After we've added the first command byte write into advance_transaction(),
the IBF=0 waiter is duplicated with the command completion waiter
implemented in the ec_poll() because:
   If IBF=1 blocked the first command byte write invoked in the task
   context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed
   out and retried again in the task context.

Remove this seperate and duplicate IBF=0 waiter.  By doing so we can
reduce the overall number of times to access the EC_SC(R) status
register.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Move the first command byte write into advance_transaction() so that all
EC register accesses that can affect the command processing state machine
can happen in this asynchronous state machine advancement function.

The advance_transaction() function then can be a complete implementation
of an asyncrhonous transaction for a single command so that:
 1. The first command byte can be written in the interrupt context;
 2. The command completion waiter can also be used to wait the first command
    byte's timeout;
 3. In BURST mode, the follow-up command bytes can be written in the
    interrupt context directly, so that it doesn't need to return to the
    task context. Returning to the task context reduces the throughput of
    the BURST mode and in the worst cases where the system workload is very
    high, this leads to the hardware driven automatic BURST mode exit.

In order not to increase memory consumption, convert 'done' into 'flags'
to contain multiple indications:
 1. ACPI_EC_COMMAND_COMPLETE: converting from original 'done' condition,
    indicating the completion of the command transaction.
 2. ACPI_EC_COMMAND_POLL: indicating the availability of writing the first
    command byte. A new command can utilize this flag to compete for the
    right of accessing the underlying hardware. There is a follow-up bug
    fix that has utilized this new flag.

The 2 flags are important because it also reflects a key concept of IO
programs' design used in the system softwares. Normally an IO program
running in the kernel should first be implemented in the asynchronous way.
And the 2 flags are the most common way to implement its synchronous
operations on top of the asynchronous operations:
1. POLL: This flag can be used to block until the asynchronous operations
         can happen.
2. COMPLETE: This flag can be used to block until the asynchronous
             operations have completed.
By constructing code cleanly in this way, many difficult problems can be
solved smoothly.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The advance_transaction() will be invoked from the IRQ context GPE handler
and the task context ec_poll(). The handling of this function is locked so
that the EC state machine are ensured to be advanced sequentially.

But there is a problem. Before invoking advance_transaction(), EC_SC(R) is
read. Then for advance_transaction(), there could be race condition around
the lock from both contexts. The first one reading the register could fail
this race and when it passes the stale register value to the state machine
advancement code, the hardware condition is totally different from when
the register is read. And the hardware accesses determined from the wrong
hardware status can break the EC state machine. And there could be cases
that the functionalities of the platform firmware are seriously affected.
For example:
 1. When 2 EC_DATA(W) writes compete the IBF=0, the 2nd EC_DATA(W) write may
    be invalid due to IBF=1 after the 1st EC_DATA(W) write. Then the
    hardware will either refuse to respond a next EC_SC(W) write of the next
    command or discard the current WR_EC command when it receives a EC_SC(W)
    write of the next command.
 2. When 1 EC_SC(W) write and 1 EC_DATA(W) write compete the IBF=0, the
    EC_DATA(W) write may be invalid due to IBF=1 after the EC_SC(W) write.
    The next EC_DATA(R) could never be responded by the hardware. This is
    the root cause of the reported issue.

Fix this issue by moving the EC_SC(R) access into the lock so that we can
ensure that the state machine is advanced consistently.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911Reported-and-tested-by: NGareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: NHans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: NBarton Xu <tank.xuhan@gmail.com>
Tested-by: NSteffen Weber <steffen.weber@gmail.com>
Tested-by: NArthur Chen <axchen@nvidia.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull devicetree bugfix from Grant Likely:
 "Important bug fix for parsing 64-bit addresses on 32-bit platforms.
  Without this patch the kernel will try to use memory ranges that
  cannot be reached"

* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux:
  of: Check for phys_addr_t overflows in early_init_dt_add_memory_arch

Pull SCSI fixes from James Bottomley:
 "This is a set of 13 fixes, a MAINTAINERS update and a sparse update.
  The fixes are mostly correct value initialisations, avoiding NULL
  derefs and some uninitialised pointer avoidance.

