Commit 2cc42bac ("x86-64/Xen: eliminate W+X mappings") introduced a
call to get_cpu_cap, which is fstack-protected.  This is works on x86-64
as commit 4f277295 ("x86/xen: init %gs very early to avoid page
faults with stack protector") ensures the stack protector is configured,
but it it did not cover x86-32.

Delay calling get_cpu_cap until after xen_setup_gdt has initialized the
stack canary.  Without this, a 32bit PV machine crashes early
in boot.
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.6.6-xc  x86_64  debug=n  Tainted:    C ]----
(XEN) CPU:    0
(XEN) RIP:    e019:[<00000000c10362f8>]

And the PV kernel IP corresponds to init_scattered_cpuid_features
   0xc10362f8 <+24>:    mov    %gs:0x14,%eax

Fixes 2cc42bac

 ("x86-64/Xen: eliminate W+X mappings")

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

By guaranteeing that the argument of XS_TRANSACTION_END is valid we can
assume that the transaction has been closed when we get an XS_ERROR
response from xenstore (Note that we already verify that it's a valid
transaction id).

Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Users of the xenbus functions should never close a non existent
transaction (for example by trying to closing the same transaction
twice) but better catch it in xs_request_exit() than to corrupt the
reference counter.

Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Commit fd8aa909 ("xen: optimize xenbus driver for multiple
concurrent xenstore accesses") made a subtle change to the semantic of
xenbus_dev_request_and_reply() and xenbus_transaction_end().

Before on an error response to XS_TRANSACTION_END
xenbus_dev_request_and_reply() would not decrement the active
transaction counter. But xenbus_transaction_end() has always counted the
transaction as finished regardless of the response.

The new behavior is that xenbus_dev_request_and_reply() and
xenbus_transaction_end() will always count the transaction as finished
regardless the response code (handled in xs_request_exit()).

But xenbus_dev_frontend tries to end a transaction on closing of the
device if the XS_TRANSACTION_END failed before. Trying to close the
transaction twice corrupts the reference count. So fix this by also
considering a transaction closed if we have sent XS_TRANSACTION_END once
regardless of the return code.

Cc: <stable@vger.kernel.org> # 4.11
Fixes: fd8aa909

 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses")
Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Pull x86/pti updates from Thomas Gleixner:
 "Another set of melted spectrum updates:

   - Iron out the last late microcode loading issues by actually
     checking whether new microcode is present and preventing the CPU
     synchronization to run into a timeout induced hang.

   - Remove Skylake C2 from the microcode blacklist according to the
     latest Intel documentation

   - Fix the VM86 POPF emulation which traps if VIP is set, but VIF is
     not. Enhance the selftests to catch that kind of issue

   - Annotate indirect calls/jumps for objtool on 32bit. This is not a
     functional issue, but for consistency sake its the right thing to
     do.

   - Fix a jump label build warning observed on SPARC64 which uses 32bit
     storage for the code location which is casted to 64 bit pointer w/o
     extending it to 64bit first.

   - Add two new cpufeature bits. Not really an urgent issue, but
     provides them for both x86 and x86/kvm work. No impact on the
     current kernel"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode: Fix CPU synchronization routine
  x86/microcode: Attempt late loading only when new microcode is present
  x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
  jump_label: Fix sparc64 warning
  x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32-bit kernels
  x86/vm86/32: Fix POPF emulation
  selftests/x86/entry_from_vm86: Add test cases for POPF
  selftests/x86/entry_from_vm86: Exit with 1 if we fail
  x86/cpufeatures: Add Intel PCONFIG cpufeature
  x86/cpufeatures: Add Intel Total Memory Encryption cpufeature

Pull x86 fix from Thomas Gleixner:
 "A single fix for vmalloc_fault() which uses p*d_huge() unconditionally
  whether CONFIG_HUGETLBFS is set or not. In case of CONFIG_HUGETLBFS=n
  this results in a crash as p*d_huge() returns 0 in that case"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix vmalloc_fault to use pXd_large

