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rtc: Handle errors correctly in rtc_irq_set_state()

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In rtc_irq_set_state, the code checks the correctness of the parameters,
but then goes on to unconditionally arms/disarms the hrtimer. Thus a
random task might arm/disarm rtc timer and surprise the real owner by
either generating events or by stopping them.

Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Thomas Gleixner
2011-07-22 09:12:50 +00:00
committed by John Stultz
parent ef68c8f87e
commit 53cc2820ac
1 changed files with 3 additions and 0 deletions
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3
drivers/rtc/interface.c
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@@ -656,6 +656,8 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled
err = -EBUSY; err = -EBUSY;
if (rtc->irq_task != task) if (rtc->irq_task != task)
err = -EACCES; err = -EACCES;
if (err)
goto out;
if (enabled) { if (enabled) {
ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
@@ -664,6 +666,7 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled
hrtimer_cancel(&rtc->pie_timer); hrtimer_cancel(&rtc->pie_timer);
} }
rtc->pie_enabled = enabled; rtc->pie_enabled = enabled;
out:
spin_unlock_irqrestore(&rtc->irq_task_lock, flags); spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
return err; return err;