On Thu, 19 Feb 2015, Josh Poimboeuf wrote: > How about with a TIF_IN_USERSPACE thread flag? It could be cleared/set > right at the border. Then for running tasks it's as simple as: > > if (test_tsk_thread_flag(task, TIF_IN_USERSPACE)) > klp_switch_task_universe(task);
That's in principle what CONTEXT_TRACKING is doing, i.e. the condition we'd be interested in would be __this_cpu_read(context_tracking.state) == IN_USER But it has overhead. -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/