Commit:

  b94f5118 ("kernel/watchdog: prevent false hardlockup on overloaded system")

tries to fix the following issue:

proc_write()
   set_sample_period()    <--- New sample period becoms visible
			  <----- Broken starts
   proc_watchdog_update()
     watchdog_enable_all_cpus()		watchdog_hrtimer_fn()
     update_watchdog_all_cpus()		   restart_timer(sample_period)
        watchdog_park_threads()

					thread->park()
					  disable_nmi()
			  <----- Broken ends

The reason why this is broken is that the update of the watchdog threshold
becomes immediately effective and visible for the hrtimer function which
uses that value to rearm the timer. But the NMI/perf side still uses the
old value up to the point where it is disabled. If the rate has been
lowered then the NMI can run fast enough to 'detect' a hard lockup because
the timer has not fired due to the longer period.

The patch 'fixed' this by adding a variable:

proc_write()
   set_sample_period()
					<----- Broken starts
   proc_watchdog_update()
     watchdog_enable_all_cpus()		watchdog_hrtimer_fn()
     update_watchdog_all_cpus()		   restart_timer(sample_period)
         watchdog_park_threads()
	  park_in_progress = 1
					<----- Broken ends
				        nmi_watchdog()
					  if (park_in_progress)
					     return;

The only effect of this variable was to make the window where the breakage
can hit small enough that it was not longer observable in testing. From a
correctness point of view it is a pointless bandaid which merily papers
over the root cause: the unsychronized update of the variable.

Looking deeper into the related code pathes unearthed similar problems in
the watchdog_start()/stop() functions.

 watchdog_start()
	perf_nmi_event_start()
	hrtimer_start()

 watchdog_stop()
	hrtimer_cancel()
	perf_nmi_event_stop()

In both cases the call order is wrong because if the tasks gets preempted
or the VM gets scheduled out long enough after the first call, then there is
a chance that the next NMI will see a stale hrtimer interrupt count and
trigger a false positive hard lockup splat.

Get rid of park_in_progress so the code can be gradually deobfuscated and
pruned from several layers of duct tape papering over the root cause,
which has been either ignored or not understood at all.

Once this is removed the underlying problem will be fixed by rewriting the
proc interface to do a proper synchronized update.

Address the start/stop() ordering problem as well by reverting the call
order, so this part is at least correct now.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1709052038270.2393@nanosSigned-off-by: Ingo Molnar <mingo@kernel.org>

The following deadlock is possible in the watchdog hotplug code:

  cpus_write_lock()
    ...
      takedown_cpu()
        smpboot_park_threads()
          smpboot_park_thread()
            kthread_park()
              ->park() := watchdog_disable()
                watchdog_nmi_disable()
                  perf_event_release_kernel();
                    put_event()
                      _free_event()
                        ->destroy() := hw_perf_event_destroy()
                          x86_release_hardware()
                            release_ds_buffers()
                              get_online_cpus()

when a per cpu watchdog perf event is destroyed which drops the last
reference to the PMU hardware. The cleanup code there invokes
get_online_cpus() which instantly deadlocks because the hotplug percpu
rwsem is write locked.

To solve this add a deferring mechanism:

  cpus_write_lock()
			   kthread_park()
			    watchdog_nmi_disable(deferred)
			      perf_event_disable(event);
			      move_event_to_deferred(event);
			   ....
  cpus_write_unlock()
  cleaup_deferred_events()
    perf_event_release_kernel()

This is still properly serialized against concurrent hotplug via the
cpu_add_remove_lock, which is held by the task which initiated the hotplug
event.

This is also used to handle event destruction when the watchdog threads are
parked via other mechanisms than CPU hotplug.
Analyzed-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.884469246@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

The self disabling feature is broken vs. CPU hotplug locking:

CPU 0			   CPU 1
cpus_write_lock();
 cpu_up(1)
   wait_for_completion()
			   ....
			   unpark_watchdog()
			   ->unpark()
			     perf_event_create() <- fails
			       watchdog_enable &= ~NMI_WATCHDOG;
			   ....
cpus_write_unlock();
			   CPU 2
cpus_write_lock()
 cpu_down(2)
   wait_for_completion()
			   wakeup(watchdog);
			     watchdog()
			     if (!(watchdog_enable & NMI_WATCHDOG))
				watchdog_nmi_disable()
				  perf_event_disable()
				  ....
				  cpus_read_lock();

			   stop_smpboot_threads()
			     park_watchdog();
			       wait_for_completion(watchdog->parked);

Result: End of hotplug and instantaneous full lockup of the machine.

There is a similar problem with disabling the watchdog via the user space
interface as the sysctl function fiddles with watchdog_enable directly.

It's very debatable whether this is required at all. If the watchdog works
nicely on N CPUs and it fails to enable on the N + 1 CPU either during
hotplug or because the user space interface disabled it via sysctl cpumask
and then some perf user grabbed the counter which is then unavailable for
the watchdog when the sysctl cpumask gets changed back.

There is no real justification for this.

One of the reasons WHY this is done is the utter stupidity of the init code
of the perf NMI watchdog. Instead of checking upfront at boot whether PERF
is available and functional at all, it just does this check at run time
over and over when user space fiddles with the sysctl. That's broken beyond
repair along with the idiotic error code dependent warn level printks and
the even more silly printk rate limiting.

If the init code checks whether perf works at boot time, then this mess can
be more or less avoided completely. Perf does not come magically into life
at runtime. Brain usage while coding is overrated.

Remove the cruft and add a temporary safe guard which gets removed later.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.806708429@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

The function is only used by the KVM init code. Mark it __init to prevent
creative abuse.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.727134632@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

Following patches will use the mutex for other purposes as well. Rename it
as it is not longer a proc specific thing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.647714850@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

The watchdog proc interface causes extensive recursive locking of the CPU
hotplug percpu rwsem, which is deadlock prone.

Replace the get/put_online_cpus() pairs with cpu_hotplug_disable()/enable()
calls for now. Later patches will remove that requirement completely.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.568079057@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

This interface has several issues:

 - It's causing recursive locking of the hotplug lock.

 - It's complete overkill to teardown all threads and then recreate them

The same can be achieved with the simple hardlockup_detector_perf_stop /
restart() interfaces. The abuse from the busy looping poweroff() loop of
PARISC has been solved as well.

Remove the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.487537732@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

The broken lockup_detector_suspend/resume() interface is going away. Use
the new lockup_detector_soft_poweroff() interface to stop the watchdog from
the busy looping power off routine.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: linux-parisc@vger.kernel.org
Link: http://lkml.kernel.org/r/20170912194146.407385557@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

PARISC has a a busy looping power off routine. If the watchdog is enabled
the watchdog timer will still fire, but the thread is not running, which
causes the softlockup watchdog to trigger.

Provide a interface which allows to turn the watchdog off.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: linux-parisc@vger.kernel.org
Link: http://lkml.kernel.org/r/20170912194146.327343752@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

The lockup_detector_suspend/resume() interface is broken in several ways
especially as it results in recursive locking of the CPU hotplug lock.

Use the new stop/restart interface in the perf NMI watchdog to temporarily
disable and reenable the already active watchdog events. That's enough to
handle it.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.247141871@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

Provide an interface to stop and restart perf NMI watchdog events on all
CPUs. This is only usable during init and especially for handling the perf
HT bug on Intel machines. It's safe to use it this way as nothing can
start/stop the NMI watchdog in parallel.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194146.167649596@linutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

Pull perf fixes from Ingo Molnar:
 "A handful of tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf stat: Wait for the correct child
  perf tools: Support running perf binaries with a dash in their name
  perf config: Check not only section->from_system_config but also item's
  perf ui progress: Fix progress update
  perf ui progress: Make sure we always define step value
  perf tools: Open perf.data with O_CLOEXEC flag
  tools lib api: Fix make DEBUG=1 build
  perf tests: Fix compile when libunwind's unwind.h is available
  tools include linux: Guard against redefinition of some macros

Pull scheduler fixes from Ingo Molnar:
 "Three CPU hotplug related fixes and a debugging improvement"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Add debugfs knob for "sched_debug"
  sched/core: WARN() when migrating to an offline CPU
  sched/fair: Plug hole between hotplug and active_load_balance()
  sched/fair: Avoid newidle balance for !active CPUs

Pull x86 fixes from Ingo Molnar:
 "The main changes are the PCID fixes from Andy, but there's also two
  hyperv fixes and two paravirt updates"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyper-v: Remove duplicated HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED definition
  x86/hyper-V: Allocate the IDT entry early in boot
  paravirt: Switch maintainer
  x86/paravirt: Remove no longer used paravirt functions
  x86/mm/64: Initialize CR4.PCIDE early
  x86/hibernate/64: Mask off CR3's PCID bits in the saved CR3
  x86/mm: Get rid of VM_BUG_ON in switch_tlb_irqs_off()

Pull OpenRISC fixlet from Stafford Horne:
 "Fix warning for upcoming work to remove linux/vmalloc.h from
  asm-generic/io.h"

* tag 'openrisc-for-linus' of git://github.com/openrisc/linux:
  openrisc: add forward declaration for struct vm_area_struct

Pull modules updates from Jessica Yu:
 "Summary of modules changes for the 4.14 merge window:

   - minor code cleanups and fixes

   - modpost: avoid building modules that have names that exceed the
     size of the name field in struct module"

* tag 'modules-for-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: Remove const attribute from alias for MODULE_DEVICE_TABLE
  module: fix ddebug_remove_module()
  modpost: abort if module name is too long

Another merge window, another MAINTAINERS file disaster.

People have serious problems with the alphabet and sorting, and poor
Jérôme Glisse and Radim Krčmář get their names mangled by locale issues,
turning them into some mangled mess (probably others do too, but those
two stood out when sorting things again).

And we now have two copies of the same 'AS3645A LED FLASH CONTROLLER
DRIVER' in the tree and in the MAINTAINERS file, but that's a separate
issue - the duplication is real, and I left them as two entries for the
same name.

This does not try to sort the actual section pattern entries, although I
may end up doing that later.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull clk updates from Stephen Boyd:
 "The diff is dominated by the Allwinner A10/A20 SoCs getting converted
  to the sunxi-ng framework. Otherwise, the heavy hitters are various
  drivers for SoCs like AT91, Amlogic, Renesas, and Rockchip. There are
  some other new clk drivers in here too but overall this is just a
  bunch of clk drivers for various different pieces of hardware and a
  collection of non-critical fixes for clk drivers.

  New Drivers:
   - Allwinner R40 SoCs
   - Renesas R-Car Gen3 USB 2.0 clock selector PHY
   - Atmel AT91 audio PLL
   - Uniphier PXs3 SoCs
   - ARC HSDK Board PLLs
   - AXS10X Board PLLs
   - STMicroelectronics STM32H743 SoCs

  Removed Drivers:
   - Non-compiling mb86s7x support

  Updates:
   - Allwinner A10/A20 SoCs converted to sunxi-ng framework
   - Allwinner H3 CPU clk fixes
   - Renesas R-Car D3 SoC
   - Renesas V2H and M3-W modules
   - Samsung Exynos5420/5422/5800 audio fixes
   - Rockchip fractional clk approximation fixes
   - Rockchip rk3126 SoC support within the rk3128 driver
   - Amlogic gxbb CEC32 and sd_emmc clks
   - Amlogic meson8b reset controller support
   - IDT VersaClock 5P49V5925/5P49V6901 support
   - Qualcomm MSM8996 SMMU clks
   - Various 'const' applications for struct clk_ops
   - si5351 PLL reset bugfix
   - Uniphier audio on LD11/LD20 and ethernet support on LD11/LD20/Pro4/PXs2
   - Assorted Tegra clk driver fixes"

* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (120 commits)
  clk: si5351: fix PLL reset
  ASoC: atmel-classd: remove aclk clock
  ASoC: atmel-classd: remove aclk clock from DT binding
  clk: at91: clk-generated: make gclk determine audio_pll rate
  clk: at91: clk-generated: create function to find best_diff
  clk: at91: add audio pll clock drivers
  dt-bindings: clk: at91: add audio plls to the compatible list
  clk: at91: clk-generated: remove useless divisor loop
  clk: mb86s7x: Drop non-building driver
  clk: ti: check for null return in strrchr to avoid null dereferencing
  clk: Don't write error code into divider register
  clk: uniphier: add video input subsystem clock
  clk: uniphier: add audio system clock
  clk: stm32h7: Add stm32h743 clock driver
  clk: gate: expose clk_gate_ops::is_enabled
  clk: nxp: clk-lpc32xx: rename clk_gate_is_enabled()
  clk: uniphier: add PXs3 clock data
  clk: hi6220: change watchdog clock source
  clk: Kconfig: Name RK805 in Kconfig for COMMON_CLK_RK808
  clk: cs2000: Add cs2000_set_saved_rate
  ...

Pull RTC updates from Alexandre Belloni:
 "Subsystem:
   - remove .open() and .release() RTC ops
   - constify i2c_device_id

  New driver:
   - Realtek RTD1295
   - Android emulator (goldfish) RTC

  Drivers:
   - ds1307: Beginning of a huge cleanup
   - s35390a: handle invalid RTC time
   - sun6i: external oscillator gate support"

* tag 'rtc-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (40 commits)
  rtc: ds1307: use octal permissions
  rtc: ds1307: fix braces
  rtc: ds1307: fix alignments and blank lines
  rtc: ds1307: use BIT
  rtc: ds1307: use u32
  rtc: ds1307: use sizeof
  rtc: ds1307: remove regs member
  rtc: Add Realtek RTD1295
  dt-bindings: rtc: Add Realtek RTD1295
  rtc: sun6i: Add support for the external oscillator gate
  rtc: goldfish: Add RTC driver for Android emulator
  dt-bindings: Add device tree binding for Goldfish RTC driver
  rtc: ds1307: add basic support for ds1341 chip
  rtc: ds1307: remove member nvram_offset from struct ds1307
  rtc: ds1307: factor out offset to struct chip_desc
  rtc: ds1307: factor out rtc_ops to struct chip_desc
  rtc: ds1307: factor out irq_handler to struct chip_desc
  rtc: ds1307: improve irq setup
  rtc: ds1307: constify struct chip_desc variables
  rtc: ds1307: improve trickle charger initialization
  ...

Pull sound fixes from Takashi Iwai:
 "Most of the commits are trivial cleanup patches, while one commit is a
  significant fix for the race at ALSA sequencer that was spotted by
  syzkaller"

* tag 'sound-fix-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: seq: Cancel pending autoload work at unbinding device
  ALSA: firewire: Use common error handling code in snd_motu_stream_start_duplex()
  ALSA: asihpi: Kill BUG_ON() usages
  ALSA: core: Use %pS printk format for direct addresses
  ALSA: ymfpci: Use common error handling code in snd_ymfpci_create()
  ALSA: ymfpci: Use common error handling code in snd_card_ymfpci_probe()
  ALSA: 6fire: Use common error handling code in usb6fire_chip_probe()
  ALSA: usx2y: Use common error handling code in submit_urbs()
  ALSA: us122l: Use common error handling code in us122l_create_card()
  ALSA: hdspm: Use common error handling code in snd_hdspm_probe()
  ALSA: rme9652: Use common code in hdsp_get_iobox_version()
  ALSA: maestro3: Use common error handling code in two functions

Pull SCSI fixes from James Bottomley:
 "A tiny update: one patch corrects a Kconfig problem with the shift of
  the SAS SMP code to BSG and the other removes a vestige of user space
  target mode"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: scsi_transport_sas: select BLK_DEV_BSGLIB
  scsi: Remove Scsi_Host.uspace_req_q

Pull block fixes from Jens Axboe:
 "Small collection of fixes that would be nice to have in -rc1. This
  contains:

   - NVMe pull request form Christoph, mostly with fixes for nvme-pci,
     host memory buffer in particular.

