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authorBrendan Jackman <brendan.jackman@arm.com>2016-08-17 17:14:59 +0200
committerZhang Rui <rui.zhang@intel.com>2016-08-19 15:32:18 +0200
commita305a4387acb01cecadeeea5151c049a022a1bfc (patch)
tree4563fb3c6b8956491b1326ba5ec3d160b9850fda /drivers/thermal
parentLinux 4.8-rc2 (diff)
downloadlinux-a305a4387acb01cecadeeea5151c049a022a1bfc.tar.xz
linux-a305a4387acb01cecadeeea5151c049a022a1bfc.zip
thermal: cpu_cooling: Fix NULL dereference in cpufreq_state2power
Currently all CPU cooling devices share a `struct thermal_cooling_device_ops` instance. The thermal core uses the presence of functions in this struct to determine if a cooling device has a power model (see cdev_is_power_actor). cpu_cooling.c adds the power model functions to the shared struct when a device is registered with a power model. Therefore, if a CPU cooling device is registered using [of_]cpufreq_power_cooling_register, _all_ devices will be determined to have a power model, including any registered with [of_]cpufreq_cooling_register. This can result in cpufreq_state2power being called on a device where dyn_power_table is NULL. With this commit, instead of having a shared thermal_cooling_device_ops which is mutated, we have two versions: one with the power functions and one without. Signed-off-by: Brendan Jackman <brendan.jackman@arm.com> Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Javi Merino <javi.merino@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Javi Merino <javi.merino@arm.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Diffstat (limited to 'drivers/thermal')
-rw-r--r--drivers/thermal/cpu_cooling.c21
1 files changed, 16 insertions, 5 deletions
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 3788ed74c9ab..a32b41783b77 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -740,12 +740,22 @@ static int cpufreq_power2state(struct thermal_cooling_device *cdev,
}
/* Bind cpufreq callbacks to thermal cooling device ops */
+
static struct thermal_cooling_device_ops cpufreq_cooling_ops = {
.get_max_state = cpufreq_get_max_state,
.get_cur_state = cpufreq_get_cur_state,
.set_cur_state = cpufreq_set_cur_state,
};
+static struct thermal_cooling_device_ops cpufreq_power_cooling_ops = {
+ .get_max_state = cpufreq_get_max_state,
+ .get_cur_state = cpufreq_get_cur_state,
+ .set_cur_state = cpufreq_set_cur_state,
+ .get_requested_power = cpufreq_get_requested_power,
+ .state2power = cpufreq_state2power,
+ .power2state = cpufreq_power2state,
+};
+
/* Notifier for cpufreq policy change */
static struct notifier_block thermal_cpufreq_notifier_block = {
.notifier_call = cpufreq_thermal_notifier,
@@ -795,6 +805,7 @@ __cpufreq_cooling_register(struct device_node *np,
struct cpumask temp_mask;
unsigned int freq, i, num_cpus;
int ret;
+ struct thermal_cooling_device_ops *cooling_ops;
cpumask_and(&temp_mask, clip_cpus, cpu_online_mask);
policy = cpufreq_cpu_get(cpumask_first(&temp_mask));
@@ -850,10 +861,6 @@ __cpufreq_cooling_register(struct device_node *np,
cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
if (capacitance) {
- cpufreq_cooling_ops.get_requested_power =
- cpufreq_get_requested_power;
- cpufreq_cooling_ops.state2power = cpufreq_state2power;
- cpufreq_cooling_ops.power2state = cpufreq_power2state;
cpufreq_dev->plat_get_static_power = plat_static_func;
ret = build_dyn_power_table(cpufreq_dev, capacitance);
@@ -861,6 +868,10 @@ __cpufreq_cooling_register(struct device_node *np,
cool_dev = ERR_PTR(ret);
goto free_table;
}
+
+ cooling_ops = &cpufreq_power_cooling_ops;
+ } else {
+ cooling_ops = &cpufreq_cooling_ops;
}
ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
@@ -885,7 +896,7 @@ __cpufreq_cooling_register(struct device_node *np,
cpufreq_dev->id);
cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
- &cpufreq_cooling_ops);
+ cooling_ops);
if (IS_ERR(cool_dev))
goto remove_idr;