tsan: fix handling of pthread_cond_wait in presence of pthread_cancel

if the thread is cancelled in pthread_cond_wait, it locks the mutex before
processing pthread_cleanup stack
but tsan was missing that, thus reporting false double-lock/wrong-unlock errors
see the test for details



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@203648 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 51 insertions, 4 deletions

diff --git a/lib/sanitizer_common/sanitizer_common_interceptors.inc b/lib/sanitizer_common/sanitizer_common_interceptors.inc
index b6ae222ac..010799aa1 100644
--- a/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -2483,6 +2483,21 @@ static void *init_cond(void *c, bool force = false) {
   return (void*)cond;
 }
 
+struct CondMutexUnlockCtx {
+  void *ctx;
+  void *m;
+};
+
+static void cond_mutex_unlock(CondMutexUnlockCtx *arg) {
+  COMMON_INTERCEPTOR_MUTEX_LOCK(arg->ctx, arg->m);
+}
+
+namespace __sanitizer {
+int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
+    void *abstime), void *c, void *m, void *abstime,
+    void(*cleanup)(void *arg), void *arg);
+}  // namespace __sanitizer
+
 INTERCEPTOR(int, pthread_cond_init, void *c, void *a) {
   void *cond = init_cond(c, true);
   void *ctx;
@@ -2497,8 +2512,12 @@ INTERCEPTOR(int, pthread_cond_wait, void *c, void *m) {
   COMMON_INTERCEPTOR_ENTER(ctx, pthread_cond_wait, cond, m);
   COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m);
   COMMON_INTERCEPTOR_READ_RANGE(ctx, c, sizeof(uptr));
-  int res = REAL(pthread_cond_wait)(cond, m);
-  COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m);
+  CondMutexUnlockCtx arg = {ctx, m};
+  // This ensures that we handle mutex lock even in case of pthread_cancel.
+  // See test/tsan/cond_cancel.cc.
+  int res = __sanitizer::call_pthread_cancel_with_cleanup(
+      (int(*)(void *c, void *m, void *abstime))REAL(pthread_cond_wait),
+      cond, m, 0, (void(*)(void *arg))cond_mutex_unlock, &arg);
   return res;
 }
 
@@ -2508,8 +2527,12 @@ INTERCEPTOR(int, pthread_cond_timedwait, void *c, void *m, void *abstime) {
   COMMON_INTERCEPTOR_ENTER(ctx, pthread_cond_timedwait, cond, m, abstime);
   COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m);
   COMMON_INTERCEPTOR_READ_RANGE(ctx, c, sizeof(uptr));
-  int res = REAL(pthread_cond_timedwait)(cond, m, abstime);
-  COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m);
+  CondMutexUnlockCtx arg = {ctx, m};
+  // This ensures that we handle mutex lock even in case of pthread_cancel.
+  // See test/tsan/cond_cancel.cc.
+  int res = __sanitizer::call_pthread_cancel_with_cleanup(
+      REAL(pthread_cond_timedwait), cond, m, abstime,
+      (void(*)(void *arg))cond_mutex_unlock, &arg);
   return res;
 }
 
diff --git a/lib/sanitizer_common/sanitizer_linux_libcdep.cc b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
index 2e3fbd2b8..94e99e0aa 100644
--- a/lib/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -515,6 +515,18 @@ void SetIndirectCallWrapper(uptr wrapper) {
   indirect_call_wrapper = wrapper;
 }
 
+int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
+    void *abstime), void *c, void *m, void *abstime,
+    void(*cleanup)(void *arg), void *arg) {
+  // pthread_cleanup_push/pop are hardcore macros mess.
+  // We can't intercept nor call them w/o including pthread.h.
+  int res;
+  pthread_cleanup_push(cleanup, arg);
+  res = fn(c, m, abstime);
+  pthread_cleanup_pop(1);
+  return res;
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
diff --git a/lib/sanitizer_common/sanitizer_mac.cc b/lib/sanitizer_common/sanitizer_mac.cc
index 747513de5..b6b3a0160 100644
--- a/lib/sanitizer_common/sanitizer_mac.cc
+++ b/lib/sanitizer_common/sanitizer_mac.cc
@@ -302,6 +302,18 @@ MacosVersion GetMacosVersion() {
   return result;
 }
 
+int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
+    void *abstime), void *c, void *m, void *abstime,
+    void(*cleanup)(void *arg), void *arg) {
+  // pthread_cleanup_push/pop are hardcore macros mess.
+  // We can't intercept nor call them w/o including pthread.h.
+  int res;
+  pthread_cleanup_push(cleanup, arg);
+  res = fn(c, m, abstime);
+  pthread_cleanup_pop(1);
+  return res;
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC