Commit 94a26271 authored by Yu Liao's avatar Yu Liao Committed by Zheng Zengkai
Browse files

rtc: Cleanup for UIE timer/polling emulation support 

hulk inclusion
category: bugfix
bugzilla: 186781, https://gitee.com/openeuler/kernel/issues/I61CEW


CVE: NA

--------------------------------

Split out a function that does not acquire ops_lock from
rtc_update_irq_enable, in preparation for fixing RTC_RD_TIME
and RTC_UIE_ON race problem.

Signed-off-by: default avatarYu Liao <liaoyu15@huawei.com>
Reviewed-by: default avatarWei Li <liwei391@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 79dcb2b8

drivers/rtc/interface.c

+20 −14
Original line number Diff line number Diff line
@@ -543,20 +543,10 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
}

EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);



int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)

int __rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)

{

	int rc = 0, err;

	int rc = 0, err = 0;



	err = mutex_lock_interruptible(&rtc->ops_lock);

	if (err)

		return err;



#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL

	if (enabled == 0 && rtc->uie_irq_active) {

		mutex_unlock(&rtc->ops_lock);

		return rtc_dev_update_irq_enable_emul(rtc, 0);

	}

#endif

	/* make sure we're changing state */

	if (rtc->uie_rtctimer.enabled == enabled)

		goto out;
@@ -583,8 +573,6 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
	}



out:

	mutex_unlock(&rtc->ops_lock);



	/*

	 * __rtc_read_time() failed, this probably means that the RTC time has

	 * never been set or less probably there is a transient error on the
@@ -594,6 +582,24 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
	if (rc)

		return rc;



	return err;

}



int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)

{

	int err;



#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL

	if (enabled == 0 && rtc->uie_irq_active)

		return rtc_dev_update_irq_enable_emul(rtc, 0);

#endif



	err = mutex_lock_interruptible(&rtc->ops_lock);

	if (err)

		return err;

	err = __rtc_update_irq_enable(rtc, enabled);

	mutex_unlock(&rtc->ops_lock);



#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL

	/*

	 * Enable emulation if the driver returned -EINVAL to signal that it has

include/linux/rtc.h

+1 −0
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ extern void rtc_class_close(struct rtc_device *rtc); 
extern int rtc_irq_set_state(struct rtc_device *rtc, int enabled);

extern int rtc_irq_set_freq(struct rtc_device *rtc, int freq);

extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);

extern int __rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);

extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);

extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,

						unsigned int enabled);