mddev_suspend() is a more general interface than
calling ->quiesce() and is so more extensible.  A
future patch will make use of this.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

responding to ->suspend_lo and ->suspend_hi is similar
to responding to ->suspended.  It is best to wait in
the common core code without incrementing ->active_io.
This allows mddev_suspend()/mddev_resume() to work while
requests are waiting for suspend_lo/hi to change.
This is will be important after a subsequent patch
which uses mddev_suspend() to synchronize updating for
suspend_lo/hi.

So move the code for testing suspend_lo/hi out of raid1.c
and raid5.c, and place it in md.c
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

bitmap_create() allocates memory with GFP_KERNEL and
so can wait for IO.
If called while the array is quiesced, it could wait indefinitely
for write out to the array - deadlock.
So call bitmap_create() before quiescing the array.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Most often mddev_suspend() is called with
reconfig_mutex held.  Make this a requirement in
preparation a subsequent patch.  Also require
reconfig_mutex to be held for mddev_resume(),
partly for symmetry and partly to guarantee
no races with incr/decr of mddev->suspend.

Taking the mutex in r5c_disable_writeback_async() is
a little tricky as this is called from a work queue
via log->disable_writeback_work, and flush_work()
is called on that while holding ->reconfig_mutex.
If the work item hasn't run before flush_work()
is called, the work function will not be able to
get the mutex.

So we use mddev_trylock() inside the wait_event() call, and have that
abort when conf->log is set to NULL, which happens before
flush_work() is called.
We wait in mddev->sb_wait and ensure this is woken
when any of the conditions change.  This requires
waking mddev->sb_wait in mddev_unlock().  This is only
like to trigger extra wake_ups of threads that needn't
be woken when metadata is being written, and that
doesn't happen often enough that the cost would be
noticeable.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Having both a bitmap and a journal is pointless.
Attempting to do so can corrupt the bitmap if the journal
replay happens before the bitmap is initialized.
Rather than try to avoid this corruption, simply
refuse to allow arrays with both a bitmap and a journal.
So:
 - if raid5_run sees both are present, fail.
 - if adding a bitmap finds a journal is present, fail
 - if adding a journal finds a bitmap is present, fail.

Cc: stable@vger.kernel.org (4.10+)
Signed-off-by: NeilBrown <neilb@suse.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Shaohua Li <shli@fb.com>

When reshaping a fully degraded raid5/raid6 to a larger
nubmer of devices, the new device(s) are not in-sync
and so that can make the newly grown stripe appear to be
"failed".
To avoid this, we set the R5_Expanded flag to say "Even though
this device is not fully in-sync, this block is safe so
don't treat the device as failed for this stripe".
This flag is set for data devices, not not for parity devices.

Consequently, if you have a RAID6 with two devices that are partly
recovered and a spare, and start a reshape to include the spare,
then when the reshape gets past the point where the recovery was
up to, it will think the stripes are failed and will get into
an infinite loop, failing to make progress.

So when contructing parity on an EXPAND_READY stripe,
set R5_Expanded.
Reported-by: Curt <lightspd@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Variables dev and bio_last_sector are assigned values that are never
read and hence these are redundant variables and can be removed.
Also remove the duplicated initialization of sectors, the latter
assignment is identical to the first and can be removed.

Cleans up 3 clang build warnings:
Value stored to 'dev' is never read
Value stored to 'bio_last_sector' is never read
Value stored to 'sectors' during its initialization is never read
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Motivated by the desire to illiminate the imprecise nature of
DM-specific patches being unnecessarily sent to both the MD maintainer
and mailing-list.  Which is born out of the fact that DM files also
reside in drivers/md/

Now all MD-specific files in drivers/md/ start with either "raid" or
"md-" and the MAINTAINERS file has been updated accordingly.

