1 files changed, 27 insertions, 30 deletions

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index b9f96c77527d..f3a2722ee4c0 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1229,6 +1229,8 @@ static void trace_sched_migrate_callback(void *data, struct task_struct *p, int
 	}
 }
 
+static bool monitor_enabled;
+
 static int register_migration_monitor(void)
 {
 	int ret = 0;
@@ -1237,16 +1239,25 @@ static int register_migration_monitor(void)
 	 * Timerlat thread migration check is only required when running timerlat in user-space.
 	 * Thus, enable callback only if timerlat is set with no workload.
 	 */
-	if (timerlat_enabled() && !test_bit(OSN_WORKLOAD, &osnoise_options))
+	if (timerlat_enabled() && !test_bit(OSN_WORKLOAD, &osnoise_options)) {
+		if (WARN_ON_ONCE(monitor_enabled))
+			return 0;
+
 		ret = register_trace_sched_migrate_task(trace_sched_migrate_callback, NULL);
+		if (!ret)
+			monitor_enabled = true;
+	}
 
 	return ret;
 }
 
 static void unregister_migration_monitor(void)
 {
-	if (timerlat_enabled() && !test_bit(OSN_WORKLOAD, &osnoise_options))
-		unregister_trace_sched_migrate_task(trace_sched_migrate_callback, NULL);
+	if (!monitor_enabled)
+		return;
+
+	unregister_trace_sched_migrate_task(trace_sched_migrate_callback, NULL);
+	monitor_enabled = false;
 }
 #else
 static int register_migration_monitor(void)
@@ -2083,26 +2094,21 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy)
 {
 	unsigned int cpu = smp_processor_id();
 
-	mutex_lock(&trace_types_lock);
+	guard(mutex)(&trace_types_lock);
 
 	if (!osnoise_has_registered_instances())
-		goto out_unlock_trace;
+		return;
 
-	mutex_lock(&interface_lock);
-	cpus_read_lock();
+	guard(mutex)(&interface_lock);
+	guard(cpus_read_lock)();
 
 	if (!cpu_online(cpu))
-		goto out_unlock;
+		return;
+
 	if (!cpumask_test_cpu(cpu, &osnoise_cpumask))
-		goto out_unlock;
+		return;
 
 	start_kthread(cpu);
-
-out_unlock:
-	cpus_read_unlock();
-	mutex_unlock(&interface_lock);
-out_unlock_trace:
-	mutex_unlock(&trace_types_lock);
 }
 
 static DECLARE_WORK(osnoise_hotplug_work, osnoise_hotplug_workfn);
@@ -2300,31 +2306,22 @@ static ssize_t
 osnoise_cpus_read(struct file *filp, char __user *ubuf, size_t count,
 		  loff_t *ppos)
 {
-	char *mask_str;
+	char *mask_str __free(kfree) = NULL;
 	int len;
 
-	mutex_lock(&interface_lock);
+	guard(mutex)(&interface_lock);
 
 	len = snprintf(NULL, 0, "%*pbl\n", cpumask_pr_args(&osnoise_cpumask)) + 1;
 	mask_str = kmalloc(len, GFP_KERNEL);
-	if (!mask_str) {
-		count = -ENOMEM;
-		goto out_unlock;
-	}
+	if (!mask_str)
+		return -ENOMEM;
 
 	len = snprintf(mask_str, len, "%*pbl\n", cpumask_pr_args(&osnoise_cpumask));
-	if (len >= count) {
-		count = -EINVAL;
-		goto out_free;
-	}
+	if (len >= count)
+		return -EINVAL;
 
 	count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len);
 
-out_free:
-	kfree(mask_str);
-out_unlock:
-	mutex_unlock(&interface_lock);
-
 	return count;
 }