getpid());
978     }
979   }
980   __sanitizer_pthread_attr_t myattr;
981   if (attr == 0) {
982     pthread_attr_init(&myattr);
983     attr = &myattr;
984   }
985   int detached = 0;
986   REAL(pthread_attr_getdetachstate)(attr, &detached);
987   AdjustStackSize(attr);
988 
989   ThreadParam p;
990   p.callback = callback;
991   p.param = param;
992   atomic_store(&p.tid, 0, memory_order_relaxed);
993   int res = -1;
994   {
995     // Otherwise we see false positives in pthread stack manipulation.
996     ScopedIgnoreInterceptors ignore;
997     ThreadIgnoreBegin(thr, pc);
998     res = REAL(pthread_create)(th, attr, __tsan_thread_start_func, &p);
999     ThreadIgnoreEnd(thr, pc);
1000   }
1001   if (res == 0) {
1002     int tid = ThreadCreate(thr, pc, *(uptr*)th, IsStateDetached(detached));
1003     CHECK_NE(tid, 0);
1004     // Synchronization on p.tid serves two purposes:
1005     // 1. ThreadCreate must finish before the new thread starts.
1006     //    Otherwise the new thread can call pthread_detach, but the pthread_t
1007     //    identifier is not yet registered in ThreadRegistry by ThreadCreate.
1008     // 2. ThreadStart must finish before this thread continues.
1009     //    Otherwise, this thread can call pthread_detach and reset thr->sync
1010     //    before the new thread got a chance to acquire from it in ThreadStart.
1011     atomic_store(&p.tid, tid, memory_order_release);
1012     while (atomic_load(&p.tid, memory_order_acquire) != 0)
1013       internal_sched_yield();
1014   }
1015   if (attr == &myattr)
1016     pthread_attr_destroy(&myattr);
1017   return res;
1018 }
1019 
TSAN_INTERCEPTOR(int,pthread_join,void * th,void ** ret)1020 TSAN_INTERCEPTOR(int, pthread_join, void *th, void **ret) {
1021   SCOPED_INTERCEPTOR_RAW(pthread_join, th, ret);
1022   int tid = ThreadConsumeTid(thr, pc, (uptr)th);
1023   ThreadIgnoreBegin(thr, pc);
1024   int res = BLOCK_REAL(pthread_join)(th, ret);
1025   ThreadIgnoreEnd(thr, pc);
1026   if (res == 0) {
1027     ThreadJoin(thr, pc, tid);
1028   }
1029   return res;
1030 }
1031 
1032 DEFINE_REAL_PTHREAD_FUNCTIONS
1033 
TSAN_INTERCEPTOR(int,pthread_detach,void * th)1034 TSAN_INTERCEPTOR(int, pthread_detach, void *th) {
1035   SCOPED_INTERCEPTOR_RAW(pthread_detach, th);
1036   int tid = ThreadConsumeTid(thr, pc, (uptr)th);
1037   int res = REAL(pthread_detach)(th);
1038   if (res == 0) {
1039     ThreadDetach(thr, pc, tid);
1040   }
1041   return res;
1042 }
1043 
TSAN_INTERCEPTOR(void,pthread_exit,void * retval)1044 TSAN_INTERCEPTOR(void, pthread_exit, void *retval) {
1045   {
1046     SCOPED_INTERCEPTOR_RAW(pthread_exit, retval);
1047 #if !SANITIZER_MAC && !SANITIZER_ANDROID
1048     CHECK_EQ(thr, &cur_thread_placeholder);
1049 #endif
1050   }
1051   REAL(pthread_exit)(retval);
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_INTERCEPTOR_RAW(pthread_tryjoin_np, th, ret);
1057   int tid = ThreadConsumeTid(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_INTERCEPTOR_RAW(pthread_timedjoin_np, th, ret, abstime);
1071   int tid = ThreadConsumeTid(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 namespace {
1122 
1123 template <class Fn>
1124 struct CondMutexUnlockCtx {
1125   ScopedInterceptor *si;
1126   ThreadState *thr;
1127   uptr pc;
1128   void *m;
1129   void *c;
1130   const Fn &fn;
1131 
Cancel__anond1b2740a0111::CondMutexUnlockCtx1132   int Cancel() const { return fn(); }
1133   void Unlock() const;
1134 };
1135 
1136 template <class Fn>
Unlock() const1137 void CondMutexUnlockCtx<Fn>::Unlock() const {
1138   // pthread_cond_wait interceptor has enabled async signal delivery
1139   // (see BlockingCall below). Disable async signals since we are running
1140   // tsan code. Also ScopedInterceptor and BlockingCall destructors won't run
1141   // since the thread is cancelled, so we have to manually execute them
1142   // (the thread still can run some user code due to pthread_cleanup_push).
1143   ThreadSignalContext *ctx = SigCtx(thr);
1144   CHECK_EQ(atomic_load(&ctx->in_blocking_func, memory_order_relaxed), 1);
1145   atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
1146   MutexPostLock(thr, pc, (uptr)m, MutexFlagDoPreLockOnPostLock);
1147   // Undo BlockingCall ctor effects.
1148   thr->ignore_interceptors--;
1149   si->~ScopedInterceptor();
1150 }
1151 }  // namespace
1152 
INTERCEPTOR(int,pthread_cond_init,void * c,void * a)1153 INTERCEPTOR(int, pthread_cond_init, void *c, void *a) {
1154   void *cond = init_cond(c, true);
1155   SCOPED_TSAN_INTERCEPTOR(pthread_cond_init, cond, a);
1156   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true);
1157   return REAL(pthread_cond_init)(cond, a);
1158 }
1159 
1160 template <class Fn>
cond_wait(ThreadState * thr,uptr pc,ScopedInterceptor * si,const Fn & fn,void * c,void * m)1161 int cond_wait(ThreadState *thr, uptr pc, ScopedInterceptor *si, const Fn &fn,
1162               void *c, void *m) {
1163   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1164   MutexUnlock(thr, pc, (uptr)m);
1165   int res = 0;
1166   // This ensures that we handle mutex lock even in case of pthread_cancel.
1167   // See test/tsan/cond_cancel.cpp.
1168   {
1169     // Enable signal delivery while the thread is blocked.
1170     BlockingCall bc(thr);
1171     CondMutexUnlockCtx<Fn> arg = {si, thr, pc, m, c, fn};
1172     res = call_pthread_cancel_with_cleanup(
1173         [](void *arg) -> int {
1174           return ((const CondMutexUnlockCtx<Fn> *)arg)->Cancel();
1175         },
1176         [](void *arg) { ((const CondMutexUnlockCtx<Fn> *)arg)->Unlock(); },
1177         &arg);
1178   }
1179   if (res == errno_EOWNERDEAD) MutexRepair(thr, pc, (uptr)m);
1180   MutexPostLock(thr, pc, (uptr)m, MutexFlagDoPreLockOnPostLock);
1181   return res;
1182 }
1183 
INTERCEPTOR(int,pthread_cond_wait,void * c,void * m)1184 INTERCEPTOR(int, pthread_cond_wait, void *c, void *m) {
1185   void *cond = init_cond(c);
1186   SCOPED_TSAN_INTERCEPTOR(pthread_cond_wait, cond, m);
1187   return cond_wait(
1188       thr, pc, &si, [=]() { return REAL(pthread_cond_wait)(cond, m); }, cond,
1189       m);
1190 }
1191 
INTERCEPTOR(int,pthread_cond_timedwait,void * c,void * m,void * abstime)1192 INTERCEPTOR(int, pthread_cond_timedwait, void *c, void *m, void *abstime) {
1193   void *cond = init_cond(c);
1194   SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait, cond, m, abstime);
1195   return cond_wait(
1196       thr, pc, &si,
1197       [=]() { return REAL(pthread_cond_timedwait)(cond, m, abstime); }, cond,
1198       m);
1199 }
1200 
1201 #if SANITIZER_LINUX
INTERCEPTOR(int,pthread_cond_clockwait,void * c,void * m,__sanitizer_clockid_t clock,void * abstime)1202 INTERCEPTOR(int, pthread_cond_clockwait, void *c, void *m,
1203             __sanitizer_clockid_t clock, void *abstime) {
1204   void *cond = init_cond(c);
1205   SCOPED_TSAN_INTERCEPTOR(pthread_cond_clockwait, cond, m, clock, abstime);
1206   return cond_wait(
1207       thr, pc, &si,
1208       [=]() { return REAL(pthread_cond_clockwait)(cond, m, clock, abstime); },
1209       cond, m);
1210 }
1211 #define TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT TSAN_INTERCEPT(pthread_cond_clockwait)
1212 #else
1213 #define TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT
1214 #endif
1215 
1216 #if SANITIZER_MAC
INTERCEPTOR(int,pthread_cond_timedwait_relative_np,void * c,void * m,void * reltime)1217 INTERCEPTOR(int, pthread_cond_timedwait_relative_np, void *c, void *m,
1218             void *reltime) {
1219   void *cond = init_cond(c);
1220   SCOPED_TSAN_INTERCEPTOR(pthread_cond_timedwait_relative_np, cond, m, reltime);
1221   return cond_wait(
1222       thr, pc, &si,
1223       [=]() {
1224         return REAL(pthread_cond_timedwait_relative_np)(cond, m, reltime);
1225       },
1226       cond, m);
1227 }
1228 #endif
1229 
INTERCEPTOR(int,pthread_cond_signal,void * c)1230 INTERCEPTOR(int, pthread_cond_signal, void *c) {
1231   void *cond = init_cond(c);
1232   SCOPED_TSAN_INTERCEPTOR(pthread_cond_signal, cond);
1233   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1234   return REAL(pthread_cond_signal)(cond);
1235 }
1236 
INTERCEPTOR(int,pthread_cond_broadcast,void * c)1237 INTERCEPTOR(int, pthread_cond_broadcast, void *c) {
1238   void *cond = init_cond(c);
1239   SCOPED_TSAN_INTERCEPTOR(pthread_cond_broadcast, cond);
1240   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), false);
1241   return REAL(pthread_cond_broadcast)(cond);
1242 }
1243 
INTERCEPTOR(int,pthread_cond_destroy,void * c)1244 INTERCEPTOR(int, pthread_cond_destroy, void *c) {
1245   void *cond = init_cond(c);
1246   SCOPED_TSAN_INTERCEPTOR(pthread_cond_destroy, cond);
1247   MemoryAccessRange(thr, pc, (uptr)c, sizeof(uptr), true);
1248   int res = REAL(pthread_cond_destroy)(cond);
1249   if (common_flags()->legacy_pthread_cond) {
1250     // Free our aux cond and zero the pointer to not leave dangling pointers.
