RE: [PATCH v3 2/6] perf probe: Fix list result when symbol can't be found

[åæéå / HIRAMATUïMASAMI]

> From: Wang Nan [mailto:wangnan0@xxxxxxxxxx]
> 
> 'perf probe -l' reports error if it is unable find symbol through
> address. Here is an example.
> 
>  # echo 'p:probe_libc/abs_5 /lib64/libc.so.6:0x5' >
>           /sys/kernel/debug/tracing/uprobe_events
>  # cat /sys/kernel/debug/tracing/uprobe_events
>   p:probe_libc/abs_5 /lib64/libc.so.6:0x0000000000000005
>  # perf probe -l
>    Error: Failed to show event list
> 
> Also, this situation triggers a logical inconsistency in
> convert_to_perf_probe_point() that, it returns ENOMEM but actually
> it never try strdup().
> 
> This patch removes !tp->module && !is_kprobe condition, so it
> always uses address to build function name if symbol not found.
> 
> Test result:
> 
>  # perf probe -l
>    probe_libc:abs_5     (on 0x5 in /lib64/libc.so.6)
> 

Looks good!

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

Thank you!

> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> ---
>  tools/perf/util/probe-event.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 6c7e538..f7bacbb 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -1866,7 +1866,7 @@ static int convert_to_perf_probe_point(struct probe_trace_point *tp,
>  	if (tp->symbol) {
>  		pp->function = strdup(tp->symbol);
>  		pp->offset = tp->offset;
> -	} else if (!tp->module && !is_kprobe) {
> +	} else {
>  		ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address);
>  		if (ret < 0)
>  			return ret;
> --
> 1.8.3.4