   - Error handling fixup for cgwb_create(), in case allocation of 'wb'
     fails. From Christophe Jaillet.

   - Ensure that trace_block_getrq() gets the 'dev' in an appropriate
     fashion, to avoid a potential NULL deref. From Greg Thelen.

   - Regression fix for dm-mq with blk-mq, fixing a problem with
     stacking IO schedulers. From me.

   - string.h fixup, fixing an issue with memcpy_and_pad(). This
     original change came in through an NVMe dependency, which is why
     I'm including it here. From Martin Wilck.

   - Fix potential int overflow in __blkdev_sectors_to_bio_pages(), from
     Mikulas.

   - MBR enable fix for sed-opal, from Scott"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: directly insert blk-mq request from blk_insert_cloned_request()
  mm/backing-dev.c: fix an error handling path in 'cgwb_create()'
  string.h: un-fortify memcpy_and_pad
  nvme-pci: implement the HMB entry number and size limitations
  nvme-pci: propagate (some) errors from host memory buffer setup
  nvme-pci: use appropriate initial chunk size for HMB allocation
  nvme-pci: fix host memory buffer allocation fallback
  nvme: fix lightnvm check
  block: fix integer overflow in __blkdev_sectors_to_bio_pages()
  block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled
  block: tolerate tracing of NULL bio

Pull documentation fixes from Jonathan Corbet:
 "A cleanup from Mauro that needed to wait for the media pull, plus a
  handful of other fixes that wandered in"

* tag 'docs-4.14' of git://git.lwn.net/linux:
  kokr/memory-barriers.txt: Apply atomic_t.txt change
  kokr/doc: Update memory-barriers.txt for read-to-write dependencies
  docs-rst: don't require adjustbox anymore
  docs-rst: conf.py: only setup notice box colors if Sphinx < 1.6
  docs-rst: conf.py: remove lscape from LaTeX preamble

Pull fuse updates from Miklos Szeredi:
 "This fixes a regression (spotted by the Sandstorm.io folks) in the pid
  namespace handling introduced in 4.12.

  There's also a fix for honoring sync/dsync flags for pwritev2()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: getattr cleanup
  fuse: honor iocb sync flags on write
  fuse: allow server to run in different pid_ns

Pull overlayfs updates from Miklos Szeredi:
 "This fixes d_ino correctness in readdir, which brings overlayfs on par
  with normal filesystems regarding inode number semantics, as long as
  all layers are on the same filesystem.

  There are also some bug fixes, one in particular (random ioctl's
  shouldn't be able to modify lower layers) that touches some vfs code,
  but of course no-op for non-overlay fs"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix false positive ESTALE on lookup
  ovl: don't allow writing ioctl on lower layer
  ovl: fix relatime for directories
  vfs: add flags to d_real()
  ovl: cleanup d_real for negative
  ovl: constant d_ino for non-merge dirs
  ovl: constant d_ino across copy up
  ovl: fix readdir error value
  ovl: check snprintf return

Commits:

  7dcf90e9 ("PCI: hv: Use vPCI protocol version 1.2")
  628f54cc ("x86/hyper-v: Support extended CPU ranges for TLB flush hypercalls")

added the same definition and they came in through different trees.
Fix the duplication.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/20170911150620.3998-1-vkuznets@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Allocate the hypervisor callback IDT entry early in the boot sequence.

The previous code would allocate the entry as part of registering the handler
when the vmbus driver loaded, and this caused a problem for the IDT cleanup
that Thomas is working on for v4.15.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: apw@canonical.com
Cc: devel@linuxdriverproject.org
Cc: gregkh@linuxfoundation.org
Cc: jasowang@redhat.com
Cc: olaf@aepfle.de
Link: http://lkml.kernel.org/r/20170908231557.2419-1-kys@exchange.microsoft.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Jeremy Fitzhardinge is stepping down as a paravirt maintainer. I'll
replace him.

While at it, update the file list to the actual pattern.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: chrisw@sous-sol.org
Cc: jeremy@goop.org
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170905143407.9227-1-jgross@suse.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

With removal of lguest some of the paravirt functions are no longer
needed:

	->read_cr4()
	->store_idt()
	->set_pmd_at()
	->set_pud_at()
	->pte_update()

Remove them.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: chrisw@sous-sol.org
Cc: jeremy@goop.org
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170904102527.25409-1-jgross@suse.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

cpu_init() is weird: it's called rather late (after early
identification and after most MMU state is initialized) on the boot
CPU but is called extremely early (before identification) on secondary
CPUs.  It's called just late enough on the boot CPU that its CR4 value
isn't propagated to mmu_cr4_features.

Even if we put CR4.PCIDE into mmu_cr4_features, we'd hit two
problems.  First, we'd crash in the trampoline code.  That's
fixable, and I tried that.  It turns out that mmu_cr4_features is
totally ignored by secondary_start_64(), though, so even with the
trampoline code fixed, it wouldn't help.

This means that we don't currently have CR4.PCIDE reliably initialized
before we start playing with cpu_tlbstate.  This is very fragile and
tends to cause boot failures if I make even small changes to the TLB
handling code.

Make it more robust: initialize CR4.PCIDE earlier on the boot CPU
and propagate it to secondary CPUs in start_secondary().

( Yes, this is ugly.  I think we should have improved mmu_cr4_features
  to actually control CR4 during secondary bootup, but that would be
  fairly intrusive at this stage. )
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: 660da7c9 ("x86/mm: Enable CR4.PCIDE on supported systems")
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Jiri reported a resume-from-hibernation failure triggered by PCID.
The root cause appears to be rather odd.  The hibernation asm
restores a CR3 value that comes from the image header.  If the image
kernel has PCID on, it's entirely reasonable for this CR3 value to
have one of the low 12 bits set.  The restore code restores it with
CR4.PCIDE=0, which means that those low 12 bits are accepted by the
CPU but are either ignored or interpreted as a caching mode.  This
is odd, but still works.  We blow up later when the image kernel
restores CR4, though, since changing CR4.PCIDE with CR3[11:0] != 0
is illegal.  Boom!

FWIW, it's entirely unclear to me what's supposed to happen if a PAE
kernel restores a non-PAE image or vice versa.  Ditto for LA57.
Reported-by: Jiri Kosina <jikos@kernel.org>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 660da7c9 ("x86/mm: Enable CR4.PCIDE on supported systems")
Link: http://lkml.kernel.org/r/18ca57090651a6341e97083883f9e814c4f14684.1504847163.git.luto@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

If we hit the VM_BUG_ON(), we're detecting a genuinely bad situation,
but we're very unlikely to get a useful call trace.

Make it a warning instead.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/3b4e06bbb382ca54a93218407c93925ff5871546.1504847163.git.luto@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-urgent-for-mingo-4.14-20170912' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

- Fix TUI progress bar when delta from new total from that of the
  previous update is greater than the progress "step" (screen width
  progress bar block))  (Jiri Olsa)

- Make tools/lib/api make DEBUG=1 build use -D_FORTIFY_SOURCE=2 not
  to cripple debuginfo, just like tools/perf/ does (Jiri Olsa)

- Avoid leaking the 'perf.data' file to workloads started from the
  'perf record' command line by using the O_CLOEXEC open flag (Jiri Olsa)

- Fix building when libunwind's 'unwind.h' file is present in the
  include path, clashing with tools/perf/util/unwind.h (Milian Wolff)

- Check per .perfconfig section entry flag, not just per section (Taeung Song)

- Support running perf binaries with a dash in their name, needed to
  run perf as an AppImage (Milian Wolff)

- Wait for the right child by using waitpid() when running workloads
  from 'perf stat', also to fix using perf as an AppImage (Milian Wolff)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've mostly tuned f2fs to provide better user
  experience for Android. Especially, we've worked on atomic write
  feature again with SQLite community in order to support it officially.
  And we added or modified several facilities to analyze and enhance IO
  behaviors.

  Major changes include:
   - add app/fs io stat
   - add inode checksum feature
   - support project/journalled quota
   - enhance atomic write with new ioctl() which exposes feature set
   - enhance background gc/discard/fstrim flows with new gc_urgent mode
   - add F2FS_IOC_FS{GET,SET}XATTR
   - fix some quota flows"

* tag 'f2fs-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (63 commits)
  f2fs: hurry up to issue discard after io interruption
  f2fs: fix to show correct discard_granularity in sysfs
  f2fs: detect dirty inode in evict_inode
  f2fs: clear radix tree dirty tag of pages whose dirty flag is cleared
  f2fs: speed up gc_urgent mode with SSR
  f2fs: better to wait for fstrim completion
  f2fs: avoid race in between read xattr & write xattr
  f2fs: make get_lock_data_page to handle encrypted inode
  f2fs: use generic terms used for encrypted block management
  f2fs: introduce f2fs_encrypted_file for clean-up
  Revert "f2fs: add a new function get_ssr_cost"
  f2fs: constify super_operations
  f2fs: fix to wake up all sleeping flusher
  f2fs: avoid race in between atomic_read & atomic_inc
  f2fs: remove unneeded parameter of change_curseg
  f2fs: update i_flags correctly
  f2fs: don't check inode's checksum if it was dirtied or writebacked
  f2fs: don't need to update inode checksum for recovery
  f2fs: trigger fdatasync for non-atomic_write file
  f2fs: fix to avoid race in between aio and gc
  ...

Pull ceph updates from Ilya Dryomov:
 "The highlights include:

   - a large series of fixes and improvements to the snapshot-handling
     code (Zheng Yan)

   - individual read/write OSD requests passed down to libceph are now
     limited to 16M in size to avoid hitting OSD-side limits (Zheng Yan)

   - encode MStatfs v2 message to allow for more accurate space usage
     reporting (Douglas Fuller)

   - switch to the new writeback error tracking infrastructure (Jeff
     Layton)"

* tag 'ceph-for-4.14-rc1' of git://github.com/ceph/ceph-client: (35 commits)
  ceph: stop on-going cached readdir if mds revokes FILE_SHARED cap
  ceph: wait on writeback after writing snapshot data
  ceph: fix capsnap dirty pages accounting
  ceph: ignore wbc->range_{start,end} when write back snapshot data
  ceph: fix "range cyclic" mode writepages
  ceph: cleanup local variables in ceph_writepages_start()
  ceph: optimize pagevec iterating in ceph_writepages_start()
  ceph: make writepage_nounlock() invalidate page that beyonds EOF
  ceph: properly get capsnap's size in get_oldest_context()
  ceph: remove stale check in ceph_invalidatepage()
  ceph: queue cap snap only when snap realm's context changes
  ceph: handle race between vmtruncate and queuing cap snap
  ceph: fix message order check in handle_cap_export()
  ceph: fix NULL pointer dereference in ceph_flush_snaps()
  ceph: adjust 36 checks for NULL pointers
  ceph: delete an unnecessary return statement in update_dentry_lease()
  ceph: ENOMEM pr_err in __get_or_create_frag() is redundant
  ceph: check negative offsets in ceph_llseek()
  ceph: more accurate statfs
  ceph: properly set snap follows for cap reconnect
  ...

If using a kernel with CONFIG_XFS_RT=y and we set the RHINHERIT flag on
a directory in a filesystem that does not have a realtime device and
create a new file in that directory, it gets marked as a real time file.
When data is written and a fsync is issued, the filesystem attempts to
flush a non-existent rt device during the fsync process.

