On Wed, 9 Sep 2020 00:09:23 +0900 Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > > > Of course make it lockless then warning is gone. > > > But even without the lockless patch, this warning can be false-positive > > > because we prohibit nested kprobe call, right? > > > > Yes, because the actual nesting is avoided by kprobe_busy, but lockdep > > can't tell. Lockdep sees a regular lock user and an in-nmi lock user and > > figures that's a bad combination. Hmm, what about introducing new LOCK_USED_KPROBE bit, which will be set if the lock is accessed when the current_kprobe is set (including kprobe_busy)? This means it is in the kprobe user-handler context. If we access the lock always in the kprobes context, it is never nested. Thank you, -- Masami Hiramatsu <mhiramat@xxxxxxxxxx>
