Pull sound updates from Takashi Iwai:
 "This became a fairly large pull request.  In addition to the usual
  driver updates / fixes, there have been a high amount of cleanups in
  ASoC area, as well as control API helpers and kernel documentations
  fixes touching through the whole tree.

  In the driver side, the biggest changes are the support for new Intel
  SoC found on new x86 machines, and the updates of FireWire dice and
  oxfw drivers.

  Some remarkable items are below:

  ALSA core:
   - PCM mmap code cleanup, removal of arch-dependent codes
   - PCM xrun injection support
   - PCM hwptr tracepoint support
   - Refactoring of snd_pcm_action(), simplification of PCM locking
   - Robustified sequecner auto-load functionality
   - New control API helpers and lots of cleanups along with them
   - Lots of kerneldoc fixes and cleanups

  USB-audio:
   - The mixer resume code was largely rewritten, and the devices with
     quirks are resumed properly.
   - New hardware support: Focusrite Scarlett, Digidesign Mbox1,
     Denon/Marantz DACs, Zoom R16/24

  FireWire:
   - DICE driver updates with better duplex and sync support, including
     MIDI support
   - New OXFW driver for Oxford Semiconductor FW970/971 chipset,
     including the previous LaCie Speakers device.  Fullduplex and MIDI
     support included as well as DICE driver.

  HD-audio:
   - Refactoring the driver-caps quirk handling in snd-hda-intel
   - More consistent control names representing the topology better
   - Fixups: HP mute LED with ALC268 codec, Ideapad S210 built-in mic
     fix, ASUS Z99He laptop EAPD

  ASoC:
   - Conversion of AC'97 drivers to use regmap, bringing us closer to
     the removal of the ASoC level I/O code
   - Clean up a lot of old drivers that were open coding things that
     have subsequently been implemented in the core
   - Some DAPM performance improvements
   - Removal of the now seldom used CODEC mutex
   - Lots of updates for the newer Intel SoC support, including support
     for the DSP and some Cherrytrail and Braswell machine drivers
   - Support for Samsung boards using rt5631 as the CODEC
   - Removal of the obsolete AFEB9260 machine driver
   - Driver support for the TI TS3A227E headset driver used in some
     Chrombeooks

  Others:
   - ASIHPI driver update and cleanups
   - Lots of dev_*() printk conversions
   - Lots of trivial cleanups for the codes spotted by Coccinelle"

* tag 'sound-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (594 commits)
  ALSA: pcxhr: NULL dereference on probe failure
  ALSA: lola: NULL dereference on probe failure
  ALSA: hda - Add "eapd" model string for AD1986A codec
  ALSA: hda - Add EAPD fixup for ASUS Z99He laptop
  ALSA: oxfw: Add hwdep interface
  ALSA: oxfw: Add support for capture/playback MIDI messages
  ALSA: oxfw: add support for capturing PCM samples
  ALSA: oxfw: Add support AMDTP in-stream
  ALSA: oxfw: Add support for Behringer/Mackie devices
  ALSA: oxfw: Change the way to start stream
  ALSA: oxfw: Add proc interface for debugging purpose
  ALSA: oxfw: Change the way to make PCM rules/constraints
  ALSA: oxfw: Add support for AV/C stream format command to get/set supported stream formation
  ALSA: oxfw: Change the way to name card
  ALSA: dice: Add support for MIDI capture/playback
  ALSA: dice: Add support for capturing PCM samples
  ALSA: dice: Support for non SYT-Match sampling clock source mode
  ALSA: dice: Add support for duplex streams with synchronization
  ALSA: dice: Change the way to start stream
  ALSA: jack: Add dummy snd_jack_set_key() definition
  ...

Pull devicetree changes from Grant Likely:
 "Lots of activity in the devicetree code for v3.18.  Most of it is
  related to getting all of the overlay support code in place, but there
  are other important things in there.

  Highlights:

   - OF_RECONFIG notifiers for SPI, I2C and Platform devices.  Those
     subsystems can now respond to live changes to the device tree.

   - CONFIG_OF_OVERLAY method for applying live changes to the device
     tree

   - Removal of the of_allnodes list.  This used to be used to iterate
     over all the nodes in the device tree, but it is unnecessary
     because the same thing can be done by iterating over the list of
     child pointers.  Getting rid of of_allnodes saves some memory and
     avoids the possibility of of_allnodes being sorted differently from
     the child lists.

   - Support for retrieving original DTB blob via sysfs.  Needed by
     kexec.

   - More unittests

   - Documentation and minor bug fixes"

* tag 'devicetree-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux: (42 commits)
  of: Delete unnecessary check before calling "of_node_put()"
  of: Drop ->next pointer from struct device_node
  spi: Check for spi_of_notifier when CONFIG_OF_DYNAMIC=y
  of: support passing console options with stdout-path
  of: add optional options parameter to of_find_node_by_path()
  of: Add bindings for chosen node, stdout-path
  of: Remove unneeded and incorrect MODULE_DEVICE_TABLE
  ARM: dt: fix up PL011 device tree bindings
  of: base, fix of_property_read_string_helper kernel-doc
  of: remove select of non-existant OF_DEVICE config symbol
  spi/of: Add OF notifier handler
  spi/of: Create new device registration method and accessors
  i2c/of: Add OF_RECONFIG notifier handler
  i2c/of: Factor out Devicetree registration code
  of/overlay: Add overlay unittests
  of/overlay: Introduce DT overlay support
  of/reconfig: Add OF_DYNAMIC notifier for platform_bus_type
  of/reconfig: Always use the same structure for notifiers
  of/reconfig: Add debug output for OF_RECONFIG notifiers
  of/reconfig: Add empty stubs for the of_reconfig methods
  ...

