trace/kprobe: remove duplicated calls of ring_buffer_event_data

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

Posted by Song Chen 3 years, 5 months ago

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>
---
 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);
-- 
2.25.1

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

Posted by Steven Rostedt 3 years, 5 months ago

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);

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

Posted by Masami Hiramatsu (Google) 3 years, 5 months ago

On Wed, 19 Oct 2022 09:30:22 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> 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?

yes, this looks good to me.

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

Thank you,

> 
> -- 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);
> 


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