1251     WRAP(free)(cond);
1252     atomic_store((atomic_uintptr_t*)c, 0, memory_order_relaxed);
1253   }
1254   return res;
1255 }
1256 
TSAN_INTERCEPTOR(int,pthread_mutex_init,void * m,void * a)1257 TSAN_INTERCEPTOR(int, pthread_mutex_init, void *m, void *a) {
1258   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_init, m, a);
1259   int res = REAL(pthread_mutex_init)(m, a);
1260   if (res == 0) {
1261     u32 flagz = 0;
1262     if (a) {
1263       int type = 0;
1264       if (REAL(pthread_mutexattr_gettype)(a, &type) == 0)
1265         if (type == PTHREAD_MUTEX_RECURSIVE ||
1266             type == PTHREAD_MUTEX_RECURSIVE_NP)
1267           flagz |= MutexFlagWriteReentrant;
1268     }
1269     MutexCreate(thr, pc, (uptr)m, flagz);
1270   }
1271   return res;
1272 }
1273 
TSAN_INTERCEPTOR(int,pthread_mutex_destroy,void * m)1274 TSAN_INTERCEPTOR(int, pthread_mutex_destroy, void *m) {
1275   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_destroy, m);
1276   int res = REAL(pthread_mutex_destroy)(m);
1277   if (res == 0 || res == errno_EBUSY) {
1278     MutexDestroy(thr, pc, (uptr)m);
1279   }
1280   return res;
1281 }
1282 
TSAN_INTERCEPTOR(int,pthread_mutex_trylock,void * m)1283 TSAN_INTERCEPTOR(int, pthread_mutex_trylock, void *m) {
1284   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_trylock, m);
1285   int res = REAL(pthread_mutex_trylock)(m);
1286   if (res == errno_EOWNERDEAD)
1287     MutexRepair(thr, pc, (uptr)m);
1288   if (res == 0 || res == errno_EOWNERDEAD)
1289     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1290   return res;
1291 }
1292 
1293 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_mutex_timedlock,void * m,void * abstime)1294 TSAN_INTERCEPTOR(int, pthread_mutex_timedlock, void *m, void *abstime) {
1295   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_timedlock, m, abstime);
1296   int res = REAL(pthread_mutex_timedlock)(m, abstime);
1297   if (res == 0) {
1298     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1299   }
1300   return res;
1301 }
1302 #endif
1303 
1304 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_spin_init,void * m,int pshared)1305 TSAN_INTERCEPTOR(int, pthread_spin_init, void *m, int pshared) {
1306   SCOPED_TSAN_INTERCEPTOR(pthread_spin_init, m, pshared);
1307   int res = REAL(pthread_spin_init)(m, pshared);
1308   if (res == 0) {
1309     MutexCreate(thr, pc, (uptr)m);
1310   }
1311   return res;
1312 }
1313 
TSAN_INTERCEPTOR(int,pthread_spin_destroy,void * m)1314 TSAN_INTERCEPTOR(int, pthread_spin_destroy, void *m) {
1315   SCOPED_TSAN_INTERCEPTOR(pthread_spin_destroy, m);
1316   int res = REAL(pthread_spin_destroy)(m);
1317   if (res == 0) {
1318     MutexDestroy(thr, pc, (uptr)m);
1319   }
1320   return res;
1321 }
1322 
TSAN_INTERCEPTOR(int,pthread_spin_lock,void * m)1323 TSAN_INTERCEPTOR(int, pthread_spin_lock, void *m) {
1324   SCOPED_TSAN_INTERCEPTOR(pthread_spin_lock, m);
1325   MutexPreLock(thr, pc, (uptr)m);
1326   int res = REAL(pthread_spin_lock)(m);
1327   if (res == 0) {
1328     MutexPostLock(thr, pc, (uptr)m);
1329   }
1330   return res;
1331 }
1332 
TSAN_INTERCEPTOR(int,pthread_spin_trylock,void * m)1333 TSAN_INTERCEPTOR(int, pthread_spin_trylock, void *m) {
1334   SCOPED_TSAN_INTERCEPTOR(pthread_spin_trylock, m);
1335   int res = REAL(pthread_spin_trylock)(m);
1336   if (res == 0) {
1337     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1338   }
1339   return res;
1340 }
1341 
TSAN_INTERCEPTOR(int,pthread_spin_unlock,void * m)1342 TSAN_INTERCEPTOR(int, pthread_spin_unlock, void *m) {
1343   SCOPED_TSAN_INTERCEPTOR(pthread_spin_unlock, m);
1344   MutexUnlock(thr, pc, (uptr)m);
1345   int res = REAL(pthread_spin_unlock)(m);
1346   return res;
1347 }
1348 #endif
1349 
TSAN_INTERCEPTOR(int,pthread_rwlock_init,void * m,void * a)1350 TSAN_INTERCEPTOR(int, pthread_rwlock_init, void *m, void *a) {
1351   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_init, m, a);
1352   int res = REAL(pthread_rwlock_init)(m, a);
1353   if (res == 0) {
1354     MutexCreate(thr, pc, (uptr)m);
1355   }
1356   return res;
1357 }
1358 
TSAN_INTERCEPTOR(int,pthread_rwlock_destroy,void * m)1359 TSAN_INTERCEPTOR(int, pthread_rwlock_destroy, void *m) {
1360   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_destroy, m);
1361   int res = REAL(pthread_rwlock_destroy)(m);
1362   if (res == 0) {
1363     MutexDestroy(thr, pc, (uptr)m);
1364   }
1365   return res;
1366 }
1367 
TSAN_INTERCEPTOR(int,pthread_rwlock_rdlock,void * m)1368 TSAN_INTERCEPTOR(int, pthread_rwlock_rdlock, void *m) {
1369   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_rdlock, m);
1370   MutexPreReadLock(thr, pc, (uptr)m);
1371   int res = REAL(pthread_rwlock_rdlock)(m);
1372   if (res == 0) {
1373     MutexPostReadLock(thr, pc, (uptr)m);
1374   }
1375   return res;
1376 }
1377 
TSAN_INTERCEPTOR(int,pthread_rwlock_tryrdlock,void * m)1378 TSAN_INTERCEPTOR(int, pthread_rwlock_tryrdlock, void *m) {
1379   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_tryrdlock, m);
1380   int res = REAL(pthread_rwlock_tryrdlock)(m);
1381   if (res == 0) {
1382     MutexPostReadLock(thr, pc, (uptr)m, MutexFlagTryLock);
1383   }
1384   return res;
1385 }
1386 
1387 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_rwlock_timedrdlock,void * m,void * abstime)1388 TSAN_INTERCEPTOR(int, pthread_rwlock_timedrdlock, void *m, void *abstime) {
1389   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedrdlock, m, abstime);
1390   int res = REAL(pthread_rwlock_timedrdlock)(m, abstime);
1391   if (res == 0) {
1392     MutexPostReadLock(thr, pc, (uptr)m);
1393   }
1394   return res;
1395 }
1396 #endif
1397 
TSAN_INTERCEPTOR(int,pthread_rwlock_wrlock,void * m)1398 TSAN_INTERCEPTOR(int, pthread_rwlock_wrlock, void *m) {
1399   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_wrlock, m);
1400   MutexPreLock(thr, pc, (uptr)m);
1401   int res = REAL(pthread_rwlock_wrlock)(m);
1402   if (res == 0) {
1403     MutexPostLock(thr, pc, (uptr)m);
1404   }
1405   return res;
1406 }
1407 
TSAN_INTERCEPTOR(int,pthread_rwlock_trywrlock,void * m)1408 TSAN_INTERCEPTOR(int, pthread_rwlock_trywrlock, void *m) {
1409   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_trywrlock, m);
1410   int res = REAL(pthread_rwlock_trywrlock)(m);
1411   if (res == 0) {
1412     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1413   }
1414   return res;
1415 }
1416 
1417 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_rwlock_timedwrlock,void * m,void * abstime)1418 TSAN_INTERCEPTOR(int, pthread_rwlock_timedwrlock, void *m, void *abstime) {
1419   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedwrlock, m, abstime);
1420   int res = REAL(pthread_rwlock_timedwrlock)(m, abstime);
1421   if (res == 0) {
1422     MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
1423   }
1424   return res;
1425 }
1426 #endif
1427 
TSAN_INTERCEPTOR(int,pthread_rwlock_unlock,void * m)1428 TSAN_INTERCEPTOR(int, pthread_rwlock_unlock, void *m) {
1429   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_unlock, m);
1430   MutexReadOrWriteUnlock(thr, pc, (uptr)m);
1431   int res = REAL(pthread_rwlock_unlock)(m);
1432   return res;
1433 }
1434 
1435 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pthread_barrier_init,void * b,void * a,unsigned count)1436 TSAN_INTERCEPTOR(int, pthread_barrier_init, void *b, void *a, unsigned count) {
1437   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_init, b, a, count);
1438   MemoryWrite(thr, pc, (uptr)b, kSizeLog1);
1439   int res = REAL(pthread_barrier_init)(b, a, count);
1440   return res;
1441 }
1442 
TSAN_INTERCEPTOR(int,pthread_barrier_destroy,void * b)1443 TSAN_INTERCEPTOR(int, pthread_barrier_destroy, void *b) {
1444   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_destroy, b);
1445   MemoryWrite(thr, pc, (uptr)b, kSizeLog1);
1446   int res = REAL(pthread_barrier_destroy)(b);
1447   return res;
1448 }
1449 
TSAN_INTERCEPTOR(int,pthread_barrier_wait,void * b)1450 TSAN_INTERCEPTOR(int, pthread_barrier_wait, void *b) {
1451   SCOPED_TSAN_INTERCEPTOR(pthread_barrier_wait, b);
1452   Release(thr, pc, (uptr)b);
1453   MemoryRead(thr, pc, (uptr)b, kSizeLog1);
1454   int res = REAL(pthread_barrier_wait)(b);
1455   MemoryRead(thr, pc, (uptr)b, kSizeLog1);
1456   if (res == 0 || res == PTHREAD_BARRIER_SERIAL_THREAD) {
1457     Acquire(thr, pc, (uptr)b);
1458   }
1459   return res;
1460 }
1461 #endif
1462 
TSAN_INTERCEPTOR(int,pthread_once,void * o,void (* f)())1463 TSAN_INTERCEPTOR(int, pthread_once, void *o, void (*f)()) {
1464   SCOPED_INTERCEPTOR_RAW(pthread_once, o, f);
1465   if (o == 0 || f == 0)
1466     return errno_EINVAL;
1467   atomic_uint32_t *a;
1468 
1469   if (SANITIZER_MAC)
1470     a = static_cast<atomic_uint32_t*>((void *)((char *)o + sizeof(long_t)));
1471   else if (SANITIZER_NETBSD)
1472     a = static_cast<atomic_uint32_t*>
1473           ((void *)((char *)o + __sanitizer::pthread_mutex_t_sz));
1474   else
1475     a = static_cast<atomic_uint32_t*>(o);
1476 
1477   u32 v = atomic_load(a, memory_order_acquire);
1478   if (v == 0 && atomic_compare_exchange_strong(a, &v, 1,
1479                                                memory_order_relaxed)) {
1480     (*f)();
1481     if (!thr->in_ignored_lib)
1482       Release(thr, pc, (uptr)o);
1483     atomic_store(a, 2, memory_order_release);
1484   } else {
1485     while (v != 2) {
1486       internal_sched_yield();
1487       v = atomic_load(a, memory_order_acquire);
1488     }
1489     if (!thr->in_ignored_lib)
1490       Acquire(thr, pc, (uptr)o);
1491   }
1492   return 0;
1493 }
1494 
1495 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,__fxstat,int version,int fd,void * buf)1496 TSAN_INTERCEPTOR(int, __fxstat, int version, int fd, void *buf) {
1497   SCOPED_TSAN_INTERCEPTOR(__fxstat, version, fd, buf);
1498   if (fd > 0)
1499     FdAccess(thr, pc, fd);
1500   return REAL(__fxstat)(version, fd, buf);
1501 }
1502 #define TSAN_MAYBE_INTERCEPT___FXSTAT TSAN_INTERCEPT(__fxstat)
1503 #else
1504 #define TSAN_MAYBE_INTERCEPT___FXSTAT
1505 #endif
1506 
TSAN_INTERCEPTOR(int,fstat,int fd,void * buf)1507 TSAN_INTERCEPTOR(int, fstat, int fd, void *buf) {
1508 #if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_ANDROID || SANITIZER_NETBSD
1509   SCOPED_TSAN_INTERCEPTOR(fstat, fd, buf);
1510   if (fd > 0)
1511     FdAccess(thr, pc, fd);
1512   return REAL(fstat)(fd, buf);
1513 #else
1514   SCOPED_TSAN_INTERCEPTOR(__fxstat, 0, fd, buf);
1515   if (fd > 0)
1516     FdAccess(thr, pc, fd);
1517   return REAL(__fxstat)(0, fd, buf);
1518 #endif
1519 }
1520 
1521 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,__fxstat64,int version,int fd,void * buf)1522 TSAN_INTERCEPTOR(int, __fxstat64, int version, int fd, void *buf) {
1523   SCOPED_TSAN_INTERCEPTOR(__fxstat64, version, fd, buf);
