Take reference of the OPP table while adding and removing OPPs, that
helps us remove special checks in _remove_opp_table().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that we have proper kernel reference infrastructure in place for OPP
tables, use it to guarantee that the OPP table isn't freed while being
used by the callers of dev_pm_opp_set_*() APIs.

Make them all return the pointer to the OPP table after taking its
reference and put the reference back with dev_pm_opp_put_*() APIs.

Now that the OPP table wouldn't get freed while these routines are
executing after dev_pm_opp_get_opp_table() is called, there is no need
to take opp_table_lock. Drop them as well.

Remove the rcu specific comments from these routines as they aren't
relevant anymore.

Note that prototypes of dev_pm_opp_{set|put}_regulators() were already
updated by another patch.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add kref to struct opp_table for easier accounting of the OPP table.

Note that the new routine dev_pm_opp_get_opp_table() takes the reference
from under the opp_table_lock, which guarantees that the OPP table
doesn't get freed unless dev_pm_opp_put_opp_table() is called for the
OPP table.

Two separate release mechanisms are added: locked and unlocked. In
unlocked version the routines aren't required to take/drop
opp_table_lock as the callers have already done that. This is required
to avoid breaking git bisect, otherwise we may get lockdeps between
commits. Once all the users of OPP table are updated the unlocked
version shall be removed.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add per OPP table lock to protect opp_table->opp_list.

Note that at few places opp_list is used under the rcu_read_lock() and
so a mutex can't be added there for now. This will be fixed by a later
patch.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Split out parts of _add_opp_table() and _remove_opp_table() into
separate routines. This improves readability as well.

Should result in no functional changes.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Let the OPP core provide helpers to register notifiers for any device,
instead of exposing srcu_head outside of the core.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There is only one user of dev_pm_opp_get_suspend_opp() and that uses it
to get the OPP rate for the suspend_opp.

Rename dev_pm_opp_get_suspend_opp() as dev_pm_opp_get_suspend_opp_freq()
and return the rate directly from it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no point in trying to find/allocate the table for every OPP
that is added for a device. It would be far more efficient to allocate
the table only once and pass its pointer to the routines that add the
OPP entry.

Locking is removed from _opp_add_static_v2() and _opp_add_v1() now as
the callers call them with that lock already held.

Call to _remove_opp_table() routine is also removed from _opp_free()
now, as opp_table isn't allocated from within _opp_allocate(). This is
handled by the routines which created the OPP table in the first place.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Later patches would want to remove OPP table (and its OPPs) using the
opp_table pointer instead of 'dev'.

In order to prepare for that, rename _dev_pm_opp_remove_table() as
_dev_pm_opp_find_and_remove_table() split out part of it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The OPPs which are never successfully added using _opp_add() are not
required to be freed with the _opp_remove() routine, as a simple kfree()
is enough for them.

Introduce a new light weight routine _opp_free(), which will do that.

That also helps us removing the 'notify' parameter to _opp_remove(),
which isn't required anymore.

Note that _opp_free() contains a call to _remove_opp_table() as the OPP
table might have been added for this very OPP only. The
_remove_opp_table() routine returns quickly if there are more OPPs in
the table. This will be simplified in later patches though.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The code adding static OPPs for V2 bindings already does so. Make the V1
bindings specific code behave the same.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the naming consistent with how other routines are named.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This TODO doesn't make sense anymore as we have all the information in a
single OPP table. Remove it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There are two types of duplicate OPPs that get different behavior from
the core:
A) An earlier OPP is marked 'available' and has same freq/voltages as
   the new one.
B) An earlier OPP with same frequency, but is marked 'unavailable' OR
   doesn't have same voltages as the new one.

The OPP core returns 0 for the first one, but -EEXIST for the second.

While the OPP core returns 0 for the first case, its callers don't free
the newly allocated OPP structure which isn't used anymore. Fix that by
returning -EBUSY instead of 0, but make the callers return 0 eventually.