This results in a crash dereferencing a null buftarg pointer in
xfs_blkdev_issue_flush():

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: xfs_blkdev_issue_flush+0xd/0x20
  .....
  Call Trace:
    xfs_file_fsync+0x188/0x1c0
    vfs_fsync_range+0x3b/0xa0
    do_fsync+0x3d/0x70
    SyS_fsync+0x10/0x20
    do_syscall_64+0x4d/0xb0
    entry_SYSCALL64_slow_path+0x25/0x25

Setting RT inode flags does not require special privileges so any
unprivileged user can cause this oops to occur.  To reproduce, confirm
kernel is compiled with CONFIG_XFS_RT=y and run:

  # mkfs.xfs -f /dev/pmem0
  # mount /dev/pmem0 /mnt/test
  # mkdir /mnt/test/foo
  # xfs_io -c 'chattr +t' /mnt/test/foo
  # xfs_io -f -c 'pwrite 0 5m' -c fsync /mnt/test/foo/bar

Or just run xfstests with MKFS_OPTIONS="-d rtinherit=1" and wait.

Kernels built with CONFIG_XFS_RT=n are not exposed to this bug.

Fixes: f538d4da ("[XFS] write barrier support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Richard Wareing <rwareing@fb.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull dma-mapping updates from Christoph Hellwig:

 - removal of the old dma_alloc_noncoherent interface

 - remove unused flags to dma_declare_coherent_memory

 - restrict OF DMA configuration to specific physical busses

 - use the iommu mailing list for dma-mapping questions and patches

* tag 'dma-mapping-4.14' of git://git.infradead.org/users/hch/dma-mapping:
  dma-coherent: fix dma_declare_coherent_memory() logic error
  ARM: imx: mx31moboard: Remove unused 'dma' variable
  dma-coherent: remove an unused variable
  MAINTAINERS: use the iommu list for the dma-mapping subsystem
  dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags
  dma-coherent: remove the DMA_MEMORY_INCLUDES_CHILDREN flag
  of: restrict DMA configuration
  dma-mapping: remove dma_alloc_noncoherent and dma_free_noncoherent
  i825xx: switch to switch to dma_alloc_attrs
  au1000_eth: switch to dma_alloc_attrs
  sgiseeq: switch to dma_alloc_attrs
  dma-mapping: reduce dma_mapping_error inline bloat

Pull uuid updates from Christoph Hellwig:
 "Just a single conversion to the new UUID API for this merge window"

* tag 'uuid-for-4.14' of git://git.infradead.org/users/hch/uuid:
  efi: switch to use new generic UUID API

Pull selinux updates from Paul Moore:
 "A relatively quiet period for SELinux, 11 patches with only two/three
  having any substantive changes.

  These noteworthy changes include another tweak to the NNP/nosuid
  handling, per-file labeling for cgroups, and an object class fix for
  AF_UNIX/SOCK_RAW sockets; the rest of the changes are minor tweaks or
  administrative updates (Stephen's email update explains the file
  explosion in the diffstat).

  Everything passes the selinux-testsuite"

[ Also a couple of small patches from the security tree from Tetsuo
  Handa for Tomoyo and LSM cleanup. The separation of security policy
  updates wasn't all that clean - Linus ]

* tag 'selinux-pr-20170831' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: constify nf_hook_ops
  selinux: allow per-file labeling for cgroupfs
  lsm_audit: update my email address
  selinux: update my email address
  MAINTAINERS: update the NetLabel and Labeled Networking information
  selinux: use GFP_NOWAIT in the AVC kmem_caches
  selinux: Generalize support for NNP/nosuid SELinux domain transitions
  selinux: genheaders should fail if too many permissions are defined
  selinux: update the selinux info in MAINTAINERS
  credits: update Paul Moore's info
  selinux: Assign proper class to PF_UNIX/SOCK_RAW sockets
  tomoyo: Update URLs in Documentation/admin-guide/LSM/tomoyo.rst
  LSM: Remove security_task_create() hook.

Pull x86 fixes from Ingo Molnar:
 "Two fixes: dead code removal, plus a SME memory encryption fix on
  32-bit kernels that crashed Xen guests"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Remove unused and undefined __generic_processor_info() declaration
  x86/mm: Make the SME mask a u64