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From:   Masami Hiramatsu <mhiramat@kernel.org>
To:     Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Masami Hiramatsu <mhiramat@kernel.org>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        stable@vger.kernel.org
Subject: [PATCH 3/3] perf-probe: Do not show the skipped events
Date:   Thu, 23 Apr 2020 20:01:22 +0900
Message-Id: <158763968263.30755.12800484151476026340.stgit@devnote2>
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When a probe point is expanded to several places (like inlined) and
if some of them are skipped because of blacklisted or __init function,
those trace_events has no event name. It must be skipped while showing
results.

Without this fix, you can see "(null):(null)" on the list,
===========
  # ./perf probe request_resource
  reserve_setup is out of .text, skip it.
  Added new events:
    (null):(null)        (on request_resource)
    probe:request_resource (on request_resource)

  You can now use it in all perf tools, such as:

  	perf record -e probe:request_resource -aR sleep 1

===========

With this fix, it is ignored.
===========
  # ./perf probe request_resource
  reserve_setup is out of .text, skip it.
  Added new events:
    probe:request_resource (on request_resource)

  You can now use it in all perf tools, such as:

  	perf record -e probe:request_resource -aR sleep 1

===========

Fixes: 5a51fcd1f30c ("perf probe: Skip kernel symbols which is out of .text")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
---
 tools/perf/builtin-probe.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 70548df2abb9..6b1507566770 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -364,6 +364,9 @@ static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
 
 		for (k = 0; k < pev->ntevs; k++) {
 			struct probe_trace_event *tev = &pev->tevs[k];
+			/* Skipped events have no event name */
+			if (!tev->event)
+				continue;
 
 			/* We use tev's name for showing new events */
 			show_perf_probe_event(tev->group, tev->event, pev,