As this isn't a critical fix, its not getting marked for stable kernel.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull x86 fix from Thomas Gleixner:
 "Restore the retrigger callbacks in the IO APIC irq chips. That
  addresses a long standing regression which got introduced with the
  rewrite of the x86 irq subsystem two years ago and went unnoticed so
  far"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ioapic: Restore IO-APIC irq_chip retrigger callback

Pull smp/hotplug fix from Thomas Gleixner:
 "Remove an unused variable which is a leftover from the notifier
  removal"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Remove unused but set variable in _cpu_down()

Pull virtio/vhost fixes from Michael Tsirkin:
 "Random fixes and cleanups that accumulated over the time"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: virtio: constify virtio_config_ops structures
  virtio/s390: add missing \n to end of dev_err message
  virtio/s390: support READ_STATUS command for virtio-ccw
  tools/virtio/ringtest: tweaks for s390
  tools/virtio/ringtest: fix run-on-all.sh for offline cpus
  virtio_console: fix a crash in config_work_handler
  vhost/scsi: silence uninitialized variable warning
  vhost: scsi: constify target_core_fabric_ops structures

Pull thermal management fixes from Zhang Rui:

 - fix a regression that thermal zone dynamically allocated sysfs
   attributes are freed before they're removed, which is introduced in
   4.10-rc1 (Jacob von Chorus)

 - fix a boot warning because deprecated hwmon API is used (Fabio
   Estevam)

 - a couple of fixes for rockchip thermal driver (Brian Norris, Caesar
   Wang)

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: rockchip: fixes the conversion table
  thermal: core: move tz->device.groups cleanup to thermal_release
  thermal: thermal_hwmon: Convert to hwmon_device_register_with_info()
  thermal: rockchip: handle set_trips without the trip points
  thermal: rockchip: optimize the conversion table
  thermal: rockchip: fixes invalid temperature case
  thermal: rockchip: don't pass table structs by value
  thermal: rockchip: improve conversion error messages

Pull USB fixes from Greg KH:
 "Here are a few small USB fixes for 4.10-rc5.

  Most of these are gadget/dwc2 fixes for reported issues, all of these
  have been in linux-next for a while. The last one is a single xhci
  WARN_ON removal to handle an issue that the dwc3 driver is hitting in
  the 4.10-rc tree. The warning is harmless and needs to be removed, and
  a "real" fix that is more complex will show up in 4.11-rc1 for this
  device.

  That last patch hasn't been in linux-next yet due to the weekend
  timing, but it's a "simple" WARN_ON() removal so what could go wrong?
  :)"

Famous last words.

* tag 'usb-4.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: remove WARN_ON if dma mask is not set for platform devices
  usb: dwc2: host: fix Wmaybe-uninitialized warning
  usb: dwc2: gadget: Fix GUSBCFG.USBTRDTIM value
  usb: gadget: udc: atmel: remove memory leak
  usb: dwc3: exynos fix axius clock error path to do cleanup
  usb: dwc2: Avoid suspending if we're in gadget mode
  usb: dwc2: use u32 for DT binding parameters
  usb: gadget: f_fs: Fix iterations on endpoints.
  usb: dwc2: gadget: Fix DMA memory freeing
  usb: gadget: composite: Fix function used to free memory

Pull libnvdimm fixes from Dan Williams:
 "Two fixes:

   - a regression fix for the multiple-pmem-namespace-per-region support
     added in 4.9. Even if an existing environment is not using that
     feature the act of creating and a destroying a single namespace
     with the ndctl utility will lead to the proliferation of extra
     unwanted namespace devices.

   - a fix for the error code returned from the pmem driver when the
     memcpy_mcsafe() routine returns -EFAULT. Btrfs seems to be the only
     block I/O consumer that tries to parse the meaning of the error
     code when it is non-zero.

