Re: ftrace_graph_filter not working correctly since v4.10

[Todd Brandt]

On Thu, 2017-03-02 at 13:05 -0500, Steven Rostedt wrote:
> Namhyung,
> 
> Just an FYI...
> 
> -- Steve
> 
> 
> On Thu, 2 Mar 2017 12:49:40 -0500
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> 
> > On Wed, 1 Mar 2017 22:47:30 -0500
> > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > 
> > > On Wed, 1 Mar 2017 22:28:43 -0500
> > > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:  
> > > > 
> > > > 4.10 is fine. It's what has been merged for 4.11 that's broken. I'm
> > > > doing a bisect now to see what broke it. Yes, lots of commits touched
> > > > that code recently.    
> > > 
> > > I found the bad commit. I'll have a patch for you to test tomorrow.
> > >   
> > 
> > Can you test this patch please.
Awesome, seems to work fine now.

I applied and tested it on bleeding edge:

commit 4977ab6e92e267afe9d8f78438c3db330ca8434c
Date:   Wed Mar 1 17:04:50 2017 -0800

and it works on both msleep and do_one_initcall.

Thanks!

> > 
> > -- Steve
> > 
> > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> > index 2d554a0..1b33a41 100644
> > --- a/kernel/trace/ftrace.c
> > +++ b/kernel/trace/ftrace.c
> > @@ -4403,10 +4403,9 @@ static void __init set_ftrace_early_graph(char *buf, int enable)
> >  	char *func;
> >  	struct ftrace_hash *hash;
> >  
> > -	if (enable)
> > -		hash = ftrace_graph_hash;
> > -	else
> > -		hash = ftrace_graph_notrace_hash;
> > +	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
> > +	if (WARN_ON(!hash))
> > +		return;
> >  
> >  	while (buf) {
> >  		func = strsep(&buf, ",");
> > @@ -4416,6 +4415,11 @@ static void __init set_ftrace_early_graph(char *buf, int enable)
> >  			printk(KERN_DEBUG "ftrace: function %s not "
> >  					  "traceable\n", func);
> >  	}
> > +
> > +	if (enable)
> > +		ftrace_graph_hash = hash;
> > +	else
> > +		ftrace_graph_notrace_hash = hash;
> >  }
> >  #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
> >  
>