Fix: notification: deadlock on cmd_queue.lock and client->lock

[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread-events.c

diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c
index 3f8cb4804ddd0800061f634afb3d6e92022e8103..6ba6c415b65b74bf2c6571fb6261d6f3f3a34f80 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-events.c
+++ b/src/bin/lttng-sessiond/notification-thread-events.c
@@ -2412,6 +2412,8 @@ int handle_notification_thread_command(
        pthread_mutex_lock(&handle->cmd_queue.lock);
        cmd = cds_list_first_entry(&handle->cmd_queue.list,
                        struct notification_thread_command, cmd_list_node);
+       cds_list_del(&cmd->cmd_list_node);
+       pthread_mutex_unlock(&handle->cmd_queue.lock);
        switch (cmd->type) {
        case NOTIFICATION_COMMAND_TYPE_REGISTER_TRIGGER:
                DBG("[notification-thread] Received register trigger command");
@@ -2474,19 +2476,16 @@ int handle_notification_thread_command(
                goto error_unlock;
        }
 end:
-       cds_list_del(&cmd->cmd_list_node);
        if (cmd->is_async) {
                free(cmd);
                cmd = NULL;
        } else {
                lttng_waiter_wake_up(&cmd->reply_waiter);
        }
-       pthread_mutex_unlock(&handle->cmd_queue.lock);
        return ret;
 error_unlock:
        /* Wake-up and return a fatal error to the calling thread. */
        lttng_waiter_wake_up(&cmd->reply_waiter);
-       pthread_mutex_unlock(&handle->cmd_queue.lock);
        cmd->reply_code = LTTNG_ERR_FATAL;
 error:
        /* Indicate a fatal error to the caller. */