1524   if (fd > 0)
1525     FdAccess(thr, pc, fd);
1526   return REAL(__fxstat64)(version, fd, buf);
1527 }
1528 #define TSAN_MAYBE_INTERCEPT___FXSTAT64 TSAN_INTERCEPT(__fxstat64)
1529 #else
1530 #define TSAN_MAYBE_INTERCEPT___FXSTAT64
1531 #endif
1532 
1533 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(int,fstat64,int fd,void * buf)1534 TSAN_INTERCEPTOR(int, fstat64, int fd, void *buf) {
1535   SCOPED_TSAN_INTERCEPTOR(__fxstat64, 0, fd, buf);
1536   if (fd > 0)
1537     FdAccess(thr, pc, fd);
1538   return REAL(__fxstat64)(0, fd, buf);
1539 }
1540 #define TSAN_MAYBE_INTERCEPT_FSTAT64 TSAN_INTERCEPT(fstat64)
1541 #else
1542 #define TSAN_MAYBE_INTERCEPT_FSTAT64
1543 #endif
1544 
TSAN_INTERCEPTOR(int,open,const char * name,int oflag,...)1545 TSAN_INTERCEPTOR(int, open, const char *name, int oflag, ...) {
1546   va_list ap;
1547   va_start(ap, oflag);
1548   mode_t mode = va_arg(ap, int);
1549   va_end(ap);
1550   SCOPED_TSAN_INTERCEPTOR(open, name, oflag, mode);
1551   READ_STRING(thr, pc, name, 0);
1552   int fd = REAL(open)(name, oflag, mode);
1553   if (fd >= 0)
1554     FdFileCreate(thr, pc, fd);
1555   return fd;
1556 }
1557 
1558 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,open64,const char * name,int oflag,...)1559 TSAN_INTERCEPTOR(int, open64, const char *name, int oflag, ...) {
1560   va_list ap;
1561   va_start(ap, oflag);
1562   mode_t mode = va_arg(ap, int);
1563   va_end(ap);
1564   SCOPED_TSAN_INTERCEPTOR(open64, name, oflag, mode);
1565   READ_STRING(thr, pc, name, 0);
1566   int fd = REAL(open64)(name, oflag, mode);
1567   if (fd >= 0)
1568     FdFileCreate(thr, pc, fd);
1569   return fd;
1570 }
1571 #define TSAN_MAYBE_INTERCEPT_OPEN64 TSAN_INTERCEPT(open64)
1572 #else
1573 #define TSAN_MAYBE_INTERCEPT_OPEN64
1574 #endif
1575 
TSAN_INTERCEPTOR(int,creat,const char * name,int mode)1576 TSAN_INTERCEPTOR(int, creat, const char *name, int mode) {
1577   SCOPED_TSAN_INTERCEPTOR(creat, name, mode);
1578   READ_STRING(thr, pc, name, 0);
1579   int fd = REAL(creat)(name, mode);
1580   if (fd >= 0)
1581     FdFileCreate(thr, pc, fd);
1582   return fd;
1583 }
1584 
1585 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,creat64,const char * name,int mode)1586 TSAN_INTERCEPTOR(int, creat64, const char *name, int mode) {
1587   SCOPED_TSAN_INTERCEPTOR(creat64, name, mode);
1588   READ_STRING(thr, pc, name, 0);
1589   int fd = REAL(creat64)(name, mode);
1590   if (fd >= 0)
1591     FdFileCreate(thr, pc, fd);
1592   return fd;
1593 }
1594 #define TSAN_MAYBE_INTERCEPT_CREAT64 TSAN_INTERCEPT(creat64)
1595 #else
1596 #define TSAN_MAYBE_INTERCEPT_CREAT64
1597 #endif
1598 
TSAN_INTERCEPTOR(int,dup,int oldfd)1599 TSAN_INTERCEPTOR(int, dup, int oldfd) {
1600   SCOPED_TSAN_INTERCEPTOR(dup, oldfd);
1601   int newfd = REAL(dup)(oldfd);
1602   if (oldfd >= 0 && newfd >= 0 && newfd != oldfd)
1603     FdDup(thr, pc, oldfd, newfd, true);
1604   return newfd;
1605 }
1606 
TSAN_INTERCEPTOR(int,dup2,int oldfd,int newfd)1607 TSAN_INTERCEPTOR(int, dup2, int oldfd, int newfd) {
1608   SCOPED_TSAN_INTERCEPTOR(dup2, oldfd, newfd);
1609   int newfd2 = REAL(dup2)(oldfd, newfd);
1610   if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd)
1611     FdDup(thr, pc, oldfd, newfd2, false);
1612   return newfd2;
1613 }
1614 
1615 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,dup3,int oldfd,int newfd,int flags)1616 TSAN_INTERCEPTOR(int, dup3, int oldfd, int newfd, int flags) {
1617   SCOPED_TSAN_INTERCEPTOR(dup3, oldfd, newfd, flags);
1618   int newfd2 = REAL(dup3)(oldfd, newfd, flags);
1619   if (oldfd >= 0 && newfd2 >= 0 && newfd2 != oldfd)
1620     FdDup(thr, pc, oldfd, newfd2, false);
1621   return newfd2;
1622 }
1623 #endif
1624 
1625 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,eventfd,unsigned initval,int flags)1626 TSAN_INTERCEPTOR(int, eventfd, unsigned initval, int flags) {
1627   SCOPED_TSAN_INTERCEPTOR(eventfd, initval, flags);
1628   int fd = REAL(eventfd)(initval, flags);
1629   if (fd >= 0)
1630     FdEventCreate(thr, pc, fd);
1631   return fd;
1632 }
1633 #define TSAN_MAYBE_INTERCEPT_EVENTFD TSAN_INTERCEPT(eventfd)
1634 #else
1635 #define TSAN_MAYBE_INTERCEPT_EVENTFD
1636 #endif
1637 
1638 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,signalfd,int fd,void * mask,int flags)1639 TSAN_INTERCEPTOR(int, signalfd, int fd, void *mask, int flags) {
1640   SCOPED_TSAN_INTERCEPTOR(signalfd, fd, mask, flags);
1641   if (fd >= 0)
1642     FdClose(thr, pc, fd);
1643   fd = REAL(signalfd)(fd, mask, flags);
1644   if (fd >= 0)
1645     FdSignalCreate(thr, pc, fd);
1646   return fd;
1647 }
1648 #define TSAN_MAYBE_INTERCEPT_SIGNALFD TSAN_INTERCEPT(signalfd)
1649 #else
1650 #define TSAN_MAYBE_INTERCEPT_SIGNALFD
1651 #endif
1652 
1653 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,inotify_init,int fake)1654 TSAN_INTERCEPTOR(int, inotify_init, int fake) {
1655   SCOPED_TSAN_INTERCEPTOR(inotify_init, fake);
1656   int fd = REAL(inotify_init)(fake);
1657   if (fd >= 0)
1658     FdInotifyCreate(thr, pc, fd);
1659   return fd;
1660 }
1661 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT TSAN_INTERCEPT(inotify_init)
1662 #else
1663 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT
1664 #endif
1665 
1666 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,inotify_init1,int flags)1667 TSAN_INTERCEPTOR(int, inotify_init1, int flags) {
1668   SCOPED_TSAN_INTERCEPTOR(inotify_init1, flags);
1669   int fd = REAL(inotify_init1)(flags);
1670   if (fd >= 0)
1671     FdInotifyCreate(thr, pc, fd);
1672   return fd;
1673 }
1674 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1 TSAN_INTERCEPT(inotify_init1)
1675 #else
1676 #define TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1
1677 #endif
1678 
TSAN_INTERCEPTOR(int,socket,int domain,int type,int protocol)1679 TSAN_INTERCEPTOR(int, socket, int domain, int type, int protocol) {
1680   SCOPED_TSAN_INTERCEPTOR(socket, domain, type, protocol);
1681   int fd = REAL(socket)(domain, type, protocol);
1682   if (fd >= 0)
1683     FdSocketCreate(thr, pc, fd);
1684   return fd;
1685 }
1686 
TSAN_INTERCEPTOR(int,socketpair,int domain,int type,int protocol,int * fd)1687 TSAN_INTERCEPTOR(int, socketpair, int domain, int type, int protocol, int *fd) {
1688   SCOPED_TSAN_INTERCEPTOR(socketpair, domain, type, protocol, fd);
1689   int res = REAL(socketpair)(domain, type, protocol, fd);
1690   if (res == 0 && fd[0] >= 0 && fd[1] >= 0)
1691     FdPipeCreate(thr, pc, fd[0], fd[1]);
1692   return res;
1693 }
1694 
TSAN_INTERCEPTOR(int,connect,int fd,void * addr,unsigned addrlen)1695 TSAN_INTERCEPTOR(int, connect, int fd, void *addr, unsigned addrlen) {
1696   SCOPED_TSAN_INTERCEPTOR(connect, fd, addr, addrlen);
1697   FdSocketConnecting(thr, pc, fd);
1698   int res = REAL(connect)(fd, addr, addrlen);
1699   if (res == 0 && fd >= 0)
1700     FdSocketConnect(thr, pc, fd);
1701   return res;
1702 }
1703 
TSAN_INTERCEPTOR(int,bind,int fd,void * addr,unsigned addrlen)1704 TSAN_INTERCEPTOR(int, bind, int fd, void *addr, unsigned addrlen) {
1705   SCOPED_TSAN_INTERCEPTOR(bind, fd, addr, addrlen);
1706   int res = REAL(bind)(fd, addr, addrlen);
1707   if (fd > 0 && res == 0)
1708     FdAccess(thr, pc, fd);
1709   return res;
1710 }
1711 
TSAN_INTERCEPTOR(int,listen,int fd,int backlog)1712 TSAN_INTERCEPTOR(int, listen, int fd, int backlog) {
1713   SCOPED_TSAN_INTERCEPTOR(listen, fd, backlog);
1714   int res = REAL(listen)(fd, backlog);
1715   if (fd > 0 && res == 0)
1716     FdAccess(thr, pc, fd);
1717   return res;
1718 }
1719 
TSAN_INTERCEPTOR(int,close,int fd)1720 TSAN_INTERCEPTOR(int, close, int fd) {
1721   SCOPED_TSAN_INTERCEPTOR(close, fd);
1722   if (fd >= 0)
1723     FdClose(thr, pc, fd);
1724   return REAL(close)(fd);
1725 }
1726 
1727 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,__close,int fd)1728 TSAN_INTERCEPTOR(int, __close, int fd) {
1729   SCOPED_TSAN_INTERCEPTOR(__close, fd);
1730   if (fd >= 0)
1731     FdClose(thr, pc, fd);
1732   return REAL(__close)(fd);
1733 }
1734 #define TSAN_MAYBE_INTERCEPT___CLOSE TSAN_INTERCEPT(__close)
1735 #else
1736 #define TSAN_MAYBE_INTERCEPT___CLOSE
1737 #endif
1738 
1739 // glibc guts
1740 #if SANITIZER_LINUX && !SANITIZER_ANDROID
TSAN_INTERCEPTOR(void,__res_iclose,void * state,bool free_addr)1741 TSAN_INTERCEPTOR(void, __res_iclose, void *state, bool free_addr) {
1742   SCOPED_TSAN_INTERCEPTOR(__res_iclose, state, free_addr);
1743   int fds[64];
1744   int cnt = ExtractResolvFDs(state, fds, ARRAY_SIZE(fds));
1745   for (int i = 0; i < cnt; i++) {
1746     if (fds[i] > 0)
1747       FdClose(thr, pc, fds[i]);
1748   }
1749   REAL(__res_iclose)(state, free_addr);
1750 }
1751 #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE TSAN_INTERCEPT(__res_iclose)
1752 #else
1753 #define TSAN_MAYBE_INTERCEPT___RES_ICLOSE
1754 #endif
1755 
TSAN_INTERCEPTOR(int,pipe,int * pipefd)1756 TSAN_INTERCEPTOR(int, pipe, int *pipefd) {
1757   SCOPED_TSAN_INTERCEPTOR(pipe, pipefd);
1758   int res = REAL(pipe)(pipefd);
1759   if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0)
1760     FdPipeCreate(thr, pc, pipefd[0], pipefd[1]);
1761   return res;
1762 }
1763 
1764 #if !SANITIZER_MAC
TSAN_INTERCEPTOR(int,pipe2,int * pipefd,int flags)1765 TSAN_INTERCEPTOR(int, pipe2, int *pipefd, int flags) {
1766   SCOPED_TSAN_INTERCEPTOR(pipe2, pipefd, flags);
1767   int res = REAL(pipe2)(pipefd, flags);
1768   if (res == 0 && pipefd[0] >= 0 && pipefd[1] >= 0)
1769     FdPipeCreate(thr, pc, pipefd[0], pipefd[1]);
1770   return res;
1771 }
1772 #endif
1773 
TSAN_INTERCEPTOR(int,unlink,char * path)1774 TSAN_INTERCEPTOR(int, unlink, char *path) {
1775   SCOPED_TSAN_INTERCEPTOR(unlink, path);
1776   Release(thr, pc, File2addr(path));
1777   int res = REAL(unlink)(path);
1778   return res;
1779 }
1780 
TSAN_INTERCEPTOR(void *,tmpfile,int fake)1781 TSAN_INTERCEPTOR(void*, tmpfile, int fake) {
1782   SCOPED_TSAN_INTERCEPTOR(tmpfile, fake);
1783   void *res = REAL(tmpfile)(fake);
1784   if (res) {
1785     int fd = fileno_unlocked(res);
1786     if (fd >= 0)
1787       FdFileCreate(thr, pc, fd);
1788   }
1789   return res;
1790 }
1791 
1792 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(void *,tmpfile64,int fake)1793 TSAN_INTERCEPTOR(void*, tmpfile64, int fake) {
1794   SCOPED_TSAN_INTERCEPTOR(tmpfile64, fake);
1795   void *res = REAL(tmpfile64)(fake);
1796   if (res) {
1797     int fd = fileno_unlocked(res);
1798     if (fd >= 0)
1799       FdFileCreate(thr, pc, fd);
1800   }
1801   return res;
1802 }
1803 #define TSAN_MAYBE_INTERCEPT_TMPFILE64 TSAN_INTERCEPT(tmpfile64)
1804 #else
1805 #define TSAN_MAYBE_INTERCEPT_TMPFILE64
1806 #endif
1807 
FlushStreams()1808 static void FlushStreams() {
1809   // Flushing all the streams here may freeze the process if a child thread is
1810   // performing file stream operations at the same time.