Pull fbdev updates from Tomi Valkeinen:
 - support for mx6sl and mx6sx
 - OMAP HDMI audio rewrite to make it finally work
 - OMAP video PLL work to prepare for new DRA7xx SoCs
 - simplefb DT related improvements

* tag 'fbdev-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux: (81 commits)
  video: uvesafb: Deletion of an unnecessary check before the function call "platform_device_put"
  video: fbdev-VIA: Deletion of an unnecessary check before the function call "framebuffer_release"
  video: fbdev-MMP: Deletion of an unnecessary check before the function call "mmp_unregister_path"
  video: mx3fb: Deletion of an unnecessary check before the function call "backlight_device_unregister"
  video: fbdev-OMAP2: Deletion of unnecessary checks before the function call "i2c_put_adapter"
  video: fbdev-SIS: Deletion of unnecessary checks before the function call "pci_dev_put"
  video: smscufx: Deletion of unnecessary checks before the function call "vfree"
  video: udlfb: Deletion of unnecessary checks before the function call "vfree"
  video: uvesafb: Deletion of an unnecessary check before the function call "uvesafb_free"
  video: fbdev-LCDC: Deletion of an unnecessary check before the function call "vfree"
  video: fbdev: arkfb: suppress build warning
  video: fbdev: s3fb: suppress build warning
  video: fbdev: vt8623fb: suppress build warning
  OMAPDSS: hdmi5: Fix bit field for IEC958_AES2_CON_SOURCE
  OMAPDSS: hdmi: Remove __exit qualifier from hdmi_uninit_output()
  OMAPDSS: hdmi5: Change hdmi_wp idlemode to to no_idle for audio playback
  OMAPDSS: Remove all references to obsolete HDMI audio callbacks
  ASoC: omap: Remove obsolete HDMI audio code and Kconfig options
  OMAPDSS: hdmi5: Register ASoC platform device for omap hdmi audio
  OMAPDSS: hdmi5: Remove callbacks for the old ASoC DAI driver
  ...

Pull virtio updates from Michael Tsirkin:
 "virtio: virtio 1.0 support, misc patches

  This adds a lot of infrastructure for virtio 1.0 support.  Notable
  missing pieces: virtio pci, virtio balloon (needs spec extension),
  vhost scsi.

  Plus, there are some minor fixes in a couple of places.

  Note: some net drivers are affected by these patches.  David said he's
  fine with merging these patches through my tree.

  Rusty's on vacation, he acked using my tree for these, too"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (70 commits)
  virtio_ccw: finalize_features error handling
  virtio_ccw: future-proof finalize_features
  virtio_pci: rename virtio_pci -> virtio_pci_common
  virtio_pci: update file descriptions and copyright
  virtio_pci: split out legacy device support
  virtio_pci: setup config vector indirectly
  virtio_pci: setup vqs indirectly
  virtio_pci: delete vqs indirectly
  virtio_pci: use priv for vq notification
  virtio_pci: free up vq->priv
  virtio_pci: fix coding style for structs
  virtio_pci: add isr field
  virtio: drop legacy_only driver flag
  virtio_balloon: drop legacy_only driver flag
  virtio_ccw: rev 1 devices set VIRTIO_F_VERSION_1
  virtio: allow finalize_features to fail
  virtio_ccw: legacy: don't negotiate rev 1/features
  virtio: add API to detect legacy devices
  virtio_console: fix sparse warnings
  vhost: remove unnecessary forward declarations in vhost.h
  ...

Pull mailbox framework updates from Jassi Brar.

* 'mailbox-devel' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  Mailbox: Add support for Platform Communication Channel
  mailbox/omap: adapt to the new mailbox framework
  mailbox: add tx_prepare client callback
  mailbox: Don't unnecessarily re-arm the polling timer

Pull spi updates from Mark Brown:
 "Not a huge amount going on this release, mainly new drivers (there's a
  couple more waiting that didn't quite make the cut for this release
  too):

   - An interface for querying if the current transfer is the last in a
     message, allowing controllers that need special handling for the
     final transfer to use the core message parsing.
   - Support for Amlogic Meson SPIFC, Imagination Technologies SFPI,
     Intel Quark X1000 and Samsung Exynos 7 controllers"

* tag 'spi-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (38 commits)
  spi/s3c64xx: Remove redundant runtime PM management
  spi: fsl-spi: remove unused variable assignment
  spi: spi-fsl-spi: Return an error code in fsl_spi_do_one_msg()
  spi: core: Do not mangle error code from kthread_run()
  spi: fsl-espi: add (un)prepare_transfer_hardware calls to save power if SPI is not in use
  spi: fsl-(e)spi: migrate to generic master queueing
  spi/txx9: Deletion of an unnecessary check before the function call "clk_disable"
  spi: cadence: Fix 3-to-8 mux mode
  spi: cadence: Init HW after reading devicetree attributes
  spi: meson: Select REGMAP_MMIO
  spi: s3c64xx: add support for exynos7 SPI controller
  spi: spi-pxa2xx: SPI support for Intel Quark X1000
  spi: meson: meson_spifc_setup_speed() can be static
  spi: spi-pxa2xx: Add helpers for regiseters' accessing
  spi: spi-mxs: Fix mapping from vmalloc-ed buffer to scatter list
  spi: atmel: introduce probe deferring
  spi: atmel: remove compat for non DT board when requesting dma chan
  spi: meson: Add support for Amlogic Meson SPIFC
  spi: meson: Add device tree bindings documentation for SPIFC
  spi: core: Add spi_transfer_is_last() helper
  ...