Pull irq fixes from Thomas Gleixner:
 "Three fixes for irq chip drivers:

   - Make sure the allocations in the GIC-V3 ITS driver are large enough
     to accomodate the interrupt space

   - Fix a misplaced __iomem annotation which causes a splat of 26
     sparse warnings

   - Remove an unused function in the IMX GPCV2 driver which causes
     build warnings"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/irq-imx-gpcv2: Remove unused function
  irqchip/gic-v3-its: Ensure nr_ites >= nr_lpis
  irqchip/gic-v3-its: Fix misplaced __iomem annotations

Pull EFI fix from Thomas Gleixner:
 "A single fix to prevent partially initialized pointers in mixed mode
  (64bit kernel on 32bit UEFI)"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/libstub/tpm: Initialize pointer variables to zero for mixed mode

Pull KVM fixes from Paolo Bonzini:
 "PPC:
   - fix bug leading to lost IPIs and smp_call_function_many() lockups
     on POWER9

  ARM:
   - locking fix
   - reset fix
   - GICv2 multi-source SGI injection fix
   - GICv2-on-v3 MMIO synchronization fix
   - make the console less verbose.

  x86:
   - fix device passthrough on AMD SME"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix device passthrough when SME is active
  kvm: arm/arm64: vgic-v3: Tighten synchronization for guests using v2 on v3
  KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid
  KVM: arm/arm64: Reduce verbosity of KVM init log
  KVM: arm/arm64: Reset mapped IRQs on VM reset
  KVM: arm/arm64: Avoid vcpu_load for other vcpu ioctls than KVM_RUN
  KVM: arm/arm64: vgic: Add missing irq_lock to vgic_mmio_read_pending
  KVM: PPC: Book3S HV: Fix trap number return from __kvmppc_vcore_entry

Just when I had decided that flush_cache_range() was always called with
a valid context, Helge reported two cases where the
"BUG_ON(!vma->vm_mm->context);" was hit on the phantom buildd:

 kernel BUG at /mnt/sdb6/linux/linux-4.15.4/arch/parisc/kernel/cache.c:587!
 CPU: 1 PID: 3254 Comm: kworker/1:2 Tainted: G D 4.15.0-1-parisc64-smp #1 Debian 4.15.4-1+b1
 Workqueue: events free_ioctx
  IAOQ[0]: flush_cache_range+0x164/0x168
  IAOQ[1]: flush_cache_page+0x0/0x1c8
  RP(r2): unmap_page_range+0xae8/0xb88
 Backtrace:
  [<00000000404a6980>] unmap_page_range+0xae8/0xb88
  [<00000000404a6ae0>] unmap_single_vma+0xc0/0x188
  [<00000000404a6cdc>] zap_page_range_single+0x134/0x1f8
  [<00000000404a702c>] unmap_mapping_range+0x1cc/0x208
  [<0000000040461518>] truncate_pagecache+0x98/0x108
  [<0000000040461624>] truncate_setsize+0x9c/0xb8
  [<00000000405d7f30>] put_aio_ring_file+0x80/0x100
  [<00000000405d803c>] aio_free_ring+0x8c/0x290
  [<00000000405d82c0>] free_ioctx+0x80/0x180
  [<0000000040284e6c>] process_one_work+0x21c/0x668
  [<00000000402854c4>] worker_thread+0x20c/0x778
  [<0000000040291d44>] kthread+0x2d4/0x2e0
  [<0000000040204020>] end_fault_vector+0x20/0xc0

This indicates that we need to handle the no context case in
flush_cache_range() as we do in flush_cache_mm().

In thinking about this, I realized that we don't need to flush the TLB
when there is no context.  So, I added context checks to the large flush
cases in flush_cache_mm() and flush_cache_range().  The large flush case
occurs frequently in flush_cache_mm() and the change should improve fork
performance.

The v2 version of this change removes the BUG_ON from flush_cache_page()
by skipping the TLB flush when there is no context.  I also added code
to flush the TLB in flush_cache_mm() and flush_cache_range() when we
have a context that's not current.  Now all three routines handle TLB
flushes in a similar manner.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Helge Deller <deller@gmx.de>

Pull btrfs fixes from David Sterba:
 "There's an important revert in this pull request that needs to go to
  stable as it causes a corruption on big endian machines.