  All the patches have been incubated in -next for a few days.  The
  final patch (use the scsi data buffer length to extract transfer size)
  has been rebased to add a cc to stable, but only the commit message
  has changed"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] use the scsi data buffer length to extract transfer size
  virtio-scsi: fix various bad behavior on aborted requests
  virtio-scsi: avoid cancelling uninitialized work items
  ibmvscsi: Add memory barriers for send / receive
  ibmvscsi: Abort init sequence during error recovery
  qla2xxx: Fix sparse warning in qla_target.c.
  bnx2fc: Improve stats update mechanism
  bnx2fc: do not scan uninitialized lists in case of error.
  fc: ensure scan_work isn't active when freeing fc_rport
  pm8001: Fix potential null pointer dereference and memory leak.
  MAINTAINERS: Update LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI) maintainers Email IDs
  be2iscsi: remove potential junk pointer free
  be2iscsi: add an missing goto in error path
  scsi_error: set DID_TIME_OUT correctly
  scsi_error: fix invalid setting of host byte

Pull drm fixes from Dave Airlie:
 "i915, tda998x and vmwgfx fixes,

  The main one is i915 fix for missing VGA connectors, along with some
  fixes for the tda998x from Russell fixing some modesetting problems.

  (still on holidays, but got a spare moment to find these)"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/vmwgfx: Fix incorrect write to read-only register v2:
  drm/i915: Drop early VLV WA to fix Voltage not getting dropped to Vmin
  drm/i915: only apply crt_present check on VLV
  drm/i915: Wait for vblank after enabling the primary plane on BDW
  drm/i2c: tda998x: add some basic mode validation
  drm/i2c: tda998x: faster polling for edid
  drm/i2c: tda998x: move drm_i2c_encoder_destroy call

Pull ARM SoC fixes from Olof Johansson:
 "This week's arm-soc fixes:

   - A set of of OMAP patches that we had missed Tony's pull request of:
     * Reset fix for am43xx
     * Proper OPP table for omap5
     * Fix for SoC detection of one of the DRA7 SoCs
     * hwmod updates to get SATA and OCP to work on omap5 (drivers
       merged in 3.16)
     * ... plus a handful of smaller fixes
   - sunxi needed to re-add machine specific restart code that was
     removed in anticipation of a watchdog driver being merged for 3.16,
     and it didn't make it in.
   - Marvell fixes for PCIe on SMP and a big-endian fix.
   - A trivial defconfig update to make my capri test board boot with
     bcm_defconfig again.

  ... and a couple of MAINTAINERS updates, one to claim new Keystone
  drivers that have been merged, and one to merge MXS and i.MX (both
  Freescale platforms).

  The largest diffs come from the hwmod code for omap5 and the re-add of
  the restart code on sunxi.  The hwmod stuff is quite late at this
  point but it slipped through cracks repeatedly while coming up the
  maintainer chain and only affects the one SoC so risk is low"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  MAINTAINERS: Add few more Keystone drivers
  MAINTAINERS: merge MXS entry into IMX one
  ARM: sunxi: Reintroduce the restart code for A10/A20 SoCs
  ARM: mvebu: fix cpuidle implementation to work on big-endian systems
  ARM: mvebu: update L2/PCIe deadlock workaround after L2CC cleanup
  ARM: mvebu: move Armada 375 external abort logic as a quirk
  ARM: bcm: Fix bcm and multi_v7 defconfigs
  ARM: dts: dra7-evm: remove interrupt binding
  ARM: OMAP2+: Fix parser-bug in platform muxing code
  ARM: DTS: dra7/dra7xx-clocks: ATL related changes
  ARM: OMAP2+: drop unused function
  ARM: dts: am43x-epos-evm: Add Missing cpsw-phy-sel for am43x-epos-evm
  ARM: dts: omap5: Update CPU OPP table as per final production Manual
  ARM: DRA722: add detection of SoC information
  ARM: dts: Enable twl4030 off-idle configuration for selected omaps
  ARM: OMAP5: hwmod: Add ocp2scp3 and sata hwmods
  ARM: OMAP2+: hwmod: Change hardreset soc_ops for AM43XX

Pull irq fixes from Thomas Gleixner:
 "A few minor fixlets in ARM SoC irq drivers and a fix for a memory leak
  which I introduced in the last round of cleanups :("

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Fix memory leak when calling irq_free_hwirqs()
  irqchip: spear_shirq: Fix interrupt offset
  irqchip: brcmstb-l2: Level-2 interrupts are edge sensitive
  irqchip: armada-370-xp: Mask all interrupts during initialization.