Shaohua: don't change module name
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>

The raid10 driver can't be built with clang since it uses a variable
length array in a structure (VLAIS):

drivers/md/raid10.c:4583:17: error: fields must have a constant size:
  'variable length array in structure' extension will never be supported

Allocate the r10bio struct with kmalloc instead of using the VLAIS
construct.

Shaohua: set the MD_RECOVERY_INTR bit
Neil Brown: use GFP_NOIO
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Shaohua Li <shli@fb.com>

The function cluster_check_sync_size is local to the source and does
not need to be in global scope, so make it static.

Cleans up sparse warning:
symbol 'cluster_check_sync_size' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shaohua Li <shli@fb.com>

If starting an array that is undergoing rebuild, make ppl recovery honor
the recovery_offset of a member disk and don't read data that is not yet
in-sync.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>

The check for degraded array is unnecessary and causes a resync to be
performed after ppl recovery and rebuild when restarting an array during
rebuilding after unclean shutdown.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>

The check used here is to avoid conflict between write and
resync, however we used the wrong logic, it should be the
inverse of the checking inside "if".

Fixes: 589a1c49 ("Suspend writes in RAID1 if within range")
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

This reverts commit 8031c3dd. That patches doesn't work well if PAGE_SIZE >
4k. We will fix the original problem with a different approach.

Fix: 8031c3dd(md/bitmap: copy correct data for bitmap super)
Reported-by: Joshua Kinard <kumba@gentoo.org>
Cc: stable@vger.kernel.org (4.10+)
Suggested-by: Neil Brown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Since commit 4ad23a97 ("MD: use per-cpu counter for writes_pending"),
the wait_queue is only got invoked if THREAD_WAKEUP is not set previously.

With above change, I can see process_metadata_update could always hang on
the wait queue, because mddev->thread could stay on 'D' status and the
THREAD_WAKEUP flag is not cleared since there are lots of place to wake up
mddev->thread. Then deadlock happened as follows:

linux175:~ # ps aux|grep md|grep D
root    20117   0.0 0.0         0   0 ? D   03:45   0:00 [md0_raid1]
root    20125   0.0 0.0         0   0 ? D   03:45   0:00 [md0_cluster_rec]
linux175:~ # cat /proc/20117/stack
[<ffffffffa0635604>] dlm_lock_sync+0x94/0xd0 [md_cluster]
[<ffffffffa0635674>] lock_token+0x34/0xd0 [md_cluster]
[<ffffffffa0635804>] metadata_update_start+0x64/0x110 [md_cluster]
[<ffffffffa04d985b>] md_update_sb.part.58+0x9b/0x860 [md_mod]
[<ffffffffa04da035>] md_update_sb+0x15/0x30 [md_mod]
[<ffffffffa04dc066>] md_check_recovery+0x266/0x490 [md_mod]
[<ffffffffa06450e2>] raid1d+0x42/0x810 [raid1]
[<ffffffffa04d2252>] md_thread+0x122/0x150 [md_mod]
[<ffffffff81091741>] kthread+0x101/0x140
linux175:~ # cat /proc/20125/stack
[<ffffffffa0636679>] recv_daemon+0x3f9/0x5c0 [md_cluster]
[<ffffffffa04d2252>] md_thread+0x122/0x150 [md_mod]
[<ffffffff81091741>] kthread+0x101/0x140

So let's revert the part of code in the commit to resovle the problem since
we can't get lots of benefits of previous change.

Fixes: 4ad23a97 ("MD: use per-cpu counter for writes_pending")
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

A recent patch aimed to cause md_write_start() to fail (rather than
block) when the mddev was suspending, so as to avoid deadlocks.
Unfortunately the test in wait_event() was wrong, and it didn't change
behaviour at all.

We wait_event() must wait until the metadata is written OR the array is
suspending.