  The other fix is for FIEMAP incorrectly reporting shared extents
  before a sync and one fix for a crash in raid56.

  So far we got only one report about the BE corruption, the stable
  kernels were out for like a week, so hopefully the scope of the damage
  is low"

* tag 'for-4.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Revert "btrfs: use proper endianness accessors for super_copy"
  btrfs: add missing initialization in btrfs_check_shared
  btrfs: Fix NULL pointer exception in find_bio_stripe

Pull microblaze fixes from Michal Simek:

 - Use NO_BOOTMEM to fix boot issue

 - Fix opt lib endian dependencies

* tag 'microblaze-4.16-rc6' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: switch to NO_BOOTMEM
  microblaze: remove unused alloc_maybe_bootmem
  microblaze: Setup dependencies for ASM optimized lib functions

Emanuel reported an issue with a hang during microcode update because my
dumb idea to use one atomic synchronization variable for both rendezvous
- before and after update - was simply bollocks:

  microcode: microcode_reload_late: late_cpus: 4
  microcode: __reload_late: cpu 2 entered
  microcode: __reload_late: cpu 1 entered
  microcode: __reload_late: cpu 3 entered
  microcode: __reload_late: cpu 0 entered
  microcode: __reload_late: cpu 1 left
  microcode: Timeout while waiting for CPUs rendezvous, remaining: 1

CPU1 above would finish, leave and the others will still spin waiting for
it to join.

So do two synchronization atomics instead, which makes the code a lot more
straightforward.

Also, since the update is serialized and it also takes quite some time per
microcode engine, increase the exit timeout by the number of CPUs on the
system.

That's ok because the moment all CPUs are done, that timeout will be cut
short.

Furthermore, panic when some of the CPUs timeout when returning from a
microcode update: we can't allow a system with not all cores updated.

Also, as an optimization, do not do the exit sync if microcode wasn't
updated.

Reported-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20180314183615.17629-2-bp@alien8.de

Return UCODE_NEW from the scanning functions to denote that new microcode
was found and only then attempt the expensive synchronization dance.

Reported-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20180314183615.17629-1-bp@alien8.de

Pull drm fixes from Dave Airlie:
 "i915, amd and nouveau fixes.

  i915:
   - backlight fix for some panels
   - pm fix
   - fencing fix
   - some GVT fixes

  amdgpu:
   - backlight fix across suspend/resume
   - object destruction ordering issue fix
   - displayport fix

  nouveau:
   - two backlight fixes
   - fix for some lockups

  Pretty quiet week, seems like everyone was fixing backlights"

* tag 'drm-fixes-for-v4.16-rc6' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau/bl: fix backlight regression
  drm/nouveau/bl: Fix oops on driver unbind
  drm/nouveau/mmu: ALIGN_DOWN correct variable
  drm/i915/gvt: fix user copy warning by whitelist workload rb_tail field
  drm/i915/gvt: Correct the privilege shadow batch buffer address
  drm/amdgpu/dce: Don't turn off DP sink when disconnected
  drm/amdgpu: save/restore backlight level in legacy dce code
  drm/radeon: fix prime teardown order
  drm/amdgpu: fix prime teardown order
  drm/i915: Kick the rps worker when changing the boost frequency
  drm/i915: Only prune fences after wait-for-all
  drm/i915: Enable VBT based BL control for DP
  drm/i915/gvt: keep oa config in shadow ctx
  drm/i915/gvt: Add runtime_pm_get/put into gvt_switch_mmio

This reverts commit 3c181c12.

The offending patch was merged in 4.16-rc4 and was promptly applied to
stable kernels 4.14.25 and 4.15.8.

The patch causes a corruption in several superblock items on big-endian
machines because of messed up endianity conversions. The damage is
manually repairable. A filesystem cannot be mounted again after it has
been unmounted once.