  Neither of these fixes are critical, the namespace leak is awkward in
  that it can cause device naming to change and complicates debugging
  namespace initialization issues. The error code fix is included out of
  caution for what other consumers might be expecting -EIO for block I/O
  errors"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, namespace: fix pmem namespace leak, delete when size set to zero
  pmem: return EIO on read_pmem() failure

Pull clk fix from Stephen Boyd:
 "One fix for Samsung Exynos524x SoCs where recent IOMMU patches have
  caused some of these clocks to turn off when they were always left on
  before"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk/samsung: exynos542x: mark some clocks as critical

Pull ARC fixes from Vineet Gupta:

 - more intc updates [Yuriv]

 - fix module build when unwinder is turned off

 - IO Coherency Programming model updates

 - other miscellaneous

* tag 'arc-4.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Revert "ARC: mm: IOC: Don't enable IOC by default"
  ARC: mm: split arc_cache_init to allow __init reaping of bulk
  ARCv2: IOC: Use actual memory size to setup aperture size
  ARCv2: IOC: Adhere to progamming model guidelines to avoid DMA corruption
  ARCv2: IOC: refactor the IOC and SLC operations into own functions
  ARC: module: Fix !CONFIG_ARC_DW2_UNWIND builds
  ARCv2: save r30 on kernel entry as gcc uses it for code-gen
  ARCv2: IRQ: Call entry/exit functions for chained handlers in MCIP
  ARC: IRQ: Use hwirq instead of virq in mask/unmask
  ARC: mmu: clarify the MMUv3 programming model

Pull powerpc fixes from Michael Ellerman:
 "Two fixes for fallout from the hugetlb changes we merged this cycle.

  Ten other fixes, four only affect Power9, and the rest are a bit of a
  mixture though nothing terrible.

  Thanks to: Aneesh Kumar K.V, Anton Blanchard, Benjamin Herrenschmidt,
  Dave Martin, Gavin Shan, Madhavan Srinivasan, Nicholas Piggin, Reza
  Arbab"

* tag 'powerpc-4.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Ignore reserved field in DCSR and PVR reads and writes
  powerpc/ptrace: Preserve previous TM fprs/vsrs on short regset write
  powerpc/ptrace: Preserve previous fprs/vsrs on short regset write
  powerpc/perf: Use MSR to report privilege level on P9 DD1
  selftest/powerpc: Wrong PMC initialized in pmc56_overflow test
  powerpc/eeh: Enable IO path on permanent error
  powerpc/perf: Fix PM_BRU_CMPL event code for power9
  powerpc/mm: Fix little-endian 4K hugetlb
  powerpc/mm/hugetlb: Don't panic when we don't find the default huge page size
  powerpc: Fix pgtable pmd cache init
  powerpc/icp-opal: Fix missing KVM case and harden replay
  powerpc/mm: Fix memory hotplug BUG() on radix

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - Fix for timer setup on VHE machines
   - Drop spurious warning when the timer races against the vcpu running
     again
   - Prevent a vgic deadlock when the initialization fails (for stable)

  s390:
   - Fix a kernel memory exposure (for stable)

  x86:
   - Fix exception injection when hypercall instruction cannot be
     patched"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: do not expose random data via facility bitmap
  KVM: x86: fix fixing of hypercalls
  KVM: arm/arm64: vgic: Fix deadlock on error handling
  KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systems
  KVM: arm/arm64: Fix occasional warning from the timer work function

Merge branch 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux

Pull SCSI target fixes from Bart Van Assche:

 - two small fixes for the ibmvscsis driver

 - ten patches with bug fixes for the target mode of the qla2xxx driver

 - four patches that avoid that the "sparse" and "smatch" static
   analyzer tools report false positives for the qla2xxx code base