Fixes: cc27b0c7 ("md: fix deadlock between mddev_suspend() and md_write_start()")
Cc: stable@vger.kernel.org
Reported-by: Xiao Ni <xni@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

Pull x86 fixes from Thomas Gleixner:
 "This contains the following fixes and improvements:

   - Avoid dereferencing an unprotected VMA pointer in the fault signal
     generation code

   - Fix inline asm call constraints for GCC 4.4

   - Use existing register variable to retrieve the stack pointer
     instead of forcing the compiler to create another indirect access
     which results in excessive extra 'mov %rsp, %<dst>' instructions

   - Disable branch profiling for the memory encryption code to prevent
     an early boot crash

   - Fix a sparse warning caused by casting the __user annotation in
     __get_user_asm_u64() away

   - Fix an off by one error in the loop termination of the error patch
     in the x86 sysfs init code

   - Add missing CPU IDs to various Intel specific drivers to enable the
     functionality on recent hardware

   - More (init) constification in the numachip code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm: Use register variable to get stack pointer value
  x86/mm: Disable branch profiling in mem_encrypt.c
  x86/asm: Fix inline asm call constraints for GCC 4.4
  perf/x86/intel/uncore: Correct num_boxes for IIO and IRP
  perf/x86/intel/rapl: Add missing CPU IDs
  perf/x86/msr: Add missing CPU IDs
  perf/x86/intel/cstate: Add missing CPU IDs
  x86: Don't cast away the __user in __get_user_asm_u64()
  x86/sysfs: Fix off-by-one error in loop termination
  x86/mm: Fix fault error path using unsafe vma pointer
  x86/numachip: Add const and __initconst to numachip2_clockevent

Pull timer fixes from Thomas Gleixner:
 "This adds a new timer wheel function which is required for the
  conversion of the timer callback function from the 'unsigned long
  data' argument to 'struct timer_list *timer'. This conversion has two
  benefits:

   1) It makes struct timer_list smaller

   2) Many callers hand in a pointer to the timer or to the structure
      containing the timer, which happens via type casting both at setup
      and in the callback. This change gets rid of the typecasts.

  Once the conversion is complete, which is planned for 4.15, the old
  setup function and the intermediate typecast in the new setup function
  go away along with the data field in struct timer_list.

  Merging this now into mainline allows a smooth queueing of the actual
  conversion in the affected maintainer trees without creating
  dependencies"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  um/time: Fixup namespace collision
  timer: Prepare to change timer callback argument type

Pull smp/hotplug fixes from Thomas Gleixner:
 "This addresses the fallout of the new lockdep mechanism which covers
  completions in the CPU hotplug code.

  The lockdep splats are false positives, but there is no way to
  annotate that reliably. The solution is to split the completions for
  CPU up and down, which requires some reshuffling of the failure
  rollback handling as well"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp/hotplug: Hotplug state fail injection
  smp/hotplug: Differentiate the AP completion between up and down
  smp/hotplug: Differentiate the AP-work lockdep class between up and down
  smp/hotplug: Callback vs state-machine consistency
  smp/hotplug: Rewrite AP state machine core
  smp/hotplug: Allow external multi-instance rollback
  smp/hotplug: Add state diagram

Pull scheduler fixes from Thomas Gleixner:
 "The scheduler pull request comes with the following updates:

   - Prevent a divide by zero issue by validating the input value of
     sysctl_sched_time_avg

   - Make task state printing consistent all over the place and have
     explicit state characters for IDLE and PARKED so they wont be
     displayed as 'D' state which confuses tools"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/sysctl: Check user input value of sysctl_sched_time_avg
  sched/debug: Add explicit TASK_PARKED printing
  sched/debug: Ignore TASK_IDLE for SysRq-W
  sched/debug: Add explicit TASK_IDLE printing
  sched/tracing: Use common task-state helpers
  sched/tracing: Fix trace_sched_switch task-state printing
  sched/debug: Remove unused variable
  sched/debug: Convert TASK_state to hex
  sched/debug: Implement consistent task-state printing

Pull perf fixes from Thomas Gleixner:

 - Prevent a division by zero in the perf aux buffer handling

 - Sync kernel headers with perf tool headers

 - Fix a build failure in the syscalltbl code

 - Make the debug messages of perf report --call-graph work correctly

 - Make sure that all required perf files are in the MANIFEST for
   container builds

 - Fix the atrr.exclude kernel handling so it respects the
   perf_event_paranoid and the user permissions

 - Make perf test on s390x work correctly

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/aux: Only update ->aux_wakeup in non-overwrite mode
  perf test: Fix vmlinux failure on s390x part 2
  perf test: Fix vmlinux failure on s390x
  perf tools: Fix syscalltbl build failure
  perf report: Fix debug messages with --call-graph option
  perf evsel: Fix attr.exclude_kernel setting for default cycles:p
  tools include: Sync kernel ABI headers with tooling headers
  perf tools: Get all of tools/{arch,include}/ in the MANIFEST

Pull  locking fixes from Thomas Gleixner:
 "Two fixes for locking:

   - Plug a hole the pi_stat->owner serialization which was changed
     recently and failed to fixup two usage sites.

   - Prevent reordering of the rwsem_has_spinner() check vs the
     decrement of rwsem count in up_write() which causes a missed
     wakeup"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem-xadd: Fix missed wakeup due to reordering of load
  futex: Fix pi_state->owner serialization

Pull irq fixes from Thomas Gleixner:

 - Add a missing NULL pointer check in free_irq()

 - Fix a memory leak/memory corruption in the generic irq chip

 - Add missing rcu annotations for radix tree access

 - Use ffs instead of fls when extracting data from a chip register in
   the MIPS GIC irq driver

 - Fix the unmasking of IPI interrupts in the MIPS GIC driver so they
   end up at the target CPU and not at CPU0

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irq/generic-chip: Don't replace domain's name
  irqdomain: Add __rcu annotations to radix tree accessors
  irqchip/mips-gic: Use effective affinity to unmask
  irqchip/mips-gic: Fix shifts to extract register fields
  genirq: Check __free_irq() return value for NULL

Pull objtool fixes from Thomas Gleixner:
 "Two small fixes for objtool:

   - Support frame pointer setup via 'lea (%rsp), %rbp' which was not
     yet supported and caused build warnings

   - Disable unreacahble warnings for GCC4.4 and older to avoid false
     positives caused by the compiler itself"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Support unoptimized frame pointer setup
  objtool: Skip unreachable warnings for GCC 4.4 and older

Pull mtd fixes from Boris Brezillon:

 - Fix partition alignment check in mtdcore.c

 - Fix a buffer overflow in the Atmel NAND driver

* tag 'mtd/fixes-for-4.14-rc3' of git://git.infradead.org/linux-mtd:
  mtd: nand: atmel: fix buffer overflow in atmel_pmecc_user
  mtd: Fix partition alignment check on multi-erasesize devices

Pull SCSI fixes from James Bottomley:
 "Eight mostly minor fixes for recently discovered issues in drivers"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ILLEGAL REQUEST + ASC==27 => target failure
  scsi: aacraid: Add a small delay after IOP reset
  scsi: scsi_transport_fc: Also check for NOTPRESENT in fc_remote_port_add()
  scsi: scsi_transport_fc: set scsi_target_id upon rescan
  scsi: scsi_transport_iscsi: fix the issue that iscsi_if_rx doesn't parse nlmsg properly
  scsi: aacraid: error: testing array offset 'bus' after use
  scsi: lpfc: Don't return internal MBXERR_ERROR code from probe function
  scsi: aacraid: Fix 2T+ drives on SmartIOC-2000

Pull x86 platform drivers fix from Darren Hart:
 "Newly discovered species of fujitsu laptops break some assumptions
  about ACPI device pairings.

  fujitsu-laptop: Don't oops when FUJ02E3 is not present"

* tag 'platform-drivers-x86-v4.14-2' of git://git.infradead.org/linux-platform-drivers-x86:
  platform/x86: fujitsu-laptop: Don't oops when FUJ02E3 is not presnt

