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authorViresh Kumar <viresh.kumar@linaro.org>2014-03-04 11:44:00 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-03-06 13:25:29 +0100
commit5a7e56a5d29071bcccd947dee6e3b9f8e4eb3309 (patch)
tree193f498e9337c598b56b00f1df8ee948a6184fe4
parent999976e0f6233322a878b0b7148c810544d6c8a8 (diff)
downloadlinux-5a7e56a5d29071bcccd947dee6e3b9f8e4eb3309.tar.gz
cpufreq: Initialize policy before making it available for others to use
Policy must be fully initialized before it is being made available for use by others. Otherwise cpufreq_cpu_get() would be able to grab a half initialized policy structure that might not have affected_cpus (for example) populated. Then, anybody accessing those fields will get a wrong value and that will lead to unpredictable results. In order to fix this, do all the necessary initialization before we make the policy structure available via cpufreq_cpu_get(). That will guarantee that any code accessing fields of the policy will get correct data from them. Reported-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [rjw: Changelog] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/cpufreq/cpufreq.c28
1 files changed, 14 insertions, 14 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index c4cacabbbb55..d6622689d000 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1109,6 +1109,20 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
goto err_set_policy_cpu;
}
+ /* related cpus should atleast have policy->cpus */
+ cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
+
+ /*
+ * affected cpus must always be the one, which are online. We aren't
+ * managing offline cpus here.
+ */
+ cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
+
+ if (!frozen) {
+ policy->user_policy.min = policy->min;
+ policy->user_policy.max = policy->max;
+ }
+
write_lock_irqsave(&cpufreq_driver_lock, flags);
for_each_cpu(j, policy->cpus)
per_cpu(cpufreq_cpu_data, j) = policy;
@@ -1162,20 +1176,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
}
}
- /* related cpus should atleast have policy->cpus */
- cpumask_or(policy->related_cpus, policy->related_cpus, policy->cpus);
-
- /*
- * affected cpus must always be the one, which are online. We aren't
- * managing offline cpus here.
- */
- cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);
-
- if (!frozen) {
- policy->user_policy.min = policy->min;
- policy->user_policy.max = policy->max;
- }
-
blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
CPUFREQ_START, policy);