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thermal: cpu_cooling: fix out of bounds access in time_in_idle 

In __cpufreq_cooling_register() we allocate the arrays for time_in_idle
and time_in_idle_timestamp to be as big as the number of cpus in this
cpufreq device.  However, in get_load() we access this array using the
cpu number as index, which can result in an out of bound access.

Index time_in_idle{,_timestamp} using the index in the cpufreq_device's
allowed_cpus mask, as we do for the load_cpu array in
cpufreq_get_requested_power()

Reported-by: Nicolas Boichat <drinkcat@chromium.org>
Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
hifive-unleashed-5.1
Javi Merino 2016-02-11 12:00:51 +00:00 committed by Eduardo Valentin
parent 26716ce124
commit a53b8394ec
1 changed files with 8 additions and 6 deletions
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14
drivers/thermal/cpu_cooling.c
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@ -377,26 +377,28 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_device,
* get_load() - get load for a cpu since last updated
* @cpufreq_device: &struct cpufreq_cooling_device for this cpu
* @cpu: cpu number
* @cpu_idx: index of the cpu in cpufreq_device->allowed_cpus
*
* Return: The average load of cpu @cpu in percentage since this
* function was last called.
*/
static u32 get_load(struct cpufreq_cooling_device *cpufreq_device, int cpu)
static u32 get_load(struct cpufreq_cooling_device *cpufreq_device, int cpu,
int cpu_idx)
{
u32 load;
u64 now, now_idle, delta_time, delta_idle;
now_idle = get_cpu_idle_time(cpu, &now, 0);
delta_idle = now_idle - cpufreq_device->time_in_idle[cpu];
delta_time = now - cpufreq_device->time_in_idle_timestamp[cpu];
delta_idle = now_idle - cpufreq_device->time_in_idle[cpu_idx];
delta_time = now - cpufreq_device->time_in_idle_timestamp[cpu_idx];
if (delta_time <= delta_idle)
load = 0;
else
load = div64_u64(100 * (delta_time - delta_idle), delta_time);
cpufreq_device->time_in_idle[cpu] = now_idle;
cpufreq_device->time_in_idle_timestamp[cpu] = now;
cpufreq_device->time_in_idle[cpu_idx] = now_idle;
cpufreq_device->time_in_idle_timestamp[cpu_idx] = now;
return load;
}
@ -598,7 +600,7 @@ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev,
u32 load;
if (cpu_online(cpu))
load = get_load(cpufreq_device, cpu);
load = get_load(cpufreq_device, cpu, i);
else
load = 0;