From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Mon, 17 Jun 2019 17:32:53 +0000 (-0300)
Subject: perf evsel: Make perf_evsel__name() accept a NULL argument
X-Git-Tag: v5.1.20~265
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0b0e0d7475465c36da6b4c1215e0648425acedc1;p=thirdparty%2Fkernel%2Fstable.git

perf evsel: Make perf_evsel__name() accept a NULL argument

[ Upstream commit fdbdd7e8580eac9bdafa532746c865644d125e34 ]

In which case it simply returns "unknown", like when it can't figure out
the evsel->name value.

This makes this code more robust and fixes a problem in 'perf trace'
where a NULL evsel was being passed to a routine that only used the
evsel for printing its name when a invalid syscall id was passed.

Reported-by: Leo Yan <leo.yan@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-f30ztaasku3z935cn3ak3h53@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 966360844fffb..7ca79cfe1aeaf 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -584,6 +584,9 @@ const char *perf_evsel__name(struct perf_evsel *evsel)
 {
 	char bf[128];
 
+	if (!evsel)
+		goto out_unknown;
+
 	if (evsel->name)
 		return evsel->name;
 
@@ -620,7 +623,10 @@ const char *perf_evsel__name(struct perf_evsel *evsel)
 
 	evsel->name = strdup(bf);
 
-	return evsel->name ?: "unknown";
+	if (evsel->name)
+		return evsel->name;
+out_unknown:
+	return "unknown";
 }
 
 const char *perf_evsel__group_name(struct perf_evsel *evsel)