We are hitting a regression with the following commit:

commit a93e7b33
Author: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Date:   Mon May 14 13:32:23 2018 +1200

    uio: Prevent device destruction while fds are open

The problem is the addition of spin_lock_irqsave in uio_write. This
leads to hitting  uio_write -> copy_from_user -> _copy_from_user ->
might_fault and the logs filling up with sleeping warnings.

I also noticed some uio drivers allocate memory, sleep, grab mutexes
from callouts like open() and release and uio is now doing
spin_lock_irqsave while calling them.
Reported-by: NMike Christie <mchristi@redhat.com>
CC: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Reviewed-by: NHamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: NXiubo Li <xiubli@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepraing for changing to use mutex lock.
Signed-off-by: NXiubo Li <xiubli@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If 'fpga_mgr_create()' fails, we should release some resources, as done
in the other error handling path of the function.

Fixes: 7085e2a9 ("fpga: manager: change api, don't use drvdata")
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NMoritz Fischer <mdf@kernel.org>
Acked-by: NAlan Tull <atull@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This read handler had a lot of custom logic and wrote outside the bounds of
the provided buffer. This could lead to kernel and userspace memory
corruption. Just use simple_read_from_buffer() with a stack buffer.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

I really need to look at driver core changes before they are applied
due to PM dependencies and they sometimes get lost in the LKML
traffic, so add myself as an official driver core reviewer.
Signed-off-by: NRafael J. Wysocki <rafael@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This fixes regression introduced by
commit 8d52af67 ("mei: speed up the power down flow")

In power down or suspend flow a message can still be received
from the FW because the clients fake disconnection.
In normal case we interpret messages w/o destination as corrupted
and link reset is performed in order to clean the channel,
but during power down link reset is already in progress resulting
in endless loop. To resolve the issue under power down flow we
discard messages silently.

Cc: <stable@vger.kernel.org> 4.16+
Fixes: 8d52af67 ("mei: speed up the power down flow")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199541Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Embarrassingly, the recent fix introduced worse problem than it solved,
causing the balloon not to inflate. The VM informed the hypervisor that
the pages for lock/unlock are sitting in the wrong address, as it used
the page that is used the uninitialized page variable.

Fixes: b23220fe ("vmw_balloon: fixing double free when batching mode is off")
Cc: stable@vger.kernel.org
Reviewed-by: NXavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: NNadav Amit <namit@vmware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull perf fixes from Thomas Gleixner:
 "A pile of perf updates:

  Kernel side:

   - Remove an incorrect warning in uprobe_init_insn() when
     insn_get_length() fails. The error return code is handled at the
     call site.

   - Move the inline keyword to the right place in the perf ringbuffer
     code to address a W=1 build warning.

  Tooling:

  perf stat:

   - Fix metric column header display alignment

   - Improve error messages for default attributes, providing better
     output for error in command line.

   - Add --interval-clear option, to provide a 'watch' like printing

  perf script:

   - Show hw-cache events too

  perf c2c:

   - Fix data dependency problem in layout of 'struct c2c_hist_entry'

  Core:

   - Do not blindly assume that 'struct perf_evsel' can be obtained via
     a straight forward container_of() as there are call sites which
     hand in a plain 'struct hist' which is not part of a container.

   - Fix error index in the PMU event parser, so that error messages can
     point to the problematic token"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Move the inline keyword at the beginning of the function declaration
  uprobes/x86: Remove incorrect WARN_ON() in uprobe_init_insn()
  perf script: Show hw-cache events
  perf c2c: Keep struct hist_entry at the end of struct c2c_hist_entry
  perf stat: Add event parsing error handling to add_default_attributes
  perf stat: Allow to specify specific metric column len
  perf stat: Fix metric column header display alignment
  perf stat: Use only color_fprintf call in print_metric_only
  perf stat: Add --interval-clear option
  perf tools: Fix error index for pmu event parser
  perf hists: Reimplement hists__has_callchains()
  perf hists browser gtk: Use hist_entry__has_callchains()
  perf hists: Make hist_entry__has_callchains() work with 'perf c2c'
  perf hists: Save the callchain_size in struct hist_entry

Pull rseq fixes from Thomas Gleixer:
 "A pile of rseq related fixups:

   - Prevent infinite recursion when delivering SIGSEGV

   - Remove the abort of rseq critical section on fork() as syscalls
     inside rseq critical sections are explicitely forbidden. So no
     point in doing the abort on the child.

