[asan] add a run-time option detect_stack_use_after_return, add verbosity output for fake stack

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@190932 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/asan/asan_thread.cc b/lib/asan/asan_thread.cc
index 322caa8ac..5c2289491 100644
--- a/lib/asan/asan_thread.cc
+++ b/lib/asan/asan_thread.cc
@@ -123,8 +123,14 @@ FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
   if (atomic_compare_exchange_strong(
       reinterpret_cast<atomic_uintptr_t *>(&fake_stack_), &old_val, 1UL,
       memory_order_relaxed)) {
-    fake_stack_ = FakeStack::Create(Log2(RoundUpToPowerOfTwo(stack_size)));
+    uptr stack_size_log = Log2(RoundUpToPowerOfTwo(stack_size));
+    fake_stack_ = FakeStack::Create(stack_size_log);
     SetTLSFakeStack(fake_stack_);
+    if (flags()->verbosity) {
+      u8 *p = reinterpret_cast<u8 *>(fake_stack_);
+      Report("T%d: FakeStack created: %p -- %p\n", tid(), p,
+             p + FakeStack::RequiredSize(stack_size_log));
+    }
     return fake_stack_;
   }
   return 0;