commit 3f2552f7e9c5abef2775c53f7af66532f8bf65bc upstream.

tick_freeze() introduced by suspend-to-idle in commit 124cf9117c5f ("PM /
sleep: Make it possible to quiesce timers during suspend-to-idle") uses
timekeeping_suspend() instead of syscore_suspend() during
suspend-to-idle. As a consequence generic sched_clock will keep going
because sched_clock_suspend() and sched_clock_resume() are not invoked
during suspend-to-idle which can result in a generic sched_clock wrap.

On a ARM system with suspend-to-idle enabled, sched_clock is registered
as "56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns", which
means the real wrapping duration is 8796093022202ns.

[  134.551779] suspend-to-idle suspend (timekeeping_suspend())
[ 1204.912239] suspend-to-idle resume (timekeeping_resume())
......
[ 1206.912239] suspend-to-idle suspend (timekeeping_suspend())
[ 5880.502807] suspend-to-idle resume (timekeeping_resume())
......
[ 6000.403724] suspend-to-idle suspend (timekeeping_suspend())
[ 8035.753167] suspend-to-idle resume  (timekeeping_resume())
......
[ 8795.786684] (2)[321:charger_thread]......
[ 8795.788387] (2)[321:charger_thread]......
[    0.057226] (0)[0:swapper/0]......
[    0.061447] (2)[0:swapper/2]......

sched_clock was not stopped during suspend-to-idle, and sched_clock_poll
hrtimer was not expired because timekeeping_suspend() was invoked during
suspend-to-idle. It makes sched_clock wrap at kernel time 8796s.

To prevent this, invoke sched_clock_suspend() and sched_clock_resume() in
tick_freeze() together with timekeeping_suspend() and timekeeping_resume().

Fixes: 124cf9117c5f (PM / sleep: Make it possible to quiesce timers during suspend-to-idle)
Signed-off-by: Chang-An Chen <chang-an.chen@mediatek.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: <linux-mediatek@lists.infradead.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: <kuohong.wang@mediatek.com>
Cc: <freddy.hsin@mediatek.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1553828349-8914-1-git-send-email-chang-an.chen@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 07d7e12091f4ab869cc6a4bb276399057e73b0b3 upstream.

To calculate a remaining time, it's required to subtract the current time
from the expiration time. In alarm_timer_remaining() the arguments of
ktime_sub are swapped.

Fixes: d653d8457c76 ("alarmtimer: Implement remaining callback")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190408041542.26338-1-avagin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ce10a5b3954f2514af726beb78ed8d7350c5e41c ]

tk_core.seq is initialized open coded, but that misses to initialize the
lockdep map when lockdep is enabled. Lockdep splats involving tk_core seq
consequently lack a name and are hard to read.

Use the proper initializer which takes care of the lockdep map
initialization.

[ tglx: Massaged changelog ]

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: tj@kernel.org
Cc: johannes.berg@intel.com
Link: https://lkml.kernel.org/r/20181128234325.110011-12-bvanassche@acm.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 93ad0fc088c5b4631f796c995bdd27a082ef33a6 upstream.

The recent commit which prevented a division by 0 issue in the alarm timer
code broke posix CPU timers as an unwanted side effect.

The reason is that the common rearm code checks for timer->it_interval
being 0 now. What went unnoticed is that the posix cpu timer setup does not
initialize timer->it_interval as it stores the interval in CPU timer
specific storage. The reason for the separate storage is historical as the
posix CPU timers always had a 64bit nanoseconds representation internally
while timer->it_interval is type ktime_t which used to be a modified
timespec representation on 32bit machines.

Instead of reverting the offending commit and fixing the alarmtimer issue
in the alarmtimer code, store the interval in timer->it_interval at CPU
timer setup time so the common code check works. This also repairs the
existing inconistency of the posix CPU timer code which kept a single shot
timer armed despite of the interval being 0.

The separate storage can be removed in mainline, but that needs to be a
separate commit as the current one has to be backported to stable kernels.

Fixes: 0e334db6bb4b ("posix-timers: Fix division by zero bug")
Reported-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190111133500.840117406@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0e334db6bb4b1fd1e2d72c1f3d8f004313cd9f94 upstream.

The signal delivery path of posix-timers can try to rearm the timer even if
the interval is zero. That's handled for the common case (hrtimer) but not
for alarm timers. In that case the forwarding function raises a division by
zero exception.

The handling for hrtimer based posix timers is wrong because it marks the
timer as active despite the fact that it is stopped.

Move the check from common_hrtimer_rearm() to posixtimer_rearm() to cure
both issues.

Reported-by: syzbot+9d38bedac9cc77b8ad5e@syzkaller.appspotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: sboyd@kernel.org
Cc: stable@vger.kernel.org
Cc: syzkaller-bugs@googlegroups.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1812171328050.1880@nanos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

I turns out that the silly spawn kthread from worker was actually needed.

clocksource_watchdog_kthread() cannot be called directly from
clocksource_watchdog_work(), because clocksource_select() calls
timekeeping_notify() which uses stop_machine(). One cannot use
stop_machine() from a workqueue() due lock inversions wrt CPU hotplug.

