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author | Thomas Gleixner <tglx@linutronix.de> | 2008-02-13 23:58:36 (GMT) |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2008-02-14 21:08:30 (GMT) |
commit | 63070a79ba482c274bad10ac8c4b587a3e011f2c (patch) | |
tree | 1ecb5e104d343d3e533b2469c54e6a1bcb19a9ac /kernel/hrtimer.c | |
parent | 5a7780e725d1bb4c3094fcc12f1c5c5faea1e988 (diff) | |
download | linux-fsl-qoriq-63070a79ba482c274bad10ac8c4b587a3e011f2c.tar.xz |
hrtimer: catch expired CLOCK_REALTIME timers early
A CLOCK_REALTIME timer, which has an absolute expiry time less than
the clock realtime offset calls with a negative delta into the clock
events code and triggers the WARN_ON() there.
This is a false positive and needs to be prevented. Check the result
of timer->expires - timer->base->offset right away and return -ETIME
right away.
Thanks to Frans Pop, who reported the problem and tested the fixes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Frans Pop <elendil@planet.nl>
Diffstat (limited to 'kernel/hrtimer.c')
-rw-r--r-- | kernel/hrtimer.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index c2893af..98bee01 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -442,6 +442,8 @@ static int hrtimer_reprogram(struct hrtimer *timer, ktime_t expires = ktime_sub(timer->expires, base->offset); int res; + WARN_ON_ONCE(timer->expires.tv64 < 0); + /* * When the callback is running, we do not reprogram the clock event * device. The timer callback is either running on a different CPU or @@ -452,6 +454,15 @@ static int hrtimer_reprogram(struct hrtimer *timer, if (hrtimer_callback_running(timer)) return 0; + /* + * CLOCK_REALTIME timer might be requested with an absolute + * expiry time which is less than base->offset. Nothing wrong + * about that, just avoid to call into the tick code, which + * has now objections against negative expiry values. + */ + if (expires.tv64 < 0) + return -ETIME; + if (expires.tv64 >= expires_next->tv64) return 0; |