Pull edac updates from Mauro Carvalho Chehab:
 - Broadwell-DE support on sb-edac driver
 - Some fixes at sb-edac driver

* tag 'edac/v3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-edac:
  sb_edac: Fix typo computing number of banks
  sb_edac: Add support for Broadwell-DE processor
  sb_edac: Fix discovery of top-of-low-memory for Haswell
  sb_edac: Fix erroneous bytes->gigabytes conversion
  sb_edac: Fix off-by-one error in number of channels

Pull media updates from Mauro Carvalho Chehab:
 - Two new dvb frontend drivers: mn88472 and mn88473
 - A new driver for some PCIe DVBSky cards
 - A new remote controller driver: meson-ir
 - One LIRC staging driver got rewritten and promoted to mainstream:
   igorplugusb
 - A new tuner driver (m88rs6000t)
 - The old omap2 media driver got removed from staging.  This driver
   uses an old DMA API and it is likely broken on recent kernels.
   Nobody cared enough to fix it
 - Media bus format moved to a separate header, as DRM will also use the
   definitions there
 - mem2mem_testdev were renamed to vim2m, in order to use the same
   naming convention taken by the other virtual test driver (vivid)
 - Added a new driver for coda SoC (coda-jpeg)
 - The cx88 driver got converted to use videobuf2 core
 - Make DMABUF export buffer to work with DMA Scatter/Gather and Vmalloc
   cores
 - Lots of other fixes, improvements and cleanups on the drivers.

* tag 'media/v3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (384 commits)
  [media] mn88473: One function call less in mn88473_init() after error
  [media] mn88473: Remove uneeded check before release_firmware()
  [media] lirc_zilog: Deletion of unnecessary checks before vfree()
  [media] MAINTAINERS: Add myself as img-ir maintainer
  [media] img-ir: Don't set driver's module owner
  [media] img-ir: Depend on METAG or MIPS or COMPILE_TEST
  [media] img-ir/hw: Drop [un]register_decoder declarations
  [media] img-ir/hw: Fix potential deadlock stopping timer
  [media] img-ir/hw: Always read data to clear buffer
  [media] redrat3: ensure dma is setup properly
  [media] ddbridge: remove unneeded check before dvb_unregister_device()
  [media] si2157: One function call less in si2157_init() after error
  [media] tuners: remove uneeded checks before release_firmware()
  [media] arm: omap2: rx51-peripherals: fix build warning
  [media] stv090x: add an extra protetion against buffer overflow
  [media] stv090x: Remove an unreachable code
  [media] stv090x: Some whitespace cleanups
  [media] em28xx: checkpatch cleanup: whitespaces/new lines cleanups
  [media] si2168: add support for firmware files in new format
  [media] si2168: debug printout for firmware version
  ...

Pull backlight updates from Lee Jones:
 - Clean-up leaky resources; pwm_bl
 - Simplify Device Tree initialisation; lp855x_bl
 - Add Regulator support; lp855x
 - Remove Bryan from the Maintainer list -- new baby, no time :)

* tag 'backlight-for-linus-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  MAINTAINERS: Remove my name from Backlight subsystem
  backlight: lp855x: Add supply regulator to lp855x
  backlight: lp855x: Refactor DT parsing code
  backlight: pwm: Clean-up pwm requested using legacy API

Pull pin control changes from Linus Walleij:
 "Here is a stash of pin control changes I have collected for the v3.19
  series.  Mainly new hardware support, with Intels new embedded SoC as
  the especially interesting thing standing out, fully using the
  subsystem.

   - Force conversion of the ux500 pin control device trees and parsers
     to use the generic pin control bindings.
   - New driver and device tree bindings for the Qualcomm PMIC MPP pin
     controller and GPIO.
   - Some ACPI infrastructure for pin controllers.
   - New driver for the Intel CherryView/Braswell pin controller, the
     first Intel pin controller to fully take advantage of the pin
     control subsystem.
   - Support the Freescale i.MX VF610 variant.
   - Support the sunxi A80 variant.
   - Support the Samsung Exynos 4415 and Exynos 7 variants.
   - Split out Intel pin controllers to their own subdirectory.
   - A large slew of rockchip pin control updates, including
     suspend/resume support.
   - A large slew of Samsung Exynos pin controller updates.
   - Various minor updates and fixes"

* tag 'pinctrl-v3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (49 commits)
  pinctrl: at91: enhance (debugfs) at91_gpio_dbg_show
  pinctrl: meson: add device tree bindings documentation
  gpio: tz1090: Fix error handling of irq_of_parse_and_map
  pinctrl: tz1090-pinctrl.txt: Fix typo in binding
  pinctrl: pinconf-generic: Declare dt_params/conf_items const
  pinctrl: exynos: Add support for Exynos4415
  pinctrl: exynos: Add initial driver data for Exynos7
  pinctrl: exynos: Add irq_chip instance for Exynos7 wakeup interrupts
  pinctrl: exynos: Consolidate irq domain callbacks
  pinctrl: exynos: Generalize the eint16_31 demux code
  pinctrl: samsung: Separate per-bank init and runtime data
  pinctrl: samsung: Constify samsung_pin_ctrl struct
  pinctrl: samsung: Constify samsung_pin_bank_type struct
  pinctrl: samsung: Drop unused label field in samsung_pin_ctrl struct
  pinctrl: samsung: Make samsung_pinctrl_get_soc_data use ERR_PTR()
  pinctrl: Add Intel Cherryview/Braswell pin controller support
  gpio / ACPI: Add knowledge about pin controllers to acpi_get_gpiod()
  pinctrl: Fix path error in documentation
  pinctrl: rockchip: save and restore gpio6_c6 pinmux in suspend/resume
  pinctrl: rockchip: add suspend/resume functions
  ...

Pull ACPI and power management updates from Rafael Wysocki:
 "This time we have some more new material than we used to have during
  the last couple of development cycles.

  The most important part of it to me is the introduction of a unified
  interface for accessing device properties provided by platform
  firmware.  It works with Device Trees and ACPI in a uniform way and
  drivers using it need not worry about where the properties come from
  as long as the platform firmware (either DT or ACPI) makes them
  available.  It covers both devices and "bare" device node objects
  without struct device representation as that turns out to be necessary
  in some cases.  This has been in the works for quite a few months (and
  development cycles) and has been approved by all of the relevant
  maintainers.

  On top of that, some drivers are switched over to the new interface
  (at25, leds-gpio, gpio_keys_polled) and some additional changes are
  made to the core GPIO subsystem to allow device drivers to manipulate
  GPIOs in the "canonical" way on platforms that provide GPIO
  information in their ACPI tables, but don't assign names to GPIO lines
  (in which case the driver needs to do that on the basis of what it
  knows about the device in question).  That also has been approved by
  the GPIO core maintainers and the rfkill driver is now going to use
  it.