Merge tag 'led_fixes-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fixes from Jacek Anaszewski:
 "Four fixes for the as3645a LED flash controller and one update to
  MAINTAINERS"

* tag 'led_fixes-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  MAINTAINERS: Add entry for MediaTek PMIC LED driver
  as3645a: Unregister indicator LED on device unbind
  as3645a: Use integer numbers for parsing LEDs
  dt: bindings: as3645a: Use LED number to refer to LEDs
  as3645a: Use ams,input-max-microamp as documented in DT bindings

Pull waitid fix from Al Viro:
 "Fix infoleak in waitid()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix infoleak in waitid(2)

Pull btrfs fixes from David Sterba:
 "We've collected a bunch of isolated fixes, for crashes, user-visible
  behaviour or missing bits from other subsystem cleanups from the past.

  The overall number is not small but I was not able to make it
  significantly smaller. Most of the patches are supposed to go to
  stable"

* 'for-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: log csums for all modified extents
  Btrfs: fix unexpected result when dio reading corrupted blocks
  btrfs: Report error on removing qgroup if del_qgroup_item fails
  Btrfs: skip checksum when reading compressed data if some IO have failed
  Btrfs: fix kernel oops while reading compressed data
  Btrfs: use btrfs_op instead of bio_op in __btrfs_map_block
  Btrfs: do not backup tree roots when fsync
  btrfs: remove BTRFS_FS_QUOTA_DISABLING flag
  btrfs: propagate error to btrfs_cmp_data_prepare caller
  btrfs: prevent to set invalid default subvolid
  Btrfs: send: fix error number for unknown inode types
  btrfs: fix NULL pointer dereference from free_reloc_roots()
  btrfs: finish ordered extent cleaning if no progress is found
  btrfs: clear ordered flag on cleaning up ordered extents
  Btrfs: fix incorrect {node,sector}size endianness from BTRFS_IOC_FS_INFO
  Btrfs: do not reset bio->bi_ops while writing bio
  Btrfs: use the new helper wbc_to_write_flags

Pull MD fixes from Shaohua Li:
 "A few fixes for MD. Mainly fix a problem introduced in 4.13, which we
  retry bio for some code paths but not all in some situations"

* tag 'md/4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/raid5: cap worker count
  dm-raid: fix a race condition in request handling
  md: fix a race condition for flush request handling
  md: separate request handling

Pull PCI fixes from Bjorn Helgaas:

 - fix CONFIG_PCI=n build error (introduced in v4.14-rc1) (Geert
   Uytterhoeven)

 - fix a race in sysfs driver_override store/show (Nicolai Stange)

* tag 'pci-v4.14-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Fix race condition with driver_override
  PCI: Add dummy pci_acs_enabled() for CONFIG_PCI=n build

Pull drm fixes from Dave Airlie:
 "Regular fixes pull, some amdkfd, amdgpu, etnaviv, sun4i, qxl, tegra
  fixes.

  I've got an outstanding pull for i915 but it wasn't on an rc2 base so
  I wanted to ship these out first, I might get to it before rc3 or I
  might not"

* tag 'drm-fixes-for-v4.14-rc3' of git://people.freedesktop.org/~airlied/linux:
  drm/tegra: trace: Fix path to include
  qxl: fix framebuffer unpinning
  drm/sun4i: cec: Enable back CEC-pin framework
  drm/amdkfd: Print event limit messages only once per process
  drm/amdkfd: Fix kernel-queue wrapping bugs
  drm/amdkfd: Fix incorrect destroy_mqd parameter
  drm/radeon: disable hard reset in hibernate for APUs
  drm/amdgpu: revert tile table update for oland
  etnaviv: fix gem object list corruption
  etnaviv: fix submit error path
  qxl: fix primary surface handling
  drm/amdkfd: check for null dev to avoid a null pointer dereference

Pull IOMMU fixes from Joerg Roedel:

 - A comment fix for 'struct iommu_ops'

 - Format string fixes for AMD IOMMU, unfortunatly I missed that during
   review.

