* Reuse existing functionality from memdup_user() instead of keeping
  duplicate source code.

  This issue was detected by using the Coccinelle software.

* Return directly if this copy operation failed.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Message-Id: <c86f7520-885e-2829-ae9c-b81caa898e84@users.sourceforge.net>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus reuse the corresponding function "kmalloc_array".
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>

  This issue was detected also by using the Coccinelle software.

* Replace the specification of data structures by pointer dereferences
  to make the corresponding size determination a bit safer according to
  the Linux coding style convention.

* Delete the local variable "size" which became unnecessary with
  this refactoring.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <c3323f6b-4af2-0bfb-9399-e529952e378e@users.sourceforge.net>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

If the SCA entries aren't used by the hardware (no SIGPIF), we
can simply not set the entries, stick to the basic sca and allow more
than 64 VCPUs.

To hinder any other facility from using these entries, let's properly
provoke intercepts by not setting the MCN and keeping the entries
unset.

This effectively allows when running KVM under KVM (vSIE) or under z/VM to
provide more than 64 VCPUs to a guest. Let's limit it to 255 for now, to
not run into problems if the CPU numbers are limited somewhere else.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Only enable runtime instrumentation if the guest issues an RI related
instruction or if userspace changes the riccb to a valid state.
This makes entry/exit a tiny bit faster.

Initial patch by Christian Borntraeger
Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

The payload data for protection exceptions is a superset of the
payload of other translation exceptions. Let's set the additional
flags and use a fall through to minimize code duplication.
Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Let's avoid working with the PER_EVENT* defines, used for control register
manipulation, when checking the u8 PER code. Introduce separate defines
based on the existing defines.
Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Let's also write the external damage code already provided by
struct kvm_s390_mchk_info.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Vector registers are only to be stored if the facility is available
and if the guest has set up the machine check extended save area.

If anything goes wrong while writing the vector registers, the vector
registers are to be marked as invalid. Please note that we are allowed
to write the registers although they are marked as invalid.

Machine checks and "store status" SIGP orders are two different concepts,
let's correctly separate these. As the SIGP part is completely handled in
user space, we can drop it.

This patch is based on a patch from Cornelia Huck.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Store status writes the prefix which is not to be done by a machine check.
Also, the psw is stored and later on overwritten by the failing-storage
address, which looks strange at first sight.

Store status and machine check handling look similar, but they are actually
two different things.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Let's factor this out to prepare for bigger changes. Reorder to calls to
match the logical order given in the PoP.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Automatically generate the KVM facility mask out of a readable list.
Manually changing the masks is very error prone, especially if the
special IBM bit numbering has to be considered.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Pull two parisc fixes from Helge Deller:
 "The first patch ensures that the high-res cr16 clocksource (which was
  added in kernel 4.7) gets choosen as default clocksource for parisc.

  The second patch moves the #define of EREFUSED down inside errno.h and
  thus unbreaks building the gccgo compiler"

* 'parisc-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix order of EREFUSED define in errno.h
  parisc: Fix automatic selection of cr16 clocksource

This is an entirely new driver instead of yet another set of patches
to sb_edac.c because:

1) Mapping from PCI devices to socket/memory controller is significantly
   different. Skylake scatters devices on a socket across a number of
   PCI buses.
2) There is an extra level of interleaving via the "mcroute" register
   that would be a little messy to squeeze into the old driver.
3) Validation is getting too expensive. Changes to sb_edac need to
   be checked against Sandy Bridge, Ivy Bridge, Haswell, Broadwell and
   Knights Landing.
Acked-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When building gccgo in userspace, errno.h gets parsed and the go include file
sysinfo.go is generated.

Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED
is defined later on in errno.h, this leads to go complaining that EREFUSED
isn't defined yet.

Fix this trivial problem by moving the define of EREFUSED down after
ECONNREFUSED in errno.h (and clean up the indenting while touching this line).
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org

Commit 54b66800 (parisc: Add native high-resolution sched_clock()
implementation) added support to use the CPU-internal cr16 counters as reliable
clocksource with the help of HAVE_UNSTABLE_SCHED_CLOCK.

