1 //===-- tsan_interface_atomic.cc ------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of ThreadSanitizer (TSan), a race detector.
11 //
12 //===----------------------------------------------------------------------===//
13
14 // ThreadSanitizer atomic operations are based on C++11/C1x standards.
15 // For background see C++11 standard. A slightly older, publicly
16 // available draft of the standard (not entirely up-to-date, but close enough
17 // for casual browsing) is available here:
18 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf
19 // The following page contains more background information:
20 // http://www.hpl.hp.com/personal/Hans_Boehm/c++mm/
21
22 #include "sanitizer_common/sanitizer_placement_new.h"
23 #include "sanitizer_common/sanitizer_stacktrace.h"
24 #include "sanitizer_common/sanitizer_mutex.h"
25 #include "tsan_flags.h"
26 #include "tsan_interface.h"
27 #include "tsan_rtl.h"
28
29 using namespace __tsan; // NOLINT
30
31 #if !defined(SANITIZER_GO) && __TSAN_HAS_INT128
32 // Protects emulation of 128-bit atomic operations.
33 static StaticSpinMutex mutex128;
34 #endif
35
IsLoadOrder(morder mo)36 static bool IsLoadOrder(morder mo) {
37 return mo == mo_relaxed || mo == mo_consume
38 || mo == mo_acquire || mo == mo_seq_cst;
39 }
40
IsStoreOrder(morder mo)41 static bool IsStoreOrder(morder mo) {
42 return mo == mo_relaxed || mo == mo_release || mo == mo_seq_cst;
43 }
44
IsReleaseOrder(morder mo)45 static bool IsReleaseOrder(morder mo) {
46 return mo == mo_release || mo == mo_acq_rel || mo == mo_seq_cst;
47 }
48
IsAcquireOrder(morder mo)49 static bool IsAcquireOrder(morder mo) {
50 return mo == mo_consume || mo == mo_acquire
51 || mo == mo_acq_rel || mo == mo_seq_cst;
52 }
53
IsAcqRelOrder(morder mo)54 static bool IsAcqRelOrder(morder mo) {
55 return mo == mo_acq_rel || mo == mo_seq_cst;
56 }
57
func_xchg(volatile T * v,T op)58 template<typename T> T func_xchg(volatile T *v, T op) {
59 T res = __sync_lock_test_and_set(v, op);
60 // __sync_lock_test_and_set does not contain full barrier.
61 __sync_synchronize();
62 return res;
63 }
64
func_add(volatile T * v,T op)65 template<typename T> T func_add(volatile T *v, T op) {
66 return __sync_fetch_and_add(v, op);
67 }
68
func_sub(volatile T * v,T op)69 template<typename T> T func_sub(volatile T *v, T op) {
70 return __sync_fetch_and_sub(v, op);
71 }
72
func_and(volatile T * v,T op)73 template<typename T> T func_and(volatile T *v, T op) {
74 return __sync_fetch_and_and(v, op);
75 }
76
func_or(volatile T * v,T op)77 template<typename T> T func_or(volatile T *v, T op) {
78 return __sync_fetch_and_or(v, op);
79 }
80
func_xor(volatile T * v,T op)81 template<typename T> T func_xor(volatile T *v, T op) {
82 return __sync_fetch_and_xor(v, op);
83 }
84
func_nand(volatile T * v,T op)85 template<typename T> T func_nand(volatile T *v, T op) {
86 // clang does not support __sync_fetch_and_nand.
87 T cmp = *v;
88 for (;;) {
89 T newv = ~(cmp & op);
90 T cur = __sync_val_compare_and_swap(v, cmp, newv);
91 if (cmp == cur)
92 return cmp;
93 cmp = cur;
94 }
95 }
96
func_cas(volatile T * v,T cmp,T xch)97 template<typename T> T func_cas(volatile T *v, T cmp, T xch) {
98 return __sync_val_compare_and_swap(v, cmp, xch);
99 }
100
101 // clang does not support 128-bit atomic ops.
102 // Atomic ops are executed under tsan internal mutex,
103 // here we assume that the atomic variables are not accessed
104 // from non-instrumented code.