1811   REAL(fflush)(stdout);
1812   REAL(fflush)(stderr);
1813 }
1814 
TSAN_INTERCEPTOR(void,abort,int fake)1815 TSAN_INTERCEPTOR(void, abort, int fake) {
1816   SCOPED_TSAN_INTERCEPTOR(abort, fake);
1817   FlushStreams();
1818   REAL(abort)(fake);
1819 }
1820 
TSAN_INTERCEPTOR(int,rmdir,char * path)1821 TSAN_INTERCEPTOR(int, rmdir, char *path) {
1822   SCOPED_TSAN_INTERCEPTOR(rmdir, path);
1823   Release(thr, pc, Dir2addr(path));
1824   int res = REAL(rmdir)(path);
1825   return res;
1826 }
1827 
TSAN_INTERCEPTOR(int,closedir,void * dirp)1828 TSAN_INTERCEPTOR(int, closedir, void *dirp) {
1829   SCOPED_TSAN_INTERCEPTOR(closedir, dirp);
1830   if (dirp) {
1831     int fd = dirfd(dirp);
1832     FdClose(thr, pc, fd);
1833   }
1834   return REAL(closedir)(dirp);
1835 }
1836 
1837 #if SANITIZER_LINUX
TSAN_INTERCEPTOR(int,epoll_create,int size)1838 TSAN_INTERCEPTOR(int, epoll_create, int size) {
1839   SCOPED_TSAN_INTERCEPTOR(epoll_create, size);
1840   int fd = REAL(epoll_create)(size);
1841   if (fd >= 0)
1842     FdPollCreate(thr, pc, fd);
1843   return fd;
1844 }
1845 
TSAN_INTERCEPTOR(int,epoll_create1,int flags)1846 TSAN_INTERCEPTOR(int, epoll_create1, int flags) {
1847   SCOPED_TSAN_INTERCEPTOR(epoll_create1, flags);
1848   int fd = REAL(epoll_create1)(flags);
1849   if (fd >= 0)
1850     FdPollCreate(thr, pc, fd);
1851   return fd;
1852 }
1853 
TSAN_INTERCEPTOR(int,epoll_ctl,int epfd,int op,int fd,void * ev)1854 TSAN_INTERCEPTOR(int, epoll_ctl, int epfd, int op, int fd, void *ev) {
1855   SCOPED_TSAN_INTERCEPTOR(epoll_ctl, epfd, op, fd, ev);
1856   if (epfd >= 0)
1857     FdAccess(thr, pc, epfd);
1858   if (epfd >= 0 && fd >= 0)
1859     FdAccess(thr, pc, fd);
1860   if (op == EPOLL_CTL_ADD && epfd >= 0)
1861     FdRelease(thr, pc, epfd);
1862   int res = REAL(epoll_ctl)(epfd, op, fd, ev);
1863   return res;
1864 }
1865 
TSAN_INTERCEPTOR(int,epoll_wait,int epfd,void * ev,int cnt,int timeout)1866 TSAN_INTERCEPTOR(int, epoll_wait, int epfd, void *ev, int cnt, int timeout) {
1867   SCOPED_TSAN_INTERCEPTOR(epoll_wait, epfd, ev, cnt, timeout);
1868   if (epfd >= 0)
1869     FdAccess(thr, pc, epfd);
1870   int res = BLOCK_REAL(epoll_wait)(epfd, ev, cnt, timeout);
1871   if (res > 0 && epfd >= 0)
1872     FdAcquire(thr, pc, epfd);
1873   return res;
1874 }
1875 
TSAN_INTERCEPTOR(int,epoll_pwait,int epfd,void * ev,int cnt,int timeout,void * sigmask)1876 TSAN_INTERCEPTOR(int, epoll_pwait, int epfd, void *ev, int cnt, int timeout,
1877                  void *sigmask) {
1878   SCOPED_TSAN_INTERCEPTOR(epoll_pwait, epfd, ev, cnt, timeout, sigmask);
1879   if (epfd >= 0)
1880     FdAccess(thr, pc, epfd);
1881   int res = BLOCK_REAL(epoll_pwait)(epfd, ev, cnt, timeout, sigmask);
1882   if (res > 0 && epfd >= 0)
1883     FdAcquire(thr, pc, epfd);
1884   return res;
1885 }
1886 
1887 #define TSAN_MAYBE_INTERCEPT_EPOLL \
1888     TSAN_INTERCEPT(epoll_create); \
1889     TSAN_INTERCEPT(epoll_create1); \
1890     TSAN_INTERCEPT(epoll_ctl); \
1891     TSAN_INTERCEPT(epoll_wait); \
1892     TSAN_INTERCEPT(epoll_pwait)
1893 #else
1894 #define TSAN_MAYBE_INTERCEPT_EPOLL
1895 #endif
1896 
1897 // The following functions are intercepted merely to process pending signals.
1898 // If program blocks signal X, we must deliver the signal before the function
1899 // returns. Similarly, if program unblocks a signal (or returns from sigsuspend)
1900 // it's better to deliver the signal straight away.
TSAN_INTERCEPTOR(int,sigsuspend,const __sanitizer_sigset_t * mask)1901 TSAN_INTERCEPTOR(int, sigsuspend, const __sanitizer_sigset_t *mask) {
1902   SCOPED_TSAN_INTERCEPTOR(sigsuspend, mask);
1903   return REAL(sigsuspend)(mask);
1904 }
1905 
TSAN_INTERCEPTOR(int,sigblock,int mask)1906 TSAN_INTERCEPTOR(int, sigblock, int mask) {
1907   SCOPED_TSAN_INTERCEPTOR(sigblock, mask);
1908   return REAL(sigblock)(mask);
1909 }
1910 
TSAN_INTERCEPTOR(int,sigsetmask,int mask)1911 TSAN_INTERCEPTOR(int, sigsetmask, int mask) {
1912   SCOPED_TSAN_INTERCEPTOR(sigsetmask, mask);
1913   return REAL(sigsetmask)(mask);
1914 }
1915 
TSAN_INTERCEPTOR(int,pthread_sigmask,int how,const __sanitizer_sigset_t * set,__sanitizer_sigset_t * oldset)1916 TSAN_INTERCEPTOR(int, pthread_sigmask, int how, const __sanitizer_sigset_t *set,
1917     __sanitizer_sigset_t *oldset) {
1918   SCOPED_TSAN_INTERCEPTOR(pthread_sigmask, how, set, oldset);
1919   return REAL(pthread_sigmask)(how, set, oldset);
1920 }
1921 
1922 namespace __tsan {
1923 
CallUserSignalHandler(ThreadState * thr,bool sync,bool acquire,bool sigact,int sig,__sanitizer_siginfo * info,void * uctx)1924 static void CallUserSignalHandler(ThreadState *thr, bool sync, bool acquire,
1925                                   bool sigact, int sig,
1926                                   __sanitizer_siginfo *info, void *uctx) {
1927   __sanitizer_sigaction *sigactions = interceptor_ctx()->sigactions;
1928   if (acquire)
1929     Acquire(thr, 0, (uptr)&sigactions[sig]);
1930   // Signals are generally asynchronous, so if we receive a signals when
1931   // ignores are enabled we should disable ignores. This is critical for sync
1932   // and interceptors, because otherwise we can miss syncronization and report
1933   // false races.
1934   int ignore_reads_and_writes = thr->ignore_reads_and_writes;
1935   int ignore_interceptors = thr->ignore_interceptors;
1936   int ignore_sync = thr->ignore_sync;
1937   if (!ctx->after_multithreaded_fork) {
1938     thr->ignore_reads_and_writes = 0;
1939     thr->fast_state.ClearIgnoreBit();
1940     thr->ignore_interceptors = 0;
1941     thr->ignore_sync = 0;
1942   }
1943   // Ensure that the handler does not spoil errno.
1944   const int saved_errno = errno;
1945   errno = 99;
1946   // This code races with sigaction. Be careful to not read sa_sigaction twice.
1947   // Also need to remember pc for reporting before the call,
1948   // because the handler can reset it.
