From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: daniel.lezcano@linaro.org
Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
Javi Merino <javi.merino@kernel.org>,
Zhang Rui <rui.zhang@intel.com>,
Amit Kucheria <amit.kucheria@verdurent.com>,
linux-pm@vger.kernel.org (open list:THERMAL/CPU_COOLING),
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] thermal/drivers/cpufreq_cooling: Remove abusing WARN_ON
Date: Sat, 21 Mar 2020 20:31:07 +0100 [thread overview]
Message-ID: <20200321193107.21590-1-daniel.lezcano@linaro.org> (raw)
The WARN_ON macros are used at the entry functions state2power() and
set_cur_state().
state2power() is called with the max_state retrieved from
get_max_state which returns cpufreq_cdev->max_level, then it check if
max_state is > cpufreq_cdev->max_level. The test does not really makes
sense but let's assume we want to make sure to catch an error if the
code evolves. However the WARN_ON is overkill.
set_cur_state() is also called from userspace if we write to the
sysfs. It is easy to see a stack dumped by just writing to sysfs
/sys/class/thermal/cooling_device0/cur_state a value greater than
"max_level". A bit scary. Returing -EINVAL is enough.
Remove these WARN_ON.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
drivers/thermal/cpufreq_cooling.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
index af55ac08e1bd..d66791a71320 100644
--- a/drivers/thermal/cpufreq_cooling.c
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -273,7 +273,7 @@ static int cpufreq_state2power(struct thermal_cooling_device *cdev,
struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;
/* Request state should be less than max_level */
- if (WARN_ON(state > cpufreq_cdev->max_level))
+ if (state > cpufreq_cdev->max_level)
return -EINVAL;
num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus);
@@ -434,7 +434,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
int ret;
/* Request state should be less than max_level */
- if (WARN_ON(state > cpufreq_cdev->max_level))
+ if (state > cpufreq_cdev->max_level)
return -EINVAL;
/* Check if the old cooling action is same as new cooling action */
--
2.17.1
next reply other threads:[~2020-03-21 19:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-21 19:31 Daniel Lezcano [this message]
2020-03-23 3:18 ` [PATCH] thermal/drivers/cpufreq_cooling: Remove abusing WARN_ON Viresh Kumar
2020-03-24 2:30 ` Amit Kucheria
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