Re: [PATCH] perf probe: Return errno when does not hit any event

From: Kefeng Wang
Date: Tue Mar 07 2017 - 02:35:11 EST


+ Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

On 2017/3/6 17:34, Kefeng Wang wrote:
> On old perf, when using perf probe -d to delete an inexistent event,
> it return errno, eg,
>
> -bash-4.3# perf probe -d xxx || echo $?
> Info: Event "*:xxx" does not exist.
> Error: Failed to delete events.
> 255
>
> But now perf_del_probe_events() will always set ret = 0, different
> from previous del_perf_probe_events(). After this, it return errno
> again, eg,
>
> -bash-4.3# ./perf probe -d xxx || echo $?
> Error: Failed to delete events.
> 254
>
> And it is more appropriate to return -ENOENT instead of -EPERM.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> ---
> tools/perf/builtin-probe.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
> index 1fcebc3..c46b41c 100644
> --- a/tools/perf/builtin-probe.c
> +++ b/tools/perf/builtin-probe.c
> @@ -444,7 +444,8 @@ static int perf_del_probe_events(struct strfilter *filter)
> if (ret == -ENOENT && ret2 == -ENOENT)
> pr_debug("\"%s\" does not hit any event.\n", str);
> /* Note that this is silently ignored */
> - ret = 0;
> + else
> + ret = 0;
>
> error:
> if (kfd >= 0)
>