We do a full revert and not a fixup so stable can pick that patch ASAP.

Fixes: 3c181c12 ("btrfs: use proper endianness accessors for super_copy")
Link: https://lkml.kernel.org/r/1521139304@msgid.manchmal.in-ulm.de


CC: stable@vger.kernel.org # 4.14+
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Signed-off-by: David Sterba <dsterba@suse.com>

When using device passthrough with SME active, the MMIO range that is
mapped for the device should not be mapped encrypted.  Add a check in
set_spte() to insure that a page is not mapped encrypted if that page
is a device MMIO page as indicated by kvm_is_mmio_pfn().

Cc: <stable@vger.kernel.org> # 4.14.x-
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Microblaze doesn't set CONFIG_NO_BOOTMEM and so memblock_virt_alloc()
doesn't work for CONFIG_HAVE_MEMBLOCK && !CONFIG_NO_BOOTMEM.

Similar change was already done by others architectures
"ARM: mm: Remove bootmem code and switch to NO_BOOTMEM"
(sha1: 84f452b1)
or
"openrisc: Consolidate setup to use memblock instead of bootmem"
(sha1: 266c7fad)
or
"parisc: Drop bootmem and switch to memblock"
(sha1: 4fe9e1d9)
or
"powerpc: Remove bootmem allocator"
(sha1: 10239733)
or
"s390/mm: Convert bootmem to memblock"
(sha1: 50be6345)
or
"sparc64: Convert over to NO_BOOTMEM."
(sha1: 625d693e)
or
"xtensa: drop sysmem and switch to memblock"
(sha1: 0e46c111)

Issue was introduced by:
"of/fdt: use memblock_virt_alloc for early alloc"
(sha1: 0fa1c579

)

Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Alvaro Gamez Machado <alvaro.gamez@hazent.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

alloc_maybe_bootmem is unused, so remove it.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

The patch:
"microblaze: Setup proper dependency for optimized lib functions"
(sha1: 7b6ce52b

)
didn't setup all dependencies properly.
Optimized lib functions in C are also present for little endian
and optimized library functions in assembler are implemented only for
big endian version.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

In accordance with Intel's microcode revision guidance from March 6 MCU
rev 0xc2 is cleared on both Skylake H/S and Skylake Xeon E3 processors
that share CPUID 506E3.

Signed-off-by: Alexander Sergeyev <sergeev917@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jia Zhang <qianyue.zj@alibaba-inc.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kyle Huey <me@kylehuey.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180313193856.GA8580@localhost.localdomain

Merge tag 'drm-intel-fixes-2018-03-15' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

Only GVT fixes:
- Two warnings fix for runtime pm and usr copy (Xiong, Zhenyu)
- OA context fix for vGPU profiling (Min)
- privilege batch buffer reloc fix (Fred)

* tag 'drm-intel-fixes-2018-03-15' of git://anongit.freedesktop.org/drm/drm-intel:
  drm/i915/gvt: fix user copy warning by whitelist workload rb_tail field
  drm/i915/gvt: Correct the privilege shadow batch buffer address
  drm/i915/gvt: keep oa config in shadow ctx
  drm/i915/gvt: Add runtime_pm_get/put into gvt_switch_mmio

nouveau regression fixes.

* 'linux-4.16' of git://github.com/skeggsb/linux:
  drm/nouveau/bl: fix backlight regression
  drm/nouveau/bl: Fix oops on driver unbind
  drm/nouveau/mmu: ALIGN_DOWN correct variable

Pull vfs fixes from Al Viro:

 - backport-friendly part of lock_parent() race fix

 - a fix for an assumption in the heurisic used by path_connected() that
   is not true on NFS

 - livelock fixes for d_alloc_parallel()

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Teach path_connected to handle nfs filesystems with multiple roots.
  fs: dcache: Use READ_ONCE when accessing i_dir_seq
  fs: dcache: Avoid livelock between d_alloc_parallel and __d_add
  lock_parent() needs to recheck if dentry got __dentry_kill'ed under it

