Messages in this thread Patch in this message | | | Date | Wed, 03 Aug 2011 15:00:35 -0700 | From | Greg KH <> | Subject | [015/102] rtc: handle errors correctly in rtc_irq_set_state() |
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3.0-stable review patch. If anyone has any objections, please let us know.
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From: Thomas Gleixner <tglx@linutronix.de>
commit 2c4f57d12df7696d65b0247bfd57fd082a7719e6 upstream.
The code checks the correctness of the parameters, but unconditionally arms/disarms the hrtimer.
The result is that a random task might arm/disarm rtc timer and surprise the real owner by either generating events or by stopping them.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ben Greear <greearb@candelatech.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/rtc/interface.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -656,6 +656,8 @@ int rtc_irq_set_state(struct rtc_device err = -EBUSY; if (rtc->irq_task != task) err = -EACCES; + if (err) + goto out; if (enabled) { ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); @@ -664,6 +666,7 @@ int rtc_irq_set_state(struct rtc_device hrtimer_cancel(&rtc->pie_timer); } rtc->pie_enabled = enabled; +out: spin_unlock_irqrestore(&rtc->irq_task_lock, flags); return err;
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