chardev: check if the chardev is registered for yanking

Not all chardevs are created via qmp_chardev_open_socket(), and those
should not call the yank function registration, as this will eventually
assert() not being registered.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210204105232.834642-20-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

chardev/char-socket.c

@@ -417,8 +417,9 @@ static void tcp_chr_free_connection(Chardev *chr)
 
     tcp_set_msgfds(chr, NULL, 0);
     remove_fd_in_watch(chr);
-    if (s->state == TCP_CHARDEV_STATE_CONNECTING
-        || s->state == TCP_CHARDEV_STATE_CONNECTED) {
+    if (s->registered_yank &&
+        (s->state == TCP_CHARDEV_STATE_CONNECTING
+        || s->state == TCP_CHARDEV_STATE_CONNECTED)) {
         yank_unregister_function(CHARDEV_YANK_INSTANCE(chr->label),
                                  yank_generic_iochannel,
                                  QIO_CHANNEL(s->sioc));
@@ -940,9 +941,11 @@ static int tcp_chr_add_client(Chardev *chr, int fd)
     }
     tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
     tcp_chr_set_client_ioc_name(chr, sioc);
-    yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
-                           yank_generic_iochannel,
-                           QIO_CHANNEL(sioc));
+    if (s->registered_yank) {
+        yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
+                               yank_generic_iochannel,
+                               QIO_CHANNEL(sioc));
+    }
     ret = tcp_chr_new_client(chr, sioc);
     object_unref(OBJECT(sioc));
     return ret;
@@ -957,9 +960,11 @@ static void tcp_chr_accept(QIONetListener *listener,
 
     tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
     tcp_chr_set_client_ioc_name(chr, cioc);
-    yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
-                           yank_generic_iochannel,
-                           QIO_CHANNEL(cioc));
+    if (s->registered_yank) {
+        yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
+                               yank_generic_iochannel,
+                               QIO_CHANNEL(cioc));
+    }
     tcp_chr_new_client(chr, cioc);
 }
 
@@ -975,9 +980,11 @@ static int tcp_chr_connect_client_sync(Chardev *chr, Error **errp)
         object_unref(OBJECT(sioc));
         return -1;
     }
-    yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
-                           yank_generic_iochannel,
-                           QIO_CHANNEL(sioc));
+    if (s->registered_yank) {
+        yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
+                               yank_generic_iochannel,
+                               QIO_CHANNEL(sioc));
+    }
     tcp_chr_new_client(chr, sioc);
     object_unref(OBJECT(sioc));
     return 0;
@@ -993,9 +1000,11 @@ static void tcp_chr_accept_server_sync(Chardev *chr)
     tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
     sioc = qio_net_listener_wait_client(s->listener);
     tcp_chr_set_client_ioc_name(chr, sioc);
-    yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
-                           yank_generic_iochannel,
-                           QIO_CHANNEL(sioc));
+    if (s->registered_yank) {
+        yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
+                               yank_generic_iochannel,
+                               QIO_CHANNEL(sioc));
+    }
     tcp_chr_new_client(chr, sioc);
     object_unref(OBJECT(sioc));
 }
@@ -1124,9 +1133,11 @@ static void qemu_chr_socket_connected(QIOTask *task, void *opaque)
 
     if (qio_task_propagate_error(task, &err)) {
         tcp_chr_change_state(s, TCP_CHARDEV_STATE_DISCONNECTED);
-        yank_unregister_function(CHARDEV_YANK_INSTANCE(chr->label),
-                                 yank_generic_iochannel,
-                                 QIO_CHANNEL(sioc));
+        if (s->registered_yank) {
+            yank_unregister_function(CHARDEV_YANK_INSTANCE(chr->label),
+                                     yank_generic_iochannel,
+                                     QIO_CHANNEL(sioc));
+        }
         check_report_connect_error(chr, err);
         goto cleanup;
     }
@@ -1160,9 +1171,11 @@ static void tcp_chr_connect_client_async(Chardev *chr)
     tcp_chr_change_state(s, TCP_CHARDEV_STATE_CONNECTING);
     sioc = qio_channel_socket_new();
     tcp_chr_set_client_ioc_name(chr, sioc);
-    yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
-                           yank_generic_iochannel,
-                           QIO_CHANNEL(sioc));
+    if (s->registered_yank) {
+        yank_register_function(CHARDEV_YANK_INSTANCE(chr->label),
+                               yank_generic_iochannel,
+                               QIO_CHANNEL(sioc));
+    }
     /*
      * Normally code would use the qio_channel_socket_connect_async
      * method which uses a QIOTask + qio_task_set_error internally