pm24.git/kernel/time, branch v4.8-rc4

timekeeping: Cap array access in timekeeping_debug

2016-08-24T07:34:32Z

It was reported that hibernation could fail on the 2nd attempt, where the system hangs at hibernate() -> syscore_resume() -> i8237A_resume() -> claim_dma_lock(), because the lock has already been taken. However there is actually no other process would like to grab this lock on that problematic platform. Further investigation showed that the problem is triggered by setting /sys/power/pm_trace to 1 before the 1st hibernation. Since once pm_trace is enabled, the rtc becomes unmeaningful after suspend, and meanwhile some BIOSes would like to adjust the 'invalid' RTC (e.g, smaller than 1970) to the release date of that motherboard during POST stage, thus after resumed, it may seem that the system had a significant long sleep time which is a completely meaningless value. Then in timekeeping_resume -> tk_debug_account_sleep_time, if the bit31 of the sleep time happened to be set to 1, fls() returns 32 and we add 1 to sleep_time_bin[32], which causes an out of bounds array access and therefor memory being overwritten. As depicted by System.map: 0xffffffff81c9d080 b sleep_time_bin 0xffffffff81c9d100 B dma_spin_lock the dma_spin_lock.val is set to 1, which caused this problem. This patch adds a sanity check in tk_debug_account_sleep_time() to ensure we don't index past the sleep_time_bin array. [jstultz: Problem diagnosed and original patch by Chen Yu, I've solved the issue slightly differently, but borrowed his excelent explanation of the issue here.] Fixes: 5c83545f24ab "power: Add option to log time spent in suspend" Reported-by: Janek Kozicki Reported-by: Chen Yu Signed-off-by: John Stultz Cc: linux-pm@vger.kernel.org Cc: Peter Zijlstra Cc: Xunlei Pang Cc: "Rafael J. Wysocki" Cc: stable Cc: Zhang Rui Link: http://lkml.kernel.org/r/1471993702-29148-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner

timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING

2016-08-24T07:34:31Z

When I added some extra sanity checking in timekeeping_get_ns() under CONFIG_DEBUG_TIMEKEEPING, I missed that the NMI safe __ktime_get_fast_ns() method was using timekeeping_get_ns(). Thus the locking added to the debug checks broke the NMI-safety of __ktime_get_fast_ns(). This patch open-codes the timekeeping_get_ns() logic for __ktime_get_fast_ns(), so can avoid any deadlocks in NMI. Fixes: 4ca22c2648f9 "timekeeping: Add warnings when overflows or underflows are observed" Reported-by: Steven Rostedt Reported-by: Peter Zijlstra Signed-off-by: John Stultz Cc: stable Link: http://lkml.kernel.org/r/1471993702-29148-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner

timers: Fix get_next_timer_interrupt() computation

2016-08-09T07:31:55Z

The tick_nohz_stop_sched_tick() routine is not properly canceling the sched timer when nothing is pending, because get_next_timer_interrupt() is no longer returning KTIME_MAX in that case. This causes periodic interrupts when none are needed. When determining the next interrupt time, we first use __next_timer_interrupt() to get the first expiring timer in the timer wheel. If no timer is found, we return the base clock value plus NEXT_TIMER_MAX_DELTA to indicate there is no timer in the timer wheel. Back in get_next_timer_interrupt(), we set the "expires" value by converting the timer wheel expiry (in ticks) to a nsec value. But we don't want to do this if the timer wheel expiry value indicates no timer; we want to return KTIME_MAX. Prior to commit 500462a9de65 ("timers: Switch to a non-cascading wheel") we checked base->active_timers to see if any timers were active, and if not, we didn't touch the expiry value and so properly returned KTIME_MAX. Now we don't have active_timers. To fix this, we now just check the timer wheel expiry value to see if it is "now + NEXT_TIMER_MAX_DELTA", and if it is, we don't try to compute a new value based on it, but instead simply let the KTIME_MAX value in expires remain. Fixes: 500462a9de65 "timers: Switch to a non-cascading wheel" Signed-off-by: Chris Metcalf Cc: Frederic Weisbecker Cc: Christoph Lameter Cc: John Stultz Link: http://lkml.kernel.org/r/1470688147-22287-1-git-send-email-cmetcalf@mellanox.com Signed-off-by: Thomas Gleixner

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-07-29T20:55:30Z

Pull smp hotplug updates from Thomas Gleixner: "This is the next part of the hotplug rework. - Convert all notifiers with a priority assigned - Convert all CPU_STARTING/DYING notifiers The final removal of the STARTING/DYING infrastructure will happen when the merge window closes. Another 700 hundred line of unpenetrable maze gone :)" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) timers/core: Correct callback order during CPU hot plug leds/trigger/cpu: Move from CPU_STARTING to ONLINE level powerpc/numa: Convert to hotplug state machine arm/perf: Fix hotplug state machine conversion irqchip/armada: Avoid unused function warnings ARC/time: Convert to hotplug state machine clocksource/atlas7: Convert to hotplug state machine clocksource/armada-370-xp: Convert to hotplug state machine clocksource/exynos_mct: Convert to hotplug state machine clocksource/arm_global_timer: Convert to hotplug state machine rcu: Convert rcutree to hotplug state machine KVM/arm/arm64/vgic-new: Convert to hotplug state machine smp/cfd: Convert core to hotplug state machine x86/x2apic: Convert to CPU hotplug state machine profile: Convert to hotplug state machine timers/core: Convert to hotplug state machine hrtimer: Convert to hotplug state machine x86/tboot: Convert to hotplug state machine arm64/armv8 deprecated: Convert to hotplug state machine hwtracing/coresight-etm4x: Convert to hotplug state machine ...