105 #if !defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16) && !defined(SANITIZER_GO) \
106 && __TSAN_HAS_INT128
func_xchg(volatile a128 * v,a128 op)107 a128 func_xchg(volatile a128 *v, a128 op) {
108 SpinMutexLock lock(&mutex128);
109 a128 cmp = *v;
110 *v = op;
111 return cmp;
112 }
113
func_add(volatile a128 * v,a128 op)114 a128 func_add(volatile a128 *v, a128 op) {
115 SpinMutexLock lock(&mutex128);
116 a128 cmp = *v;
117 *v = cmp + op;
118 return cmp;
119 }
120
func_sub(volatile a128 * v,a128 op)121 a128 func_sub(volatile a128 *v, a128 op) {
122 SpinMutexLock lock(&mutex128);
123 a128 cmp = *v;
124 *v = cmp - op;
125 return cmp;
126 }
127
func_and(volatile a128 * v,a128 op)128 a128 func_and(volatile a128 *v, a128 op) {
129 SpinMutexLock lock(&mutex128);
130 a128 cmp = *v;
131 *v = cmp & op;
132 return cmp;
133 }
134
func_or(volatile a128 * v,a128 op)135 a128 func_or(volatile a128 *v, a128 op) {
136 SpinMutexLock lock(&mutex128);
137 a128 cmp = *v;
138 *v = cmp | op;
139 return cmp;
140 }
141
func_xor(volatile a128 * v,a128 op)142 a128 func_xor(volatile a128 *v, a128 op) {
143 SpinMutexLock lock(&mutex128);
144 a128 cmp = *v;
145 *v = cmp ^ op;
146 return cmp;
147 }
148
func_nand(volatile a128 * v,a128 op)149 a128 func_nand(volatile a128 *v, a128 op) {
150 SpinMutexLock lock(&mutex128);
151 a128 cmp = *v;
152 *v = ~(cmp & op);
153 return cmp;
154 }
155
func_cas(volatile a128 * v,a128 cmp,a128 xch)156 a128 func_cas(volatile a128 *v, a128 cmp, a128 xch) {
157 SpinMutexLock lock(&mutex128);
158 a128 cur = *v;
159 if (cur == cmp)
160 *v = xch;
161 return cur;
162 }
163 #endif
164
165 template<typename T>
SizeLog()166 static int SizeLog() {
167 if (sizeof(T) <= 1)
168 return kSizeLog1;
169 else if (sizeof(T) <= 2)
170 return kSizeLog2;
171 else if (sizeof(T) <= 4)
172 return kSizeLog4;
173 else
174 return kSizeLog8;
175 // For 16-byte atomics we also use 8-byte memory access,
176 // this leads to false negatives only in very obscure cases.
177 }
178
179 #ifndef SANITIZER_GO
to_atomic(const volatile a8 * a)180 static atomic_uint8_t *to_atomic(const volatile a8 *a) {
181 return reinterpret_cast<atomic_uint8_t *>(const_cast<a8 *>(a));
182 }
183
to_atomic(const volatile a16 * a)184 static atomic_uint16_t *to_atomic(const volatile a16 *a) {
185 return reinterpret_cast<atomic_uint16_t *>(const_cast<a16 *>(a));
186 }
187 #endif
188
to_atomic(const volatile a32 * a)189 static atomic_uint32_t *to_atomic(const volatile a32 *a) {
190 return reinterpret_cast<atomic_uint32_t *>(const_cast<a32 *>(a));
191 }
192
to_atomic(const volatile a64 * a)193 static atomic_uint64_t *to_atomic(const volatile a64 *a) {
194 return reinterpret_cast<atomic_uint64_t *>(const_cast<a64 *>(a));
195 }
196
to_mo(morder mo)197 static memory_order to_mo(morder mo) {
198 switch (mo) {
199 case mo_relaxed: return memory_order_relaxed;
200 case mo_consume: return memory_order_consume;
201 case mo_acquire: return memory_order_acquire;
202 case mo_release: return memory_order_release;
203 case mo_acq_rel: return memory_order_acq_rel;
204 case mo_seq_cst: return memory_order_seq_cst;
205 }
206 CHECK(0);
207 return memory_order_seq_cst;
208 }
209
210 template<typename T>
NoTsanAtomicLoad(const volatile T * a,morder mo)211 static T NoTsanAtomicLoad(const volatile T *a, morder mo) {
212 return atomic_load(to_atomic(a), to_mo(mo));
213 }
214
215 #if __TSAN_HAS_INT128 && !defined(SANITIZER_GO)
NoTsanAtomicLoad(const volatile a128 * a,morder mo)216 static a128 NoTsanAtomicLoad(const volatile a128 *a, morder mo) {
217 SpinMutexLock lock(&mutex128);
218 return *a;
219 }
220 #endif
221
222 template<typename T>
AtomicLoad(ThreadState * thr,uptr pc,const volatile T * a,morder mo)223 static T AtomicLoad(ThreadState *thr, uptr pc, const volatile T *a,
224 morder mo) {
225 CHECK(IsLoadOrder(mo));
226 // This fast-path is critical for performance.
227 // Assume the access is atomic.
228 if (!IsAcquireOrder(mo)) {
229 MemoryReadAtomic(thr, pc, (uptr)a, SizeLog<T>());
230 return NoTsanAtomicLoad(a, mo);
231 }
232 SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, (uptr)a, false);
233 AcquireImpl(thr, pc, &s->clock);
234 T v = NoTsanAtomicLoad(a, mo);
235 s->mtx.ReadUnlock();
236 MemoryReadAtomic(thr, pc, (uptr)a, SizeLog<T>());
237 return v;
238 }
239
240 template<typename T>
NoTsanAtomicStore(volatile T * a,T v,morder mo)241 static void NoTsanAtomicStore(volatile T *a, T v, morder mo) {
242 atomic_store(to_atomic(a), v, to_mo(mo));
243 }
244
245 #if __TSAN_HAS_INT128 && !defined(SANITIZER_GO)
NoTsanAtomicStore(volatile a128 * a,a128 v,morder mo)246 static void NoTsanAtomicStore(volatile a128 *a, a128 v, morder mo) {
247 SpinMutexLock lock(&mutex128);
248 *a = v;
249 }
250 #endif
251
252 template<typename T>
AtomicStore(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)253 static void AtomicStore(ThreadState *thr, uptr pc, volatile T *a, T v,
254 morder mo) {
255 CHECK(IsStoreOrder(mo));
256 MemoryWriteAtomic(thr, pc, (uptr)a, SizeLog<T>());
257 // This fast-path is critical for performance.
258 // Assume the access is atomic.