Sadly the commit missed to remove the hack which prevented cr16 to become the
default clocksource even on SMP systems.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.7+

The kernel test robot reported a usercopy failure in the new hardened
sanity checks, due to a page-crossing copy of the FPU state into the
task structure.

This happened because the kernel test robot was testing with SLOB, which
doesn't actually do the required book-keeping for slab allocations, and
as a result the hardening code didn't realize that the task struct
allocation was one single allocation - and the sanity checks fail.

Since SLOB doesn't even claim to support hardening (and you really
shouldn't use it), the straightforward solution is to just make the
usercopy hardening code depend on the allocator supporting it.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull i2c fixes from Wolfram Sang:
 "I2C has some pretty standard driver bugfixes and one minor cleanup"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: meson: Use complete() instead of complete_all()
  i2c: brcmstb: Use complete() instead of complete_all()
  i2c: bcm-kona: Use complete() instead of complete_all()
  i2c: bcm-iproc: Use complete() instead of complete_all()
  i2c: at91: fix support of the "alternative command" feature
  i2c: ocores: add missed clk_disable_unprepare() on failure paths
  i2c: cros-ec-tunnel: Fix usage of cros_ec_cmd_xfer()
  i2c: mux: demux-pinctrl: properly roll back when adding adapter fails

Pull device mapper fixes from Mike Snitzer:

 - a stable fix for DM round robin multipath path selector to disable
   preemption before using this_cpu_ptr()

 - a slight increase in DM crypt's mempool reserves to make swap ontop
   of DM crypt more performant

 - a few DM raid fixes to issues found while testing changes that were
   merged in v4.8-rc1

* tag 'dm-4.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm raid: support raid0 with missing metadata devices
  dm raid: enhance attempt_restore_of_faulty_devices() to support more devices
  dm raid: fix restoring of failed devices regression
  dm raid: fix frozen recovery regression
  dm crypt: increase mempool reserve to better support swapping
  dm round robin: do not use this_cpu_ptr() without having preemption disabled

Pull SCSI fixes from James Bottomley:
 "Six fairly small fixes.  The ipr, mpt3sas and ses ones all trigger
  oopses.  The megaraid one fixes an attach failure on io mapped only
  cards, the fcoe one is an obvious problem in the error path and the
  aacraid one is a theoretical security issue (ability to trick the
  kernel into a buffer overrun)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  ses: Fix racy cleanup of /sys in remove_dev()
  mpt3sas: Fix resume on WarpDrive flash cards
  ipr: Fix sync scsi scan
  megaraid_sas: Fix probing cards without io port
  aacraid: Check size values after double-fetch from user
  fcoe: Use kfree_skb() instead of kfree()

Pull USB fixes from Greg KH:
 "Here are a number of USB fixes for reported issues for your tree.

  The normal amount of gadget fixes, xhci fixes, new device ids, and a
  few other minor things.  All of them have been in linux-next for a
  while, the full details are in the shortlog below"

* tag 'usb-4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (43 commits)
  xhci: don't dereference a xhci member after removing xhci
  usb: xhci: Fix panic if disconnect
  xhci: really enqueue zero length TRBs.
  xhci: always handle "Command Ring Stopped" events
  cdc-acm: fix wrong pipe type on rx interrupt xfers
  usb: misc: usbtest: add fix for driver hang
  usb: dwc3: gadget: stop processing on HWO set
  usb: dwc3: don't set last bit for ISOC endpoints
  usb: gadget: rndis: free response queue during REMOTE_NDIS_RESET_MSG
  usb: udc: core: fix error handling
  usb: gadget: fsl_qe_udc: off by one in setup_received_handle()
  usb/gadget: fix gadgetfs aio support.
  usb: gadget: composite: Fix return value in case of error
  usb: gadget: uvc: Fix return value in case of error
  usb: gadget: fix check in sync read from ep in gadgetfs
  usb: misc: usbtest: usbtest_do_ioctl may return positive integer
  usb: dwc3: fix missing platform_set_drvdata() in dwc3_of_simple_probe()
  usb: phy: omap-otg: Fix missing platform_set_drvdata() in omap_otg_probe()
  usb: gadget: configfs: add mutex lock before unregister gadget
  usb: gadget: u_ether: fix dereference after null check coverify warning
  ...

