[tsan] workaround for a crash in deadlock detector, bug https://github.com/google/sanitizers/issues/594

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@246592 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 15 insertions, 1 deletions

diff --git a/lib/tsan/rtl/tsan_rtl_mutex.cc b/lib/tsan/rtl/tsan_rtl_mutex.cc
index 09180d88a..62ab7aa6b 100644
--- a/lib/tsan/rtl/tsan_rtl_mutex.cc
+++ b/lib/tsan/rtl/tsan_rtl_mutex.cc
@@ -472,7 +472,7 @@ void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
   for (int i = 0; i < r->n; i++) {
     for (int j = 0; j < (flags()->second_deadlock_stack ? 2 : 1); j++) {
       u32 stk = r->loop[i].stk[j];
-      if (stk) {
+      if (stk && stk != 0xffffffff) {
         rep.AddStack(StackDepotGet(stk), true);
       } else {
         // Sometimes we fail to extract the stack trace (FIXME: investigate),
diff --git a/test/tsan/deadlock_detector_stress_test.cc b/test/tsan/deadlock_detector_stress_test.cc
index c77ffe555..efc13ae26 100644
--- a/test/tsan/deadlock_detector_stress_test.cc
+++ b/test/tsan/deadlock_detector_stress_test.cc
@@ -498,6 +498,19 @@ class LockTest {
     delete [] l;
   }
 
+  void Test19() {
+    if (test_number > 0 && test_number != 19) return;
+    fprintf(stderr, "Starting Test19: lots of lock inversions\n");
+    const int kNumLocks = 45;
+    Init(kNumLocks);
+    for (int i = 0; i < kNumLocks; i++) {
+      for (int j = 0; j < kNumLocks; j++)
+        L((i + j) % kNumLocks);
+      for (int j = 0; j < kNumLocks; j++)
+        U((i + j) % kNumLocks);
+    }
+  }
+
  private:
   void Lock2(size_t l1, size_t l2) { L(l1); L(l2); U(l2); U(l1); }
 
@@ -602,6 +615,7 @@ int main(int argc, char **argv) {
   LockTest().Test16();
   LockTest().Test17();
   LockTest().Test18();
+  LockTest().Test19();
   fprintf(stderr, "ALL-DONE\n");
   // CHECK: ALL-DONE
 }