259 // Strictly saying even relaxed store cuts off release sequence,
260 // so must reset the clock.
261 if (!IsReleaseOrder(mo)) {
262 NoTsanAtomicStore(a, v, mo);
263 return;
264 }
265 __sync_synchronize();
266 SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, (uptr)a, true);
267 thr->fast_state.IncrementEpoch();
268 // Can't increment epoch w/o writing to the trace as well.
269 TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
270 ReleaseImpl(thr, pc, &s->clock);
271 NoTsanAtomicStore(a, v, mo);
272 s->mtx.Unlock();
273 }
274
275 template<typename T, T (*F)(volatile T *v, T op)>
AtomicRMW(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)276 static T AtomicRMW(ThreadState *thr, uptr pc, volatile T *a, T v, morder mo) {
277 MemoryWriteAtomic(thr, pc, (uptr)a, SizeLog<T>());
278 SyncVar *s = 0;
279 if (mo != mo_relaxed) {
280 s = ctx->metamap.GetOrCreateAndLock(thr, pc, (uptr)a, true);
281 thr->fast_state.IncrementEpoch();
282 // Can't increment epoch w/o writing to the trace as well.
283 TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
284 if (IsAcqRelOrder(mo))
285 AcquireReleaseImpl(thr, pc, &s->clock);
286 else if (IsReleaseOrder(mo))
287 ReleaseImpl(thr, pc, &s->clock);
288 else if (IsAcquireOrder(mo))
289 AcquireImpl(thr, pc, &s->clock);
290 }
291 v = F(a, v);
292 if (s)
293 s->mtx.Unlock();
294 return v;
295 }
296
297 template<typename T>
NoTsanAtomicExchange(volatile T * a,T v,morder mo)298 static T NoTsanAtomicExchange(volatile T *a, T v, morder mo) {
299 return func_xchg(a, v);
300 }
301
302 template<typename T>
NoTsanAtomicFetchAdd(volatile T * a,T v,morder mo)303 static T NoTsanAtomicFetchAdd(volatile T *a, T v, morder mo) {
304 return func_add(a, v);
305 }
306
307 template<typename T>
NoTsanAtomicFetchSub(volatile T * a,T v,morder mo)308 static T NoTsanAtomicFetchSub(volatile T *a, T v, morder mo) {
309 return func_sub(a, v);
310 }
311
312 template<typename T>
NoTsanAtomicFetchAnd(volatile T * a,T v,morder mo)313 static T NoTsanAtomicFetchAnd(volatile T *a, T v, morder mo) {
314 return func_and(a, v);
315 }
316
317 template<typename T>
NoTsanAtomicFetchOr(volatile T * a,T v,morder mo)318 static T NoTsanAtomicFetchOr(volatile T *a, T v, morder mo) {
319 return func_or(a, v);
320 }
321
322 template<typename T>
NoTsanAtomicFetchXor(volatile T * a,T v,morder mo)323 static T NoTsanAtomicFetchXor(volatile T *a, T v, morder mo) {
324 return func_xor(a, v);
325 }
326
327 template<typename T>
NoTsanAtomicFetchNand(volatile T * a,T v,morder mo)328 static T NoTsanAtomicFetchNand(volatile T *a, T v, morder mo) {
329 return func_nand(a, v);
330 }
331
332 template<typename T>
AtomicExchange(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)333 static T AtomicExchange(ThreadState *thr, uptr pc, volatile T *a, T v,
334 morder mo) {
335 return AtomicRMW<T, func_xchg>(thr, pc, a, v, mo);
336 }
337
338 template<typename T>
AtomicFetchAdd(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)339 static T AtomicFetchAdd(ThreadState *thr, uptr pc, volatile T *a, T v,
340 morder mo) {
341 return AtomicRMW<T, func_add>(thr, pc, a, v, mo);
342 }
343
344 template<typename T>
AtomicFetchSub(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)345 static T AtomicFetchSub(ThreadState *thr, uptr pc, volatile T *a, T v,
346 morder mo) {
347 return AtomicRMW<T, func_sub>(thr, pc, a, v, mo);
348 }
349
350 template<typename T>
AtomicFetchAnd(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)351 static T AtomicFetchAnd(ThreadState *thr, uptr pc, volatile T *a, T v,
352 morder mo) {
353 return AtomicRMW<T, func_and>(thr, pc, a, v, mo);
354 }
355
356 template<typename T>
AtomicFetchOr(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)357 static T AtomicFetchOr(ThreadState *thr, uptr pc, volatile T *a, T v,
358 morder mo) {
359 return AtomicRMW<T, func_or>(thr, pc, a, v, mo);
360 }
361
362 template<typename T>
AtomicFetchXor(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)363 static T AtomicFetchXor(ThreadState *thr, uptr pc, volatile T *a, T v,
364 morder mo) {
365 return AtomicRMW<T, func_xor>(thr, pc, a, v, mo);
366 }
367
368 template<typename T>
AtomicFetchNand(ThreadState * thr,uptr pc,volatile T * a,T v,morder mo)369 static T AtomicFetchNand(ThreadState *thr, uptr pc, volatile T *a, T v,
370 morder mo) {
371 return AtomicRMW<T, func_nand>(thr, pc, a, v, mo);
372 }
373
374 template<typename T>
NoTsanAtomicCAS(volatile T * a,T * c,T v,morder mo,morder fmo)375 static bool NoTsanAtomicCAS(volatile T *a, T *c, T v, morder mo, morder fmo) {
376 return atomic_compare_exchange_strong(to_atomic(a), c, v, to_mo(mo));
377 }
378
379 #if __TSAN_HAS_INT128
NoTsanAtomicCAS(volatile a128 * a,a128 * c,a128 v,morder mo,morder fmo)380 static bool NoTsanAtomicCAS(volatile a128 *a, a128 *c, a128 v,
381 morder mo, morder fmo) {
382 a128 old = *c;
383 a128 cur = func_cas(a, old, v);
384 if (cur == old)
385 return true;
386 *c = cur;
387 return false;
388 }
389 #endif
390
391 template<typename T>
NoTsanAtomicCAS(volatile T * a,T c,T v,morder mo,morder fmo)392 static T NoTsanAtomicCAS(volatile T *a, T c, T v, morder mo, morder fmo) {
393 NoTsanAtomicCAS(a, &c, v, mo, fmo);
394 return c;
395 }
396
397 template<typename T>
AtomicCAS(ThreadState * thr,uptr pc,volatile T * a,T * c,T v,morder mo,morder fmo)398 static bool AtomicCAS(ThreadState *thr, uptr pc,
399 volatile T *a, T *c, T v, morder mo, morder fmo) {
400 (void)fmo; // Unused because llvm does not pass it yet.
