From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> [ 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@xxxxxxxxxx> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Link: https://lkml.kernel.org/n/tip-f30ztaasku3z935cn3ak3h53@xxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/perf/util/evsel.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 966360844fff..7ca79cfe1aea 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) -- 2.20.1