Merge tag 'xfs-iomap-for-linus-4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs and iomap fixes from Dave Chinner:
 "Changes in this update:

  Regression fixes for XFS changes introduce in 4.8-rc1:
   - buffer IO accounting assert failure
   - ENOSPC block accounting reservation issue
   - DAX IO path page cache invalidation fix
   - rmapbt on-disk block count in agf
   - correct classification of rmap block type when updating AGFL.
   - iomap support for attribute fork mapping

  Regression fixes for iomap infrastructure in 4.8-rc1:
   - fiemap: honor FIEMAP_FLAG_SYNC
   - fiemap: implement FIEMAP_FLAG_XATTR support to fix XFS regression
   - make mark_page_accessed and pagefault_disable usage consistent with
     other IO paths"

* tag 'xfs-iomap-for-linus-4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: remove OWN_AG rmap when allocating a block from the AGFL
  xfs: (re-)implement FIEMAP_FLAG_XATTR
  xfs: simplify xfs_file_iomap_begin
  iomap: mark ->iomap_end as optional
  iomap: prepare iomap_fiemap for attribute mappings
  iomap: fiemap should honor the FIEMAP_FLAG_SYNC flag
  iomap: remove superflous pagefault_disable from iomap_write_actor
  iomap: remove superflous mark_page_accessed from iomap_write_actor
  xfs: store rmapbt block count in the AGF
  xfs: don't invalidate whole file on DAX read/write
  xfs: fix bogus space reservation in xfs_iomap_write_allocate
  xfs: don't assert fail on non-async buffers on ioacct decrement

Merge tag 'hwmon-for-linus-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Fix a bug in it87 driver and URLs in ftsteutates driver"

* tag 'hwmon-for-linus-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (ftsteutates) Correct ftp urls in driver documentation
  hwmon: (it87) Features mask must be 32 bit wide

Pull more drm fixes from Dave Airlie:
 "Daniel pointed out I'd missed some i915 fixes, and I also found a
  single etnaviv fix I missed.

  So here they are"

* tag 'drm-fixes-for-4.8-rc3-2' of git://people.freedesktop.org/~airlied/linux:
  drm/etnaviv: take GPU lock later in the submit process
  drm/i915: Fix modeset handling during gpu reset, v5.
  drm/i915: fix aliasing_ppgtt leak
  drm/i915: fix WaInsertDummyPushConstPs
  drm/i915: Fix iboost setting for SKL Y/U DP DDI buffer translation entry 2
  drm/i915/gen9: Give one extra block per line for SKL plane WM calculations
  drm/i915: Acquire audio powerwell for HD-Audio registers
  drm/i915: Add missing rpm wakelock to GGTT pread
  drm/i915/fbc: FBC causes display flicker when VT-d is enabled on Skylake
  drm/i915: Clean up the extra RPM ref on CHV with i915.enable_rc6=0
  drm/i915: Program iboost settings for HDMI/DVI on SKL
  drm/i915: Fix iboost setting for DDI with 4 lanes on SKL
  drm/i915: Handle ENOSPC after failing to insert a mappable node
  drm/i915: Flush GT idle status upon reset

Pull DeviceTree fixes from Rob Herring:

 - a couple of DT node ref counting fixes

 - fix __unflatten_device_tree for PPC PCI hotplug case

 - rework marking irq controllers as OF_POPULATED in cases where real
   driver is used.

 - disable of_platform_default_populate_init on PPC.  The change in
   initcall order causes problems which need to be sorted out later.

