tsan: improve "destroy of a locked mutex" reports

1. Allow to suppress by current stack.
We generally allow to suppress by all main stacks.
Current is probably the stack one wants to use to
suppress such reports.

2. Fix last lock stack restoration.
We trimmed shadow value by storing it in u32.
This magically worked for the test that provoked
the report on the main thread. But this breaks
for locks in any other threads.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@331023 91177308-0d34-0410-b5e6-96231b3b80d8

Author: dvyukov

lib/tsan/rtl/tsan_rtl_mutex.cc

@@ -104,7 +104,7 @@ void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
     unlock_locked = true;
   }
   u64 mid = s->GetId();
-  u32 last_lock = s->last_lock;
+  u64 last_lock = s->last_lock;
   if (!unlock_locked)
     s->Reset(thr->proc());  // must not reset it before the report is printed
   s->mtx.Unlock();
@@ -114,7 +114,7 @@ void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
     rep.AddMutex(mid);
     VarSizeStackTrace trace;
     ObtainCurrentStack(thr, pc, &trace);
-    rep.AddStack(trace);
+    rep.AddStack(trace, true);
     FastState last(last_lock);
     RestoreStack(last.tid(), last.epoch(), &trace, 0);
     rep.AddStack(trace, true);

test/tsan/mutex_destroy_locked2.cc

@@ -0,0 +1,29 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
+#include <pthread.h>
+#include <unistd.h>
+
+void *thread(void *arg) {
+  pthread_mutex_t m;
+  pthread_mutex_init(&m, 0);
+  pthread_mutex_lock(&m);
+  pthread_mutex_destroy(&m);
+  return 0;
+}
+
+int main() {
+  pthread_t th;
+  pthread_create(&th, 0, thread, 0);
+  pthread_join(th, 0);
+  return 0;
+}
+
+// CHECK: WARNING: ThreadSanitizer: destroy of a locked mutex
+// CHECK:     #0 pthread_mutex_destroy
+// CHECK:     #1 thread
+// CHECK:   and:
+// CHECK:     #0 pthread_mutex_lock
+// CHECK:     #1 thread
+// CHECK:   Mutex {{.*}} created at:
+// CHECK:     #0 pthread_mutex_init
+// CHECK:     #1 thread
+// CHECK: SUMMARY: ThreadSanitizer: destroy of a locked mutex {{.*}} in thread

test/tsan/suppressions_mutex.cc

@@ -0,0 +1,19 @@
+// RUN: %clang_tsan -O1 %s -o %t && %env_tsan_opts=suppressions='%s.supp' %run %t 2>&1 | FileCheck %s
+#include "test.h"
+
+void __attribute__((noinline)) suppress_this(pthread_mutex_t *mu) {
+  pthread_mutex_destroy(mu);
+}
+
+int main() {
+  pthread_mutex_t mu;
+  pthread_mutex_init(&mu, 0);
+  pthread_mutex_lock(&mu);
+  suppress_this(&mu);
+  fprintf(stderr, "DONE\n");
+  return 0;
+}
+
+// CHECK-NOT: failed to open suppressions file
+// CHECK-NOT: WARNING: ThreadSanitizer:
+// CHECK: DONE

test/tsan/suppressions_mutex.cc.supp

@@ -0,0 +1,2 @@
+mutex:suppress_this
+