1949   volatile uptr pc =
1950       sigact ? (uptr)sigactions[sig].sigaction : (uptr)sigactions[sig].handler;
1951   if (pc != sig_dfl && pc != sig_ign) {
1952     if (sigact)
1953       ((__sanitizer_sigactionhandler_ptr)pc)(sig, info, uctx);
1954     else
1955       ((__sanitizer_sighandler_ptr)pc)(sig);
1956   }
1957   if (!ctx->after_multithreaded_fork) {
1958     thr->ignore_reads_and_writes = ignore_reads_and_writes;
1959     if (ignore_reads_and_writes)
1960       thr->fast_state.SetIgnoreBit();
1961     thr->ignore_interceptors = ignore_interceptors;
1962     thr->ignore_sync = ignore_sync;
1963   }
1964   // We do not detect errno spoiling for SIGTERM,
1965   // because some SIGTERM handlers do spoil errno but reraise SIGTERM,
1966   // tsan reports false positive in such case.
1967   // It's difficult to properly detect this situation (reraise),
1968   // because in async signal processing case (when handler is called directly
1969   // from rtl_generic_sighandler) we have not yet received the reraised
1970   // signal; and it looks too fragile to intercept all ways to reraise a signal.
1971   if (flags()->report_bugs && !sync && sig != SIGTERM && errno != 99) {
1972     VarSizeStackTrace stack;
1973     // StackTrace::GetNestInstructionPc(pc) is used because return address is
1974     // expected, OutputReport() will undo this.
1975     ObtainCurrentStack(thr, StackTrace::GetNextInstructionPc(pc), &stack);
1976     ThreadRegistryLock l(ctx->thread_registry);
1977     ScopedReport rep(ReportTypeErrnoInSignal);
1978     if (!IsFiredSuppression(ctx, ReportTypeErrnoInSignal, stack)) {
1979       rep.AddStack(stack, true);
1980       OutputReport(thr, rep);
1981     }
1982   }
1983   errno = saved_errno;
1984 }
1985 
ProcessPendingSignals(ThreadState * thr)1986 void ProcessPendingSignals(ThreadState *thr) {
1987   ThreadSignalContext *sctx = SigCtx(thr);
1988   if (sctx == 0 ||
1989       atomic_load(&sctx->have_pending_signals, memory_order_relaxed) == 0)
1990     return;
1991   atomic_store(&sctx->have_pending_signals, 0, memory_order_relaxed);
1992   atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed);
1993   internal_sigfillset(&sctx->emptyset);
1994   int res = REAL(pthread_sigmask)(SIG_SETMASK, &sctx->emptyset, &sctx->oldset);
1995   CHECK_EQ(res, 0);
1996   for (int sig = 0; sig < kSigCount; sig++) {
1997     SignalDesc *signal = &sctx->pending_signals[sig];
1998     if (signal->armed) {
1999       signal->armed = false;
2000       CallUserSignalHandler(thr, false, true, signal->sigaction, sig,
2001           &signal->siginfo, &signal->ctx);
2002     }
2003   }
2004   res = REAL(pthread_sigmask)(SIG_SETMASK, &sctx->oldset, 0);
2005   CHECK_EQ(res, 0);
2006   atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed);
2007 }
2008 
2009 }  // namespace __tsan
2010 
is_sync_signal(ThreadSignalContext * sctx,int sig)2011 static bool is_sync_signal(ThreadSignalContext *sctx, int sig) {
2012   return sig == SIGSEGV || sig == SIGBUS || sig == SIGILL || sig == SIGTRAP ||
2013          sig == SIGABRT || sig == SIGFPE || sig == SIGPIPE || sig == SIGSYS ||
2014          // If we are sending signal to ourselves, we must process it now.
2015          (sctx && sig == sctx->int_signal_send);
2016 }
2017 
rtl_generic_sighandler(bool sigact,int sig,__sanitizer_siginfo * info,void * ctx)2018 void ALWAYS_INLINE rtl_generic_sighandler(bool sigact, int sig,
2019                                           __sanitizer_siginfo *info,
2020                                           void *ctx) {
2021   cur_thread_init();
2022   ThreadState *thr = cur_thread();
2023   ThreadSignalContext *sctx = SigCtx(thr);
2024   if (sig < 0 || sig >= kSigCount) {
2025     VPrintf(1, "ThreadSanitizer: ignoring signal %d\n", sig);
2026     return;
2027   }
2028   // Don't mess with synchronous signals.
2029   const bool sync = is_sync_signal(sctx, sig);
2030   if (sync ||
2031       // If we are in blocking function, we can safely process it now
2032       // (but check if we are in a recursive interceptor,
2033       // i.e. pthread_join()->munmap()).
2034       (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed))) {
2035     atomic_fetch_add(&thr->in_signal_handler, 1, memory_order_relaxed);
2036     if (sctx && atomic_load(&sctx->in_blocking_func, memory_order_relaxed)) {
2037       atomic_store(&sctx->in_blocking_func, 0, memory_order_relaxed);
2038       CallUserSignalHandler(thr, sync, true, sigact, sig, info, ctx);
2039       atomic_store(&sctx->in_blocking_func, 1, memory_order_relaxed);
2040     } else {
2041       // Be very conservative with when we do acquire in this case.
2042       // It's unsafe to do acquire in async handlers, because ThreadState
2043       // can be in inconsistent state.
2044       // SIGSYS looks relatively safe -- it's synchronous and can actually
2045       // need some global state.
2046       bool acq = (sig == SIGSYS);
2047       CallUserSignalHandler(thr, sync, acq, sigact, sig, info, ctx);
2048     }
2049     atomic_fetch_add(&thr->in_signal_handler, -1, memory_order_relaxed);
2050     return;
2051   }
2052 
2053   if (sctx == 0)
2054     return;
2055   SignalDesc *signal = &sctx->pending_signals[sig];
2056   if (signal->armed == false) {
2057     signal->armed = true;
2058     signal->sigaction = sigact;
2059     if (info)
2060       internal_memcpy(&signal->siginfo, info, sizeof(*info));
2061     if (ctx)
2062       internal_memcpy(&signal->ctx, ctx, sizeof(signal->ctx));
2063     atomic_store(&sctx->have_pending_signals, 1, memory_order_relaxed);
2064   }
2065 }
2066 
rtl_sighandler(int sig)2067 static void rtl_sighandler(int sig) {
2068   rtl_generic_sighandler(false, sig, 0, 0);
2069 }
2070 
rtl_sigaction(int sig,__sanitizer_siginfo * info,void * ctx)2071 static void rtl_sigaction(int sig, __sanitizer_siginfo *info, void *ctx) {
2072   rtl_generic_sighandler(true, sig, info, ctx);
2073 }
2074 
TSAN_INTERCEPTOR(int,raise,int sig)2075 TSAN_INTERCEPTOR(int, raise, int sig) {
2076   SCOPED_TSAN_INTERCEPTOR(raise, sig);
2077   ThreadSignalContext *sctx = SigCtx(thr);
2078   CHECK_NE(sctx, 0);
2079   int prev = sctx->int_signal_send;
2080   sctx->int_signal_send = sig;
2081   int res = REAL(raise)(sig);
2082   CHECK_EQ(sctx->int_signal_send, sig);
2083   sctx->int_signal_send = prev;
2084   return res;
2085 }
2086 
TSAN_INTERCEPTOR(int,kill,int pid,int sig)2087 TSAN_INTERCEPTOR(int, kill, int pid, int sig) {
2088   SCOPED_TSAN_INTERCEPTOR(kill, pid, sig);
2089   ThreadSignalContext *sctx = SigCtx(thr);
2090   CHECK_NE(sctx, 0);
2091   int prev = sctx->int_signal_send;
2092   if (pid == (int)internal_getpid()) {
2093     sctx->int_signal_send = sig;
2094   }
2095   int res = REAL(kill)(pid, sig);
2096   if (pid == (int)internal_getpid()) {
2097     CHECK_EQ(sctx->int_signal_send, sig);
2098     sctx->int_signal_send = prev;
2099   }
2100   return res;
2101 }
2102 
TSAN_INTERCEPTOR(int,pthread_kill,void * tid,int sig)2103 TSAN_INTERCEPTOR(int, pthread_kill, void *tid, int sig) {
2104   SCOPED_TSAN_INTERCEPTOR(pthread_kill, tid, sig);
2105   ThreadSignalContext *sctx = SigCtx(thr);
2106   CHECK_NE(sctx, 0);
2107   int prev = sctx->int_signal_send;
2108   if (tid == pthread_self()) {
2109     sctx->int_signal_send = sig;
2110   }
2111   int res = REAL(pthread_kill)(tid, sig);
2112   if (tid == pthread_self()) {
2113     CHECK_EQ(sctx->int_signal_send, sig);
2114     sctx->int_signal_send = prev;
2115   }
2116   return res;
2117 }
2118 
TSAN_INTERCEPTOR(int,gettimeofday,void * tv,void * tz)2119 TSAN_INTERCEPTOR(int, gettimeofday, void *tv, void *tz) {
2120   SCOPED_TSAN_INTERCEPTOR(gettimeofday, tv, tz);
2121   // It's intercepted merely to process pending signals.
2122   return REAL(gettimeofday)(tv, tz);
2123 }
2124 
TSAN_INTERCEPTOR(int,getaddrinfo,void * node,void * service,void * hints,void * rv)2125 TSAN_INTERCEPTOR(int, getaddrinfo, void *node, void *service,
2126     void *hints, void *rv) {
2127   SCOPED_TSAN_INTERCEPTOR(getaddrinfo, node, service, hints, rv);
2128   // We miss atomic synchronization in getaddrinfo,
2129   // and can report false race between malloc and free
2130   // inside of getaddrinfo. So ignore memory accesses.
2131   ThreadIgnoreBegin(thr, pc);
2132   int res = REAL(getaddrinfo)(node, service, hints, rv);
2133   ThreadIgnoreEnd(thr, pc);
2134   return res;
2135 }
2136 
TSAN_INTERCEPTOR(int,fork,int fake)2137 TSAN_INTERCEPTOR(int, fork, int fake) {
2138   if (in_symbolizer())
2139     return REAL(fork)(fake);
2140   SCOPED_INTERCEPTOR_RAW(fork, fake);
2141   ForkBefore(thr, pc);
2142   int pid;
2143   {
2144     // On OS X, REAL(fork) can call intercepted functions (OSSpinLockLock), and
2145     // we'll assert in CheckNoLocks() unless we ignore interceptors.
2146     ScopedIgnoreInterceptors ignore;
2147     pid = REAL(fork)(fake);
2148   }
2149   if (pid == 0) {
2150     // child
2151     ForkChildAfter(thr, pc);
2152     FdOnFork(thr, pc);
2153   } else if (pid > 0) {
2154     // parent
2155     ForkParentAfter(thr, pc);
2156   } else {
2157     // error
2158     ForkParentAfter(thr, pc);
2159   }
2160   return pid;
2161 }
2162 
TSAN_INTERCEPTOR(int,vfork,int fake)2163 TSAN_INTERCEPTOR(int, vfork, int fake) {
2164   // Some programs (e.g. openjdk) call close for all file descriptors
2165   // in the child process. Under tsan it leads to false positives, because
2166   // address space is shared, so the parent process also thinks that
2167   // the descriptors are closed (while they are actually not).
2168   // This leads to false positives due to missed synchronization.
2169   // Strictly saying this is undefined behavior, because vfork child is not
2170   // allowed to call any functions other than exec/exit. But this is what
2171   // openjdk does, so we want to handle it.
2172   // We could disable interceptors in the child process. But it's not possible
2173   // to simply intercept and wrap vfork, because vfork child is not allowed
2174   // to return from the function that calls vfork, and that's exactly what
2175   // we would do. So this would require some assembly trickery as well.
2176   // Instead we simply turn vfork into fork.
2177   return WRAP(fork)(fake);
2178 }
2179 
2180 #if !SANITIZER_MAC && !SANITIZER_ANDROID
2181 typedef int (*dl_iterate_phdr_cb_t)(__sanitizer_dl_phdr_info *info, SIZE_T size,
2182                                     void *data);
2183 struct dl_iterate_phdr_data {
2184   ThreadState *thr;
2185   uptr pc;
2186   dl_iterate_phdr_cb_t cb;
2187   void *data;
2188 };
2189 
IsAppNotRodata(uptr addr)2190 static bool IsAppNotRodata(uptr addr) {
2191   return IsAppMem(addr) && *(u64*)MemToShadow(addr) != kShadowRodata;
2192 }
2193 
dl_iterate_phdr_cb(__sanitizer_dl_phdr_info * info,SIZE_T size,void * data)2194 static int dl_iterate_phdr_cb(__sanitizer_dl_phdr_info *info, SIZE_T size,
2195                               void *data) {
2196   dl_iterate_phdr_data *cbdata = (dl_iterate_phdr_data *)data;
2197   // dlopen/dlclose allocate/free dynamic-linker-internal memory, which is later
2198   // accessible in dl_iterate_phdr callback. But we don't see synchronization
2199   // inside of dynamic linker, so we "unpoison" it here in order to not
2200   // produce false reports. Ignoring malloc/free in dlopen/dlclose is not enough
2201   // because some libc functions call __libc_dlopen.
2202   if (info && IsAppNotRodata((uptr)info->dlpi_name))
2203     MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name,
2204                      internal_strlen(info->dlpi_name));
2205   int res = cbdata->cb(info, size, cbdata->data);
2206   // Perform the check one more time in case info->dlpi_name was overwritten
2207   // by user callback.
2208   if (info && IsAppNotRodata((uptr)info->dlpi_name))
2209     MemoryResetRange(cbdata->thr, cbdata->pc, (uptr)info->dlpi_name,
2210                      internal_strlen(info->dlpi_name));
2211   return res;
2212 }
2213 
TSAN_INTERCEPTOR(int,dl_iterate_phdr,dl_iterate_phdr_cb_t cb,void * data)2214 TSAN_INTERCEPTOR(int, dl_iterate_phdr, dl_iterate_phdr_cb_t cb, void *data) {
2215   SCOPED_TSAN_INTERCEPTOR(dl_iterate_phdr, cb, data);
2216   dl_iterate_phdr_data cbdata;
2217   cbdata.thr = thr;
2218   cbdata.pc = pc;
2219   cbdata.cb = cb;
2220   cbdata.data = data;
2221   int res = REAL(dl_iterate_phdr)(dl_iterate_phdr_cb, &cbdata);
2222   return res;
2223 }
2224 #endif
2225 
OnExit(ThreadState * thr)2226 static int OnExit(ThreadState *thr) {
2227   int status = Finalize(thr);
2228   FlushStreams();
2229   return status;
2230 }
2231 
2232 struct TsanInterceptorContext {
2233   ThreadState *thr;
2234   const uptr caller_pc;
2235   const uptr pc;
2236 };
2237 
2238 #if !SANITIZER_MAC
HandleRecvmsg(ThreadState * thr,uptr pc,__sanitizer_msghdr * msg)2239 static void HandleRecvmsg(ThreadState *thr, uptr pc,
2240     __sanitizer_msghdr *msg) {
2241   int fds[64];
2242   int cnt = ExtractRecvmsgFDs(msg, fds, ARRAY_SIZE(fds));
2243   for (int i = 0; i < cnt; i++)
2244     FdEventCreate(thr, pc, fds[i]);
2245 }
2246 #endif
2247 
2248 #include "sanitizer_common/sanitizer_platform_interceptors.h"
2249 // Causes interceptor recursion (getaddrinfo() and fopen())
2250 #undef SANITIZER_INTERCEPT_GETADDRINFO
2251 // We define our own.
2252 #if SANITIZER_INTERCEPT_TLS_GET_ADDR
2253 #define NEED_TLS_GET_ADDR
2254 #endif
2255 #undef SANITIZER_INTERCEPT_TLS_GET_ADDR
2256 #undef SANITIZER_INTERCEPT_PTHREAD_SIGMASK
2257 
2258 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
2259 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver)                          \
2260   INTERCEPT_FUNCTION_VER(name, ver)
2261 
2262 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size)                    \
2263   MemoryAccessRange(((TsanInterceptorContext *)ctx)->thr,                 \
2264                     ((TsanInterceptorContext *)ctx)->pc, (uptr)ptr, size, \
2265                     true)
2266 
2267 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size)                       \
2268   MemoryAccessRange(((TsanInterceptorContext *) ctx)->thr,                  \
2269                     ((TsanInterceptorContext *) ctx)->pc, (uptr) ptr, size, \
2270                     false)
2271 
2272 #define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)      \
2273   SCOPED_TSAN_INTERCEPTOR(func, __VA_ARGS__);         \
2274   TsanInterceptorContext _ctx = {thr, caller_pc, pc}; \
2275   ctx = (void *)&_ctx;                                \
2276   (void) ctx;
2277 
2278 #define COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, func, ...) \
2279   SCOPED_INTERCEPTOR_RAW(func, __VA_ARGS__);              \
2280   TsanInterceptorContext _ctx = {thr, caller_pc, pc};     \
2281   ctx = (void *)&_ctx;                                    \
2282   (void) ctx;
2283 
2284 #define COMMON_INTERCEPTOR_FILE_OPEN(ctx, file, path) \
2285   if (path)                                           \
2286     Acquire(thr, pc, File2addr(path));                \
2287   if (file) {                                         \
2288     int fd = fileno_unlocked(file);                   \
2289     if (fd >= 0) FdFileCreate(thr, pc, fd);           \
2290   }
2291 
2292 #define COMMON_INTERCEPTOR_FILE_CLOSE(ctx, file) \
2293   if (file) {                                    \
2294     int fd = fileno_unlocked(file);              \
2295     if (fd >= 0) FdClose(thr, pc, fd);           \
2296   }
2297 
2298 #define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
2299   libignore()->OnLibraryLoaded(filename)
2300 
2301 #define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() \
2302   libignore()->OnLibraryUnloaded()
2303 
2304 #define COMMON_INTERCEPTOR_ACQUIRE(ctx, u) \
2305   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, u)
2306 
2307 #define COMMON_INTERCEPTOR_RELEASE(ctx, u) \
2308   Release(((TsanInterceptorContext *) ctx)->thr, pc, u)
2309 
2310 #define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
2311   Acquire(((TsanInterceptorContext *) ctx)->thr, pc, Dir2addr(path))
2312 
2313 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
2314   FdAcquire(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2315 
2316 #define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
2317   FdRelease(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2318 
2319 #define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) \
2320   FdAccess(((TsanInterceptorContext *) ctx)->thr, pc, fd)
2321 
2322 #define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
2323   FdSocketAccept(((TsanInterceptorContext *) ctx)->thr, pc, fd, newfd)
2324 
2325 #define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) \
2326   ThreadSetName(((TsanInterceptorContext *) ctx)->thr, name)
2327 
2328 #define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
2329   __tsan::ctx->thread_registry->SetThreadNameByUserId(thread, name)
2330 
2331 #define COMMON_INTERCEPTOR_BLOCK_REAL(name) BLOCK_REAL(name)
2332 
2333 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) \
2334   OnExit(((TsanInterceptorContext *) ctx)->thr)
2335 
2336 #define COMMON_INTERCEPTOR_MUTEX_PRE_LOCK(ctx, m) \
2337   MutexPreLock(((TsanInterceptorContext *)ctx)->thr, \
2338             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2339 
2340 #define COMMON_INTERCEPTOR_MUTEX_POST_LOCK(ctx, m) \
2341   MutexPostLock(((TsanInterceptorContext *)ctx)->thr, \
2342             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2343 
2344 #define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) \
2345   MutexUnlock(((TsanInterceptorContext *)ctx)->thr, \
2346             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2347 
2348 #define COMMON_INTERCEPTOR_MUTEX_REPAIR(ctx, m) \
2349   MutexRepair(((TsanInterceptorContext *)ctx)->thr, \
2350             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2351 
2352 #define COMMON_INTERCEPTOR_MUTEX_INVALID(ctx, m) \
2353   MutexInvalidAccess(((TsanInterceptorContext *)ctx)->thr, \
2354                      ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
2355 
2356 #define COMMON_INTERCEPTOR_MMAP_IMPL(ctx, mmap, addr, sz, prot, flags, fd,  \
2357                                      off)                                   \
2358   do {                                                                      \
2359     return mmap_interceptor(thr, pc, REAL(mmap), addr, sz, prot, flags, fd, \
2360                             off);                                           \
2361   } while (false)
2362 
2363 #if !SANITIZER_MAC
2364 #define COMMON_INTERCEPTOR_HANDLE_RECVMSG(ctx, msg) \
2365   HandleRecvmsg(((TsanInterceptorContext *)ctx)->thr, \
2366       ((TsanInterceptorContext *)ctx)->pc, msg)
2367 #endif
2368 
2369 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
2370   if (TsanThread *t = GetCurrentThread()) {                                    \
2371     *begin = t->tls_begin();                                                   \
2372     *end = t->tls_end();                                                       \
2373   } else {                                                                     \
2374     *begin = *end = 0;                                                         \
2375   }
2376 
2377 #define COMMON_INTERCEPTOR_USER_CALLBACK_START() \
2378   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START()
2379 
2380 #define COMMON_INTERCEPTOR_USER_CALLBACK_END() \
2381   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END()
2382 
2383 #include "sanitizer_common/sanitizer_common_interceptors.inc"
2384 
2385 static int sigaction_impl(int sig, const __sanitizer_sigaction *act,
2386                           __sanitizer_sigaction *old);
2387 static __sanitizer_sighandler_ptr signal_impl(int sig,
2388                                               __sanitizer_sighandler_ptr h);
2389 
2390 #define SIGNAL_INTERCEPTOR_SIGACTION_IMPL(signo, act, oldact) \
2391   { return sigaction_impl(signo, act, oldact); }
2392 
2393 #define SIGNAL_INTERCEPTOR_SIGNAL_IMPL(func, signo, handler) \
2394   { return (uptr)signal_impl(signo, (__sanitizer_sighandler_ptr)handler); }
2395 
2396 #include "sanitizer_common/sanitizer_signal_interceptors.inc"
2397 
sigaction_impl(int sig,const __sanitizer_sigaction * act,__sanitizer_sigaction * old)2398 int sigaction_impl(int sig, const __sanitizer_sigaction *act,
2399                    __sanitizer_sigaction *old) {
2400   // Note: if we call REAL(sigaction) directly for any reason without proxying
2401   // the signal handler through rtl_sigaction, very bad things will happen.
2402   // The handler will run synchronously and corrupt tsan per-thread state.
2403   SCOPED_INTERCEPTOR_RAW(sigaction, sig, act, old);
2404   __sanitizer_sigaction *sigactions = interceptor_ctx()->sigactions;
2405   __sanitizer_sigaction old_stored;
2406   if (old) internal_memcpy(&old_stored, &sigactions[sig], sizeof(old_stored));
2407   __sanitizer_sigaction newact;
2408   if (act) {
2409     // Copy act into sigactions[sig].
2410     // Can't use struct copy, because compiler can emit call to memcpy.
2411     // Can't use internal_memcpy, because it copies byte-by-byte,
2412     // and signal handler reads the handler concurrently. It it can read
2413     // some bytes from old value and some bytes from new value.
2414     // Use volatile to prevent insertion of memcpy.