401 MemoryWriteAtomic(thr, pc, (uptr)a, SizeLog<T>());
402 SyncVar *s = 0;
403 bool write_lock = mo != mo_acquire && mo != mo_consume;
404 if (mo != mo_relaxed) {
405 s = ctx->metamap.GetOrCreateAndLock(thr, pc, (uptr)a, write_lock);
406 thr->fast_state.IncrementEpoch();
407 // Can't increment epoch w/o writing to the trace as well.
408 TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
409 if (IsAcqRelOrder(mo))
410 AcquireReleaseImpl(thr, pc, &s->clock);
411 else if (IsReleaseOrder(mo))
412 ReleaseImpl(thr, pc, &s->clock);
413 else if (IsAcquireOrder(mo))
414 AcquireImpl(thr, pc, &s->clock);
415 }
416 T cc = *c;
417 T pr = func_cas(a, cc, v);
418 if (s) {
419 if (write_lock)
420 s->mtx.Unlock();
421 else
422 s->mtx.ReadUnlock();
423 }
424 if (pr == cc)
425 return true;
426 *c = pr;
427 return false;
428 }
429
430 template<typename T>
AtomicCAS(ThreadState * thr,uptr pc,volatile T * a,T c,T v,morder mo,morder fmo)431 static T AtomicCAS(ThreadState *thr, uptr pc,
432 volatile T *a, T c, T v, morder mo, morder fmo) {
433 AtomicCAS(thr, pc, a, &c, v, mo, fmo);
434 return c;
435 }
436
437 #ifndef SANITIZER_GO
NoTsanAtomicFence(morder mo)438 static void NoTsanAtomicFence(morder mo) {
439 __sync_synchronize();
440 }
441
AtomicFence(ThreadState * thr,uptr pc,morder mo)442 static void AtomicFence(ThreadState *thr, uptr pc, morder mo) {
443 // FIXME(dvyukov): not implemented.
444 __sync_synchronize();
445 }
446 #endif
447
448 // Interface functions follow.
449 #ifndef SANITIZER_GO
450
451 // C/C++
452
453 #define SCOPED_ATOMIC(func, ...) \
454 const uptr callpc = (uptr)__builtin_return_address(0); \
455 uptr pc = StackTrace::GetCurrentPc(); \
456 mo = flags()->force_seq_cst_atomics ? (morder)mo_seq_cst : mo; \
457 ThreadState *const thr = cur_thread(); \
458 if (thr->ignore_interceptors) \
459 return NoTsanAtomic##func(__VA_ARGS__); \
460 AtomicStatInc(thr, sizeof(*a), mo, StatAtomic##func); \
461 ScopedAtomic sa(thr, callpc, a, mo, __func__); \
462 return Atomic##func(thr, pc, __VA_ARGS__); \
463 /**/
464
465 class ScopedAtomic {
466 public:
ScopedAtomic(ThreadState * thr,uptr pc,const volatile void * a,morder mo,const char * func)467 ScopedAtomic(ThreadState *thr, uptr pc, const volatile void *a,
468 morder mo, const char *func)
469 : thr_(thr) {
470 FuncEntry(thr_, pc);
471 DPrintf("#%d: %s(%p, %d)\n", thr_->tid, func, a, mo);
472 }
~ScopedAtomic()473 ~ScopedAtomic() {
474 ProcessPendingSignals(thr_);
475 FuncExit(thr_);
476 }
477 private:
478 ThreadState *thr_;
479 };
480
AtomicStatInc(ThreadState * thr,uptr size,morder mo,StatType t)481 static void AtomicStatInc(ThreadState *thr, uptr size, morder mo, StatType t) {
482 StatInc(thr, StatAtomic);
483 StatInc(thr, t);
484 StatInc(thr, size == 1 ? StatAtomic1
485 : size == 2 ? StatAtomic2
486 : size == 4 ? StatAtomic4
487 : size == 8 ? StatAtomic8
488 : StatAtomic16);
489 StatInc(thr, mo == mo_relaxed ? StatAtomicRelaxed
490 : mo == mo_consume ? StatAtomicConsume
491 : mo == mo_acquire ? StatAtomicAcquire
492 : mo == mo_release ? StatAtomicRelease
493 : mo == mo_acq_rel ? StatAtomicAcq_Rel
494 : StatAtomicSeq_Cst);
495 }
496
497 extern "C" {
498 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_load(const volatile a8 * a,morder mo)499 a8 __tsan_atomic8_load(const volatile a8 *a, morder mo) {
500 SCOPED_ATOMIC(Load, a, mo);
501 }
502
503 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_load(const volatile a16 * a,morder mo)504 a16 __tsan_atomic16_load(const volatile a16 *a, morder mo) {
505 SCOPED_ATOMIC(Load, a, mo);
506 }
507
508 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_load(const volatile a32 * a,morder mo)509 a32 __tsan_atomic32_load(const volatile a32 *a, morder mo) {
510 SCOPED_ATOMIC(Load, a, mo);
511 }
512
513 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_load(const volatile a64 * a,morder mo)514 a64 __tsan_atomic64_load(const volatile a64 *a, morder mo) {
515 SCOPED_ATOMIC(Load, a, mo);
516 }
517
518 #if __TSAN_HAS_INT128
519 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_load(const volatile a128 * a,morder mo)520 a128 __tsan_atomic128_load(const volatile a128 *a, morder mo) {
521 SCOPED_ATOMIC(Load, a, mo);
522 }
523 #endif
524
525 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_store(volatile a8 * a,a8 v,morder mo)526 void __tsan_atomic8_store(volatile a8 *a, a8 v, morder mo) {
527 SCOPED_ATOMIC(Store, a, v, mo);
