On Thu, 29 Oct 2020 14:51:06 +0100 (CET) Miroslav Benes <mbenes@xxxxxxx> wrote: > > index b552cf2d85f8..6c0164d24bbd 100644 > > --- a/kernel/livepatch/patch.c > > +++ b/kernel/livepatch/patch.c > > @@ -45,9 +45,13 @@ static void notrace klp_ftrace_handler(unsigned long ip, > > struct klp_ops *ops; > > struct klp_func *func; > > int patch_state; > > + int bit; > > > > ops = container_of(fops, struct klp_ops, fops); > > > > + bit = ftrace_test_recursion_trylock(); > > + if (bit < 0) > > + return; > > This means that the original function will be called in case of recursion. > That's probably fair, but I'm wondering if we should at least WARN about > it. It's probably what happens today. But if you add a WARN_ON_ONCE() it may not hurt. I also plan on adding code that reports when recursion has happened, because even if it's not a problem, recursion adds extra overhead. -- Steve