  Second is support for hardware P-states in the intel_pstate driver.
  It uses CPUID to detect whether or not the feature is supported by the
  processor in which case it will be enabled by default.  However, it
  can be disabled entirely from the kernel command line if necessary.

  Next is support for a platform firmware interface based on ACPI
  operation regions used by the PMIC (Power Management Integrated
  Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
  That interface is used for manipulating power resources and for
  thermal management: sensor temperature reporting, trip point setting
  and so on.

  Also the ACPI core is now going to support the _DEP configuration
  information in a limited way.  Basically, _DEP it supposed to reflect
  off-the-hierarchy dependencies between devices which may be very
  indirect, like when AML for one device accesses locations in an
  operation region handled by another device's driver (usually, the
  device depended on this way is a serial bus or GPIO controller).  The
  support added this time is sufficient to make the ACPI battery driver
  work on Asus T100A, but it is general enough to be able to cover some
  other use cases in the future.

  Finally, we have a new cpufreq driver for the Loongson1B processor.

  In addition to the above, there are fixes and cleanups all over the
  place as usual and a traditional ACPICA update to a recent upstream
  release.

  As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
  Intel platforms should be able to handle power management of the DMA
  engine correctly, the cpufreq-dt driver should interact with the
  thermal subsystem in a better way and the ACPI backlight driver should
  handle some more corner cases, among other things.

  On top of the ACPICA update there are fixes for race conditions in the
  ACPICA's interrupt handling code which might lead to some random and
  strange looking failures on some systems.

  In the cleanups department the most visible part is the series of
  commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
  option.  That was triggered by a discussion regarding the generic
  power domains code during which we realized that trying to support
  certain combinations of PM config options was painful and not really
  worth it, because nobody would use them in production anyway.  For
  this reason, we decided to make CONFIG_PM_SLEEP select
  CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
  became redundant and CONFIG_PM could be used instead of it.  The
  material here makes that replacement in a major part of the tree, but
  there will be at least one more batch of that in the second part of
  the merge window.

  Specifics:

   - Support for retrieving device properties information from ACPI _DSD
     device configuration objects and a unified device properties
     interface for device drivers (and subsystems) on top of that.  As
     stated above, this works with Device Trees and ACPI and allows
     device drivers to be written in a platform firmware (DT or ACPI)
     agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers are
     now going to use this new interface and the GPIO subsystem is
     additionally modified to allow device drivers to assign names to
     GPIO resources returned by ACPI _CRS objects (in case _DSD is not
     present or does not provide the expected data).  The changes in
     this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
     Lu, and Darren Hart with some fixes from others (Fabio Estevam,
     Geert Uytterhoeven).

   - Support for Hardware Managed Performance States (HWP) as described
     in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
     driver.  CPUID is used to detect whether or not the feature is
     supported by the processor.  If supported, it will be enabled
     automatically unless the intel_pstate=no_hwp switch is present in
     the kernel command line.  From Dirk Brandewie.

   - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).

   - Support for firmware interface based on ACPI operation regions used
     by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
     platforms for power resource control and thermal management (Aaron
     Lu).

   - Limited support for retrieving off-the-hierarchy dependencies
     between devices from ACPI _DEP device configuration objects and
     deferred probing support for the ACPI battery driver based on the
     _DEP information to make that driver work on Asus T100A (Lan
     Tianyu).

   - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).

   - ACPICA update to upstream revision 20141107 which only affects
     tools (Bob Moore).

   - Fixes for race conditions in the ACPICA's interrupt handling code
     and in the ACPI code related to system suspend and resume (Lv Zheng
     and Rafael J Wysocki).

   - ACPI core fix for an RCU-related issue in the ioremap() regions
     management code that slowed down significantly after CPUs had been
     allowed to enter idle states even if they'd had RCU callbakcs
     queued and triggered some problems in certain proprietary graphics
     driver (and elsewhere).  The fix replaces synchronize_rcu() in that
     code with synchronize_rcu_expedited() which makes the issue go
     away.  From Konstantin Khlebnikov.

   - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
     management of the DMA engine included into the LPSS correctly.  The
     problem is that the DMA engine doesn't have ACPI PM support of its
     own and it simply is turned off when the last LPSS device having
     ACPI PM support goes into D3cold.  To work around that, the PM
     domain used by the ACPI LPSS driver is redesigned so at least one
     device with ACPI PM support will be on as long as the DMA engine is
     in use.  From Andy Shevchenko.

   - ACPI backlight driver fix to avoid using it on "Win8-compatible"
     systems where it doesn't work and where it was used by default by
     mistake (Aaron Lu).

   - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
     Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
     Chaugule (mostly related to the upcoming ARM64 support).

   - Intel RAPL (Running Average Power Limit) power capping driver fixes
     and improvements including new processor IDs (Jacob Pan).

   - Generic power domains modification to power up domains after
     attaching devices to them to meet the expectations of device
     drivers and bus types assuming devices to be accessible at probe
     time (Ulf Hansson).

   - Preliminary support for controlling device clocks from the generic
     power domains core code and modifications of the ARM/shmobile
     platform to use that feature (Ulf Hansson).

   - Assorted minor fixes and cleanups of the generic power domains core
     code (Ulf Hansson, Geert Uytterhoeven).

   - Assorted minor fixes and cleanups of the device clocks control code
     in the PM core (Geert Uytterhoeven, Grygorii Strashko).

   - Consolidation of device power management Kconfig options by making
     CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
     which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
     is the first batch of the changes needed for this purpose.

   - Core device runtime power management support code cleanup related
     to the execution of callbacks (Andrzej Hajda).

   - cpuidle ARM support improvements (Lorenzo Pieralisi).

   - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
     new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
     Bartlomiej Zolnierkiewicz).

