Jason Wessel deda2e8196 timekeeping: Fix overflow in rawtime tv_nsec on 32 bit archs ... The tv_nsec is a long and when added to the shifted interval it can wrap and become negative which later causes looping problems in the getrawmonotonic(). The edge case occurs when the system has slept for a short period of time of ~2 seconds. A trace printk of the values in this patch illustrate the problem: ftrace time stamp: log 43.716079: logarithmic_accumulation: raw: 3d0913 tv_nsec d687faa 43.718513: logarithmic_accumulation: raw: 3d0913 tv_nsec da588bd 43.722161: logarithmic_accumulation: raw: 3d0913 tv_nsec de291d0 46.349925: logarithmic_accumulation: raw: 7a122600 tv_nsec e1f9ae3 46.349930: logarithmic_accumulation: raw: 1e848980 tv_nsec 8831c0e3 The kernel starts looping at 46.349925 in the getrawmonotonic() due to the negative value from adding the raw value to tv_nsec. A simple solution is to accumulate into a u64, and then normalize it to a timespec_t. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> [ Reworked variable names and simplified some of the code. - John ] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2010-08-12 09:53:39 -07:00
..
clockevents.c	clockevent: Don't remove broadcast device when cpu is dead	2010-01-18 14:44:50 +01:00
clocksource.c	clocksource: Add __clocksource_updatefreq_hz/khz methods	2010-07-27 12:40:55 +02:00
jiffies.c	clocksource: Cleanup clocksource selection	2009-08-15 10:55:46 +02:00
Kconfig	time: Kill off CONFIG_GENERIC_TIME	2010-07-27 12:40:54 +02:00
Makefile	time: add function to convert between calendar time and broken-down time for universal use	2009-09-24 07:20:56 -07:00
ntp.c	ntp: Make time_adjust static	2010-03-23 17:19:37 +01:00
tick-broadcast.c	fix comment/printk typos concerning "already"	2010-07-11 21:45:40 +02:00
tick-common.c	clockevents: Convert to raw_spinlock	2009-12-14 23:55:34 +01:00
tick-internal.h	clockevents: Make tick_device_lock static	2009-12-14 23:55:34 +01:00
tick-oneshot.c	clockevents: Sanitize min_delta_ns adjustment and prevent overflows	2010-03-12 19:10:29 +01:00
tick-sched.c	Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-08-06 13:12:36 -07:00
timecompare.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
timeconv.c	time: add function to convert between calendar time and broken-down time for universal use	2009-09-24 07:20:56 -07:00
timekeeping.c	timekeeping: Fix overflow in rawtime tv_nsec on 32 bit archs	2010-08-12 09:53:39 -07:00
timer_list.c	sched: Intoduce get_cpu_iowait_time_us()	2010-05-09 19:35:27 +02:00
timer_stats.c	hrtimers: Convert to raw_spinlocks	2009-12-14 23:55:34 +01:00