[Lldb-commits] [lldb] fix: Target Process may crash or freezes on detaching process on windows (PR #115712)

[Pavel Labath via lldb-commits]

================
@@ -169,6 +169,38 @@ Status ProcessWindows::DoDetach(bool keep_stopped) {
   Log *log = GetLog(WindowsLog::Process);
   StateType private_state = GetPrivateState();
   if (private_state != eStateExited && private_state != eStateDetached) {
+    if (!keep_stopped) {
+      // if the thread is suspended by lldb, we have to resume threads before
+      // detaching process. When we do after DetachProcess(), thread handles
+      // become invalid so we do before detach.
+      if (private_state == eStateStopped || private_state == eStateCrashed) {
+        LLDB_LOG(log, "process {0} is in state {1}.  Resuming for detach...",
+                 m_session_data->m_debugger->GetProcess().GetProcessId(),
+                 GetPrivateState());
+
+        LLDB_LOG(log, "resuming {0} threads for detach.",
+                 m_thread_list.GetSize());
+
+        bool failed = false;
+        for (uint32_t i = 0; i < m_thread_list.GetSize(); ++i) {
+          auto thread = std::static_pointer_cast<TargetThreadWindows>(
+              m_thread_list.GetThreadAtIndex(i));
+          Status result = thread->DoResume();
----------------
labath wrote:

Does this mean that if the thread/process gets another exception before we manage to detach from it, it will remain suspended? I'm not familiar with windows debugging API, so I don't know if there's a way to handle this, but I believe this is the reason why linux (and others) have a PTRACE_DETACH call which (atomically) detaches from a process/thread *and* resumes it.

https://github.com/llvm/llvm-project/pull/115712