   - New cpufreq driver callback (->ready) to be executed when the
     cpufreq core is ready to use a given policy object and cpufreq-dt
     driver modification to use that callback for cooling device
     registration (Viresh Kumar).

   - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
     Geboski, Tomeu Vizoso).

   - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
     cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
     Stefan Wahren, Petr Cvek).

   - OPP (Operating Performance Points) framework modification to allow
     OPPs to be removed too and update of a few cpufreq drivers
     (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
     during initialization) on driver removal (Viresh Kumar).

   - Hibernation core fixes and cleanups (Tina Ruchandani and Markus
     Elfring).

   - PM Kconfig fix related to CPU power management (Pankaj Dubey).

   - cpupower tool fix (Prarit Bhargava)"

* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tools: cpupower: fix return checks for sysfs_get_idlestate_count()
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  leds: leds-gpio: Fix multiple instances registration without 'label' property
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  ...

Pull PCI changes from Bjorn Helgaas:
 "Here are the PCI changes intended for v3.19.  I don't think there's
  anything very exciting here, but there was a lot of MSI-related stuff
  coming via Thomas.

  Details:

  NUMA
    - Allow numa_node override via sysfs (Prarit Bhargava)

  Resource management
    - Restore detection of read-only BARs (Myron Stowe)
    - Shrink decoding-disabled window while sizing BARs (Myron Stowe)
    - Add informational printk for invalid BARs (Myron Stowe)
    - Remove fixed parameter in pci_iov_resource_bar() (Myron Stowe)

  MSI
    - Add pci_msi_ignore_mask to prevent writes to MSI/MSI-X Mask Bits (Yijing Wang)
    - Revert "PCI: Add x86_msi.msi_mask_irq() and msix_mask_irq()" (Yijing Wang)
    - s390/MSI: Use __msi_mask_irq() instead of default_msi_mask_irq() (Yijing Wang)

  Virtualization
    - xen: Process failure for pcifront_(re)scan_root() (Chen Gang)
    - Make FLR and AF FLR reset warning messages different (Gavin Shan)

  Generic host bridge driver
    - Allocate config space windows after limiting bus number range (Lorenzo Pieralisi)
    - Convert to DT resource parsing API (Lorenzo Pieralisi)

  Freescale Layerscape
    - Add Freescale Layerscape PCIe driver (Minghuan Lian)

  NVIDIA Tegra
    - Do not build on 64-bit ARM (Thierry Reding)
    - Add Kconfig help text (Thierry Reding)

  Renesas R-Car
    - Make rcar_pci static (Jingoo Han)

  Samsung Exynos
    - Add exynos prefix to add_pcie_port(), pcie_init() (Jingoo Han)

  ST Microelectronics SPEAr13xx
    - Add spear prefix to add_pcie_port(), pcie_init() (Jingoo Han)
    - Make spear13xx_add_pcie_port() __init (Jingoo Han)
    - Remove unnecessary OOM message (Jingoo Han)

  TI DRA7xx
    - Add dra7xx prefix to add_pcie_port() (Jingoo Han)
    - Make dra7xx_add_pcie_port() __init (Jingoo Han)

  TI Keystone
    - Make ks_dw_pcie_msi_domain_ops static (Jingoo Han)
    - Remove unnecessary OOM message (Jingoo Han)

  Miscellaneous
    - Delete unnecessary NULL pointer checks (Markus Elfring)
    - Remove unused to_hotplug_slot() (Gavin Shan)
    - Whitespace cleanup (Jingoo Han)
    - Simplify if-return sequences (Quentin Lambert)"

* tag 'pci-v3.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (28 commits)
  PCI: Remove fixed parameter in pci_iov_resource_bar()
  PCI: Add informational printk for invalid BARs
  PCI: tegra: Add Kconfig help text
  PCI: tegra: Do not build on 64-bit ARM
  PCI: spear: Remove unnecessary OOM message
  PCI: mvebu: Add a blank line after declarations
  PCI: designware: Add a blank line after declarations
  PCI: exynos: Remove unnecessary return statement
  PCI: imx6: Use tabs for indentation
  PCI: keystone: Remove unnecessary OOM message
  PCI: Remove unused and broken to_hotplug_slot()
  PCI: Make FLR and AF FLR reset warning messages different
  PCI: dra7xx: Add __init annotation to dra7xx_add_pcie_port()
  PCI: spear: Add __init annotation to spear13xx_add_pcie_port()
  PCI: spear: Rename add_pcie_port(), pcie_init() to spear13xx_add_pcie_port(), etc.
  PCI: dra7xx: Rename add_pcie_port() to dra7xx_add_pcie_port()
  PCI: layerscape: Add Freescale Layerscape PCIe driver
  PCI: Simplify if-return sequences
  PCI: Delete unnecessary NULL pointer checks
  PCI: Shrink decoding-disabled window while sizing BARs
  ...

Pull ktest changes from Steven Rostedt:
 "The following ktest updates were done:

   - Fix handling the make kernelrelease change
   - Fix make_min_config that was broken by new bisect_config changes
   - Allow tests to undefine default options (not just being able to
     override them)
   - Print name of test (if defined) to start of test output"

* tag 'ktest-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
  ktest: Add back "tail -1" to kernelrelease make
  ktest: Add name to running title
  ktest: Allow tests to undefine default options
  ktest: Fix make_min_config to handle new assign_configs call
  ktest: Use make -s kernelrelease

Pull nmi-safe seq_buf printk update from Steven Rostedt:
 "This code is a fork from the trace-3.19 pull as it needed the
  trace_seq clean ups from that branch.

  This code solves the issue of performing stack dumps from NMI context.
  The issue is that printk() is not safe from NMI context as if the NMI
  were to trigger when a printk() was being performed, the NMI could
  deadlock from the printk() internal locks.  This has been seen in
  practice.

  With lots of review from Petr Mladek, this code went through several
  iterations, and we feel that it is now at a point of quality to be
  accepted into mainline.