Fixes: 3c66c87d

 ("drm/nouveau/disp: remove hw-specific customisation
of output paths")
Suggested-by: Ben Skeggs <skeggsb@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Unbinding nouveau on a dual GPU MacBook Pro oopses because we iterate
over the bl_connectors list in nouveau_backlight_exit() but skipped
initializing it in nouveau_backlight_init().  Stacktrace for posterity:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
    IP: nouveau_backlight_exit+0x2b/0x70 [nouveau]
    nouveau_display_destroy+0x29/0x80 [nouveau]
    nouveau_drm_unload+0x65/0xe0 [nouveau]
    drm_dev_unregister+0x3c/0xe0 [drm]
    drm_put_dev+0x2e/0x60 [drm]
    nouveau_drm_device_remove+0x47/0x70 [nouveau]
    pci_device_remove+0x36/0xb0
    device_release_driver_internal+0x157/0x220
    driver_detach+0x39/0x70
    bus_remove_driver+0x51/0xd0
    pci_unregister_driver+0x2a/0xa0
    nouveau_drm_exit+0x15/0xfb0 [nouveau]
    SyS_delete_module+0x18c/0x290
    system_call_fast_compare_end+0xc/0x6f

Fixes: b53ac1ee

 ("drm/nouveau/bl: Do not register interface if Apple GMUX detected")
Cc: stable@vger.kernel.org # v4.10+
Cc: Pierre Moreau <pierre.morrow@free.fr>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Commit 7110c89bb8852ff8b0f88ce05b332b3fe22bd11e ("mmu: swap out round
for ALIGN") replaced two calls to round/rounddown with ALIGN/ALIGN_DOWN,
but erroneously applied ALIGN_DOWN to a different variable (addr) and left
intended variable (tail) not rounded/ALIGNed.

As a result screen corruption, X lockups are observable. An example of kernel
log of affected system with NV98 card where it was bisected:

nouveau 0000:01:00.0: gr: TRAP_M2MF 00000002 [IN]
nouveau 0000:01:00.0: gr: TRAP_M2MF 00320951 400007c0 00000000 04000000
nouveau 0000:01:00.0: gr: 00200000 [] ch 1 [000fbbe000 DRM] subc 4 class 5039
mthd 0100 data 00000000
nouveau 0000:01:00.0: fb: trapped read at 0040000000 on channel 1
[0fbbe000 DRM]
engine 00 [PGRAPH] client 03 [DISPATCH] subclient 04 [M2M_IN] reason 00000006
[NULL_DMAOBJ]

Fixes bug 105173 ("[MCP79][Regression] Unhandled NULL pointer dereference in
nvkm_object_unmap since kernel 4.15")
https://bugs.freedesktop.org/show_bug.cgi?id=105173



Fixes: 7110c89bb885 ("mmu: swap out round for ALIGN ")
Tested-by: Pierre Moreau <pierre.morrow@free.fr>
Reviewed-by: Pierre Moreau <pierre.morrow@free.fr>
Signed-off-by: Maris Nartiss <maris.nartiss@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Cc: stable@vger.kernel.org # v4.15+

On nfsv2 and nfsv3 the nfs server can export subsets of the same
filesystem and report the same filesystem identifier, so that the nfs
client can know they are the same filesystem.  The subsets can be from
disjoint directory trees.  The nfsv2 and nfsv3 filesystems provides no
way to find the common root of all directory trees exported form the
server with the same filesystem identifier.

The practical result is that in struct super s_root for nfs s_root is
not necessarily the root of the filesystem.  The nfs mount code sets
s_root to the root of the first subset of the nfs filesystem that the
kernel mounts.

This effects the dcache invalidation code in generic_shutdown_super
currently called shrunk_dcache_for_umount and that code for years
has gone through an additional list of dentries that might be dentry
trees that need to be freed to accomodate nfs.

When I wrote path_connected I did not realize nfs was so special, and
it's hueristic for avoiding calling is_subdir can fail.