   - Align the rseq structure on 32 bytes in the ARM selftest code.

   - Fix file permissions of the test script"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq: Avoid infinite recursion when delivering SIGSEGV
  rseq/cleanup: Do not abort rseq c.s. in child on fork()
  rseq/selftests/arm: Align 'struct rseq_cs' on 32 bytes
  rseq/selftests: Make run_param_test.sh executable

Pull EFI fixes from Thomas Gleixner:
 "Two fixlets for the EFI maze:

   - Properly zero variables to prevent an early boot hang on EFI mixed
     mode systems

   - Fix the fallout of merging the 32bit and 64bit variants of EFI PCI
     related code which ended up chosing the 32bit variant of the actual
     EFi call invocation which leads to failures on 64bit"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/x86: Fix incorrect invocation of PciIo->Attributes()
  efi/libstub/tpm: Initialize efi_physical_addr_t vars to zero for mixed mode

Pull core fixes from Thomas Gleixner:
 "Two tiny fixes:

   - Add the missing machine_real_restart() to objtools noreturn list so
     it stops complaining

   - Fix a trivial comment typo"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kernel.h: Fix a typo in comment
  objtool: Add machine_real_restart() to the noreturn list

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for x86:

   - Make Xen PV guest deal with speculative store bypass correctly

   - Address more fallout from the 5-Level pagetable handling. Undo an
     __initdata annotation to avoid section mismatch and malfunction
     when post init code would touch the freed variable.

   - Handle exception fixup in math_error() before calling notify_die().
     The reverse call order incorrectly triggers notify_die() listeners
     for soemthing which is handled correctly at the site which issues
     the floating point instruction.

   - Fix an off by one in the LLC topology calculation on AMD

   - Handle non standard memory block sizes gracefully un UV platforms

   - Plug a memory leak in the microcode loader

   - Sanitize the purgatory build magic

   - Add the x86 specific device tree bindings directory to the x86
     MAINTAINER file patterns"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Fix 'no5lvl' handling
  Revert "x86/mm: Mark __pgtable_l5_enabled __initdata"
  x86/CPU/AMD: Fix LLC ID bit-shift calculation
  MAINTAINERS: Add file patterns for x86 device tree bindings
  x86/microcode/intel: Fix memleak in save_microcode_patch()
  x86/platform/UV: Add kernel parameter to set memory block size
  x86/platform/UV: Use new set memory block size function
  x86/platform/UV: Add adjustable set memory block size function
  x86/build: Remove unnecessary preparation for purgatory
  Revert "kexec/purgatory: Add clean-up for purgatory directory"
  x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths
  x86: Call fixup_exception() before notify_die() in math_error()

Pull x86 pti fixes from Thomas Gleixner:
 "Two small updates for the speculative distractions:

   - Make it more clear to the compiler that array_index_mask_nospec()
     is not subject for optimizations. It's not perfect, but ...

   - Don't report XEN PV guests as vulnerable because their mitigation
     state depends on the hypervisor. Report unknown and refer to the
     hypervisor requirement"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/spectre_v1: Disable compiler optimizations over array_index_mask_nospec()
  x86/pti: Don't report XenPV as vulnerable

Pull locking fixes from Thomas Gleixner:
 "A set of fixes and updates for the locking code:

   - Prevent lockdep from updating irq state within its own code and
     thereby confusing itself.

   - Buid fix for older GCCs which mistreat anonymous unions

   - Add a missing lockdep annotation in down_read_non_onwer() which
     causes up_read_non_owner() to emit a lockdep splat

   - Remove the custom alpha dec_and_lock() implementation which is
     incorrect in terms of ordering and use the generic one.

  The remaining two commits are not strictly fixes. They provide irqsave
  variants of atomic_dec_and_lock() and refcount_dec_and_lock(). These
  are required to merge the relevant updates and cleanups into different
  maintainer trees for 4.19, so routing them into mainline without
  actual users is the sanest approach.

  They should have been in -rc1, but last weekend I took the liberty to
  just avoid computers in order to regain some mental sanity"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/qspinlock: Fix build for anonymous union in older GCC compilers
  locking/lockdep: Do not record IRQ state within lockdep code
  locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
  locking/refcounts: Implement refcount_dec_and_lock_irqsave()
  atomic: Add irqsave variant of atomic_dec_and_lock()
  alpha: Remove custom dec_and_lock() implementation

Pull ras fixes from Thomas Gleixner:
 "A set of fixes for RAS/MCE:

   - Improve the error message when the kernel cannot recover from a MCE
     so the maximum amount of information gets provided.

