Messages in this thread | | | Date | Wed, 27 Dec 2017 07:27:22 +0530 | From | gaurav jindal <> | Subject | Re: [PATCH]cpuidle: preventive check in cpuidle_select against crash |
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On Wed, Dec 27, 2017 at 01:42:58AM +0100, Rafael J. Wysocki wrote: > On Tue, Dec 26, 2017 at 8:26 AM, gaurav jindal > <gauravjindal1104@gmail.com> wrote: > > When selecting the idle state using cpuidle_select, there is no > > check on cpuidle_curr_governor. In cpuidle_switch_governor, > > cpuidle_currr_governor can be set to NULL to specify "disabled". > > How exactly?
In cpuidle_switch_governor:
/** * cpuidle_switch_governor - changes the governor * @gov: the new target governor * * NOTE: "gov" can be NULL to specify disabled * Must be called with cpuidle_lock acquired. */ int cpuidle_switch_governor(struct cpuidle_governor *gov) { struct cpuidle_device *dev;
if (gov == cpuidle_curr_governor) return 0;
cpuidle_uninstall_idle_handler();
if (cpuidle_curr_governor) { list_for_each_entry(dev, &cpuidle_detected_devices, device_list) cpuidle_disable_device(dev); }
cpuidle_curr_governor = gov;
This allows to set the cpuidle_switch_governor as NULL. Although there is no current code flow leading here, but it has a potential for bug in future. So may be better to have prevention.
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