[libsanitizer] merge from upstream r169392

From-SVN: r194255

4 files changed, 31 insertions, 16 deletions

diff --git a/libsanitizer/tsan/tsan_interceptors.cc b/libsanitizer/tsan/tsan_interceptors.cc
index 0463fbd4..dea6415 100644
--- a/libsanitizer/tsan/tsan_interceptors.cc
+++ b/libsanitizer/tsan/tsan_interceptors.cc
@@ -617,21 +617,31 @@ TSAN_INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr sz) {
 }
 
 // Used in thread-safe function static initialization.
-TSAN_INTERCEPTOR(int, __cxa_guard_acquire, char *m) {
-  SCOPED_TSAN_INTERCEPTOR(__cxa_guard_acquire, m);
-  int res = REAL(__cxa_guard_acquire)(m);
-  if (res) {
-    // This thread does the init.
-  } else {
-    Acquire(thr, pc, (uptr)m);
+extern "C" int INTERFACE_ATTRIBUTE __cxa_guard_acquire(atomic_uint32_t *g) {
+  SCOPED_INTERCEPTOR_RAW(__cxa_guard_acquire, g);
+  for (;;) {
+    u32 cmp = atomic_load(g, memory_order_acquire);
+    if (cmp == 0) {
+      if (atomic_compare_exchange_strong(g, &cmp, 1<<16, memory_order_relaxed))
+        return 1;
+    } else if (cmp == 1) {
+      Acquire(thr, pc, (uptr)g);
+      return 0;
+    } else {
+      internal_sched_yield();
+    }
   }
-  return res;
 }
 
-TSAN_INTERCEPTOR(void, __cxa_guard_release, char *m) {
-  SCOPED_TSAN_INTERCEPTOR(__cxa_guard_release, m);
-  Release(thr, pc, (uptr)m);
-  REAL(__cxa_guard_release)(m);
+extern "C" void INTERFACE_ATTRIBUTE __cxa_guard_release(atomic_uint32_t *g) {
+  SCOPED_INTERCEPTOR_RAW(__cxa_guard_release, g);
+  Release(thr, pc, (uptr)g);
+  atomic_store(g, 1, memory_order_release);
+}
+
+extern "C" void INTERFACE_ATTRIBUTE __cxa_guard_abort(atomic_uint32_t *g) {
+  SCOPED_INTERCEPTOR_RAW(__cxa_guard_abort, g);
+  atomic_store(g, 0, memory_order_relaxed);
 }
 
 static void thread_finalize(void *v) {
@@ -1508,9 +1518,6 @@ void InitializeInterceptors() {
   TSAN_INTERCEPT(strncpy);
   TSAN_INTERCEPT(strstr);
 
-  TSAN_INTERCEPT(__cxa_guard_acquire);
-  TSAN_INTERCEPT(__cxa_guard_release);
-
   TSAN_INTERCEPT(pthread_create);
   TSAN_INTERCEPT(pthread_join);
   TSAN_INTERCEPT(pthread_detach);
diff --git a/libsanitizer/tsan/tsan_interface_atomic.cc b/libsanitizer/tsan/tsan_interface_atomic.cc
index 25f171e..63860ed 100644
--- a/libsanitizer/tsan/tsan_interface_atomic.cc
+++ b/libsanitizer/tsan/tsan_interface_atomic.cc
@@ -113,7 +113,10 @@ static morder ConvertOrder(morder mo) {
 }
 
 template<typename T> T func_xchg(volatile T *v, T op) {
-  return __sync_lock_test_and_set(v, op);
+  T res = __sync_lock_test_and_set(v, op);
+  // __sync_lock_test_and_set does not contain full barrier.
+  __sync_synchronize();
+  return res;
 }
 
 template<typename T> T func_add(volatile T *v, T op) {
@@ -253,6 +256,9 @@ static void AtomicStore(ThreadState *thr, uptr pc, volatile T *a, T v,
   thr->clock.ReleaseStore(&s->clock);
   *a = v;
   s->mtx.Unlock();
+  // Trainling memory barrier to provide sequential consistency
+  // for Dekker-like store-load synchronization.
+  __sync_synchronize();
 }
 
 template<typename T, T (*F)(volatile T *v, T op)>
diff --git a/libsanitizer/tsan/tsan_stat.cc b/libsanitizer/tsan/tsan_stat.cc
index f8ecec1..7b91330 100644
--- a/libsanitizer/tsan/tsan_stat.cc
+++ b/libsanitizer/tsan/tsan_stat.cc
@@ -136,6 +136,7 @@ void StatOutput(u64 *stat) {
   name[StatInt_atexit]                   = "  atexit                          ";
   name[StatInt___cxa_guard_acquire]      = "  __cxa_guard_acquire             ";
   name[StatInt___cxa_guard_release]      = "  __cxa_guard_release             ";
+  name[StatInt___cxa_guard_abort]        = "  __cxa_guard_abort               ";
   name[StatInt_pthread_create]           = "  pthread_create                  ";
   name[StatInt_pthread_join]             = "  pthread_join                    ";
   name[StatInt_pthread_detach]           = "  pthread_detach                  ";
diff --git a/libsanitizer/tsan/tsan_stat.h b/libsanitizer/tsan/tsan_stat.h
index 51e4c4a..0dc1cd9 100644
--- a/libsanitizer/tsan/tsan_stat.h
+++ b/libsanitizer/tsan/tsan_stat.h
@@ -133,6 +133,7 @@ enum StatType {
   StatInt_atexit,
   StatInt___cxa_guard_acquire,
   StatInt___cxa_guard_release,
+  StatInt___cxa_guard_abort,
   StatInt_pthread_create,
   StatInt_pthread_join,
   StatInt_pthread_detach,