The practical case where this fails is when there is a move of a
directory from the subtree exposed by one nfs mount to the subtree
exposed by another nfs mount.  This move can happen either locally or
remotely.  With the remote case requiring that the move directory be cached
before the move and that after the move someone walks the path
to where the move directory now exists and in so doing causes the
already cached directory to be moved in the dcache through the magic
of d_splice_alias.

If someone whose working directory is in the move directory or a
subdirectory and now starts calling .. from the initial mount of nfs
(where s_root == mnt_root), then path_connected as a heuristic will
not bother with the is_subdir check.  As s_root really is not the root
of the nfs filesystem this heuristic is wrong, and the path may
actually not be connected and path_connected can fail.

The is_subdir function might be cheap enough that we can call it
unconditionally.  Verifying that will take some benchmarking and
the result may not be the same on all kernels this fix needs
to be backported to.  So I am avoiding that for now.

Filesystems with snapshots such as nilfs and btrfs do something
similar.  But as the directory tree of the snapshots are disjoint
from one another and from the main directory tree rename won't move
things between them and this problem will not occur.

Cc: stable@vger.kernel.org
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Fixes: 397d425d

 ("vfs: Test for and handle paths that are unreachable from their mnt_root")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

gvt-fixes-2018-03-15

- Two warnings fix for runtime pm and usr copy (Xiong, Zhenyu)
- OA context fix for vGPU profiling (Min)
- privilege batch buffer reloc fix (Fred)

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180315100023.5n5a74afky6qinoh@zhen-hp.sh.intel.com

pmdp_invalidate() was changed to update the pmd atomically
(to not lose dirty/access bits) and return the original pmd
value.

However, in doing so, we lost a lot of the essential work that
set_pmd_at() does, namely to update hugepage mapping counts and
queuing up the batched TLB flush entry.

Thus we were not flushing entries out of the TLB when making
such PMD changes.

Fix this by abstracting the accounting work of set_pmd_at() out into a
separate function, and call it from pmdp_establish().

Fixes: a8e654f0

 ("sparc64: update pmdp_invalidate() to return old pmd value")
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'kvm-ppc-fixes-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

Fix for PPC KVM for 4.16

- Fix bug leading to lost IPIs on POWER9 and hence to other CPUs reporting
  lockups in smp_call_function_many().

Merge tag 'kvm-arm-fixes-for-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

kvm/arm fixes for 4.16, take 2

- Peace of mind locking fix in vgic_mmio_read_pending
- Allow hw-mapped interrupts to be reset when the VM resets
- Fix GICv2 multi-source SGI injection
- Fix MMIO synchronization for GICv2 on v3 emulation
- Remove excess verbosity on the console

Pull sound fixes from Takashi Iwai:
 "A series of small fixes in ASoC, HD-audio and core stuff:

   - a UAF fix in ALSA PCM core

   - yet more hardening for ALSA sequencer

   - a regression fix for the previous HD-audio power_save option change

   - various ASoC codec fixes (sgtl5000, rt5651, hdmi-codec, wm_adsp)

   - minor ASoC platform fixes (AMD ACP, sun4i)"

* tag 'sound-4.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Revert power_save option default value
  ALSA: pcm: Fix UAF in snd_pcm_oss_get_formats()
  ALSA: seq: Clear client entry before deleting else at closing
  ALSA: seq: Fix possible UAF in snd_seq_check_queue()
  ASoC: amd: 16bit resolution support for i2s sp instance
  ASoC: wm_adsp: For TLV controls only register TLV get/set
  ASoC: sun4i-i2s: Fix RX slot number of SUN8I
  ASoC: hdmi-codec: Fix module unloading caused kernel crash
  ASoC: rt5651: Fix regcache sync errors on resume
  ASoC: sgtl5000: Fix suspend/resume
  MAINTAINERS: Add myself as sgtl5000 maintainer
  ASoC: samsung: Add the DT binding files entry to MAINTAINERS
  sgtl5000: change digital_mute policy

Merge tag 'for-4.16/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a stable DM multipath fix to restore ability to pass integrity data