Fixes for 3.16-rc3; most importantly Jesse brings back VGA he took away
on a bunch of machines. Also a vblank fix for BDW and a power workaround
fix for VLV.

* tag 'drm-intel-fixes-2014-07-03' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Drop early VLV WA to fix Voltage not getting dropped to Vmin
  drm/i915: only apply crt_present check on VLV
  drm/i915: Wait for vblank after enabling the primary plane on BDW

fix to a 3.15 commit.

* 'vmwgfx-fixes-3.16' of git://people.freedesktop.org/~thomash/linux:
  drm/vmwgfx: Fix incorrect write to read-only register v2:

mode fixes for tda998x.

* 'tda998x-fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-cubox:
  drm/i2c: tda998x: add some basic mode validation
  drm/i2c: tda998x: faster polling for edid
  drm/i2c: tda998x: move drm_i2c_encoder_destroy call

irq_free_hwirqs() always calls irq_free_descs() with a cnt == 0
which makes it a no-op since the interrupt count to free is
decremented in itself.

Fixes: 7b6ef126Signed-off-by: NKeith Busch <keith.busch@intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1404167084-8070-1-git-send-email-keith.busch@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Pull ARM64 fixes from Catalin Marinas:
 - Exception level check at boot time (for completeness, not triggering
   any bug before)
 - I/D-cache synchronisation logic for huge pages
 - Config symbol typo

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: fix el2_setup check of CurrentEL
  arm64: mm: Make icache synchronisation logic huge page aware
  arm64: mm: Fix horrendous config typo

Update MAINTAINERS file for recently added reset controller, AEMIF
and clocksource driver for Keystone SOCs.

The EMIF memory controller driver is also added along with AEMIF.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

The mach-mxs platform is actually co-maintained by myself and
pengutronix folks.  Also it's hosted in the same kernel tree as IMX.
So let's merge the entry into IMX one.
Signed-off-by: NShawn Guo <shawn.guo@freescale.com>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NOlof Johansson <olof@lixom.net>

mvebu fixes for v3.16 (round #2)

 - mvebu
    - Fix PCIe deadlock now that SMP is enabled
    - Fix cpuidle for big-endian systems

* tag 'mvebu-fixes-3.16-2' of git://git.infradead.org/linux-mvebu:
  ARM: mvebu: fix cpuidle implementation to work on big-endian systems
  ARM: mvebu: update L2/PCIe deadlock workaround after L2CC cleanup
  ARM: mvebu: move Armada 375 external abort logic as a quirk
Signed-off-by: NOlof Johansson <olof@lixom.net>

This partly reverts commits 55360050 (ARM: sunxi: Remove reset code from
the platform) and 5e669ec5 (ARM: sunxi: Remove init_machine callback) for
the sun4i, sun5i and sun7i families.

This is needed because the watchdog counterpart of these commits was dropped,
and didn't make it into 3.16. In order to still be able to reboot the board, we
need to reintroduce that code. Of course, the long term view is still to get
rid of that code in mach-sunxi.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Merge tag 'omap-for-v3.16/fixes-against-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Merge OMAP fixes from Tony Lindgren:

Fixes for omaps for issues discovered during the merge window and
enabling of a few features that had to wait for the driver
dependencies to clear.

