perf evlist: Factor out asprintf routine to build a tracepoint pid filter

Will be used to append such lists to existing filters.

Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Luis Cláudio Gonçalves <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 15 insertions, 4 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index b4c43ac4583f..c1b46080426b 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1053,6 +1053,9 @@ int perf_evlist__set_tp_filter(struct evlist *evlist, const char *filter)
 	struct evsel *evsel;
 	int err = 0;
 
+	if (filter == NULL)
+		return -1;
+
 	evlist__for_each_entry(evlist, evsel) {
 		if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
 			continue;
@@ -1065,16 +1068,15 @@ int perf_evlist__set_tp_filter(struct evlist *evlist, const char *filter)
 	return err;
 }
 
-int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
+static char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
 {
 	char *filter;
-	int ret = -1;
 	size_t i;
 
 	for (i = 0; i < npids; ++i) {
 		if (i == 0) {
 			if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
-				return -1;
+				return NULL;
 		} else {
 			char *tmp;
 
@@ -1086,9 +1088,18 @@ int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *
 		}
 	}
 
-	ret = perf_evlist__set_tp_filter(evlist, filter);
+	return filter;
 out_free:
 	free(filter);
+	return NULL;
+}
+
+int perf_evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
+{
+	char *filter = asprintf__tp_filter_pids(npids, pids);
+	int ret = perf_evlist__set_tp_filter(evlist, filter);
+
+	free(filter);
 	return ret;
 }