* tag 'devicetree-fixes-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: fix reference counting in of_graph_get_endpoint_by_regs
  of/platform: disable the of_platform_default_populate_init() for all the ppc boards
  ARM: imx6: mark GPC node as not populated after irq init to probe pm domain driver
  of/irq: Mark interrupt controllers as populated before initialisation
  drivers/of: Validate device node in __unflatten_device_tree()
  of: Delete an unnecessary check before the function call "of_node_put"

Pull documentation fixes from Jonathan Corbet:
 "Three small fixes for Sphinx-formatted documentation generation"

* tag '4.8-doc-fixes' of git://git.lwn.net/linux:
  doc-rst: customize RTD theme, drop padding of inline literal
  docs: kernel-documentation: remove some highlight directives
  docs: Set the Sphinx default highlight language to "guess"

Collection of i915 fixes.

* tag 'drm-intel-fixes-2016-08-15' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Fix modeset handling during gpu reset, v5.
  drm/i915: fix aliasing_ppgtt leak
  drm/i915: fix WaInsertDummyPushConstPs
  drm/i915: Fix iboost setting for SKL Y/U DP DDI buffer translation entry 2
  drm/i915/gen9: Give one extra block per line for SKL plane WM calculations
  drm/i915: Acquire audio powerwell for HD-Audio registers
  drm/i915: Add missing rpm wakelock to GGTT pread
  drm/i915/fbc: FBC causes display flicker when VT-d is enabled on Skylake
  drm/i915: Clean up the extra RPM ref on CHV with i915.enable_rc6=0
  drm/i915: Program iboost settings for HDMI/DVI on SKL
  drm/i915: Fix iboost setting for DDI with 4 lanes on SKL
  drm/i915: Handle ENOSPC after failing to insert a mappable node
  drm/i915: Flush GT idle status upon reset

Single GPU recovery fix
* 'drm-etnaviv-fixes' of git://git.pengutronix.de/git/lst/linux:
  drm/etnaviv: take GPU lock later in the submit process

Pull x86 fixes from Ingo Molnar:
 "An initrd microcode loading fix, and an SMP bootup topology setup fix
  to resolve crashes on SGI/UV systems if the BIOS is configured in a
  certain way"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/smp: Fix __max_logical_packages value setup
  x86/microcode/AMD: Fix initrd loading with CONFIG_RANDOMIZE_MEMORY=y

Pull timer fixes from Ingo Molnar:
 "Three clocksource driver fixes"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/mips-gic-timer: Make gic_clocksource_of_init() return int
  clocksource/drivers/kona: Fix get_counter() error handling
  clocksource/drivers/time-armada-370-xp: Fix the clock reference

Pull scheduler fixes from Ingo Molnar:
 "Two cputime fixes - hopefully the last ones"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/cputime: Resync steal time when guest & host lose sync
  sched/cputime: Fix NO_HZ_FULL getrusage() monotonicity regression

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also start/stop filter related fixes, a perf
  event read() fix, a fix uncovered by fuzzing, and an uprobes leak fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Check return value of the perf_event_read() IPI
  perf/core: Enable mapping of the stop filters
  perf/core: Update filters only on executable mmap
  perf/core: Fix file name handling for start/stop filters
  perf/core: Fix event_function_local()
  uprobes: Fix the memcg accounting
  perf intel-pt: Fix occasional decoding errors when tracing system-wide
  tools: Sync kvm related header files for arm64 and s390
  perf probe: Release resources on error when handling exit paths
  perf probe: Check for dup and fdopen failures
  perf symbols: Fix annotation of objects with debuginfo files
  perf script: Don't disable use_callchain if input is pipe
  perf script: Show proper message when failed list scripts
  perf jitdump: Add the right header to get the major()/minor() definitions
  perf ppc64le: Fix build failure when libelf is not present
  perf tools mem: Fix -t store option for record command
  perf intel-pt: Fix ip compression

Pull locking fixes from Ingo Molnar:
 "Two lockless_dereference() related fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/barriers: Suppress sparse warnings in lockless_dereference()
  Revert "drm/fb-helper: Reduce READ_ONCE(master) to lockless_dereference"

Pull arm64 fixes from Catalin Marinas:

 - Avoid a literal load with the MMU off on the CPU resume path
   (potential inconsistency between cache and RAM)

 - Build error with CONFIG_ACPI=n fixed

 - Compiler warning in the arch/arm64/mm/dump.c code fixed

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Fix shift warning in arch/arm64/mm/dump.c
  arm64: kernel: avoid literal load of virtual address with MMU off
  arm64: Fix NUMA build error when !CONFIG_ACPI

Pull ARM fixes from Russell King:
 "Only three fixes this time:

   - Emil found an overflow problem with the memory layout sanity check.