   - Individually check MCE recovery features on SkyLake CPUs instead of
     assuming none when the CAPID0 register does not advertise the
     general ability for recovery.

   - Prevent MCE to output inconsistent messages which first show an
     error location and then claim that the source is unknown.

   - Prevent overwriting MCi_STATUS in the attempt to gather more
     information when a fatal MCE has alreay been detected. This leads
     to empty status values in the printout and failing to react
     promptly on the fatal event"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Fix incorrect "Machine check from unknown source" message
  x86/mce: Do not overwrite MCi_STATUS in mce_no_way_out()
  x86/mce: Check for alternate indication of machine check recovery on Skylake
  x86/mce: Improve error message when kernel cannot recover

Pull timer fixes from Thomas Gleixner:
 "A small set of fixes for time(r) related issues:

   - Fix a long standing conversion issue in jiffies_to_msecs() for odd
     HZ values like 1024 or 1200 which resulted in returning 0 for small
     jiffies values due to rounding down.

   - Use the proper CONFIG symbol in the new Y2038 safe compat code for
     posix-timers. Not yet a visible breakage, but this will immediately
     trigger when the architecture support for the new interfaces is
     merged.

   - Return an error code in the STM32 clocksource driver on failure
     instead of success.

   - Remove the redundant and stale irq disabled check in the posix cpu
     timer code. The check is at the wrong place anyway and lockdep
     already covers it via the sighand lock locking coverage"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Make sure jiffies_to_msecs() preserves non-zero time periods
  posix-timers: Fix nanosleep_copyout() for CONFIG_COMPAT_32BIT_TIME
  clocksource/drivers/stm32: Fix error return code
  posix-cpu-timers: Remove lockdep_assert_irqs_disabled()

Pull irq fixes from Thomas Gleixner:
 "A set of fixes mostly for the ARM/GIC world:

   - Fix the MSI affinity handling in the ls-scfg irq chip driver so it
     updates and uses the effective affinity mask correctly

   - Prevent binding LPIs to offline CPUs and respect the Cavium erratum
     which requires that LPIs which belong to an offline NUMA node are
     not bound to a CPU on a different NUMA node.

   - Free only the amount of allocated interrupts in the GIC-V2M driver
     instead of trying to free log2(nrirqs).

   - Prevent emitting SYNC and VSYNC targetting non existing interrupt
     collections in the GIC-V3 ITS driver

   - Ensure that the GIV-V3 interrupt redistributor is correctly
     reprogrammed on CPU hotplug

   - Remove a stale unused helper function"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqdesc: Delete irq_desc_get_msi_desc()
  irqchip/gic-v3-its: Fix reprogramming of redistributors on CPU hotplug
  irqchip/gic-v3-its: Only emit VSYNC if targetting a valid collection
  irqchip/gic-v3-its: Only emit SYNC if targetting a valid collection
  irqchip/gic-v3-its: Don't bind LPI to unavailable NUMA node
  irqchip/gic-v2m: Fix SPI release on error path
  irqchip/ls-scfg-msi: Fix MSI affinity handling
  genirq/debugfs: Add missing IRQCHIP_SUPPORTS_LEVEL_MSI debug

Pull MIPS fixes from Paul Burton:
 "A few MIPS fixes for 4.18:

   - a GPIO device name fix for a regression in v4.15-rc1.

   - an errata workaround for the BCM5300X platform.

   - a fix to ftrace function graph tracing, broken for a long time with
     the fix applying cleanly back as far as v3.17.

   - addition of read barriers to in{b,w,l,q}() functions, matching
     behavior of other architectures & mirroring the equivalent addition
     to read{b,w,l,q} in v4.17-rc2.

  Plus changes to wire up new syscalls introduced in the 4.18 cycle:

   - Restartable sequences support is added, including MIPS support in
     the selftests.

