On 2021/10/12 下午8:17, Steven Rostedt wrote: > 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. Will keep that in v2. Regards, Michael Wang > > -- Steve > > >> - preempt_disable_notrace(); >> >> func = list_first_or_null_rcu(&ops->func_stack, struct klp_func, >> stack_node);
