Pull timer updates from Thomas Gleixner:
 "Rather large, but nothing exiting:

   - new range check for settimeofday() to prevent that boot time
     becomes negative.
   - fix for file time rounding
   - a few simplifications of the hrtimer code
   - fix for the proc/timerlist code so the output of clock realtime
     timers is accurate
   - more y2038 work
   - tree wide conversion of clockevent drivers to the new callbacks"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
  hrtimer: Handle failure of tick_init_highres() gracefully
  hrtimer: Unconfuse switch_hrtimer_base() a bit
  hrtimer: Simplify get_target_base() by returning current base
  hrtimer: Drop return code of hrtimer_switch_to_hres()
  time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
  time: Introduce current_kernel_time64()
  time: Introduce struct itimerspec64
  time: Add the common weak version of update_persistent_clock()
  time: Always make sure wall_to_monotonic isn't positive
  time: Fix nanosecond file time rounding in timespec_trunc()
  timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
  cris/time: Migrate to new 'set-state' interface
  kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
  xtensa/time: Migrate to new 'set-state' interface
  unicore/time: Migrate to new 'set-state' interface
  um/time: Migrate to new 'set-state' interface
  sparc/time: Migrate to new 'set-state' interface
  sh/localtimer: Migrate to new 'set-state' interface
  score/time: Migrate to new 'set-state' interface
  s390/time: Migrate to new 'set-state' interface
  ...

Pull NOHZ updates from Ingo Molnar:
 "The main changes, mostly written by Frederic Weisbecker, include:

   - Fix some jiffies based cputime assumptions.  (No real harm because
     the concerned code isn't used by full dynticks.)

   - Simplify jiffies <-> usecs conversions.  Remove dead code.

   - Remove early hacks on nohz full code that avoided messing up idle
     nohz internals.  Now nohz integrates well full and idle and such
     hack have become needless.

   - Restart nohz full tick from irq exit.  (A simplification and a
     preparation for future optimization on scheduler kick to nohz
     full)

   - Code cleanups.

   - Tile driver isolation enhancement on top of nohz.  (Chris Metcalf)"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz: Remove useless argument on tick_nohz_task_switch()
  nohz: Move tick_nohz_restart_sched_tick() above its users
  nohz: Restart nohz full tick from irq exit
  nohz: Remove idle task special case
  nohz: Prevent tilegx network driver interrupts
  alpha: Fix jiffies based cputime assumption
  apm32: Fix cputime == jiffies assumption
  jiffies: Remove HZ > USEC_PER_SEC special case

Pull RCU updates from Ingo Molnar:
 "The main RCU changes in this cycle are:

   - the combination of tree geometry-initialization simplifications and
     OS-jitter-reduction changes to expedited grace periods.  These two
     are stacked due to the large number of conflicts that would
     otherwise result.

   - privatize smp_mb__after_unlock_lock().

     This commit moves the definition of smp_mb__after_unlock_lock() to
     kernel/rcu/tree.h, in recognition of the fact that RCU is the only
     thing using this, that nothing else is likely to use it, and that
     it is likely to go away completely.

   - documentation updates.

   - torture-test updates.

   - misc fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  rcu,locking: Privatize smp_mb__after_unlock_lock()
  rcu: Silence lockdep false positive for expedited grace periods
  rcu: Don't disable CPU hotplug during OOM notifiers
  scripts: Make checkpatch.pl warn on expedited RCU grace periods
  rcu: Update MAINTAINERS entry
  rcu: Clarify CONFIG_RCU_EQS_DEBUG help text
  rcu: Fix backwards RCU_LOCKDEP_WARN() in synchronize_rcu_tasks()
  rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN()
  rcu: Make rcu_is_watching() really notrace
  cpu: Wait for RCU grace periods concurrently
  rcu: Create a synchronize_rcu_mult()
  rcu: Fix obsolete priority-boosting comment
  rcu: Use WRITE_ONCE in RCU_INIT_POINTER
  rcu: Hide RCU_NOCB_CPU behind RCU_EXPERT
  rcu: Add RCU-sched flavors of get-state and cond-sync
  rcu: Add fastpath bypassing funnel locking
  rcu: Rename RCU_GP_DONE_FQS to RCU_GP_DOING_FQS
  rcu: Pull out wait_event*() condition into helper function
  documentation: Describe new expedited stall warnings
  rcu: Add stall warnings to synchronize_sched_expedited()
  ...

Commit 75e3b37d0598 ("hrtimer: Drop return code of hrtimer_switch_to_hres()")
drops the return code of hrtimer_switch_to_hres(). While doing so, it also
drops the return statement itself on failure. This may cause a system hang.
Seen when running arm:multi_v7_defconfig in qemu with devicetree file
vexpress-v2p-ca9.

Fixes: 75e3b37d0598 ("hrtimer: Drop return code of hrtimer_switch_to_hres()")
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/1440231047-16256-1-git-send-email-linux@roeck-us.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

- A handful or y2038 related items
- A walltime to monotonic limit
- Small fixes for timespec_trunc() and timer_list output

The variable called "this_base" is confusing because its name suggests
it's of "struct hrtimer_clock_base" type, along with "base" and "new_base"
which doesn't help understanding this complicated function.

Make its name clearer and fix the misleading comment while at it.

[ tglx: Fixed the comment for real ]

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1439907509-9553-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Instead of fetching again the current cpu base, just take it from the
parameter.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1439907509-9553-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

lock_timer_base() cannot prevent the following :

CPU1 ( in __mod_timer()
timer->flags |= TIMER_MIGRATING;
spin_unlock(&base->lock);
base = new_base;
spin_lock(&base->lock);
// The next line clears TIMER_MIGRATING
timer->flags &= ~TIMER_BASEMASK;
                                  CPU2 (in lock_timer_base())
                                  see timer base is cpu0 base
                                  spin_lock_irqsave(&base->lock, *flags);
                                  if (timer->flags == tf)
                                       return base; // oops, wrong base
timer->flags |= base->cpu // too late

We must write timer->flags in one go, otherwise we can fool other cpus.

Fixes: bc7a34b8b9eb ("timer: Reduce timer migration overhead if disabled")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Christopherson <jon@jons.org>
Cc: David Miller <davem@davemloft.net>
Cc: xen-devel@lists.xen.org
Cc: david.vrabel@citrix.com
Cc: Sander Eikelenboom <linux@eikelenboom.it>
Link: http://lkml.kernel.org/r/1439831928.32680.11.camel@edumazet-glaptop2.roam.corp.google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>

It's not checked by the caller.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Link: http://lkml.kernel.org/r/20150811164043.538241ef@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The conversion between struct timespec and jiffies is not year 2038
safe on 32bit systems. Introduce timespec64_to_jiffies() and
jiffies_to_timespec64() functions which use struct timespec64 to
make it ready for 2038 issue.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>