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Date:   Wed, 19 Oct 2022 00:22:43 +0900
From:   Masami Hiramatsu (Google) <mhiramat@kernel.org>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Song Chen <chensong_2000@189.cn>, mingo@redhat.com,
        linux-kernel@vger.kernel.org, xiehuan09@gmail.com,
        Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [PATCH] trace/kprobe: remove duplicated call of
 ring_buffer_event_data
Message-Id: <20221019002243.8729040161290e17c6581e84@kernel.org>
In-Reply-To: <20221018095932.7b955e96@gandalf.local.home>
References: <1666077186-6042-1-git-send-email-chensong_2000@189.cn>
        <20221018095932.7b955e96@gandalf.local.home>
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Hi,

On Tue, 18 Oct 2022 09:59:32 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> 
> [ Added Masami who's the new co-maintainer, and this is his code ]
> 
> On Tue, 18 Oct 2022 15:13:06 +0800
> Song Chen <chensong_2000@189.cn> wrote:
> 
> > Function __kprobe_trace_func calls ring_buffer_event_data to get
> > a ring buffer, however, it has been done in above call
> > trace_event_buffer_reserve.
> > 
> > So remove one of them.
> > 
> 
> May as well add:
> 
> Fixes: 5e6cd84e2f8bd ("tracing/kprobes: Do not open code event reserve logic")
> 
> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Oops, and we have another line in __kretprobe_trace_func() too.

Song, can you update this patch to fix the __kretprobe_trace_func() too?

Thank you,

> 
> -- Steve
> 
> 
> > Signed-off-by: Song Chen <chensong_2000@189.cn>
> > ---
> >  kernel/trace/trace_kprobe.c | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> > index 23f7f0ec4f4c..dfd5809a4a65 100644
> > --- a/kernel/trace/trace_kprobe.c
> > +++ b/kernel/trace/trace_kprobe.c
> > @@ -1394,7 +1394,6 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
> >  		return;
> >  
> >  	fbuffer.regs = regs;
> > -	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
> >  	entry->ip = (unsigned long)tk->rp.kp.addr;
> >  	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
> >  
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>