   - Ard Biesheuvel noticed that late-allocated page tables (for EFI)
     weren't being properly constructed.

   - Guenter Roeck reported a problem found on qemu caused by the recent
     addr_limit changes"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: fix address limit restoration for undefined instructions
  ARM: 8591/1: mm: use fully constructed struct pages for EFI pgd allocations
  ARM: 8590/1: sanity_check_meminfo(): avoid overflow on vmalloc_limit

Pull power management fixes from Rafael Wysocki:
 "More hibernation-related material: one fix for a recent regression in
  the core, one small cleanup of the x86-64 resume code and a
  documentation update.

  Specifics:

   - Fix a hibernate core regression resulting from uncovering a latent
     bug in its implementation of memory bitmaps by a recent commit
     (James Morse).

   - Use __pa() to compute a physical address in the x86-64 code
     finalizing resume from hibernation (Rafael Wysocki).

   - Update power management documentation related to system sleep
     states to remove outdated information from it and to add a
     description of a recently introduced hibernation debug feature to
     it (Rafael Wysocki)"

* tag 'pm-4.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / hibernate: Fix rtree_next_node() to avoid walking off list ends
  x86/power/64: Use __pa() for physical address computation
  PM / sleep: Update some system sleep documentation

Pull drm fixes from Dave Airlie:
 "Pretty quiet so far:

   - a few amdgpu/radeon fixup for pcie pm changes
   - a couple of amdgpu fixes
   - some build fixes
   - printk fix"

* tag 'drm-fixes-for-4.8-rc3' of git://people.freedesktop.org/~airlied/linux:
  drm/amdgpu: Change GART offset to 64-bit
  drm/mediatek: add ARM_SMCCC dependency
  drm/mediatek: add CONFIG_OF dependency
  drm/mediatek: add COMMON_CLK dependency
  drm/amdgpu: Fix memory trashing if UVD ring test fails
  drm/amdgpu: fix vm init error path
  drm/amdkfd: print doorbell offset as a hex value
  Revert "drm/radeon: work around lack of upstream ACPI support for D3cold"
  Revert "drm/amdgpu: work around lack of upstream ACPI support for D3cold"

After Peter's commit:

  331b6d8c ("locking/barriers: Validate lockless_dereference() is used on a pointer type")

... we get a lot of sparse warnings (one for every rcu_dereference, and more)
since the expression here is assigning to the wrong address space.

Instead of validating that 'p' is a pointer this way, instead make
it fail compilation when it's not by using sizeof(*(p)). This will
not cause any sparse warnings (tested, likely since the address
space is irrelevant for sizeof), and will fail compilation when
'p' isn't a pointer type.
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 331b6d8c ("locking/barriers: Validate lockless_dereference() is used on a pointer type")
Link: http://lkml.kernel.org/r/1470909022-687-2-git-send-email-johannes@sipsolutions.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

This reverts commit:

  fa7d81bb ("drm/fb-helper: Reduce READ_ONCE(master) to lockless_dereference")

As Peter explained:

  [...] lockless_dereference() is _stronger_ than READ_ONCE(), not weaker.

  [...]

  Also, clue is in the name: 'dereference', you don't actually dereference
  the pointer here, only load it.

My next patch breaks the compile without this revert, because it assumes
you want to deference and thus also need the struct type visible (which
it isn't here), so revert it.
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
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/1470909022-687-1-git-send-email-johannes@sipsolutions.netSigned-off-by: Ingo Molnar <mingo@kernel.org>