   - io_pgetevents is wired up"

* tag 'mips_fixes_4.18_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Wire up io_pgetevents syscall
  rseq/selftests: Implement MIPS support
  MIPS: Wire up the restartable sequences (rseq) syscall
  MIPS: Add syscall detection for restartable sequences
  MIPS: Add support for restartable sequences
  MIPS: io: Add barrier after register read in inX()
  mips: ftrace: fix static function graph tracing
  MIPS: BCM47XX: Enable 74K Core ExternalSync for PCIe erratum
  MIPS: pb44: Fix i2c-gpio GPIO descriptor table

The following commit:

  2c3625cb ("efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() into one function")

... merged the two versions of __setup_efi_pciXX(), without taking into
account that the 32-bit version used a rather dodgy trick to pass an
immediate 0 constant as argument for a uint64_t parameter.

The issue is caused by the fact that on x86, UEFI protocol method calls
are redirected via struct efi_config::call(), which is a variadic function,
and so the compiler has to infer the types of the parameters from the
arguments rather than from the prototype.

As the 32-bit x86 calling convention passes arguments via the stack,
passing the unqualified constant 0 twice is the same as passing 0ULL,
which is why the 32-bit code in __setup_efi_pci32() contained the
following call:

  status = efi_early->call(pci->attributes, pci,
                           EfiPciIoAttributeOperationGet, 0, 0,
                           &attributes);

to invoke this UEFI protocol method:

  typedef
  EFI_STATUS
  (EFIAPI *EFI_PCI_IO_PROTOCOL_ATTRIBUTES) (
    IN  EFI_PCI_IO_PROTOCOL                     *This,
    IN  EFI_PCI_IO_PROTOCOL_ATTRIBUTE_OPERATION Operation,
    IN  UINT64                                  Attributes,
    OUT UINT64                                  *Result OPTIONAL
    );

After the merge, we inadvertently ended up with this version for both
32-bit and 64-bit builds, breaking the latter.

So replace the two zeroes with the explicitly typed constant 0ULL,
which works as expected on both 32-bit and 64-bit builds.

Wilfried tested the 64-bit build, and I checked the generated assembly
of a 32-bit build with and without this patch, and they are identical.
Reported-by: NWilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
Tested-by: NWilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: hdegoede@redhat.com
Cc: linux-efi@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull block fixes from Jens Axboe:

 - Further timeout fixes. We aren't quite there yet, so expect another
   round of fixes for that to completely close some of the IRQ vs
   completion races. (Christoph/Bart)

 - Set of NVMe fixes from the usual suspects, mostly error handling

 - Two off-by-one fixes (Dan)

 - Another bdi race fix (Jan)

 - Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron)

* tag 'for-linus-20180623' of git://git.kernel.dk/linux-block:
  blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE
  bdi: Fix another oops in wb_workfn()
  lightnvm: Remove depends on HAS_DMA in case of platform dependency
  nvme-pci: limit max IO size and segments to avoid high order allocations
  nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl
  nvme-fc: release io queues to allow fast fail
  nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.
  block: sed-opal: Fix a couple off by one bugs
  blk-mq-debugfs: Off by one in blk_mq_rq_state_name()
  nvmet: reset keep alive timer in controller enable
  nvme-rdma: don't override opts->queue_size
  nvme-rdma: Fix command completion race at error recovery
  nvme-rdma: fix possible free of a non-allocated async event buffer
  nvme-rdma: fix possible double free condition when failing to create a controller
  Revert "block: Add warning for bi_next not NULL in bio_endio()"
  block: fix timeout changes for legacy request drivers

Pull crypto fixes from Herbert Xu:

 - Fix use after free in chtls

 - Fix RBP breakage in sha3

 - Fix use after free in hwrng_unregister

 - Fix overread in morus640

 - Move sleep out of kernel_neon in arm64/aes-blk

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  hwrng: core - Always drop the RNG in hwrng_unregister()
  crypto: morus640 - Fix out-of-bounds access
  crypto: don't optimize keccakf()
  crypto: arm64/aes-blk - fix and move skcipher_walk_done out of kernel_neon_begin, _end
  crypto: chtls - use after free in chtls_pt_recvmsg()

Merge tag 'linux-kselftest-4.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:

 - fix new sparc64 adi driver test compile errors on non-sparc systems

 - fix config fragment for sync framework for improved test coverage

 - fix several tests to return correct Kselftest skip code

* tag 'linux-kselftest-4.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: sparc64: Add missing SPDX License Identifiers
  selftests: sparc64: delete RUN_TESTS and EMIT_TESTS overrides
  selftests: sparc64: Fix to do nothing on non-sparc64
  selftests: sync: add config fragment for testing sync framework
  selftests: vm: return Kselftest Skip code for skipped tests
  selftests: zram: return Kselftest Skip code for skipped tests
  selftests: user: return Kselftest Skip code for skipped tests
  selftests: sysctl: return Kselftest Skip code for skipped tests
  selftests: static_keys: return Kselftest Skip code for skipped tests
  selftests: pstore: return Kselftest Skip code for skipped tests

Pull tracing fixes from Steven Rostedt:
 "This contains a few fixes and a clean up.

