On Friday, March 24, 2017 02:41:14 PM Steven Rostedt wrote: > On Fri, 24 Mar 2017 13:12:54 -0500 > Josh Poimboeuf <jpoim...@redhat.com> wrote: > > > > Instead I was able to "fix" it by ignoring ftrace calls in real mode: > > > > ----- > > index 8f3d9cf..5c0d0c6 100644 > > --- a/arch/x86/kernel/ftrace.c > > +++ b/arch/x86/kernel/ftrace.c > > @@ -983,6 +983,9 @@ void prepare_ftrace_return(unsigned long self_addr, > > unsigned long *parent, > > unsigned long return_hooker = (unsigned long) > > &return_to_handler; > > > > + if (__builtin_return_address(0) < TASK_SIZE_MAX) > > + return; > > + > > if (unlikely(ftrace_graph_is_dead())) > > return; > > --------------- > > > > I'm not sure what the best fix should really be. A few ideas off the > > top of my head: > > > > - A real mode check similar to the above (except it should probably be > > more precise) > > The real mode check hack may be good enough for now. Make sure that > it's commented well.
Agreed. Thanks, Rafael
