perf parse-events: Minor __add_event refactoring

Rename cpu_list to user_cpus. If a PMU isn't given, find it early from
the perf_event_attr. Make the pmu_cpus more explicitly a copy from the
PMU (except when user_cpus are given). Derive the cpus from pmu_cpus
and user_cpus as appropriate. Handle strdup errors on name and
metric_id.

Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250719030517.1990983-11-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Author: captain5050

tools/perf/util/parse-events.c

@@ -259,12 +259,12 @@ __add_event(struct list_head *list, int *idx,
 	    bool init_attr,
 	    const char *name, const char *metric_id, struct perf_pmu *pmu,
 	    struct list_head *config_terms, struct evsel *first_wildcard_match,
-	    struct perf_cpu_map *cpu_list, u64 alternate_hw_config)
+	    struct perf_cpu_map *user_cpus, u64 alternate_hw_config)
 {
 	struct evsel *evsel;
 	bool is_pmu_core;
-	struct perf_cpu_map *cpus;
-	bool has_cpu_list = !perf_cpu_map__is_empty(cpu_list);
+	struct perf_cpu_map *cpus, *pmu_cpus;
+	bool has_user_cpus = !perf_cpu_map__is_empty(user_cpus);
 
 	/*
 	 * Ensure the first_wildcard_match's PMU matches that of the new event
@@ -288,8 +288,6 @@ __add_event(struct list_head *list, int *idx,
 	}
 
 	if (pmu) {
-		is_pmu_core = pmu->is_core;
-		cpus = perf_cpu_map__get(has_cpu_list ? cpu_list : pmu->cpus);
 		perf_pmu__warn_invalid_formats(pmu);
 		if (attr->type == PERF_TYPE_RAW || attr->type >= PERF_TYPE_MAX) {
 			perf_pmu__warn_invalid_config(pmu, attr->config, name,
@@ -301,48 +299,77 @@ __add_event(struct list_head *list, int *idx,
 			perf_pmu__warn_invalid_config(pmu, attr->config3, name,
 						PERF_PMU_FORMAT_VALUE_CONFIG3, "config3");
 		}
+	}
+	/*
+	 * If a PMU wasn't given, such as for legacy events, find now that
+	 * warnings won't be generated.
+	 */
+	if (!pmu)
+		pmu = perf_pmus__find_by_attr(attr);
+
+	if (pmu) {
+		is_pmu_core = pmu->is_core;
+		pmu_cpus = perf_cpu_map__get(pmu->cpus);
 	} else {
 		is_pmu_core = (attr->type == PERF_TYPE_HARDWARE ||
 			       attr->type == PERF_TYPE_HW_CACHE);
-		if (has_cpu_list)
-			cpus = perf_cpu_map__get(cpu_list);
-		else
-			cpus = is_pmu_core ? cpu_map__online() : NULL;
+		pmu_cpus = is_pmu_core ? cpu_map__online() : NULL;
+	}
+
+	if (has_user_cpus) {
+		cpus = perf_cpu_map__get(user_cpus);
+		/* Existing behavior that pmu_cpus matches the given user ones. */
+		perf_cpu_map__put(pmu_cpus);
+		pmu_cpus = perf_cpu_map__get(user_cpus);
+	} else {
+		cpus = perf_cpu_map__get(pmu_cpus);
 	}
+
 	if (init_attr)
 		event_attr_init(attr);
 
 	evsel = evsel__new_idx(attr, *idx);
-	if (!evsel) {
-		perf_cpu_map__put(cpus);
-		return NULL;
+	if (!evsel)
+		goto out_err;
+
+	if (name) {
+		evsel->name = strdup(name);
+		if (!evsel->name)
+			goto out_err;
+	}
+
+	if (metric_id) {
+		evsel->metric_id = strdup(metric_id);
+		if (!evsel->metric_id)
+			goto out_err;
 	}
 
 	(*idx)++;
 	evsel->core.cpus = cpus;
-	evsel->core.pmu_cpus = perf_cpu_map__get(cpus);
+	evsel->core.pmu_cpus = pmu_cpus;
 	evsel->core.requires_cpu = pmu ? pmu->is_uncore : false;
 	evsel->core.is_pmu_core = is_pmu_core;
 	evsel->pmu = pmu;
 	evsel->alternate_hw_config = alternate_hw_config;
 	evsel->first_wildcard_match = first_wildcard_match;
 
-	if (name)
-		evsel->name = strdup(name);
-
-	if (metric_id)
-		evsel->metric_id = strdup(metric_id);
-
 	if (config_terms)
 		list_splice_init(config_terms, &evsel->config_terms);
 
 	if (list)
 		list_add_tail(&evsel->core.node, list);
 
-	if (has_cpu_list)
-		evsel__warn_user_requested_cpus(evsel, cpu_list);
+	if (has_user_cpus)
+		evsel__warn_user_requested_cpus(evsel, user_cpus);
 
 	return evsel;
+out_err:
+	perf_cpu_map__put(cpus);
+	perf_cpu_map__put(pmu_cpus);
+	zfree(&evsel->name);
+	zfree(&evsel->metric_id);
+	free(evsel);
+	return NULL;
 }
 
 struct evsel *parse_events__add_event(int idx, struct perf_event_attr *attr,