fix: Fix dde-session not start after treeland logged in

src/daemon/Display.cpp

@@ -336,7 +336,13 @@ namespace DDM {
 
         // Exec the desktop process
         connect(auth, &Auth::userProcessFinished, this, &Display::userProcessFinished);
+        // FIXME: Someone is triggering VT RELDISP signal during
+        // fork(), which will cause dead lock on glibc malloc arena
+        // lock. We have to disable our own VT signal handling
+        // temporarily...
+        VirtualTerminal::setVtSignalHandler(nullptr, nullptr);
         auth->startUserProcess(session.exec(), cookie);
+        daemonApp->treelandConnector()->setSignalHandler();
 
         // The user process is ongoing, append to active auths
         // The auth will be delete later in userProcessFinished()

src/daemon/TreelandConnector.cpp

@@ -130,7 +130,7 @@ static void onReleaseDisplay() {
 // TreelandConnector
 
 TreelandConnector::TreelandConnector() : QObject(nullptr) {
-    VirtualTerminal::setVtSignalHandler(onAcquireDisplay, onReleaseDisplay);
+    setSignalHandler();
 }
 
 TreelandConnector::~TreelandConnector() {
@@ -146,6 +146,10 @@ void TreelandConnector::setPrivateObject(struct treeland_ddm *ddm) {
     m_ddm = ddm;
 }
 
+void TreelandConnector::setSignalHandler() {
+    VirtualTerminal::setVtSignalHandler(onAcquireDisplay, onReleaseDisplay);
+}
+
 // Event implementation
 
 static void switchToVt([[maybe_unused]] void *data, [[maybe_unused]] struct treeland_ddm *ddm, int32_t vtnr) {

src/daemon/TreelandConnector.h

@@ -16,6 +16,7 @@ class TreelandConnector : QObject {
     ~TreelandConnector();
     bool isConnected();
     void setPrivateObject(struct treeland_ddm *ddm);
+    void setSignalHandler();
     void connect(const QString socketPath);
 
     void switchToGreeter();