528 }
529
530 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_store(volatile a16 * a,a16 v,morder mo)531 void __tsan_atomic16_store(volatile a16 *a, a16 v, morder mo) {
532 SCOPED_ATOMIC(Store, a, v, mo);
533 }
534
535 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_store(volatile a32 * a,a32 v,morder mo)536 void __tsan_atomic32_store(volatile a32 *a, a32 v, morder mo) {
537 SCOPED_ATOMIC(Store, a, v, mo);
538 }
539
540 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_store(volatile a64 * a,a64 v,morder mo)541 void __tsan_atomic64_store(volatile a64 *a, a64 v, morder mo) {
542 SCOPED_ATOMIC(Store, a, v, mo);
543 }
544
545 #if __TSAN_HAS_INT128
546 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_store(volatile a128 * a,a128 v,morder mo)547 void __tsan_atomic128_store(volatile a128 *a, a128 v, morder mo) {
548 SCOPED_ATOMIC(Store, a, v, mo);
549 }
550 #endif
551
552 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_exchange(volatile a8 * a,a8 v,morder mo)553 a8 __tsan_atomic8_exchange(volatile a8 *a, a8 v, morder mo) {
554 SCOPED_ATOMIC(Exchange, a, v, mo);
555 }
556
557 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_exchange(volatile a16 * a,a16 v,morder mo)558 a16 __tsan_atomic16_exchange(volatile a16 *a, a16 v, morder mo) {
559 SCOPED_ATOMIC(Exchange, a, v, mo);
560 }
561
562 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_exchange(volatile a32 * a,a32 v,morder mo)563 a32 __tsan_atomic32_exchange(volatile a32 *a, a32 v, morder mo) {
564 SCOPED_ATOMIC(Exchange, a, v, mo);
565 }
566
567 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_exchange(volatile a64 * a,a64 v,morder mo)568 a64 __tsan_atomic64_exchange(volatile a64 *a, a64 v, morder mo) {
569 SCOPED_ATOMIC(Exchange, a, v, mo);
570 }
571
572 #if __TSAN_HAS_INT128
573 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_exchange(volatile a128 * a,a128 v,morder mo)574 a128 __tsan_atomic128_exchange(volatile a128 *a, a128 v, morder mo) {
575 SCOPED_ATOMIC(Exchange, a, v, mo);
576 }
577 #endif
578
579 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_fetch_add(volatile a8 * a,a8 v,morder mo)580 a8 __tsan_atomic8_fetch_add(volatile a8 *a, a8 v, morder mo) {
581 SCOPED_ATOMIC(FetchAdd, a, v, mo);
582 }
583
584 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_fetch_add(volatile a16 * a,a16 v,morder mo)585 a16 __tsan_atomic16_fetch_add(volatile a16 *a, a16 v, morder mo) {
586 SCOPED_ATOMIC(FetchAdd, a, v, mo);
587 }
588
589 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_fetch_add(volatile a32 * a,a32 v,morder mo)590 a32 __tsan_atomic32_fetch_add(volatile a32 *a, a32 v, morder mo) {
591 SCOPED_ATOMIC(FetchAdd, a, v, mo);
592 }
593
594 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_fetch_add(volatile a64 * a,a64 v,morder mo)595 a64 __tsan_atomic64_fetch_add(volatile a64 *a, a64 v, morder mo) {
596 SCOPED_ATOMIC(FetchAdd, a, v, mo);
597 }
598
599 #if __TSAN_HAS_INT128
600 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_fetch_add(volatile a128 * a,a128 v,morder mo)601 a128 __tsan_atomic128_fetch_add(volatile a128 *a, a128 v, morder mo) {
602 SCOPED_ATOMIC(FetchAdd, a, v, mo);
603 }
604 #endif
605
606 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_fetch_sub(volatile a8 * a,a8 v,morder mo)607 a8 __tsan_atomic8_fetch_sub(volatile a8 *a, a8 v, morder mo) {
608 SCOPED_ATOMIC(FetchSub, a, v, mo);
609 }
610
611 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_fetch_sub(volatile a16 * a,a16 v,morder mo)612 a16 __tsan_atomic16_fetch_sub(volatile a16 *a, a16 v, morder mo) {
613 SCOPED_ATOMIC(FetchSub, a, v, mo);
614 }
615
616 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_fetch_sub(volatile a32 * a,a32 v,morder mo)617 a32 __tsan_atomic32_fetch_sub(volatile a32 *a, a32 v, morder mo) {
618 SCOPED_ATOMIC(FetchSub, a, v, mo);
619 }
620
621 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_fetch_sub(volatile a64 * a,a64 v,morder mo)622 a64 __tsan_atomic64_fetch_sub(volatile a64 *a, a64 v, morder mo) {
623 SCOPED_ATOMIC(FetchSub, a, v, mo);
624 }
625
626 #if __TSAN_HAS_INT128
627 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_fetch_sub(volatile a128 * a,a128 v,morder mo)628 a128 __tsan_atomic128_fetch_sub(volatile a128 *a, a128 v, morder mo) {
629 SCOPED_ATOMIC(FetchSub, a, v, mo);
630 }
631 #endif
632
