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

[Song Chen <chensong_2000@189.cn>]

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@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,
> 

will do

Song
>>
>> -- 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);
>>>   
>>
> 
>