The fixes included are:

- Fix am43xx hard reset flags
- Fix SoC detection for DRA722
- Fix CPU OPP table for omap5
- Fix legacy mux parser bug if requested muxname is a prefix of
  multiple mux entries
- Fix qspi interrupt binding that relies on the irq crossbar
  that has not yet been enabled
- Add missing phy_sel for am43x-epos-evm
- Drop unused gic_init_irq() that is no longer needed

And the enabling of features that had driver dependencies are:

- Change dra7 to use Audio Tracking Logic clock instead of a fixed
  clock now that the clock driver for it has been merged

- Enable off idle configuration for selected omaps as all the kernel
  dependencies for device tree based booting are finally merged as
  this is needed to get the automated PM tests working finally with
  device tree based booting

- Add hwmod entry for ocp2scp3 for omap5 to get sata working as
  all the driver dependencies are now in the kernel and this patch
  fell through the cracks during the merge window

* tag 'omap-for-v3.16/fixes-against-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: dts: dra7-evm: remove interrupt binding
  ARM: OMAP2+: Fix parser-bug in platform muxing code
  ARM: DTS: dra7/dra7xx-clocks: ATL related changes
  ARM: OMAP2+: drop unused function
  ARM: dts: am43x-epos-evm: Add Missing cpsw-phy-sel for am43x-epos-evm
  ARM: dts: omap5: Update CPU OPP table as per final production Manual
  ARM: DRA722: add detection of SoC information
  ARM: dts: Enable twl4030 off-idle configuration for selected omaps
  ARM: OMAP5: hwmod: Add ocp2scp3 and sata hwmods
  ARM: OMAP2+: hwmod: Change hardreset soc_ops for AM43XX

Pull md bugfixes from Neil Brown:
 "Two minor bugfixes for md in 3.16"

* tag 'md/3.16-fixes' of git://neil.brown.name/md:
  md: flush writes before starting a recovery.
  md: make sure GET_ARRAY_INFO ioctl reports correct "clean" status

Pull sound fixes from Takashi Iwai:
 "This contains a few fixes for HD-audio: yet another Dell headset pin
  quirk, a fixup for Thinkpad T540P, and an improved fix for
  Haswell/Broadwell HDMI clock setup"

* tag 'sound-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - restore BCLK M/N value as per CDCLK for HSW/BDW display HDA controller
  drm/i915: provide interface for audio driver to query cdclk
  ALSA: hda - Add a fixup for Thinkpad T540p
  ALSA: hda - Add another headset pin quirk for some Dell machines

Pull btrfs fixes from Chris Mason:
 "We've queued up a few fixes in my for-linus branch"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix crash when starting transaction
  Btrfs: fix btrfs_print_leaf for skinny metadata
  Btrfs: fix race of using total_bytes_pinned
  btrfs: use E2BIG instead of EIO if compression does not help
  btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
  Btrfs: fix use-after-free when cloning a trailing file hole
  btrfs: fix null pointer dereference in btrfs_show_devname when name is null
  btrfs: fix null pointer dereference in clone_fs_devices when name is null
  btrfs: fix nossd and ssd_spread mount option regression
  Btrfs: fix race between balance recovery and root deletion
  Btrfs: atomically set inode->i_flags in btrfs_update_iflags
  btrfs: only unlock block in verify_parent_transid if we locked it
  Btrfs: assert send doesn't attempt to start transactions
  btrfs compression: reuse recently used workspace
  Btrfs: fix crash when mounting raid5 btrfs with missing disks
  btrfs: create sprout should rename fsid on the sysfs as well
  btrfs: dev replace should replace the sysfs entry
  btrfs: dev add should add its sysfs entry
  btrfs: dev delete should remove sysfs entry
  btrfs: rename add_device_membership to btrfs_kobj_add_device

The CurrentEL system register reports the Current Exception Level
of the CPU. It doesn't say anything about the stack handling, and
yet we compare it to PSR_MODE_EL2t and PSR_MODE_EL2h.

It works by chance because PSR_MODE_EL2t happens to match the right
bits, but that's otherwise a very bad idea. Just check for the EL
value instead.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: fixed arch/arm64/kernel/efi-entry.S]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The __sync_icache_dcache routine will only flush the dcache for the
first page of a compound page, potentially leading to stale icache
data residing further on in a hugetlb page.

This patch addresses this issue by taking into consideration the
order of the page when flushing the dcache.
Reported-by: NMark Brown <broonie@linaro.org>
Tested-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org> # v3.11+

The define ARM64_64K_PAGES is tested for rather than
CONFIG_ARM64_64K_PAGES. Correct that typo here.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

For HSW/BDW display HD-A controller, hda_set_bclk() is defined to set BCLK
by programming the M/N values as per the core display clock (CDCLK) queried from
i915 display driver.

