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authorThomas Gleixner <tglx@linutronix.de>2011-07-26 16:08:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-26 16:49:41 -0700
commit2c4f57d12df7696d65b0247bfd57fd082a7719e6 (patch)
tree920060fbbbc18643711e61526be4040e57118145
parentb45d59fb92f60c9c3cda01355d42b907b863e47a (diff)
rtc: handle errors correctly in rtc_irq_set_state()
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> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rtc/interface.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index df68618f6db..b6bf57f25cc 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -656,6 +656,8 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled
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 *rtc, struct rtc_task *task, int enabled
hrtimer_cancel(&rtc->pie_timer);
}
rtc->pie_enabled = enabled;
+out:
spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
return err;