Re: [PATCH 4/4] perf probe: Propagate error code when write(2) failed

From: Masami Hiramatsu
Date: Mon Jan 12 2015 - 06:18:05 EST


(2015/01/10 19:33), Namhyung Kim wrote:
> When it failed to write probe commands to the probe_event file in
> debugfs, it needs to propagate the error code properly. Current code
> blindly uses the return value of the write(2) so it always uses
> -1 (-EPERM) and it might confuse users.
>

Good catch! :)

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

> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/util/probe-event.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 6fe5aa357efc..ddc295885af0 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2052,9 +2052,11 @@ static int write_probe_trace_event(int fd, struct probe_trace_event *tev)
> pr_debug("Writing event: %s\n", buf);
> if (!probe_event_dry_run) {
> ret = write(fd, buf, strlen(buf));
> - if (ret <= 0)
> + if (ret <= 0) {
> + ret = -errno;
> pr_warning("Failed to write event: %s\n",
> strerror_r(errno, sbuf, sizeof(sbuf)));
> + }
> }
> free(buf);
> return ret;
>


--
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Research Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx


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