   - a bad merge caused an "endif" to go in the wrong place in
     scripts/Makefile.build

   - softirq tracing fix for tracing that corrupts lockdep and causes a
     false splat

   - histogram documentation typo fixes

   - fix a bad memory reference when passing in no filter to the filter
     code

   - simplify code by using the swap macro instead of open coding the
     swap"

* tag 'trace-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount
  tracing: Fix some errors in histogram documentation
  tracing: Use swap macro in update_max_tr
  softirq: Reorder trace_softirqs_on to prevent lockdep splat
  tracing: Check for no filter when processing event filters

Make sure that RQF_TIMED_OUT is cleared when a request is reused
after a block driver timeout handler has returned BLK_EH_DONE.

Fixes: da661267 ("blk-mq: don't time out requests again that are in the timeout handler")
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Andrew Randrianasulu <randrianasulu@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Pull powerpc fixes from Michael Ellerman:

 - a fix for hugetlb with 4K pages, broken by our recent changes for
   split PMD PTL.

 - set the correct assembler machine type on e500mc, needed since
   binutils 2.26 introduced two forms for the "wait" instruction.

 - a fix for potential missed TLB flushes with MADV_[FREE|DONTNEED] etc.
   and THP on Power9 Radix.

 - three fixes to try and make our panic handling more robust by hard
   disabling interrupts, and not marking stopped CPUs as offline because
   they haven't been properly offlined.

 - three other minor fixes.

Thanks to: Aneesh Kumar K.V, Michael Jeanson, Nicholas Piggin.

* tag 'powerpc-4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm/hash/4k: Free hugetlb page table caches correctly.
  powerpc/64s/radix: Fix radix_kvm_prefetch_workaround paca access of not possible CPU
  powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n
  powerpc/64: hard disable irqs on the panic()ing CPU
  powerpc: smp_send_stop do not offline stopped CPUs
  powerpc/64: hard disable irqs in panic_smp_self_stop
  powerpc/64s: Fix DT CPU features Power9 DD2.1 logic
  powerpc/64s/radix: Fix MADV_[FREE|DONTNEED] TLB flush miss problem with THP
  powerpc/e500mc: Set assembler machine type to e500mc

Pull arm64 fixes from Catalin Marinas:

 - clear buffers allocated with FORCE_CONTIGUOUS explicitly until the
   CMA code honours __GFP_ZERO

 - notrace annotation for secondary_start_kernel()

 - use early_param() instead of __setup() for "kpti=" as it is needed
   for the cpufeature callback remapping swapper to non-global mappings

 - ensure writes to swapper are ordered wrt subsequent cache maintenance
   in the kpti non-global remapping code

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: Ensure writes to swapper are ordered wrt subsequent cache maintenance
  arm64: kpti: Use early_param for kpti= command-line option
  arm64: make secondary_start_kernel() notrace
  arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - Lazy FPSIMD switching fixes
   - Really disable compat ioctls on architectures that don't want it
   - Disable compat on arm64 (it was never implemented...)
   - Rely on architectural requirements for GICV on GICv3
   - Detect bad alignments in unmap_stage2_range

  x86:
   - Add nested VM entry checks to avoid broken error recovery path
   - Minor documentation fix"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: fix KVM_CAP_HYPERV_TLBFLUSH paragraph number
  kvm: vmx: Nested VM-entry prereqs for event inj.
  KVM: arm64: Prevent KVM_COMPAT from being selected
  KVM: Enforce error in ioctl for compat tasks when !KVM_COMPAT
  KVM: arm/arm64: add WARN_ON if size is not PAGE_SIZE aligned in unmap_stage2_range
  KVM: arm64: Avoid mistaken attempts to save SVE state for vcpus
  KVM: arm64/sve: Fix SVE trap restoration for non-current tasks
  KVM: arm64: Don't mask softirq with IRQs disabled in vcpu_put()
  arm64: Introduce sysreg_clear_set()
  KVM: arm/arm64: Drop resource size check for GICV window