2415     sigactions[sig].handler =
2416         *(volatile __sanitizer_sighandler_ptr const *)&act->handler;
2417     sigactions[sig].sa_flags = *(volatile int const *)&act->sa_flags;
2418     internal_memcpy(&sigactions[sig].sa_mask, &act->sa_mask,
2419                     sizeof(sigactions[sig].sa_mask));
2420 #if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
2421     sigactions[sig].sa_restorer = act->sa_restorer;
2422 #endif
2423     internal_memcpy(&newact, act, sizeof(newact));
2424     internal_sigfillset(&newact.sa_mask);
2425     if ((uptr)act->handler != sig_ign && (uptr)act->handler != sig_dfl) {
2426       if (newact.sa_flags & SA_SIGINFO)
2427         newact.sigaction = rtl_sigaction;
2428       else
2429         newact.handler = rtl_sighandler;
2430     }
2431     ReleaseStore(thr, pc, (uptr)&sigactions[sig]);
2432     act = &newact;
2433   }
2434   int res = REAL(sigaction)(sig, act, old);
2435   if (res == 0 && old) {
2436     uptr cb = (uptr)old->sigaction;
2437     if (cb == (uptr)rtl_sigaction || cb == (uptr)rtl_sighandler) {
2438       internal_memcpy(old, &old_stored, sizeof(*old));
2439     }
2440   }
2441   return res;
2442 }
2443 
signal_impl(int sig,__sanitizer_sighandler_ptr h)2444 static __sanitizer_sighandler_ptr signal_impl(int sig,
2445                                               __sanitizer_sighandler_ptr h) {
2446   __sanitizer_sigaction act;
2447   act.handler = h;
2448   internal_memset(&act.sa_mask, -1, sizeof(act.sa_mask));
2449   act.sa_flags = 0;
2450   __sanitizer_sigaction old;
2451   int res = sigaction_symname(sig, &act, &old);
2452   if (res) return (__sanitizer_sighandler_ptr)sig_err;
2453   return old.handler;
2454 }
2455 
2456 #define TSAN_SYSCALL() \
2457   ThreadState *thr = cur_thread(); \
2458   if (thr->ignore_interceptors) \
2459     return; \
2460   ScopedSyscall scoped_syscall(thr) \
2461 /**/
2462 
2463 struct ScopedSyscall {
2464   ThreadState *thr;
2465 
ScopedSyscallScopedSyscall2466   explicit ScopedSyscall(ThreadState *thr)
2467       : thr(thr) {
2468     Initialize(thr);
2469   }
2470 
~ScopedSyscallScopedSyscall2471   ~ScopedSyscall() {
2472     ProcessPendingSignals(thr);
2473   }
2474 };
2475 
2476 #if !SANITIZER_FREEBSD && !SANITIZER_MAC
syscall_access_range(uptr pc,uptr p,uptr s,bool write)2477 static void syscall_access_range(uptr pc, uptr p, uptr s, bool write) {
2478   TSAN_SYSCALL();
2479   MemoryAccessRange(thr, pc, p, s, write);
2480 }
2481 
syscall_acquire(uptr pc,uptr addr)2482 static USED void syscall_acquire(uptr pc, uptr addr) {
2483   TSAN_SYSCALL();
2484   Acquire(thr, pc, addr);
2485   DPrintf("syscall_acquire(%p)\n", addr);
2486 }
2487 
syscall_release(uptr pc,uptr addr)2488 static USED void syscall_release(uptr pc, uptr addr) {
2489   TSAN_SYSCALL();
2490   DPrintf("syscall_release(%p)\n", addr);
2491   Release(thr, pc, addr);
2492 }
2493 
syscall_fd_close(uptr pc,int fd)2494 static void syscall_fd_close(uptr pc, int fd) {
2495   TSAN_SYSCALL();
2496   FdClose(thr, pc, fd);
2497 }
2498 
syscall_fd_acquire(uptr pc,int fd)2499 static USED void syscall_fd_acquire(uptr pc, int fd) {
2500   TSAN_SYSCALL();
2501   FdAcquire(thr, pc, fd);
2502   DPrintf("syscall_fd_acquire(%p)\n", fd);
2503 }
2504 
syscall_fd_release(uptr pc,int fd)2505 static USED void syscall_fd_release(uptr pc, int fd) {
2506   TSAN_SYSCALL();
2507   DPrintf("syscall_fd_release(%p)\n", fd);
2508   FdRelease(thr, pc, fd);
2509 }
2510 
syscall_pre_fork(uptr pc)2511 static void syscall_pre_fork(uptr pc) {
2512   TSAN_SYSCALL();
2513   ForkBefore(thr, pc);
2514 }
2515 
syscall_post_fork(uptr pc,int pid)2516 static void syscall_post_fork(uptr pc, int pid) {
2517   TSAN_SYSCALL();
2518   if (pid == 0) {
2519     // child
2520     ForkChildAfter(thr, pc);
2521     FdOnFork(thr, pc);
2522   } else if (pid > 0) {
2523     // parent
2524     ForkParentAfter(thr, pc);
2525   } else {
2526     // error
2527     ForkParentAfter(thr, pc);
2528   }
2529 }
2530 #endif
2531 
2532 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) \
2533   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), false)
2534 
2535 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) \
2536   syscall_access_range(GET_CALLER_PC(), (uptr)(p), (uptr)(s), true)
2537 
2538 #define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
2539   do {                                       \
2540     (void)(p);                               \
2541     (void)(s);                               \
2542   } while (false)
2543 
2544 #define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
2545   do {                                        \
2546     (void)(p);                                \
2547     (void)(s);                                \
2548   } while (false)
2549 
2550 #define COMMON_SYSCALL_ACQUIRE(addr) \
2551     syscall_acquire(GET_CALLER_PC(), (uptr)(addr))
2552 
2553 #define COMMON_SYSCALL_RELEASE(addr) \
2554     syscall_release(GET_CALLER_PC(), (uptr)(addr))
2555 
2556 #define COMMON_SYSCALL_FD_CLOSE(fd) syscall_fd_close(GET_CALLER_PC(), fd)
2557 
2558 #define COMMON_SYSCALL_FD_ACQUIRE(fd) syscall_fd_acquire(GET_CALLER_PC(), fd)
2559 
2560 #define COMMON_SYSCALL_FD_RELEASE(fd) syscall_fd_release(GET_CALLER_PC(), fd)
2561 
2562 #define COMMON_SYSCALL_PRE_FORK() \
2563   syscall_pre_fork(GET_CALLER_PC())
2564 
2565 #define COMMON_SYSCALL_POST_FORK(res) \
2566   syscall_post_fork(GET_CALLER_PC(), res)
2567 
2568 #include "sanitizer_common/sanitizer_common_syscalls.inc"
2569 #include "sanitizer_common/sanitizer_syscalls_netbsd.inc"
2570 
2571 #ifdef NEED_TLS_GET_ADDR
2572 // Define own interceptor instead of sanitizer_common's for three reasons:
2573 // 1. It must not process pending signals.
2574 //    Signal handlers may contain MOVDQA instruction (see below).
2575 // 2. It must be as simple as possible to not contain MOVDQA.
2576 // 3. Sanitizer_common version uses COMMON_INTERCEPTOR_INITIALIZE_RANGE which
2577 //    is empty for tsan (meant only for msan).
2578 // Note: __tls_get_addr can be called with mis-aligned stack due to:
2579 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066
2580 // So the interceptor must work with mis-aligned stack, in particular, does not
2581 // execute MOVDQA with stack addresses.
TSAN_INTERCEPTOR(void *,__tls_get_addr,void * arg)2582 TSAN_INTERCEPTOR(void *, __tls_get_addr, void *arg) {
2583   void *res = REAL(__tls_get_addr)(arg);
2584   ThreadState *thr = cur_thread();
2585   if (!thr)
2586     return res;
2587   DTLS::DTV *dtv = DTLS_on_tls_get_addr(arg, res, thr->tls_addr,
2588                                         thr->tls_addr + thr->tls_size);
2589   if (!dtv)
2590     return res;
2591   // New DTLS block has been allocated.
2592   MemoryResetRange(thr, 0, dtv->beg, dtv->size);
2593   return res;
2594 }
2595 #endif
2596 
2597 #if SANITIZER_NETBSD
TSAN_INTERCEPTOR(void,_lwp_exit)2598 TSAN_INTERCEPTOR(void, _lwp_exit) {
2599   SCOPED_TSAN_INTERCEPTOR(_lwp_exit);
2600   DestroyThreadState();
2601   REAL(_lwp_exit)();
2602 }
2603 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT TSAN_INTERCEPT(_lwp_exit)
2604 #else
2605 #define TSAN_MAYBE_INTERCEPT__LWP_EXIT
2606 #endif
2607 
2608 #if SANITIZER_FREEBSD
TSAN_INTERCEPTOR(void,thr_exit,tid_t * state)2609 TSAN_INTERCEPTOR(void, thr_exit, tid_t *state) {
2610   SCOPED_TSAN_INTERCEPTOR(thr_exit, state);
2611   DestroyThreadState();
2612   REAL(thr_exit(state));
2613 }
2614 #define TSAN_MAYBE_INTERCEPT_THR_EXIT TSAN_INTERCEPT(thr_exit)
2615 #else
2616 #define TSAN_MAYBE_INTERCEPT_THR_EXIT
2617 #endif
2618 
2619 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_init, void *c, void *a)
2620 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_signal, void *c)
2621 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_broadcast, void *c)
2622 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_wait, void *c, void *m)
2623 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, cond_destroy, void *c)
2624 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_init, void *m, void *a)
2625 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_destroy, void *m)
2626 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, mutex_trylock, void *m)
2627 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_init, void *m, void *a)
2628 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_destroy, void *m)
2629 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_rdlock, void *m)
2630 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_tryrdlock, void *m)
2631 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_wrlock, void *m)
2632 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_trywrlock, void *m)
2633 TSAN_INTERCEPTOR_NETBSD_ALIAS(int, rwlock_unlock, void *m)
2634 TSAN_INTERCEPTOR_NETBSD_ALIAS_THR(int, once, void *o, void (*f)())
2635 TSAN_INTERCEPTOR_NETBSD_ALIAS_THR2(int, sigsetmask, sigmask, int a, void *b,
2636   void *c)
2637 
2638 namespace __tsan {
2639 
finalize(void * arg)2640 static void finalize(void *arg) {
2641   ThreadState *thr = cur_thread();
2642   int status = Finalize(thr);
2643   // Make sure the output is not lost.
2644   FlushStreams();
2645   if (status)
2646     Die();
2647 }
2648 
2649 #if !SANITIZER_MAC && !SANITIZER_ANDROID
unreachable()2650 static void unreachable() {
2651   Report("FATAL: ThreadSanitizer: unreachable called\n");
2652   Die();
2653 }
2654 #endif
2655 
2656 // Define default implementation since interception of libdispatch  is optional.
InitializeLibdispatchInterceptors()2657 SANITIZER_WEAK_ATTRIBUTE void InitializeLibdispatchInterceptors() {}
2658 
InitializeInterceptors()2659 void InitializeInterceptors() {
2660 #if !SANITIZER_MAC
2661   // We need to setup it early, because functions like dlsym() can call it.
2662   REAL(memset) = internal_memset;
2663   REAL(memcpy) = internal_memcpy;
2664 #endif
2665 
2666   // Instruct libc malloc to consume less memory.
2667 #if SANITIZER_GLIBC
2668   mallopt(1, 0);  // M_MXFAST
2669   mallopt(-3, 32*1024);  // M_MMAP_THRESHOLD
2670 #endif
2671 
2672   new(interceptor_ctx()) InterceptorContext();
2673 
2674   InitializeCommonInterceptors();
2675   InitializeSignalInterceptors();
2676   InitializeLibdispatchInterceptors();
2677 
2678 #if !SANITIZER_MAC
2679   // We can not use TSAN_INTERCEPT to get setjmp addr,
2680   // because it does &setjmp and setjmp is not present in some versions of libc.