* 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux:
  qla2xxx: Disable out-of-order processing by default in firmware
  qla2xxx: Fix erroneous invalid handle message
  qla2xxx: Reduce exess wait during chip reset
  qla2xxx: Terminate exchange if corrupted
  qla2xxx: Fix crash due to null pointer access
  qla2xxx: Collect additional information to debug fw dump
  qla2xxx: Reset reserved field in firmware options to 0
  qla2xxx: Set tcm_qla2xxx version to automatically track qla2xxx version
  qla2xxx: Include ATIO queue in firmware dump when in target mode
  qla2xxx: Fix wrong IOCB type assumption
  qla2xxx: Avoid that building with W=1 triggers complaints about set-but-not-used variables
  qla2xxx: Move two arrays from header files to .c files
  qla2xxx: Declare an array with file scope static
  qla2xxx: Fix indentation
  ibmvscsis: Fix sleeping in interrupt context
  ibmvscsis: Fix max transfer length

Pull block fixes from Jens Axboe:
 "Just two small fixes for this -rc.

  One is just killing an unused variable from Keith, but the other
  fixes a performance regression for nbd in this series, where we
  inadvertently flipped when we set MSG_MORE when outputting data"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nbd: only set MSG_MORE when we have more to send
  blk-mq: Remove unused variable

Pull spi fixes from Mark Brown:
 "The usual small smattering of driver specific fixes. A few bits that
  stand out here:

   - the R-Car patches adding fallbacks are just adding new compatible
     strings to the driver so that device trees are written in a more
     robustly future proof fashion, this isn't strictly a fix but it's
     just new IDs and it's better to get it into mainline sooner to
     improve the ABI

   - the DesignWare "switch to new API part 2" patch is actually a
     misleadingly titled fix for a bit that got missed in the original
     conversion"

* tag 'spi-fix-v4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: davinci: use dma_mapping_error()
  spi: spi-axi: Free resources on error path
  spi: pxa2xx: add missed break
  spi: dw-mid: switch to new dmaengine_terminate_* API (part 2)
  spi: dw: Make debugfs name unique between instances
  spi: sh-msiof: Do not use C++ style comment
  spi: armada-3700: Set mode bits correctly
  spi: armada-3700: fix unsigned compare than zero on irq
  spi: sh-msiof: Add R-Car Gen 2 and 3 fallback bindings
  spi: SPI_FSL_DSPI should depend on HAS_DMA

Pull ceph fixes from Ilya Dryomov:
 "Three filesystem endianness fixes (one goes back to the 2.6 era, all
  marked for stable) and two fixups for this merge window's patches"

* tag 'ceph-for-4.10-rc5' of git://github.com/ceph/ceph-client:
  ceph: fix bad endianness handling in parse_reply_info_extra
  ceph: fix endianness bug in frag_tree_split_cmp
  ceph: fix endianness of getattr mask in ceph_d_revalidate
  libceph: make sure ceph_aes_crypt() IV is aligned
  ceph: fix ceph_get_caps() interruption

Pull overlayfs fix from Miklos Szeredi:
 "This fixes a regression introduced in this cycle"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix possible use after free on redirect dir lookup

Pull fuse fixes from Miklos Szeredi:
 "Fix two regressions, one introduced in 4.9 and a less recent one in
  4.2"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: fix time_to_jiffies nsec sanity check
  fuse: clear FR_PENDING flag when moving requests out of pending queue

Pull SCSI fixes from James Bottomley:
 "This is a set of 12 fixes including the mpt3sas one that was causing
  hangs on ATA passthrough.

