Re: [PATCH] trace/kprobe: remove duplicated call of ring_buffer_event_data

[Google]

Hi,

On Tue, 18 Oct 2022 09:59:32 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> 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@xxxxxx> 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@xxxxxxxxxxx>

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@xxxxxx>
> > ---
> >  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@xxxxxxxxxx>