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

[Song Chen]

Hi,

在 2022/10/18 23:22, Masami Hiramatsu (Google) 写道:
> 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,

will do

Song
> > -- 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);
> > >