Pull xen fixes from Juergen Gross:
 "This contains the following fixes/cleanups:

   - the removal of a BUG_ON() which wasn't necessary and which could
     trigger now due to a recent change

   - a correction of a long standing bug happening very rarely in Xen
     dom0 when a hypercall buffer from user land was not accessible by
     the hypervisor for very short periods of time due to e.g. page
     migration or compaction

   - usage of EXPORT_SYMBOL_GPL() instead of EXPORT_SYMBOL() in a
     Xen-related driver (no breakage possible as using those symbols
     without others already exported via EXPORT-SYMBOL_GPL() wouldn't
     make any sense)

   - a simplification for Xen PVH or Xen ARM guests

   - some additional error handling for callers of xenbus_printf()"

* tag 'for-linus-4.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Remove unnecessary BUG_ON from __unbind_from_irq()
  xen: add new hypercall buffer mapping device
  xen/scsiback: add error handling for xenbus_printf
  scsi: xen-scsifront: add error handling for xenbus_printf
  xen/grant-table: Export gnttab_{alloc|free}_pages as GPL
  xen: add error handling for xenbus_printf
  xen: share start flags between PV and PVH

early_identify_cpu() has to use early version of pgtable_l5_enabled()
that doesn't rely on cpu_feature_enabled().

Defining USE_EARLY_PGTABLE_L5 before all includes does the trick.

I lost the define in one of reworks of the original patch.

Fixes: 372fddf7 ("x86/mm: Introduce the 'no5lvl' kernel parameter")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180622220841.54135-3-kirill.shutemov@linux.intel.com

This reverts commit e4e961e3.

We need to use early version of pgtable_l5_enabled() in
early_identify_cpu() as this code runs before cpu_feature_enabled() is
usable.

But it leads to section mismatch:

cpu_init()
  load_mm_ldt()
    ldt_slot_va()
      LDT_BASE_ADDR
        LDT_PGD_ENTRY
	  pgtable_l5_enabled()
	    __pgtable_l5_enabled

__pgtable_l5_enabled marked as __initdata, but cpu_init() is not __init.

It's fixable: early code can be isolated into a separate translation unit,
but such change collides with other work in the area.  That's too much
hassle to save 4 bytes of memory.

Return __pgtable_l5_enabled back to be __ro_after_init.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180622220841.54135-2-kirill.shutemov@linux.intel.com

The current logic incorrectly calculates the LLC ID from the APIC ID.

Unless specified otherwise, the LLC ID should be calculated by removing
the Core and Thread ID bits from the least significant end of the APIC
ID. For more info, see "ApicId Enumeration Requirements" in any Fam17h
PPR document.

[ bp: Improve commit message. ]

Fixes: 68091ee7 ("Calculate last level cache ID from number of sharing threads")
Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1528915390-30533-1-git-send-email-suravee.suthikulpanit@amd.com

Required to queue a dependent fix.

syzbot is reporting NULL pointer dereference at wb_workfn() [1] due to
wb->bdi->dev being NULL. And Dmitry confirmed that wb->state was
WB_shutting_down after wb->bdi->dev became NULL. This indicates that
unregister_bdi() failed to call wb_shutdown() on one of wb objects.

The problem is in cgwb_bdi_unregister() which does cgwb_kill() and thus
drops bdi's reference to wb structures before going through the list of
wbs again and calling wb_shutdown() on each of them. This way the loop
iterating through all wbs can easily miss a wb if that wb has already
passed through cgwb_remove_from_bdi_list() called from wb_shutdown()
from cgwb_release_workfn() and as a result fully shutdown bdi although
wb_workfn() for this wb structure is still running. In fact there are
also other ways cgwb_bdi_unregister() can race with
cgwb_release_workfn() leading e.g. to use-after-free issues:

CPU1                            CPU2
                                cgwb_bdi_unregister()
                                  cgwb_kill(*slot);

cgwb_release()
  queue_work(cgwb_release_wq, &wb->release_work);
cgwb_release_workfn()
                                  wb = list_first_entry(&bdi->wb_list, ...)
                                  spin_unlock_irq(&cgwb_lock);
  wb_shutdown(wb);
  ...
  kfree_rcu(wb, rcu);
                                  wb_shutdown(wb); -> oops use-after-free

