Check that the FakeStack size is non-zero before looking into it.

Sometimes DescribeStackAddress is called before another thread's FakeStack is initialized, which could previously cause a check to fire.

llvm-svn: 151046

2 files changed, 2 insertions, 1 deletions

diff --git a/compiler-rt/lib/asan/asan_allocator.h b/compiler-rt/lib/asan/asan_allocator.h
index c754eed5a3a..cc6ac8487d5 100644
--- a/compiler-rt/lib/asan/asan_allocator.h
+++ b/compiler-rt/lib/asan/asan_allocator.h
@@ -107,6 +107,7 @@ class FakeStack {
   static void OnFree(size_t ptr, size_t size, size_t real_stack);
   // Return the bottom of the maped region.
   uintptr_t AddrIsInFakeStack(uintptr_t addr);
+  bool StackSize() { return stack_size_; }
  private:
   static const size_t kMinStackFrameSizeLog = 9;  // Min frame is 512B.
   static const size_t kMaxStackFrameSizeLog = 16;  // Max stack frame is 64K.
diff --git a/compiler-rt/lib/asan/asan_thread_registry.cc b/compiler-rt/lib/asan/asan_thread_registry.cc
index 56208e62a2c..198b2f66246 100644
--- a/compiler-rt/lib/asan/asan_thread_registry.cc
+++ b/compiler-rt/lib/asan/asan_thread_registry.cc
@@ -141,7 +141,7 @@ AsanThread *AsanThreadRegistry::FindThreadByStackAddress(uintptr_t addr) {
   // Scanning the thread list backwards makes this function more reliable.
   for (int tid = n_threads_ - 1; tid >= 0; tid--) {
     AsanThread *t = thread_summaries_[tid]->thread();
-    if (!t) continue;
+    if (!t || !(t->fake_stack().StackSize())) continue;
     if (t->fake_stack().AddrIsInFakeStack(addr) || t->AddrIsInStack(addr)) {
       return t;
     }