linux-kernel - [PATCH] powercap: DTPM: Fix the missing cpufreq_cpu

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Message-Id: <20231201123205.1996790-1-lukasz.luba@arm.com>
Date:   Fri,  1 Dec 2023 12:32:05 +0000
From:   Lukasz Luba <lukasz.luba@....com>
To:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        daniel.lezcano@...aro.org
Cc:     lukasz.luba@....com, rafael@...nel.org, stable@...r.kernel.org
Subject: [PATCH] powercap: DTPM: Fix the missing cpufreq_cpu_put() calls

The policy returned by cpufreq_cpu_get() has to be released with
the help of cpufreq_cpu_put() to balance its kobject reference counter
properly.

Add the missing calls to cpufreq_cpu_put() in the code.

Fixes: 0aea2e4ec2a2 ("powercap/dtpm_cpu: Reset per_cpu variable in the release function")
Fixes: 0e8f68d7f048 ("powercap/drivers/dtpm: Add CPU energy model based support")
Cc: <stable@...r.kernel.org> # v5.10+
Signed-off-by: Lukasz Luba <lukasz.luba@....com>
---
 drivers/powercap/dtpm_cpu.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c
index 45bb7e2849d7..aac278e162d9 100644
--- a/drivers/powercap/dtpm_cpu.c
+++ b/drivers/powercap/dtpm_cpu.c
@@ -152,6 +152,8 @@ static void pd_release(struct dtpm *dtpm)
 	if (policy) {
 		for_each_cpu(dtpm_cpu->cpu, policy->related_cpus)
 			per_cpu(dtpm_per_cpu, dtpm_cpu->cpu) = NULL;
+
+		cpufreq_cpu_put(policy);
 	}
 	
 	kfree(dtpm_cpu);
@@ -204,12 +206,16 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
 		return 0;
 
 	pd = em_cpu_get(cpu);
-	if (!pd || em_is_artificial(pd))
-		return -EINVAL;
+	if (!pd || em_is_artificial(pd)) {
+		ret = -EINVAL;
+		goto release_policy;
+	}
 
 	dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL);
-	if (!dtpm_cpu)
-		return -ENOMEM;
+	if (!dtpm_cpu) {
+		ret = -ENOMEM;
+		goto release_policy;
+	}
 
 	dtpm_init(&dtpm_cpu->dtpm, &dtpm_ops);
 	dtpm_cpu->cpu = cpu;
@@ -231,6 +237,7 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
 	if (ret)
 		goto out_dtpm_unregister;
 
+	cpufreq_cpu_put(policy);
 	return 0;
 
 out_dtpm_unregister:
@@ -242,6 +249,8 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
 		per_cpu(dtpm_per_cpu, cpu) = NULL;
 	kfree(dtpm_cpu);
 
+release_policy:
+	cpufreq_cpu_put(policy);
 	return ret;
 }
 
-- 
2.25.1