We solve these issues by synchronizing writeback structure shutdown from
cgwb_bdi_unregister() with cgwb_release_workfn() using a new mutex. That
way we also no longer need synchronization using WB_shutting_down as the
mutex provides it for CONFIG_CGROUP_WRITEBACK case and without
CONFIG_CGROUP_WRITEBACK wb_shutdown() can be called only once from
bdi_unregister().
Reported-by: Nsyzbot <syzbot+4a7438e774b21ddd8eca@syzkaller.appspotmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove dependencies on HAS_DMA where a Kconfig symbol depends on another
symbol that implies HAS_DMA, and, optionally, on "|| COMPILE_TEST".
In most cases this other symbol is an architecture or platform specific
symbol, or PCI.

Generic symbols and drivers without platform dependencies keep their
dependencies on HAS_DMA, to prevent compiling subsystems or drivers that
cannot work anyway.

This simplifies the dependencies, and allows to improve compile-testing.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NMark Brown <broonie@kernel.org>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Reviewed-by: NMatias Bjørling <mb@lightnvm.io>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When delivering a signal to a task that is using rseq, we call into
__rseq_handle_notify_resume() so that the registers pushed in the
sigframe are updated to reflect the state of the restartable sequence
(for example, ensuring that the signal returns to the abort handler if
necessary).

However, if the rseq management fails due to an unrecoverable fault when
accessing userspace or certain combinations of RSEQ_CS_* flags, then we
will attempt to deliver a SIGSEGV. This has the potential for infinite
recursion if the rseq code continuously fails on signal delivery.

Avoid this problem by using force_sigsegv() instead of force_sig(), which
is explicitly designed to reset the SEGV handler to SIG_DFL in the case
of a recursive fault. In doing so, remove rseq_signal_deliver() from the
internal rseq API and have an optional struct ksignal * parameter to
rseq_handle_notify_resume() instead.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: peterz@infradead.org
Cc: paulmck@linux.vnet.ibm.com
Cc: boqun.feng@gmail.com
Link: https://lkml.kernel.org/r/1529664307-983-1-git-send-email-will.deacon@arm.com

When rewriting swapper using nG mappings, we must performance cache
maintenance around each page table access in order to avoid coherency
problems with the host's cacheable alias under KVM. To ensure correct
ordering of the maintenance with respect to Device memory accesses made
with the Stage-1 MMU disabled, DMBs need to be added between the
maintenance and the corresponding memory access.

This patch adds a missing DMB between writing a new page table entry and
performing a clean+invalidate on the same line.

Fixes: f992b4df ("arm64: kpti: Add ->enable callback to remap swapper using nG mappings")
Cc: <stable@vger.kernel.org> # 4.16.x-
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

We inspect __kpti_forced early on as part of the cpufeature enable
callback which remaps the swapper page table using non-global entries.

Ensure that __kpti_forced has been updated to reflect the kpti=
command-line option before we start using it.

Fixes: ea1e3de8 ("arm64: entry: Add fake CPU feature for unmapping the kernel at EL0")
Cc: <stable@vger.kernel.org> # 4.16.x-
Reported-by: NWei Xu <xuwei5@hisilicon.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NWei Xu <xuwei5@hisilicon.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Submitters of device tree binding documentation may forget to CC
the subsystem maintainer if this is missing.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Link: https://lkml.kernel.org/r/20180622100820.29616-1-geert@linux-m68k.org

For the common cases where 1000 is a multiple of HZ, or HZ is a multiple of
1000, jiffies_to_msecs() never returns zero when passed a non-zero time
period.

However, if HZ > 1000 and not an integer multiple of 1000 (e.g. 1024 or
1200, as used on alpha and DECstation), jiffies_to_msecs() may return zero
for small non-zero time periods.  This may break code that relies on
receiving back a non-zero value.

jiffies_to_usecs() does not need such a fix: one jiffy can only be less
than one µs if HZ > 1000000, and such large values of HZ are already
rejected at build time, twice:

  - include/linux/jiffies.h does #error if HZ >= 12288,
  - kernel/time/time.c has BUILD_BUG_ON(HZ > USEC_PER_SEC).

Broken since forever.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180622143357.7495-1-geert@linux-m68k.org