 - two DM multipath fixes for a fix that was merged into 4.16-rc5

* tag 'for-4.16/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: fix passing integrity data
  dm mpath: eliminate need to use scsi_device_from_queue
  dm mpath: fix uninitialized 'pg_init_wait' waitqueue_head NULL pointer

This is to fix warning got as:

[ 6730.476938] ------------[ cut here ]------------
[ 6730.476979] Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLAB object 'gvt-g_vgpu_workload' (offset 120, size 4)!
[ 6730.477021] WARNING: CPU: 2 PID: 441 at mm/usercopy.c:81 usercopy_warn+0x7e/0xa0
[ 6730.477042] Modules linked in: tun(E) bridge(E) stp(E) llc(E) kvmgt(E) x86_pkg_temp_thermal(E) vfio_mdev(E) intel_powerclamp(E) mdev(E) coretemp(E) vfio_iommu_type1(E) vfio(E) kvm_intel(E) kvm(E) hid_generic(E) irqbypass(E) crct10dif_pclmul(E) crc32_pclmul(E) usbhid(E) i915(E) crc32c_intel(E) hid(E) ghash_clmulni_intel(E) pcbc(E) aesni_intel(E) aes_x86_64(E) crypto_simd(E) cryptd(E) glue_helper(E) intel_cstate(E) idma64(E) evdev(E) virt_dma(E) iTCO_wdt(E) intel_uncore(E) intel_rapl_perf(E) intel_lpss_pci(E) sg(E) shpchp(E) mei_me(E) pcspkr(E) iTCO_vendor_support(E) intel_lpss(E) intel_pch_thermal(E) prime_numbers(E) mei(E) mfd_core(E) video(E) acpi_pad(E) button(E) binfmt_misc(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc16(E) mbcache(E) jbd2(E) fscrypto(E) sd_mod(E) e1000e(E) xhci_pci(E) sdhci_pci(E)
[ 6730.477244]  ptp(E) cqhci(E) xhci_hcd(E) pps_core(E) sdhci(E) mmc_core(E) i2c_i801(E) usbcore(E) thermal(E) fan(E)
[ 6730.477276] CPU: 2 PID: 441 Comm: gvt workload 0 Tainted: G            E    4.16.0-rc1-gvt-staging-0213+ #127
[ 6730.477303] Hardware name:  /NUC6i5SYB, BIOS SYSKLi35.86A.0039.2016.0316.1747 03/16/2016
[ 6730.477326] RIP: 0010:usercopy_warn+0x7e/0xa0
[ 6730.477340] RSP: 0018:ffffba6301223d18 EFLAGS: 00010286
[ 6730.477355] RAX: 0000000000000000 RBX: ffff8f41caae9838 RCX: 0000000000000006
[ 6730.477375] RDX: 0000000000000007 RSI: 0000000000000082 RDI: ffff8f41dad166f0
[ 6730.477395] RBP: 0000000000000004 R08: 0000000000000576 R09: 0000000000000000
[ 6730.477415] R10: ffffffffb1293fb2 R11: 00000000ffffffff R12: 0000000000000001
[ 6730.477447] R13: ffff8f41caae983c R14: ffff8f41caae9838 R15: 00007f183ca2b000
[ 6730.477467] FS:  0000000000000000(0000) GS:ffff8f41dad00000(0000) knlGS:0000000000000000
[ 6730.477489] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6730.477506] CR2: 0000559462817291 CR3: 000000028b46c006 CR4: 00000000003626e0
[ 6730.477526] Call Trace:
[ 6730.477537]  __check_object_size+0x9c/0x1a0
[ 6730.477562]  __kvm_write_guest_page+0x45/0x90 [kvm]
[ 6730.477585]  kvm_write_guest+0x46/0x80 [kvm]
[ 6730.477599]  kvmgt_rw_gpa+0x9b/0xf0 [kvmgt]
[ 6730.477642]  workload_thread+0xa38/0x1040 [i915]
[ 6730.477659]  ? do_wait_intr_irq+0xc0/0xc0
[ 6730.477673]  ? finish_wait+0x80/0x80
[ 6730.477707]  ? clean_workloads+0x120/0x120 [i915]
[ 6730.477722]  kthread+0x111/0x130
[ 6730.477733]  ? _kthread_create_worker_on_cpu+0x60/0x60
[ 6730.477750]  ? exit_to_usermode_loop+0x6f/0xb0
[ 6730.477766]  ret_from_fork+0x35/0x40
[ 6730.477777] Code: 48 c7 c0 20 e3 25 b1 48 0f 44 c2 41 50 51 41 51 48 89 f9 49 89 f1 4d 89 d8 4c 89 d2 48 89 c6 48 c7 c7 78 e3 25 b1 e8 b2 bc e4 ff <0f> ff 48 83 c4 18 c3 48 c7 c6 09 d0 26 b1 49 89 f1 49 89 f3 eb
[ 6730.477849] ---[ end trace cae869c1c323e45a ]---

