perf/core: Clean up perf_try_init_event()

Make sure that perf_try_init_event() doesn't leave event->pmu nor
event->destroy set on failure.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Ravi Bangoria <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Peter Zijlstra

kernel/events/core.c

@@ -12109,40 +12109,51 @@ static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
 	if (ctx)
 		perf_event_ctx_unlock(event->group_leader, ctx);
 
-	if (!ret) {
-		if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
-		    has_extended_regs(event))
-			ret = -EOPNOTSUPP;
+	if (ret)
+		goto err_pmu;
 
-		if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE &&
-		    event_has_any_exclude_flag(event))
-			ret = -EINVAL;
+	if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
+	    has_extended_regs(event)) {
+		ret = -EOPNOTSUPP;
+		goto err_destroy;
+	}
 
-		if (pmu->scope != PERF_PMU_SCOPE_NONE && event->cpu >= 0) {
-			const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(pmu->scope, event->cpu);
-			struct cpumask *pmu_cpumask = perf_scope_cpumask(pmu->scope);
-			int cpu;
-
-			if (pmu_cpumask && cpumask) {
-				cpu = cpumask_any_and(pmu_cpumask, cpumask);
-				if (cpu >= nr_cpu_ids)
-					ret = -ENODEV;
-				else
-					event->event_caps |= PERF_EV_CAP_READ_SCOPE;
-			} else {
-				ret = -ENODEV;
-			}
-		}
+	if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE &&
+	    event_has_any_exclude_flag(event)) {
+		ret = -EINVAL;
+		goto err_destroy;
+	}
 
-		if (ret && event->destroy)
-			event->destroy(event);
+	if (pmu->scope != PERF_PMU_SCOPE_NONE && event->cpu >= 0) {
+		const struct cpumask *cpumask;
+		struct cpumask *pmu_cpumask;
+		int cpu;
+
+		cpumask = perf_scope_cpu_topology_cpumask(pmu->scope, event->cpu);
+		pmu_cpumask = perf_scope_cpumask(pmu->scope);
+
+		ret = -ENODEV;
+		if (!pmu_cpumask || !cpumask)
+			goto err_destroy;
+
+		cpu = cpumask_any_and(pmu_cpumask, cpumask);
+		if (cpu >= nr_cpu_ids)
+			goto err_destroy;
+
+		event->event_caps |= PERF_EV_CAP_READ_SCOPE;
 	}
 
-	if (ret) {
-		event->pmu = NULL;
-		module_put(pmu->module);
+	return 0;
+
+err_destroy:
+	if (event->destroy) {
+		event->destroy(event);
+		event->destroy = NULL;
 	}
 
+err_pmu:
+	event->pmu = NULL;
+	module_put(pmu->module);
 	return ret;
 }