On 30-07-15, 01:45, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <[email protected]> > > To protect against races with concurrent CPU online/offline, call > get_online_cpus() before registering a cpufreq driver. > > Signed-off-by: Rafael J. Wysocki <[email protected]> > --- > drivers/cpufreq/cpufreq.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > Index: linux-pm/drivers/cpufreq/cpufreq.c > =================================================================== > --- linux-pm.orig/drivers/cpufreq/cpufreq.c > +++ linux-pm/drivers/cpufreq/cpufreq.c > @@ -2471,10 +2471,14 @@ int cpufreq_register_driver(struct cpufr > > pr_debug("trying to register driver %s\n", driver_data->name); > > + /* Protect against concurrent CPU online/offline. */ > + get_online_cpus(); > + > write_lock_irqsave(&cpufreq_driver_lock, flags); > if (cpufreq_driver) { > write_unlock_irqrestore(&cpufreq_driver_lock, flags); > - return -EEXIST; > + ret = -EEXIST; > + goto out; > } > cpufreq_driver = driver_data; > write_unlock_irqrestore(&cpufreq_driver_lock, flags); > @@ -2513,7 +2517,10 @@ int cpufreq_register_driver(struct cpufr > register_hotcpu_notifier(&cpufreq_cpu_notifier); > pr_debug("driver %s up and running\n", driver_data->name); > > - return 0; > +out: > + put_online_cpus(); > + return ret; > + > err_if_unreg: > subsys_interface_unregister(&cpufreq_interface); > err_boost_unreg: > @@ -2523,7 +2530,7 @@ err_null_driver: > write_lock_irqsave(&cpufreq_driver_lock, flags); > cpufreq_driver = NULL; > write_unlock_irqrestore(&cpufreq_driver_lock, flags); > - return ret; > + goto out; > } > EXPORT_SYMBOL_GPL(cpufreq_register_driver);
Acked-by: Viresh Kumar <[email protected]> -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