2681   using __interception::InterceptFunction;
2682   InterceptFunction(TSAN_STRING_SETJMP, (uptr*)&REAL(setjmp_symname), 0, 0);
2683   InterceptFunction("_setjmp", (uptr*)&REAL(_setjmp), 0, 0);
2684   InterceptFunction(TSAN_STRING_SIGSETJMP, (uptr*)&REAL(sigsetjmp_symname), 0,
2685                     0);
2686 #if !SANITIZER_NETBSD
2687   InterceptFunction("__sigsetjmp", (uptr*)&REAL(__sigsetjmp), 0, 0);
2688 #endif
2689 #endif
2690 
2691   TSAN_INTERCEPT(longjmp_symname);
2692   TSAN_INTERCEPT(siglongjmp_symname);
2693 #if SANITIZER_NETBSD
2694   TSAN_INTERCEPT(_longjmp);
2695 #endif
2696 
2697   TSAN_INTERCEPT(malloc);
2698   TSAN_INTERCEPT(__libc_memalign);
2699   TSAN_INTERCEPT(calloc);
2700   TSAN_INTERCEPT(realloc);
2701   TSAN_INTERCEPT(reallocarray);
2702   TSAN_INTERCEPT(free);
2703   TSAN_INTERCEPT(cfree);
2704   TSAN_INTERCEPT(munmap);
2705   TSAN_MAYBE_INTERCEPT_MEMALIGN;
2706   TSAN_INTERCEPT(valloc);
2707   TSAN_MAYBE_INTERCEPT_PVALLOC;
2708   TSAN_INTERCEPT(posix_memalign);
2709 
2710   TSAN_INTERCEPT(strcpy);
2711   TSAN_INTERCEPT(strncpy);
2712   TSAN_INTERCEPT(strdup);
2713 
2714   TSAN_INTERCEPT(pthread_create);
2715   TSAN_INTERCEPT(pthread_join);
2716   TSAN_INTERCEPT(pthread_detach);
2717   TSAN_INTERCEPT(pthread_exit);
2718   #if SANITIZER_LINUX
2719   TSAN_INTERCEPT(pthread_tryjoin_np);
2720   TSAN_INTERCEPT(pthread_timedjoin_np);
2721   #endif
2722 
2723   TSAN_INTERCEPT_VER(pthread_cond_init, PTHREAD_ABI_BASE);
2724   TSAN_INTERCEPT_VER(pthread_cond_signal, PTHREAD_ABI_BASE);
2725   TSAN_INTERCEPT_VER(pthread_cond_broadcast, PTHREAD_ABI_BASE);
2726   TSAN_INTERCEPT_VER(pthread_cond_wait, PTHREAD_ABI_BASE);
2727   TSAN_INTERCEPT_VER(pthread_cond_timedwait, PTHREAD_ABI_BASE);
2728   TSAN_INTERCEPT_VER(pthread_cond_destroy, PTHREAD_ABI_BASE);
2729 
2730   TSAN_MAYBE_PTHREAD_COND_CLOCKWAIT;
2731 
2732   TSAN_INTERCEPT(pthread_mutex_init);
2733   TSAN_INTERCEPT(pthread_mutex_destroy);
2734   TSAN_INTERCEPT(pthread_mutex_trylock);
2735   TSAN_INTERCEPT(pthread_mutex_timedlock);
2736 
2737   TSAN_INTERCEPT(pthread_spin_init);
2738   TSAN_INTERCEPT(pthread_spin_destroy);
2739   TSAN_INTERCEPT(pthread_spin_lock);
2740   TSAN_INTERCEPT(pthread_spin_trylock);
2741   TSAN_INTERCEPT(pthread_spin_unlock);
2742 
2743   TSAN_INTERCEPT(pthread_rwlock_init);
2744   TSAN_INTERCEPT(pthread_rwlock_destroy);
2745   TSAN_INTERCEPT(pthread_rwlock_rdlock);
2746   TSAN_INTERCEPT(pthread_rwlock_tryrdlock);
2747   TSAN_INTERCEPT(pthread_rwlock_timedrdlock);
2748   TSAN_INTERCEPT(pthread_rwlock_wrlock);
2749   TSAN_INTERCEPT(pthread_rwlock_trywrlock);
2750   TSAN_INTERCEPT(pthread_rwlock_timedwrlock);
2751   TSAN_INTERCEPT(pthread_rwlock_unlock);
2752 
2753   TSAN_INTERCEPT(pthread_barrier_init);
2754   TSAN_INTERCEPT(pthread_barrier_destroy);
2755   TSAN_INTERCEPT(pthread_barrier_wait);
2756 
2757   TSAN_INTERCEPT(pthread_once);
2758 
2759   TSAN_INTERCEPT(fstat);
2760   TSAN_MAYBE_INTERCEPT___FXSTAT;
2761   TSAN_MAYBE_INTERCEPT_FSTAT64;
2762   TSAN_MAYBE_INTERCEPT___FXSTAT64;
2763   TSAN_INTERCEPT(open);
2764   TSAN_MAYBE_INTERCEPT_OPEN64;
2765   TSAN_INTERCEPT(creat);
2766   TSAN_MAYBE_INTERCEPT_CREAT64;
2767   TSAN_INTERCEPT(dup);
2768   TSAN_INTERCEPT(dup2);
2769   TSAN_INTERCEPT(dup3);
2770   TSAN_MAYBE_INTERCEPT_EVENTFD;
2771   TSAN_MAYBE_INTERCEPT_SIGNALFD;
2772   TSAN_MAYBE_INTERCEPT_INOTIFY_INIT;
2773   TSAN_MAYBE_INTERCEPT_INOTIFY_INIT1;
2774   TSAN_INTERCEPT(socket);
2775   TSAN_INTERCEPT(socketpair);
2776   TSAN_INTERCEPT(connect);
2777   TSAN_INTERCEPT(bind);
2778   TSAN_INTERCEPT(listen);
2779   TSAN_MAYBE_INTERCEPT_EPOLL;
2780   TSAN_INTERCEPT(close);
2781   TSAN_MAYBE_INTERCEPT___CLOSE;
2782   TSAN_MAYBE_INTERCEPT___RES_ICLOSE;
2783   TSAN_INTERCEPT(pipe);
2784   TSAN_INTERCEPT(pipe2);
2785 
2786   TSAN_INTERCEPT(unlink);
2787   TSAN_INTERCEPT(tmpfile);
2788   TSAN_MAYBE_INTERCEPT_TMPFILE64;
2789   TSAN_INTERCEPT(abort);
2790   TSAN_INTERCEPT(rmdir);
2791   TSAN_INTERCEPT(closedir);
2792 
2793   TSAN_INTERCEPT(sigsuspend);
2794   TSAN_INTERCEPT(sigblock);
2795   TSAN_INTERCEPT(sigsetmask);
2796   TSAN_INTERCEPT(pthread_sigmask);
2797   TSAN_INTERCEPT(raise);
2798   TSAN_INTERCEPT(kill);
2799   TSAN_INTERCEPT(pthread_kill);
2800   TSAN_INTERCEPT(sleep);
2801   TSAN_INTERCEPT(usleep);
2802   TSAN_INTERCEPT(nanosleep);
2803   TSAN_INTERCEPT(pause);
2804   TSAN_INTERCEPT(gettimeofday);
2805   TSAN_INTERCEPT(getaddrinfo);
2806 
2807   TSAN_INTERCEPT(fork);
2808   TSAN_INTERCEPT(vfork);
2809 #if !SANITIZER_ANDROID
2810   TSAN_INTERCEPT(dl_iterate_phdr);
2811 #endif
2812   TSAN_MAYBE_INTERCEPT_ON_EXIT;
2813   TSAN_INTERCEPT(__cxa_atexit);
2814   TSAN_INTERCEPT(_exit);
2815 
2816 #ifdef NEED_TLS_GET_ADDR
2817   TSAN_INTERCEPT(__tls_get_addr);
2818 #endif
2819 
2820   TSAN_MAYBE_INTERCEPT__LWP_EXIT;
2821   TSAN_MAYBE_INTERCEPT_THR_EXIT;
2822 
2823 #if !SANITIZER_MAC && !SANITIZER_ANDROID
2824   // Need to setup it, because interceptors check that the function is resolved.
2825   // But atexit is emitted directly into the module, so can't be resolved.
2826   REAL(atexit) = (int(*)(void(*)()))unreachable;
2827 #endif
2828 
2829   if (REAL(__cxa_atexit)(&finalize, 0, 0)) {
2830     Printf("ThreadSanitizer: failed to setup atexit callback\n");
2831     Die();
2832   }
2833 
2834 #if !SANITIZER_MAC && !SANITIZER_NETBSD && !SANITIZER_FREEBSD
2835   if (pthread_key_create(&interceptor_ctx()->finalize_key, &thread_finalize)) {
2836     Printf("ThreadSanitizer: failed to create thread key\n");
2837     Die();
2838   }
2839 #endif
2840 
2841   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_init);
2842   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_signal);
2843   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_broadcast);
2844   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_wait);
2845   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(cond_destroy);
2846   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_init);
2847   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_destroy);
2848   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(mutex_trylock);
2849   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_init);
2850   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_destroy);
2851   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_rdlock);
2852   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_tryrdlock);
2853   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_wrlock);
2854   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_trywrlock);
2855   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS(rwlock_unlock);
2856   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(once);
2857   TSAN_MAYBE_INTERCEPT_NETBSD_ALIAS_THR(sigsetmask);
2858 
2859   FdInit();
2860 }
2861 
2862 }  // namespace __tsan
2863 
2864 // Invisible barrier for tests.
2865 // There were several unsuccessful iterations for this functionality:
2866 // 1. Initially it was implemented in user code using
2867 //    REAL(pthread_barrier_wait). But pthread_barrier_wait is not supported on
2868 //    MacOS. Futexes are linux-specific for this matter.
2869 // 2. Then we switched to atomics+usleep(10). But usleep produced parasitic
2870 //    "as-if synchronized via sleep" messages in reports which failed some
2871 //    output tests.
2872 // 3. Then we switched to atomics+sched_yield. But this produced tons of tsan-
2873 //    visible events, which lead to "failed to restore stack trace" failures.
2874 // Note that no_sanitize_thread attribute does not turn off atomic interception
2875 // so attaching it to the function defined in user code does not help.
2876 // That's why we now have what we have.
2877 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
__tsan_testonly_barrier_init(u64 * barrier,u32 count)2878 void __tsan_testonly_barrier_init(u64 *barrier, u32 count) {
2879   if (count >= (1 << 8)) {
2880       Printf("barrier_init: count is too large (%d)\n", count);
2881       Die();
2882   }
2883   // 8 lsb is thread count, the remaining are count of entered threads.
2884   *barrier = count;
2885 }
2886 
2887 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
__tsan_testonly_barrier_wait(u64 * barrier)2888 void __tsan_testonly_barrier_wait(u64 *barrier) {
2889   unsigned old = __atomic_fetch_add(barrier, 1 << 8, __ATOMIC_RELAXED);
2890   unsigned old_epoch = (old >> 8) / (old & 0xff);
2891   for (;;) {
2892     unsigned cur = __atomic_load_n(barrier, __ATOMIC_RELAXED);
2893     unsigned cur_epoch = (cur >> 8) / (cur & 0xff);
2894     if (cur_epoch != old_epoch)
2895       return;
2896     internal_sched_yield();
2897   }
2898 }
2899