Messages in this thread Patch in this message | | | Date | Fri, 22 Feb 2008 16:31:18 -0800 | From | Greg KH <> | Subject | [patch 29/38] hrtimer: catch expired CLOCK_REALTIME timers early |
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2.6.24-stable review patch. If anyone has any objections, please let us know.
------------------ From: Thomas Gleixner <tglx@linutronix.de>
commit 63070a79ba482c274bad10ac8c4b587a3e011f2c
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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- kernel/hrtimer.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -427,6 +427,8 @@ static int hrtimer_reprogram(struct hrti 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 @@ -437,6 +439,15 @@ static int hrtimer_reprogram(struct hrti 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; --
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