And the audio driver will also set BCLK in azx_first_init() since the display
driver can turn off the shared power in boot phase if only eDP is connected
and M/N values will be lost and must be reprogrammed.
Signed-off-by: NMengdong Lin <mengdong.lin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

For Haswell and Broadwell, if the display power well has been disabled,
the display audio controller divider values EM4 M VALUE and EM5 N VALUE
will have been lost. The CDCLK frequency is required for reprogramming them
to generate 24MHz HD-A link BCLK. So provide a private interface for the
audio driver to query CDCLK.

This is a stopgap solution until a more generic interface between audio
and display drivers has been implemented.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NMengdong Lin <mengdong.lin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Pull USB bugfixes from Greg KH:
 "Here's a round of USB bugfixes, quirk additions, and new device ids
  for 3.16-rc4.  Nothing major in here at all, just a bunch of tiny
  changes.  All have been in linux-next with no reported issues"

* tag 'usb-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: chipidea: udc: delete td from req's td list at ep_dequeue
  usb: Kconfig: make EHCI_MSM selectable for QCOM SOCs
  usb-storage/SCSI: Add broken_fua blacklist flag
  usb: musb: dsps: fix the base address for accessing the mode register
  tools: ffs-test: fix header values endianess
  usb: phy: msm: Do not do runtime pm if the phy is not idle
  usb: musb: Ensure that cppi41 timer gets armed on premature DMA TX irq
  usb: gadget: gr_udc: Fix check for invalid number of microframes
  usb: musb: Fix panic upon musb_am335x module removal
  usb: gadget: f_fs: resurect usb_functionfs_descs_head structure
  Revert "tools: ffs-test: convert to new descriptor format fixing compilation error"
  xhci: Fix runtime suspended xhci from blocking system suspend.
  xhci: clear root port wake on bits if controller isn't wake-up capable
  xhci: correct burst count field for isoc transfers on 1.0 xhci hosts
  xhci: Use correct SLOT ID when handling a reset device command
  MAINTAINERS: update e-mail address
  usb: option: add/modify Olivetti Olicard modems
  USB: ftdi_sio: fix null deref at port probe
  MAINTAINERS: drop two usb-serial subdriver entries
  USB: option: add device ID for SpeedUp SU9800 usb 3g modem
  ...

Pull staging driver bugfixes from Greg KH:
 "Nothing major here, just 4 small bugfixes that resolve some issues
  reported for the IIO (staging and non-staging) and the tidspbridge
  driver"

* tag 'staging-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: tidspbridge: fix an erroneous removal of parentheses
  iio: of_iio_channel_get_by_name() returns non-null pointers for error legs
  staging: iio/ad7291: fix error code in ad7291_probe()
  iio:adc:ad799x: Fix reading and writing of event values, apply shift

Merge tag 'driver-core-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Well, one drivercore fix for kernfs to resolve a reported issue with
  sysfs files being updated from atomic contexts, and another lz4 bugfix
  for testing potential buffer overflows"

* tag 'driver-core-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  lz4: add overrun checks to lz4_uncompress_unknownoutputsize()
  kernfs: kernfs_notify() must be useable from non-sleepable contexts

Merge tag 'trace-fixes-v3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Oleg Nesterov found and fixed a bug in the perf/ftrace/uprobes code
  where running:

    # perf probe -x /lib/libc.so.6 syscall
    # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable
    # perf record -e probe_libc:syscall whatever

  kills the uprobe.  Along the way he found some other minor bugs and
  clean ups that he fixed up making it a total of 4 patches.