  Here's what is contained in this patch set:

   - Creates a "seq_buf" generic buffer utility that allows a descriptor
     to be passed around where functions can write their own "printk()"
     formatted strings into it.  The generic version was pulled out of
     the trace_seq() code that was made specifically for tracing.

   - The seq_buf code was change to model the seq_file code.  I have a
     patch (not included for 3.19) that converts the seq_file.c code
     over to use seq_buf.c like the trace_seq.c code does.  This was
     done to make sure that seq_buf.c is compatible with seq_file.c.  I
     may try to get that patch in for 3.20.

   - The seq_buf.c file was moved to lib/ to remove it from being
     dependent on CONFIG_TRACING.

   - The printk() was updated to allow for a per_cpu "override" of the
     internal calls.  That is, instead of writing to the console, a call
     to printk() may do something else.  This made it easier to allow
     the NMI to change what printk() does in order to call dump_stack()
     without needing to update that code as well.

   - Finally, the dump_stack from all CPUs via NMI code was converted to
     use the seq_buf code.  The caller to trigger the NMI code would
     wait till all the NMIs finished, and then it would print the
     seq_buf data to the console safely from a non NMI context

  One added bonus is that this code also makes the NMI dump stack work
  on PREEMPT_RT kernels.  As printk() includes sleeping locks on
  PREEMPT_RT, printk() only writes to console if the console does not
  use any rt_mutex converted spin locks.  Which a lot do"

* tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  x86/nmi: Fix use of unallocated cpumask_var_t
  printk/percpu: Define printk_func when printk is not defined
  x86/nmi: Perform a safe NMI stack trace on all CPUs
  printk: Add per_cpu printk func to allow printk to be diverted
  seq_buf: Move the seq_buf code to lib/
  seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
  tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
  tracing: Have seq_buf use full buffer
  seq_buf: Add seq_buf_can_fit() helper function
  tracing: Add paranoid size check in trace_printk_seq()
  tracing: Use trace_seq_used() and seq_buf_used() instead of len
  tracing: Clean up tracing_fill_pipe_page()
  seq_buf: Create seq_buf_used() to find out how much was written
  tracing: Add a seq_buf_clear() helper and clear len and readpos in init
  tracing: Convert seq_buf fields to be like seq_file fields
  tracing: Convert seq_buf_path() to be like seq_path()
  tracing: Create seq_buf layer in trace_seq

Pull ftrace self-test updates from Steven Rostedt:
 "Updates for the ftrace self tests:

   - Added kprobes on ftrace testcase
   - Sort test cases
   - Add file to hold helper functions
   - Use logfile name supported by busybox's mktemp
   - Clear trace buffer after running kprobe test
   - Fix show descriptions when run on dash shell
   - Add --verbose option for showing echo output"

* tag 'ftracetest-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftracetest: Add --verbose option for showing echo output
  ftracetest: Fix to show descriptions on dash
  ftracetest: Add basic event tracing test cases
  ftracetest: Clear trace buffer after running kprobe testcases
  ftracetest: Use logfile name supported by busybox's mktemp
  ftracetest: Add a couple of ftrace test cases
  ftracetest: Add functions file that holds helper functions
  ftracetest: Sort testcases
  ftracetest: Add kprobes on ftrace testcase

Pull tracing updates from Steven Rostedt:
 "There was a lot of clean ups and minor fixes.  One of those clean ups
  was to the trace_seq code.  It also removed the return values to the
  trace_seq_*() functions and use trace_seq_has_overflowed() to see if
  the buffer filled up or not.  This is similar to work being done to
  the seq_file code as well in another tree.

  Some of the other goodies include:

   - Added some "!" (NOT) logic to the tracing filter.

   - Fixed the frame pointer logic to the x86_64 mcount trampolines

   - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
     That is, the ftrace trampoline can be dynamically allocated and be
     called directly by functions that only have a single hook to them"

* tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits)
  tracing: Truncated output is better than nothing
  tracing: Add additional marks to signal very large time deltas
  Documentation: describe trace_buf_size parameter more accurately
  tracing: Allow NOT to filter AND and OR clauses
  tracing: Add NOT to filtering logic
  ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter
  ftrace/x86: Get rid of ftrace_caller_setup
  ftrace/x86: Have save_mcount_regs macro also save stack frames if needed
  ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs
  ftrace/x86: Simplify save_mcount_regs on getting RIP
  ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
  ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments
  ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file
  ftrace/x86: Have static tracing also use ftrace_caller_setup
  ftrace/x86: Have static function tracing always test for function graph
  kprobes: Add IPMODIFY flag to kprobe_ftrace_ops
  ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
  kprobes/ftrace: Recover original IP if pre_handler doesn't change it
  tracing/trivial: Fix typos and make an int into a bool
  tracing: Deletion of an unnecessary check before iput()
  ...

Merge first patchbomb from Andrew Morton:
 - a few minor cifs fixes
 - dma-debug upadtes
 - ocfs2
 - slab
 - about half of MM
 - procfs
 - kernel/exit.c
 - panic.c tweaks
 - printk upates
 - lib/ updates
 - checkpatch updates
 - fs/binfmt updates
 - the drivers/rtc tree
 - nilfs
 - kmod fixes
 - more kernel/exit.c
 - various other misc tweaks and fixes

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  exit: pidns: fix/update the comments in zap_pid_ns_processes()
  exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting
  exit: exit_notify: re-use "dead" list to autoreap current
  exit: reparent: call forget_original_parent() under tasklist_lock
  exit: reparent: avoid find_new_reaper() if no children
  exit: reparent: introduce find_alive_thread()
  exit: reparent: introduce find_child_reaper()
  exit: reparent: document the ->has_child_subreaper checks
  exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper()
  exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting
  exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting
  exit: proc: don't try to flush /proc/tgid/task/tgid
  exit: release_task: fix the comment about group leader accounting
  exit: wait: drop tasklist_lock before psig->c* accounting
  exit: wait: don't use zombie->real_parent
  exit: wait: cleanup the ptrace_reparented() checks
  usermodehelper: kill the kmod_thread_locker logic
  usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper()
  fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp
  nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races
  ...

