On Tue, 12 Oct 2021 13:40:08 +0800 王贇 <yun.wang@xxxxxxxxxxxxxxxxx> wrote: > @@ -52,11 +52,6 @@ static void notrace klp_ftrace_handler(unsigned long ip, > bit = ftrace_test_recursion_trylock(ip, parent_ip); > if (WARN_ON_ONCE(bit < 0)) > return; > - /* > - * A variant of synchronize_rcu() is used to allow patching functions > - * where RCU is not watching, see klp_synchronize_transition(). > - */ I have to take a deeper look at this patch set, but do not remove this comment, as it explains the protection here, that is not obvious with the changes you made. -- Steve > - preempt_disable_notrace(); > > func = list_first_or_null_rcu(&ops->func_stack, struct klp_func, > stack_node);