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-07-26T03:43:12Z

Pull timer updates from Thomas Gleixner: "This update provides the following changes: - The rework of the timer wheel which addresses the shortcomings of the current wheel (cascading, slow search for next expiring timer, etc). That's the first major change of the wheel in almost 20 years since Finn implemted it. - A large overhaul of the clocksource drivers init functions to consolidate the Device Tree initialization - Some more Y2038 updates - A capability fix for timerfd - Yet another clock chip driver - The usual pile of updates, comment improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits) tick/nohz: Optimize nohz idle enter clockevents: Make clockevents_subsys static clocksource/drivers/time-armada-370-xp: Fix return value check timers: Implement optimization for same expiry time in mod_timer() timers: Split out index calculation timers: Only wake softirq if necessary timers: Forward the wheel clock whenever possible timers/nohz: Remove pointless tick_nohz_kick_tick() function timers: Optimize collect_expired_timers() for NOHZ timers: Move __run_timers() function timers: Remove set_timer_slack() leftovers timers: Switch to a non-cascading wheel timers: Reduce the CPU index space to 256k timers: Give a few structs and members proper names hlist: Add hlist_is_singular_node() helper signals: Use hrtimer for sigtimedwait() timers: Remove the deprecated mod_timer_pinned() API timers, net/ipv4/inet: Initialize connection request timers as pinned timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned timers, drivers/tty/metag_da: Initialize the poll timer as pinned ...

Merge tag 'staging-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

2016-07-24T23:55:23Z

Pull staging and IIO driver updates from Greg KH: "Here is the big Staging and IIO driver update for 4.8-rc1. We ended up adding more code than removing, again, but it's not all that bad. Lots of cleanups all over the staging tree, and new IIO drivers, full details in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'staging-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (417 commits) drivers:iio:accel:mma8452: removed unwanted return statements drivers:iio:accel:mma8452: added cleanup provision in case of failure. iio: Add iio.git tree to MAINTAINERS iio:st_pressure: clean useless static channel initializers iio:st_pressure:lps22hb: temperature support iio:st_pressure:lps22hb: open drain support iio:st_pressure: temperature triggered buffering iio:st_pressure: document sampling gains iio:st_pressure: align storagebits on power of 2 iio:st_sensors: align on storagebits boundaries staging:iio:lis3l02dq drop separate driver iio: accel: st_accel: Add lis3l02dq support iio: adc: add missing of_node references to iio_dev iio: adc: ti-ads1015: add indio_dev->dev.of_node reference iio: potentiometer: Fix typo in Kconfig iio: potentiometer: mcp4531: Add device tree binding iio: potentiometer: mcp4531: Add device tree binding documentation iio: potentiometer: mcp4531: Add support for MCP454x, MCP456x, MCP464x and MCP466x iio:imu:mpu6050: icm20608 initial support iio: adc: max1363: Add device tree binding ...

tick/nohz: Optimize nohz idle enter

2016-07-19T11:48:24Z

tick_nohz_start_idle is called before checking whether the idle tick can be stopped. If the tick cannot be stopped, calling tick_nohz_start_idle() is pointless and just wasting CPU cycles. Only invoke tick_nohz_start_idle() when can_stop_idle_tick() returns true. A short one minute observation of the effect on ARM64 shows a reduction of calls by 1.5% thus optimizing the idle entry sequence. [tglx: Massaged changelog ] Co-developed-by: Sanjeev Yadav Signed-off-by: Gaurav Jindal Link: http://lkml.kernel.org/r/20160714120416.GB21099@gaurav.jindal@spreadtrum.com Signed-off-by: Thomas Gleixner

clockevents: Make clockevents_subsys static

2016-07-19T08:48:06Z

The clockevents_subsys struct is used for sysfs support and is not declared or used outside the file it is defined in. Fix the following warning by making it static: kernel/time/clockevents.c:648:17: warning: symbol 'clockevents_subsys' was not declared. Should it be static? Signed-off-by: Ben Dooks Cc: linux-kernel@lists.codethink.co.uk Link: http://lkml.kernel.org/r/1466178974-7105-1-git-send-email-ben.dooks@codethink.co.uk Signed-off-by: Thomas Gleixner

timers/core: Convert to hotplug state machine

2016-07-15T08:41:42Z

When tearing down, call timers_dead_cpu() before notify_dead(). There is a hidden dependency between: - timers - block multiqueue - rcutree If timers_dead_cpu() comes later than blk_mq_queue_reinit_notify() that latter function causes a RCU stall. Signed-off-by: Richard Cochran Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: John Stultz Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Thomas Gleixner Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.566790058@linutronix.de Signed-off-by: Ingo Molnar

hrtimer: Convert to hotplug state machine

2016-07-15T08:41:37Z

Split out the clockevents callbacks instead of piggybacking them on hrtimers. This gets rid of a POST_DEAD user. See commit: 54e88fad223c ("sched: Make sure timers have migrated before killing the migration_thread") We just move the callback state to the proper place in the state machine. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Rusty Russell Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.485419196@linutronix.de Signed-off-by: Ingo Molnar