The comments in zap_pid_ns_processes() are not clear, we need to explain
how this code actually works.

1. "Ignore SIGCHLD" looks like optimization but it is not, we also
   need this for correctness.

2. The comment above sys_wait4() could tell more.

   EXIT_ZOMBIE child is only possible if it has exited before we
   ignored SIGCHLD. Or if it is traced from the parent namespace,
   but in this case it will be reaped by debugger after detach,
   sys_wait4() acts as a synchronization point.

3. The comment about TASK_DEAD (EXIT_DEAD in fact) children is
   outdated. Contrary to what it says we do not need to make sure
   they all go away after 0a01f2cc "pidns: Make the pidns proc
   mount/umount logic obvious".

   At the same time, we do need to wait for nr_hashed==init_pids,
   but the reasons are quite different and not obvious: setns().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alloc_pid() does get_pid_ns() beforehand but forgets to put_pid_ns() if it
fails because disable_pid_allocation() was called by the exiting
child_reaper.

We could simply move get_pid_ns() down to successful return, but this fix
tries to be as trivial as possible.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After the previous change we can add just the exiting EXIT_DEAD task to
the "dead" list and remove another release_task(tsk).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Shift "release dead children" loop from forget_original_parent() to its
caller, exit_notify().  It is safe to reap them even if our parent reaps
us right after we drop tasklist_lock, those children no longer have any
connection to the exiting task.

And this allows us to avoid write_lock_irq(tasklist_lock) right after it
was released by forget_original_parent(), we can simply call it with
tasklist_lock held.

While at it, move the comment about forget_original_parent() up to
this function.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now that pid_ns logic was isolated we can change forget_original_parent()
to return right after find_child_reaper() when father->children is empty,
there is nothing to reparent in this case.

In particular this avoids find_alive_thread() and this can help if the
whole process exits and it has a lot of PF_EXITING threads at the start of
the thread list, this can easily lead to O(nr_threads ** 2) iterations.

Trivial test case (tested under KVM, 2 CPUs):

    static void *tfunc(void *arg)
    {
        pause();
        return NULL;
    }

    static int child(unsigned int nt)
    {
        pthread_t pt;

        while (nt--)
            assert(pthread_create(&pt, NULL, tfunc, NULL) == 0);

        pthread_kill(pt, SIGTRAP);
        pause();
        return 0;
    }

    int main(int argc, const char *argv[])
    {
        int stat;
        unsigned int nf = atoi(argv[1]);
        unsigned int nt = atoi(argv[2]);

        while (nf--) {
            if (!fork())
                return child(nt);

            wait(&stat);
            assert(stat == SIGTRAP);
        }

        return 0;
    }

$ time ./test 16 16536 shows:

              real        user         sys
    -    5m37.628s    0m4.437s    8m5.560s
    +    0m50.032s    0m7.130s    1m4.927s
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add the new simple helper to factor out the for_each_thread() code in
find_child_reaper() and find_new_reaper().  It can also simplify the
potential PF_EXITING -> exit_state change, plus perhaps we can change this
code to take SIGNAL_GROUP_EXIT into account.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

find_new_reaper() does 2 completely different things.  Not only it finds a
reaper, it also updates pid_ns->child_reaper or kills the whole namespace
if the caller is ->child_reaper.

Now that has_child_subreaper logic doesn't depend on child_reaper check we
can move that pid_ns code into a separate helper.  IMHO this makes the
code more clean, and this allows the next changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Swap the "init_task" and same_thread_group() checks.  This way it is more
simple to document these checks and we can remove the link to the previous
discussion on lkml.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change find_new_reaper() to use for_each_thread() instead of deprecated
while_each_thread().  We do not bother to check "thread != father" in the
1st loop, we can rely on PF_EXITING check.

Note: this means the minor behavioural change: for_each_thread() starts
from the group leader.  But this should be fine, nobody should make any
assumption about do_wait(__WNOTHREAD) when it comes to reparented tasks.
And this can avoid the pointless reparenting to a short-living thread
While zombie leaders are not that common.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

find_new_reaper() assumes that "has_child_subreaper" logic is safe as
long as we are not the exiting ->child_reaper and this is doubly wrong:

1. In fact it is safe if "pid_ns->child_reaper == father"; there must
   be no children after zap_pid_ns_processes() returns, so it doesn't
   matter what we return in this case and even pid_ns->child_reaper is
   wrong otherwise: we can't reparent to ->child_reaper == current.

   This is not a bug, but this is confusing.

2. It is not safe if we are not pid_ns->child_reaper but from the same
   thread group. We drop tasklist_lock before zap_pid_ns_processes(),
   so another thread can lock it and choose the new reaper from the
   upper namespace if has_child_subreaper == T, and this is obviously
   wrong.

   This is not that bad, zap_pid_ns_processes() won't return until the
   the new reaper reaps all zombies, but this should be fixed anyway.

We could change for_each_thread() loop to use ->exit_state instead of
PF_EXITING which we had to use until 8aac6270, or we could change
copy_signal() to check CLONE_NEWPID before setting has_child_subreaper,
but lets change this code so that it is clear we can't look outside of
our namespace, otherwise same_thread_group(reaper, child_reaper) check
will look wrong and confusing anyway.

We can simply start from "father" and fix the problem. We can't wrongly
return a thread from the same thread group if ->is_child_subreaper == T,
we know that all threads have PF_EXITING set.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The ->has_child_subreaper code in find_new_reaper() finds alive "thread"
but returns another "reaper" thread which can be dead.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc_flush_task_mnt() always tries to flush task/pid, but this is
pointless if we reap the leader. d_invalidate() is recursive, and
if nothing else the next d_hash_and_lookup(tgid) should fail anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Contrary to what the comment in __exit_signal() says we do account the
group leader. Fix this and explain why.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

wait_task_zombie() no longer needs tasklist_lock to accumulate the
psig->c* counters, we can drop it right after cmpxchg(exit_state).
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1. wait_task_zombie() uses p->real_parent to get psig/siglock. This is
   correct but needs tasklist_lock, ->real_parent can exit.

