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authorKonstantin Khlebnikov <khlebnikov@openvz.org>2012-12-15 00:22:02 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-01-03 13:11:18 +0100
commit56836fb4dab8fe906b934b231b04c33c180f8da5 (patch)
tree4ad98361223482eeb8b0f3a4485b7bb4ba4c012d /drivers/cpufreq/cpufreq_stats.c
parentd1c3ed669a2d452cacfb48c2d171a1f364dae2ed (diff)
downloadlinux-56836fb4dab8fe906b934b231b04c33c180f8da5.tar.bz2
cpufreq / stats: fix race between stats allocation and first usage
This patch forces complete struct cpufreq_stats allocation for all cpus before registering CPUFREQ_TRANSITION_NOTIFIER notifier, otherwise in some conditions cpufreq_stat_notifier_trans() can be called in the middle of stats allocation, in this case cpufreq_stats_table already exists, but stat->freq_table is NULL. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/cpufreq_stats.c')
-rw-r--r--drivers/cpufreq/cpufreq_stats.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index e40e50809644..9d7732b81044 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -364,18 +364,21 @@ static int __init cpufreq_stats_init(void)
if (ret)
return ret;
+ register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
+ for_each_online_cpu(cpu)
+ cpufreq_update_policy(cpu);
+
ret = cpufreq_register_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
if (ret) {
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
+ unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
+ for_each_online_cpu(cpu)
+ cpufreq_stats_free_table(cpu);
return ret;
}
- register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
- for_each_online_cpu(cpu) {
- cpufreq_update_policy(cpu);
- }
return 0;
}
static void __exit cpufreq_stats_exit(void)