633 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_fetch_and(volatile a8 * a,a8 v,morder mo)634 a8 __tsan_atomic8_fetch_and(volatile a8 *a, a8 v, morder mo) {
635 SCOPED_ATOMIC(FetchAnd, a, v, mo);
636 }
637
638 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_fetch_and(volatile a16 * a,a16 v,morder mo)639 a16 __tsan_atomic16_fetch_and(volatile a16 *a, a16 v, morder mo) {
640 SCOPED_ATOMIC(FetchAnd, a, v, mo);
641 }
642
643 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_fetch_and(volatile a32 * a,a32 v,morder mo)644 a32 __tsan_atomic32_fetch_and(volatile a32 *a, a32 v, morder mo) {
645 SCOPED_ATOMIC(FetchAnd, a, v, mo);
646 }
647
648 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_fetch_and(volatile a64 * a,a64 v,morder mo)649 a64 __tsan_atomic64_fetch_and(volatile a64 *a, a64 v, morder mo) {
650 SCOPED_ATOMIC(FetchAnd, a, v, mo);
651 }
652
653 #if __TSAN_HAS_INT128
654 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_fetch_and(volatile a128 * a,a128 v,morder mo)655 a128 __tsan_atomic128_fetch_and(volatile a128 *a, a128 v, morder mo) {
656 SCOPED_ATOMIC(FetchAnd, a, v, mo);
657 }
658 #endif
659
660 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_fetch_or(volatile a8 * a,a8 v,morder mo)661 a8 __tsan_atomic8_fetch_or(volatile a8 *a, a8 v, morder mo) {
662 SCOPED_ATOMIC(FetchOr, a, v, mo);
663 }
664
665 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_fetch_or(volatile a16 * a,a16 v,morder mo)666 a16 __tsan_atomic16_fetch_or(volatile a16 *a, a16 v, morder mo) {
667 SCOPED_ATOMIC(FetchOr, a, v, mo);
668 }
669
670 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_fetch_or(volatile a32 * a,a32 v,morder mo)671 a32 __tsan_atomic32_fetch_or(volatile a32 *a, a32 v, morder mo) {
672 SCOPED_ATOMIC(FetchOr, a, v, mo);
673 }
674
675 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_fetch_or(volatile a64 * a,a64 v,morder mo)676 a64 __tsan_atomic64_fetch_or(volatile a64 *a, a64 v, morder mo) {
677 SCOPED_ATOMIC(FetchOr, a, v, mo);
678 }
679
680 #if __TSAN_HAS_INT128
681 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_fetch_or(volatile a128 * a,a128 v,morder mo)682 a128 __tsan_atomic128_fetch_or(volatile a128 *a, a128 v, morder mo) {
683 SCOPED_ATOMIC(FetchOr, a, v, mo);
684 }
685 #endif
686
687 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_fetch_xor(volatile a8 * a,a8 v,morder mo)688 a8 __tsan_atomic8_fetch_xor(volatile a8 *a, a8 v, morder mo) {
689 SCOPED_ATOMIC(FetchXor, a, v, mo);
690 }
691
692 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_fetch_xor(volatile a16 * a,a16 v,morder mo)693 a16 __tsan_atomic16_fetch_xor(volatile a16 *a, a16 v, morder mo) {
694 SCOPED_ATOMIC(FetchXor, a, v, mo);
695 }
696
697 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_fetch_xor(volatile a32 * a,a32 v,morder mo)698 a32 __tsan_atomic32_fetch_xor(volatile a32 *a, a32 v, morder mo) {
699 SCOPED_ATOMIC(FetchXor, a, v, mo);
700 }
701
702 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_fetch_xor(volatile a64 * a,a64 v,morder mo)703 a64 __tsan_atomic64_fetch_xor(volatile a64 *a, a64 v, morder mo) {
704 SCOPED_ATOMIC(FetchXor, a, v, mo);
705 }
706
707 #if __TSAN_HAS_INT128
708 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_fetch_xor(volatile a128 * a,a128 v,morder mo)709 a128 __tsan_atomic128_fetch_xor(volatile a128 *a, a128 v, morder mo) {
710 SCOPED_ATOMIC(FetchXor, a, v, mo);
711 }
712 #endif
713
714 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_fetch_nand(volatile a8 * a,a8 v,morder mo)715 a8 __tsan_atomic8_fetch_nand(volatile a8 *a, a8 v, morder mo) {
716 SCOPED_ATOMIC(FetchNand, a, v, mo);
717 }
718
719 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_fetch_nand(volatile a16 * a,a16 v,morder mo)720 a16 __tsan_atomic16_fetch_nand(volatile a16 *a, a16 v, morder mo) {
721 SCOPED_ATOMIC(FetchNand, a, v, mo);
722 }
723
724 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_fetch_nand(volatile a32 * a,a32 v,morder mo)725 a32 __tsan_atomic32_fetch_nand(volatile a32 *a, a32 v, morder mo) {
726 SCOPED_ATOMIC(FetchNand, a, v, mo);
727 }
728
729 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_fetch_nand(volatile a64 * a,a64 v,morder mo)730 a64 __tsan_atomic64_fetch_nand(volatile a64 *a, a64 v, morder mo) {
731 SCOPED_ATOMIC(FetchNand, a, v, mo);
732 }
733
734 #if __TSAN_HAS_INT128
735 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_fetch_nand(volatile a128 * a,a128 v,morder mo)736 a128 __tsan_atomic128_fetch_nand(volatile a128 *a, a128 v, morder mo) {
