Re: [PATCH 1/1] uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

(2013/04/10 23:58), Oleg Nesterov wrote:
> uprobe_perf_print() passes addr=ip to perf_trace_buf_submit() for
> no reason. This sets perf_sample_data->addr for PERF_SAMPLE_ADDR,
> we already have perf_sample_data->ip initialized if PERF_SAMPLE_IP.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thank you!

> ---
>  kernel/trace/trace_uprobe.c |    8 +++-----
>  1 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index 2d08bea..37ccb72 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -811,7 +811,6 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
>  	struct ftrace_event_call *call = &tu->call;
>  	struct uprobe_trace_entry_head *entry;
>  	struct hlist_head *head;
> -	unsigned long ip;
>  	void *data;
>  	int size, rctx, i;
>  
> @@ -825,13 +824,12 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
>  	if (!entry)
>  		goto out;
>  
> -	ip = instruction_pointer(regs);
>  	if (is_ret_probe(tu)) {
>  		entry->vaddr[0] = func;
> -		entry->vaddr[1] = ip;
> +		entry->vaddr[1] = instruction_pointer(regs);
>  		data = DATAOF_TRACE_ENTRY(entry, true);
>  	} else {
> -		entry->vaddr[0] = ip;
> +		entry->vaddr[0] = instruction_pointer(regs);
>  		data = DATAOF_TRACE_ENTRY(entry, false);
>  	}
>  
> @@ -839,7 +837,7 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
>  		call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
>  
>  	head = this_cpu_ptr(call->perf_events);
> -	perf_trace_buf_submit(entry, size, rctx, ip, 1, regs, head, NULL);
> +	perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
>   out:
>  	preempt_enable();
>  }
> 


-- 
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com