  The others are a couple of zoned block device fixes, a SAS device
  detection bug which lead to SATA drives not being matched to bays, two
  qla2xxx MSI fixes, a qla2xxx req for rsp confusion caused by cut and
  paste, and a few other minor fixes"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: mpt3sas: fix hang on ata passthrough commands
  scsi: lpfc: Set elsiocb contexts to NULL after freeing it
  scsi: sd: Ignore zoned field for host-managed devices
  scsi: sd: Fix wrong DPOFUA disable in sd_read_cache_type
  scsi: bfa: fix wrongly initialized variable in bfad_im_bsg_els_ct_request()
  scsi: ses: Fix SAS device detection in enclosure
  scsi: libfc: Fix variable name in fc_set_wwpn
  scsi: lpfc: avoid double free of resource identifiers
  scsi: qla2xxx: remove irq_affinity_notifier
  scsi: qla2xxx: fix MSI-X vector affinity
  scsi: qla2xxx: Fix apparent cut-n-paste error.
  scsi: qla2xxx: Get mutex lock before checking optrom_state

Pull arm64 fixes from Catalin Marinas:

 - avoid potential stack information leak via the ptrace ABI caused by
   uninitialised variables

 - SWIOTLB DMA API fall-back allocation fix when the SWIOTLB buffer is
   not initialised (all RAM is suitable for 32-bit DMA masks)

 - fix the bad_mode function returning for unhandled exceptions coming
   from user space

 - fix name clash in __page_to_voff()

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: avoid returning from bad_mode
  arm64/ptrace: Reject attempts to set incomplete hardware breakpoint fields
  arm64/ptrace: Avoid uninitialised struct padding in fpr_set()
  arm64/ptrace: Preserve previous registers for short regset write
  arm64/ptrace: Preserve previous registers for short regset write
  arm64/ptrace: Preserve previous registers for short regset write
  arm64: mm: avoid name clash in __page_to_voff()
  arm64: Fix swiotlb fallback allocation

KVM: s390: Fix for 4.10 (via kvm/master)

Fix a kernel memory exposure.

kvm_s390_get_machine() populates the facility bitmap by copying bytes
from the host results that are stored in a 256 byte array in the prefix
page. The KVM code does use the size of the target buffer (2k), thus
copying and exposing unrelated kernel memory (mostly machine check
related logout data).

Let's use the size of the source buffer instead.  This is ok, as the
target buffer will always be greater or equal than the source buffer as
the KVM internal buffers (and thus S390_ARCH_FAC_LIST_SIZE_BYTE) cover
the maximum possible size that is allowed by STFLE, which is 256
doublewords. All structures are zero allocated so we can leave bytes
256-2047 unchanged.

Add a similar fix for kvm_arch_init_vm().
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
[found with smatch]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>

The warn on is a bit too much, we will anyway set the dma mask if not set
previously.

The main reason for this fix is that 4.10-rc1  has a dwc3 change that
pass a parent sysdev dev pointer instead of setting the dma mask of
its xhci platform device. xhci platform driver can then get more
attributes from the sysdev than just the dma mask.

The usb core and xhci changes are not yet in 4.10, and a fix like
this was preferred instead of taking those big changes this late in
the rc-cycle.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

IBM bit 31 (for the rest of us - bit 0) is a reserved field in the
instruction definition of mtspr and mfspr. Hardware is encouraged to
(and does) ignore it.

As a result, if userspace executes an mtspr DSCR with the reserved bit
set, we get a DSCR facility unavailable exception. The kernel fails to
match against the expected value/mask, and we silently return to
userspace to try and re-execute the same mtspr DSCR instruction. We
loop forever until the process is killed.

We should do something here, and it seems mirroring what hardware does
is the better option vs killing the process. While here, relax the
matching of mfspr PVR too.

Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET
to fill all the check pointed registers, the thread's old check pointed
registers are preserved.

Fixes: 9d3918f7 ("powerpc/ptrace: Enable support for NT_PPC_CVSX")
Fixes: 19cbcbf7 ("powerpc/ptrace: Enable support for NT_PPC_CFPR")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET
to fill all the registers, the thread's old registers are preserved.

Fixes: c6e6771b ("powerpc: Introduce VSX thread_struct and CONFIG_VSX")
Cc: stable@vger.kernel.org # v2.6.27+
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>