737 SCOPED_ATOMIC(FetchNand, a, v, mo);
738 }
739 #endif
740
741 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_compare_exchange_strong(volatile a8 * a,a8 * c,a8 v,morder mo,morder fmo)742 int __tsan_atomic8_compare_exchange_strong(volatile a8 *a, a8 *c, a8 v,
743 morder mo, morder fmo) {
744 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
745 }
746
747 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_compare_exchange_strong(volatile a16 * a,a16 * c,a16 v,morder mo,morder fmo)748 int __tsan_atomic16_compare_exchange_strong(volatile a16 *a, a16 *c, a16 v,
749 morder mo, morder fmo) {
750 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
751 }
752
753 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_compare_exchange_strong(volatile a32 * a,a32 * c,a32 v,morder mo,morder fmo)754 int __tsan_atomic32_compare_exchange_strong(volatile a32 *a, a32 *c, a32 v,
755 morder mo, morder fmo) {
756 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
757 }
758
759 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_compare_exchange_strong(volatile a64 * a,a64 * c,a64 v,morder mo,morder fmo)760 int __tsan_atomic64_compare_exchange_strong(volatile a64 *a, a64 *c, a64 v,
761 morder mo, morder fmo) {
762 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
763 }
764
765 #if __TSAN_HAS_INT128
766 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_compare_exchange_strong(volatile a128 * a,a128 * c,a128 v,morder mo,morder fmo)767 int __tsan_atomic128_compare_exchange_strong(volatile a128 *a, a128 *c, a128 v,
768 morder mo, morder fmo) {
769 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
770 }
771 #endif
772
773 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_compare_exchange_weak(volatile a8 * a,a8 * c,a8 v,morder mo,morder fmo)774 int __tsan_atomic8_compare_exchange_weak(volatile a8 *a, a8 *c, a8 v,
775 morder mo, morder fmo) {
776 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
777 }
778
779 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_compare_exchange_weak(volatile a16 * a,a16 * c,a16 v,morder mo,morder fmo)780 int __tsan_atomic16_compare_exchange_weak(volatile a16 *a, a16 *c, a16 v,
781 morder mo, morder fmo) {
782 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
783 }
784
785 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_compare_exchange_weak(volatile a32 * a,a32 * c,a32 v,morder mo,morder fmo)786 int __tsan_atomic32_compare_exchange_weak(volatile a32 *a, a32 *c, a32 v,
787 morder mo, morder fmo) {
788 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
789 }
790
791 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_compare_exchange_weak(volatile a64 * a,a64 * c,a64 v,morder mo,morder fmo)792 int __tsan_atomic64_compare_exchange_weak(volatile a64 *a, a64 *c, a64 v,
793 morder mo, morder fmo) {
794 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
795 }
796
797 #if __TSAN_HAS_INT128
798 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_compare_exchange_weak(volatile a128 * a,a128 * c,a128 v,morder mo,morder fmo)799 int __tsan_atomic128_compare_exchange_weak(volatile a128 *a, a128 *c, a128 v,
800 morder mo, morder fmo) {
801 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
802 }
803 #endif
804
805 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic8_compare_exchange_val(volatile a8 * a,a8 c,a8 v,morder mo,morder fmo)806 a8 __tsan_atomic8_compare_exchange_val(volatile a8 *a, a8 c, a8 v,
807 morder mo, morder fmo) {
808 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
809 }
810
811 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic16_compare_exchange_val(volatile a16 * a,a16 c,a16 v,morder mo,morder fmo)812 a16 __tsan_atomic16_compare_exchange_val(volatile a16 *a, a16 c, a16 v,
813 morder mo, morder fmo) {
814 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
815 }
816
817 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic32_compare_exchange_val(volatile a32 * a,a32 c,a32 v,morder mo,morder fmo)818 a32 __tsan_atomic32_compare_exchange_val(volatile a32 *a, a32 c, a32 v,
819 morder mo, morder fmo) {
820 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
821 }
822
823 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic64_compare_exchange_val(volatile a64 * a,a64 c,a64 v,morder mo,morder fmo)824 a64 __tsan_atomic64_compare_exchange_val(volatile a64 *a, a64 c, a64 v,
