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Date:   Wed, 25 Jul 2018 10:05:41 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Josh Poimboeuf <jpoimboe@redhat.com>
Cc:     Artem Savkov <asavkov@redhat.com>, Ingo Molnar <mingo@redhat.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kprobes: fix trace_probe flags in enable_trace_kprobe
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In-Reply-To: <20180725135632.zmjq7cuqc7eshpsh@treble>
References: <20180725102826.8300-1-asavkov@redhat.com>
        <20180725135632.zmjq7cuqc7eshpsh@treble>
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On Wed, 25 Jul 2018 08:56:32 -0500
Josh Poimboeuf <jpoimboe@redhat.com> wrote:

> On Wed, Jul 25, 2018 at 12:28:26PM +0200, Artem Savkov wrote:
> > If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
> > it returns an error, but does not unset the tp flags it set previosly.  
> 
> "previously"

I tentatively added this to my queue. I updated the subject as:

 tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure

But yeah, that needs to be fixed.

> 
> > @@ -424,6 +423,16 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
> >  		else
> >  			ret = enable_kprobe(&tk->rp.kp);
> >  	}
> > +
> > +	if (ret) {
> > +		if (file) {
> > +			list_del(&link->list);  
> 
> Should this be list_del_rcu(), since it was added to the list with
> list_add_tail_rcu()?
> 

Good catch. Yes, that should be list_del_rcu().

Artem,

Can you send a v2 with the changes.

Thanks,

-- Steve