Revert the patch but add a comment that explain why we jump through such
apparently silly hoops.

Fixes: 7197e77abcb6 ("clocksource: Remove kthread")
Reported-by: Siegfried Metz <frame@mailbox.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Tested-by: Kevin Shanahan <kevin@shanahan.id.au>
Tested-by: viktor_jaegerskuepper@freenet.de
Tested-by: Siegfried Metz <frame@mailbox.org>
Cc: rafael.j.wysocki@intel.com
Cc: len.brown@intel.com
Cc: diego.viola@gmail.com
Cc: rui.zhang@intel.com
Cc: bjorn.andersson@linaro.org
Link: https://lkml.kernel.org/r/20180905084158.GR24124@hirez.programming.kicks-ass.net

Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...

Pull parisc updates from Helge Deller:

 - parisc now uses the generic dma_noncoherent_ops implementation
   (Christoph Hellwig)

 - further memory barrier and spinlock improvements (John David Anglin)

 - prepare removal of current_text_addr() functions (Nick Desaulniers)

 - improve kernel stack unwinding on parisc (me)

 - drop ENOTSUP which was defined on parisc only (me)

* 'parisc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix and improve kernel stack unwinding
  parisc: Remove unnecessary barriers from spinlock.h
  parisc: Remove ordered stores from syscall.S
  parisc: prefer _THIS_IP_ and _RET_IP_ statement expressions
  parisc: Add HAVE_REGS_AND_STACK_ACCESS_API feature
  parisc: Drop architecture-specific ENOTSUP define
  parisc: use generic dma_noncoherent_ops
  parisc: always use flush_kernel_dcache_range for DMA cache maintainance
  parisc: merge pcx_dma_ops and pcxl_dma_ops

Pull x86 timer updates from Thomas Gleixner:
 "Early TSC based time stamping to allow better boot time analysis.

  This comes with a general cleanup of the TSC calibration code which
  grew warts and duct taping over the years and removes 250 lines of
  code. Initiated and mostly implemented by Pavel with help from various
  folks"

* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  x86/kvmclock: Mark kvm_get_preset_lpj() as __init
  x86/tsc: Consolidate init code
  sched/clock: Disable interrupts when calling generic_sched_clock_init()
  timekeeping: Prevent false warning when persistent clock is not available
  sched/clock: Close a hole in sched_clock_init()
  x86/tsc: Make use of tsc_calibrate_cpu_early()
  x86/tsc: Split native_calibrate_cpu() into early and late parts
  sched/clock: Use static key for sched_clock_running
  sched/clock: Enable sched clock early
  sched/clock: Move sched clock initialization and merge with generic clock
  x86/tsc: Use TSC as sched clock early
  x86/tsc: Initialize cyc2ns when tsc frequency is determined
  x86/tsc: Calibrate tsc only once
  ARM/time: Remove read_boot_clock64()
  s390/time: Remove read_boot_clock64()
  timekeeping: Default boot time offset to local_clock()
  timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()
  s390/time: Add read_persistent_wall_and_boot_offset()
  x86/xen/time: Output xen sched_clock time from 0
  x86/xen/time: Initialize pv xen time in init_hypervisor_platform()
  ...

Pull timer updates from Thomas Gleixner:
 "The timers departement more or less proudly presents:

   - More Y2038 timekeeping work mostly in the core code. The work is
     slowly, but steadily targeting the actuall syscalls.

   - Enhanced timekeeping suspend/resume support by utilizing
     clocksources which do not stop during suspend, but are otherwise
     not the main timekeeping clocksources.

   - Make NTP adjustmets more accurate and immediate when the frequency
     is set directly and not incrementally.

   - Sanitize the overrung handing of posix timers

   - A new timer driver for Mediatek SoCs

   - The usual pile of fixes and updates all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  clockevents: Warn if cpu_all_mask is used as cpumask
  tick/broadcast-hrtimer: Use cpu_possible_mask for ce_broadcast_hrtimer
  clocksource/drivers/arm_arch_timer: Fix bogus cpu_all_mask usage
  clocksource: ti-32k: Remove CLOCK_SOURCE_SUSPEND_NONSTOP flag
  timers: Clear timer_base::must_forward_clk with timer_base::lock held
  clocksource/drivers/sprd: Register one always-on timer to compensate suspend time
  clocksource/drivers/timer-mediatek: Add support for system timer
  clocksource/drivers/timer-mediatek: Convert the driver to timer-of
  clocksource/drivers/timer-mediatek: Use specific prefix for GPT
  clocksource/drivers/timer-mediatek: Rename mtk_timer to timer-mediatek
  clocksource/drivers/timer-mediatek: Add system timer bindings
  clocksource/drivers: Set clockevent device cpumask to cpu_possible_mask
  time: Introduce one suspend clocksource to compensate the suspend time
  time: Fix extra sleeptime injection when suspend fails
  timekeeping/ntp: Constify some function arguments
  ntp: Use kstrtos64 for s64 variable
  ntp: Remove redundant arguments
  timer: Fix coding style
  ktime: Provide typesafe ktime_to_ns()
  hrtimer: Improve kernel message printing
  ...