  Doing unrelated work, I found that the reading of the ftrace trace
  file disables all function tracer callbacks.  This was fine when
  ftrace was the only user, but now that it's used by perf and kprobes,
  this is a bug where reading trace can disable kprobes and perf.  A
  very unexpected side effect and should be fixed"

* tag 'trace-fixes-v3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Remove ftrace_stop/start() from reading the trace file
  tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable()
  tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in uprobe_dispatcher()
  uprobes: Change unregister/apply to WARN() if uprobe/consumer is gone
  tracing/uprobes: Revert "Support mix of ftrace and perf"

Pull kbuild fix from Michal Marek:
 "There is one more fix for the relative paths series from -rc1: Print
  the path to the build directory at the start of the build, so that
  editors and IDEs can match the relative paths to source files"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Print the name of the build directory

Pull nfsd bugfixes from Bruce Fields:
 "By coincidence, two NFSv4 symlink bugs, one introduced in the 3.16 xdr
  encoding rewrite, the other a decoding bug that I think we've had
  since the start but that just doesn't trigger very often"

* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
  nfs: fix nfs4d readlink truncated packet
  nfsd: fix rare symlink decoding bug

The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values.  That is
very much part of why it's faster than 'iret'.

Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.

However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'.  Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.

Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Jan points out that I forgot to make the needed fixes to the
lz4_uncompress_unknownoutputsize() function to mirror the changes done
in lz4_decompress() with regards to potential pointer overflows.

The only in-kernel user of this function is the zram code, which only
takes data from a valid compressed buffer that it made itself, so it's
not a big issue.  But due to external kernel modules using this
function, it's better to be safe here.
Reported-by: NJan Beulich <JBeulich@suse.com>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 8846bab1 introduced a helper that can be used to query the
wire transfer size for a SCSI command taking protection information into
account.

However, some commands do not have a 1:1 mapping between the block range
they work on and the payload size (discard, write same). After the
scatterlist has been set up these requests use __data_len to store the
number of bytes to report completion on. This means that callers of
scsi_transfer_length() would get the wrong byte count for these types of
requests.

To overcome this we make scsi_transfer_length() use the scatterlist
length in the scsi_data_buffer as basis for the wire transfer
calculation instead of __data_len.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Debugged-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Fixes: d77e6535
Cc: stable@vger.kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Merge fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  shmem: fix init_page_accessed use to stop !PageLRU bug
  kernel/printk/printk.c: revert "printk: enable interrupts before calling console_trylock_for_printk()"
  tools/testing/selftests/ipc/msgque.c: improve error handling when not running as root
  fs/seq_file: fallback to vmalloc allocation
  /proc/stat: convert to single_open_size()
  hwpoison: fix the handling path of the victimized page frame that belong to non-LRU
  mm:vmscan: update the trace-vmscan-postprocess.pl for event vmscan/mm_vmscan_lru_isolate
  msync: fix incorrect fstart calculation
  zram: revalidate disk after capacity change
  tools: memory-hotplug fix unexpected operator error
  tools: cpu-hotplug fix unexpected operator error
  autofs4: fix false positive compile error
  slub: fix off by one in number of slab tests
  mm: page_alloc: fix CMA area initialisation when pageblock > MAX_ORDER

Under shmem swapping load, I sometimes hit the VM_BUG_ON_PAGE(!PageLRU)
in isolate_lru_pages() at mm/vmscan.c:1281!

Commit 2457aec6 ("mm: non-atomically mark page accessed during page
cache allocation where possible") looks like interrupted work-in-progress.

mm/filemap.c's call to init_page_accessed() is fine, but not mm/shmem.c's
- shmem_write_begin() is clearly wrong to use it after shmem_getpage(),
when the page is always visible in radix_tree, and often already on LRU.

Revert change to shmem_write_begin(), and use init_page_accessed() or
mark_page_accessed() appropriately for SGP_WRITE in shmem_getpage_gfp().

SGP_WRITE also covers shmem_symlink(), which did not mark_page_accessed()
before; but since many other filesystems use [__]page_symlink(), which did
and does mark the page accessed, consider this as rectifying an oversight.
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/printk/printk.c: revert "printk: enable interrupts before calling console_trylock_for_printk()"

Revert commit 939f04be ("printk: enable interrupts before calling
console_trylock_for_printk()").

Andreas reported:

: None of the post 3.15 kernel boot for me. They all hang at the GRUB
: screen telling me it loaded and started the kernel, but the kernel
: itself stops before it prints anything (or even replaces the GRUB
: background graphics).

939f04be is modest latency reduction.  Revert it until we understand
the reason for these failures.
Reported-by: NAndreas Bombe <aeb@debian.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>