By whitelist guest page write from workload struct allocated from kmem cache.

Reviewed-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
(cherry picked from commit 5627705406874df57fdfad3b4e0c9aedd3b007df)

Once the ring buffer is copied to ring_scan_buffer and scanned,
the shadow batch buffer start address is only updated into
ring_scan_buffer, not the real ring address allocated through
intel_ring_begin in later copy_workload_to_ring_buffer.

This patch is only to set the right shadow batch buffer address
from Ring buffer, not include the shadow_wa_ctx.

v2:
- refine some comments. (Zhenyu)
v3:
- fix typo in title. (Zhenyu)
v4:
- remove the unnecessary comments. (Zhenyu)
- add comments in bb_start_cmd_va update. (Zhenyu)

Fixes: 0a53bc07

 ("drm/i915/gvt: Separate cmd scan from request allocation")
Cc: stable@vger.kernel.org  # v4.15
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Yulei Zhang <yulei.zhang@intel.com>
Signed-off-by: fred gao <fred.gao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Pull SCSI fixes from James Bottomley:
 "This is four patches, consisting of one regression from the merge
  window (qla2xxx), one long-standing memory leak (sd_zbc), one event
  queue mislabelling which we want to eliminate to discourage the
  pattern (mpt3sas), and one behaviour change because re-reading the
  partition table shouldn't clear the ro flag"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: sd: Keep disk read-only when re-reading partition
  scsi: qla2xxx: Fix crashes in qla2x00_probe_one on probe failure
  scsi: sd_zbc: Fix potential memory leak
  scsi: mpt3sas: Do not mark fw_event workqueue as WQ_MEM_RECLAIM

geo->keylen cannot be larger than 4.  So we might as well make
fixed-size allocations.

Given the one remaining user, geo->keylen cannot even be larger than 1.
Logfs used to have 64bit and 128bit keys, tcm_qla2xxx only has 32bit
keys.  But let's not break the code if we don't have to.

Signed-off-by: Joern Engel <joern@purestorage.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull percpu_ref rcu fixes from Tejun Heo:
 "Jann Horn found that aio was depending on the internal RCU grace
  periods of percpu-ref and that it's broken because aio uses regular
  RCU while percpu_ref uses sched-RCU.

  Depending on percpu_ref's internal grace periods isn't a good idea
  because

   - The RCU type might not match.

   - percpu_ref's grace periods are used to switch to atomic mode. They
     aren't between the last put and the invocation of the last release.
     This is easy to get confused about and can lead to subtle bugs.

   - percpu_ref might not have grace periods at all depending on its
     current operation mode.

  This patchset audits and fixes percpu_ref users for their RCU usages"

[ There's a continuation of this series that clarifies percpu_ref
  documentation that the internal grace periods must not be depended
  upon, and introduces rcu_work to simplify bouncing to a workqueue
  after an RCU grace period.

  That will go in for 4.17 - this is just the minimal set with the fixes
  that are tagged for -stable ]

* 'percpu_ref-rcu-audit-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
  RDMAVT: Fix synchronization around percpu_ref
  fs/aio: Use RCU accessors for kioctx_table->table[]
  fs/aio: Add explicit RCU grace period when freeing kioctx