Re: [PATCH v2] trace/kprobe: remove duplicated calls of ring_buffer_event_data

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 19 Oct 2022 10:11:18 +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 does __kretprobe_trace_func.
> 
> This patch removes those duplicated calls.
> 
> Signed-off-by: Song Chen <chensong_2000@189.cn>

Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Masami, want to take this one?

-- Steve

> ---
>  kernel/trace/trace_kprobe.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 23f7f0ec4f4c..f905829b856b 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);
>  
> @@ -1435,7 +1434,6 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
>  		return;
>  
>  	fbuffer.regs = regs;
> -	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
>  	entry->func = (unsigned long)tk->rp.kp.addr;
>  	entry->ret_ip = get_kretprobe_retaddr(ri);
>  	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);