 - Limit mediatek physical addresses to 32 bit for v7s to fix a warning
   triggered in io-page-table code.

 - Fix dma-sync in io-pgtable-arm-v7s code

* tag 'iommu-fixes-v4.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu: Fix comment for iommu_ops.map_sg
  iommu/amd: pr_err() strings should end with newlines
  iommu/mediatek: Limit the physical address in 32bit for v7s
  iommu/io-pgtable-arm-v7s: Need dma-sync while there is no QUIRK_NO_DMA

Pull arm64 fixes from Catalin Marinas:

 - SPsel register initialisation on reset as the architecture defines
   its state as unknown

 - Use READ_ONCE when dereferencing pmd_t pointers to avoid race
   conditions in page_vma_mapped_walk() (or fast GUP) with concurrent
   modifications of the page table

 - Avoid invoking the mm fault handling code for kernel addresses (check
   against TASK_SIZE) which would otherwise result in calling
   might_sleep() in atomic context

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: fault: Route pte translation faults via do_translation_fault
  arm64: mm: Use READ_ONCE when dereferencing pointer to pte table
  arm64: Make sure SPsel is always set

Pull xen fixes from Juergen Gross:

 - avoid a warning when compiling with clang

 - consider read-only bits in xen-pciback when writing to a BAR

 - fix a boot crash of pv-domains

* tag 'for-linus-4.14c-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/mmu: Call xen_cleanhighmap() with 4MB aligned for page tables mapping
  xen-pciback: relax BAR sizing write value check
  x86/xen: clean up clang build warning

Pull kvm fixes from Paolo Bonzini:
 "Mixed bugfixes. Perhaps the most interesting one is a latent bug that
  was finally triggered by PCID support"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm/x86: Handle async PF in RCU read-side critical sections
  KVM: nVMX: Fix nested #PF intends to break L1's vmlauch/vmresume
  KVM: VMX: use cmpxchg64
  KVM: VMX: simplify and fix vmx_vcpu_pi_load
  KVM: VMX: avoid double list add with VT-d posted interrupts
  KVM: VMX: extract __pi_post_block
  KVM: PPC: Book3S HV: Check for updated HDSISR on P9 HDSI exception
  KVM: nVMX: fix HOST_CR3/HOST_CR4 cache

kernel_waitid() can return a PID, an error or 0.  rusage is filled in the first
case and waitid(2) rusage should've been copied out exactly in that case, *not*
whenever kernel_waitid() has not returned an error.  Compat variant shares that
braino; none of kernel_wait4() callers do, so the below ought to fix it.
Reported-and-tested-by: Alexander Potapenko <glider@google.com>
Fixes: ce72a16f ("wait4(2)/waitid(2): separate copying rusage to userland")
Cc: stable@vger.kernel.org # v4.13
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Currently we use current_stack_pointer() function to get the value
of the stack pointer register. Since commit:

  f5caf621 ("x86/asm: Fix inline asm call constraints for Clang")

... we have a stack register variable declared. It can be used instead of
current_stack_pointer() function which allows to optimize away some
excessive "mov %rsp, %<dst>" instructions:

 -mov    %rsp,%rdx
 -sub    %rdx,%rax
 -cmp    $0x3fff,%rax
 -ja     ffffffff810722fd <ist_begin_non_atomic+0x2d>

 +sub    %rsp,%rax
 +cmp    $0x3fff,%rax
 +ja     ffffffff810722fa <ist_begin_non_atomic+0x2a>

Remove current_stack_pointer(), rename __asm_call_sp to current_stack_pointer
and use it instead of the removed function.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170929141537.29167-1-aryabinin@virtuozzo.comSigned-off-by: Ingo Molnar <mingo@kernel.org>