825 morder mo, morder fmo) {
826 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
827 }
828
829 #if __TSAN_HAS_INT128
830 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic128_compare_exchange_val(volatile a128 * a,a128 c,a128 v,morder mo,morder fmo)831 a128 __tsan_atomic128_compare_exchange_val(volatile a128 *a, a128 c, a128 v,
832 morder mo, morder fmo) {
833 SCOPED_ATOMIC(CAS, a, c, v, mo, fmo);
834 }
835 #endif
836
837 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic_thread_fence(morder mo)838 void __tsan_atomic_thread_fence(morder mo) {
839 char* a = 0;
840 SCOPED_ATOMIC(Fence, mo);
841 }
842
843 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_atomic_signal_fence(morder mo)844 void __tsan_atomic_signal_fence(morder mo) {
845 }
846 } // extern "C"
847
848 #else // #ifndef SANITIZER_GO
849
850 // Go
851
852 #define ATOMIC(func, ...) \
853 if (thr->ignore_sync) { \
854 NoTsanAtomic##func(__VA_ARGS__); \
855 } else { \
856 FuncEntry(thr, cpc); \
857 Atomic##func(thr, pc, __VA_ARGS__); \
858 FuncExit(thr); \
859 } \
860 /**/
861
862 #define ATOMIC_RET(func, ret, ...) \
863 if (thr->ignore_sync) { \
864 (ret) = NoTsanAtomic##func(__VA_ARGS__); \
865 } else { \
866 FuncEntry(thr, cpc); \
867 (ret) = Atomic##func(thr, pc, __VA_ARGS__); \
868 FuncExit(thr); \
869 } \
870 /**/
871
872 extern "C" {
873 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic32_load(ThreadState * thr,uptr cpc,uptr pc,u8 * a)874 void __tsan_go_atomic32_load(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
875 ATOMIC_RET(Load, *(a32*)(a+8), *(a32**)a, mo_acquire);
876 }
877
878 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic64_load(ThreadState * thr,uptr cpc,uptr pc,u8 * a)879 void __tsan_go_atomic64_load(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
880 ATOMIC_RET(Load, *(a64*)(a+8), *(a64**)a, mo_acquire);
881 }
882
883 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic32_store(ThreadState * thr,uptr cpc,uptr pc,u8 * a)884 void __tsan_go_atomic32_store(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
885 ATOMIC(Store, *(a32**)a, *(a32*)(a+8), mo_release);
886 }
887
888 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic64_store(ThreadState * thr,uptr cpc,uptr pc,u8 * a)889 void __tsan_go_atomic64_store(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
890 ATOMIC(Store, *(a64**)a, *(a64*)(a+8), mo_release);
891 }
892
893 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic32_fetch_add(ThreadState * thr,uptr cpc,uptr pc,u8 * a)894 void __tsan_go_atomic32_fetch_add(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
895 ATOMIC_RET(FetchAdd, *(a32*)(a+16), *(a32**)a, *(a32*)(a+8), mo_acq_rel);
896 }
897
898 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic64_fetch_add(ThreadState * thr,uptr cpc,uptr pc,u8 * a)899 void __tsan_go_atomic64_fetch_add(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
900 ATOMIC_RET(FetchAdd, *(a64*)(a+16), *(a64**)a, *(a64*)(a+8), mo_acq_rel);
901 }
902
903 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic32_exchange(ThreadState * thr,uptr cpc,uptr pc,u8 * a)904 void __tsan_go_atomic32_exchange(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
905 ATOMIC_RET(Exchange, *(a32*)(a+16), *(a32**)a, *(a32*)(a+8), mo_acq_rel);
906 }
907
908 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic64_exchange(ThreadState * thr,uptr cpc,uptr pc,u8 * a)909 void __tsan_go_atomic64_exchange(ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
910 ATOMIC_RET(Exchange, *(a64*)(a+16), *(a64**)a, *(a64*)(a+8), mo_acq_rel);
911 }
912
913 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic32_compare_exchange(ThreadState * thr,uptr cpc,uptr pc,u8 * a)914 void __tsan_go_atomic32_compare_exchange(
915 ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
916 a32 cur = 0;
917 a32 cmp = *(a32*)(a+8);
918 ATOMIC_RET(CAS, cur, *(a32**)a, cmp, *(a32*)(a+12), mo_acq_rel, mo_acquire);
919 *(bool*)(a+16) = (cur == cmp);
920 }
921
922 SANITIZER_INTERFACE_ATTRIBUTE
__tsan_go_atomic64_compare_exchange(ThreadState * thr,uptr cpc,uptr pc,u8 * a)923 void __tsan_go_atomic64_compare_exchange(
924 ThreadState *thr, uptr cpc, uptr pc, u8 *a) {
925 a64 cur = 0;
926 a64 cmp = *(a64*)(a+8);
927 ATOMIC_RET(CAS, cur, *(a64**)a, cmp, *(a64*)(a+16), mo_acq_rel, mo_acquire);
928 *(bool*)(a+24) = (cur == cmp);
929 }
930 } // extern "C"
931 #endif // #ifndef SANITIZER_GO
932