commit 15fee822470654e722879e1e5d6b50008637af0c
author Christopher Ferris <cferris@google.com> Mon Sep 12 18:00:10 2022 -0700
committer Christopher Ferris <cferris@google.com> Mon Sep 12 18:37:22 2022 -0700
tree bc13e36b4efcdcac08eb8e72f9ad1ecf226afde8
parent 61c82abe24ae265e41b1176077696814dceef137

Fix thread unwind in CallStack.

The CallStack unwind of a different thread was broken since it
wasn't properly setting the tid value.

Fix this problem and add new unit tests to verify the behavior.

Bug: 246405269

Test: New unit tests pass.
Test: Ran unit tests for 1000 operations to verify not flaky.
Change-Id: I00342e6cdcdb4bcb68f29734dadee6c987c98040

libutils/CallStack.cpp

diff --git a/libutils/CallStack.cpp b/libutils/CallStack.cpp
index f19ba6a..4dcb35b 100644
--- a/libutils/CallStack.cpp
+++ b/libutils/CallStack.cpp
@@ -49,7 +49,7 @@
     unwindstack::AndroidUnwinderData data;
     std::optional<pid_t> tid_val;
     if (tid != -1) {
-        *tid_val = tid;
+        tid_val = tid;
     }
     if (!unwinder.Unwind(tid_val, data)) {
         ALOGW("%s: Failed to unwind callstack: %s", __FUNCTION__, data.GetErrorString().c_str());