   We can use "current" instead. This is our natural child, its parent
   must be our sub-thread.

2. Read psig/sig outside of ->siglock, ->signal is no longer protected
   by this lock.

3. Fix the outdated comments about tasklist_lock. We can not race with
   __exit_signal(), the whole thread group is dead, nobody but us can
   call it.

   Also clarify the usage of ->stats_lock and ->siglock.

Note: thread_group_cputime_adjusted() is sub-optimal in this case, we
probably want to export cputime_adjust() to avoid thread_group_cputime().
The comment says "all threads" but there are no other threads.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now that EXIT_DEAD is the terminal state we can kill "int traced"
variable and check "state == EXIT_DEAD" instead to cleanup the code.  In
particular, this way it is clear that the check obviously doesn't need
tasklist_lock.

Also fix the type of "unsigned long state", "long" was always wrong
although this doesn't matter because cmpxchg/xchg uses typeof(*ptr).

[akpm@linux-foundation.org: don't make me google the C Operator Precedence table]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sterling Alexander <stalexan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now that we do not call kernel_thread(CLONE_VFORK) from the worker
thread we can not deadlock if do_execve() in turn triggers another
call_usermodehelper(), we can remove the kmod_thread_locker code.

Note: we should probably kill khelper_wq and simply use one of the
global workqueues, say, system_unbound_wq, this special wq for umh buys
nothing nowadays.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After "kernel/kmod: fix use-after-free of the sub_infostructure"
CLONE_VFORK in __call_usermodehelper() buys nothing, we rely on on
umh_complete() in ____call_usermodehelper() anyway.

Remove it.  This also eliminates the unnecessary sleep/wakeup in the
likely case, and this allows the next change.

While at it, kill the "int wait" locals in ____call_usermodehelper() and
__call_usermodehelper(), they can safely use sub_info->wait.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Relying on the sign (after casting to int) of the difference of two
quantities for comparison is usually wrong.  For example, should a-b
turn out to be 2^31, the return value of cmp(a,b) is -2^31; but that
would also be the return value from cmp(b, a).  So a compares less than
b and b compares less than a.  One can also easily find three values
a,b,c such that a compares less than b, b compares less than c, but a
does not compare less than c.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Same story as in commit 41080b5a ("nfsd race fixes: ext2") (similar
ext2 fix) except that nilfs2 needs to use insert_inode_locked4() instead
of insert_inode_locked() and a bug of a check for dead inodes needs to
be fixed.

If nilfs_iget() is called from nfsd after nilfs_new_inode() calls
insert_inode_locked4(), nilfs_iget() will wait for unlock_new_inode() at
the end of nilfs_mkdir()/nilfs_create()/etc to unlock the inode.

If nilfs_iget() is called before nilfs_new_inode() calls
insert_inode_locked4(), it will create an in-core inode and read its
data from the on-disk inode.  But, nilfs_iget() will find i_nlink equals
zero and fail at nilfs_read_inode_common(), which will lead it to call
iget_failed() and cleanly fail.

However, this sanity check doesn't work as expected for reused on-disk
inodes because they leave a non-zero value in i_mode field and it
hinders the test of i_nlink.  This patch also fixes the issue by
removing the test on i_mode that nilfs2 doesn't need.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The iput() function tests whether its argument is NULL and then returns
immediately.  Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch removes filemap_write_and_wait_range() from nilfs_sync_file(),
because it triggers a data segment construction by calling
nilfs_writepages() with WB_SYNC_ALL.  A data segment construction does not
remove the inode from the i_dirty list and it does not clear the
NILFS_I_DIRTY flag.  Therefore nilfs_inode_dirty() still returns true,
which leads to an unnecessary duplicate segment construction in
nilfs_sync_file().

A call to filemap_write_and_wait_range() is not needed, because NILFS2
does not rely on the generic writeback mechanisms.  Instead it implements
its own mechanism to collect all dirty pages and write them into segments.
 It is more efficient to initiate the segment construction directly in
nilfs_sync_file() without the detour over filemap_write_and_wait_range().

Additionally the lock of i_mutex is not needed, because all code blocks
that are protected by i_mutex are also protected by a NILFS transaction:

  Function                i_mutex     nilfs_transaction
  ------------------------------------------------------
  nilfs_ioctl_setflags:   yes         yes
  nilfs_fiemap:           yes         no
  nilfs_write_begin:      yes         yes
  nilfs_write_end:        yes         yes
  nilfs_lookup:           yes         no
  nilfs_create:           yes         yes
  nilfs_link:             yes         yes
  nilfs_mknod:            yes         yes
  nilfs_symlink:          yes         yes
  nilfs_mkdir:            yes         yes
  nilfs_unlink:           yes         yes
  nilfs_rmdir:            yes         yes
  nilfs_rename:           yes         yes
  nilfs_setattr:          yes         yes

For nilfs_lookup() i_mutex is held for the parent directory, to protect it
from modification.  The segment construction does not modify directory
inodes, so no lock is needed.

nilfs_fiemap() reads the block layout on the disk, by using
nilfs_bmap_lookup_contig(). This is already protected by bmap->b_sem.
Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc_timer_do_work() only judges -ETIME failure of__rtc_set_alarm(), but
doesn't handle other failures like -EIO, -EBUSY, etc.

If there is a failure other than -ETIME, the next rtc_timer will stay in
the timerqueue.  Then later rtc_timers will be enqueued directly because
they have a later expires time, so the alarm irq will never be programmed.

When such failures happen, this patch will retry __rtc_set_alarm(), if
still can't program the alarm time, it will remove current rtc_timer from
timerqueue and fetch next one, thus preventing it from affecting other rtc
timers.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>