Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5 ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...

Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity updates from Mimi Zohar:
 "The major feature in this time is IMA support for measuring and
  appraising appended file signatures. In addition are a couple of bug
  fixes and code cleanup to use struct_size().

  In addition to the PE/COFF and IMA xattr signatures, the kexec kernel
  image may be signed with an appended signature, using the same
  scripts/sign-file tool that is used to sign kernel modules.

  Similarly, the initramfs may contain an appended signature.

  This contained a lot of refactoring of the existing appended signature
  verification code, so that IMA could retain the existing framework of
  calculating the file hash once, storing it in the IMA measurement list
  and extending the TPM, verifying the file's integrity based on a file
  hash or signature (eg. xattrs), and adding an audit record containing
  the file hash, all based on policy. (The IMA support for appended
  signatures patch set was posted and reviewed 11 times.)

  The support for appended signature paves the way for adding other
  signature verification methods, such as fs-verity, based on a single
  system-wide policy. The file hash used for verifying the signature and
  the signature, itself, can be included in the IMA measurement list"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: ima_api: Use struct_size() in kzalloc()
  ima: use struct_size() in kzalloc()
  sefltest/ima: support appended signatures (modsig)
  ima: Fix use after free in ima_read_modsig()
  MODSIGN: make new include file self contained
  ima: fix freeing ongoing ahash_request
  ima: always return negative code for error
  ima: Store the measurement again when appraising a modsig
  ima: Define ima-modsig template
  ima: Collect modsig
  ima: Implement support for module-style appended signatures
  ima: Factor xattr_verify() out of ima_appraise_measurement()
  ima: Add modsig appraise_type option for module-style appended signatures
  integrity: Select CONFIG_KEYS instead of depending on it
  PKCS#7: Introduce pkcs7_get_digest()
  PKCS#7: Refactor verify_pkcs7_signature()
  MODSIGN: Export module signature definitions
  ima: initialize the "template" field with the default template

Pull nfsd updates from Bruce Fields:
 "Highlights:

   - Add a new knfsd file cache, so that we don't have to open and close
     on each (NFSv2/v3) READ or WRITE. This can speed up read and write
     in some cases. It also replaces our readahead cache.

   - Prevent silent data loss on write errors, by treating write errors
     like server reboots for the purposes of write caching, thus forcing
     clients to resend their writes.

   - Tweak the code that allocates sessions to be more forgiving, so
     that NFSv4.1 mounts are less likely to hang when a server already
     has a lot of clients.

   - Eliminate an arbitrary limit on NFSv4 ACL sizes; they should now be
     limited only by the backend filesystem and the maximum RPC size.

   - Allow the server to enforce use of the correct kerberos credentials
     when a client reclaims state after a reboot.

  And some miscellaneous smaller bugfixes and cleanup"

* tag 'nfsd-5.4' of git://linux-nfs.org/~bfields/linux: (34 commits)
  sunrpc: clean up indentation issue
  nfsd: fix nfs read eof detection
  nfsd: Make nfsd_reset_boot_verifier_locked static
  nfsd: degraded slot-count more gracefully as allocation nears exhaustion.
  nfsd: handle drc over-allocation gracefully.
  nfsd: add support for upcall version 2
  nfsd: add a "GetVersion" upcall for nfsdcld
  nfsd: Reset the boot verifier on all write I/O errors
  nfsd: Don't garbage collect files that might contain write errors
  nfsd: Support the server resetting the boot verifier
  nfsd: nfsd_file cache entries should be per net namespace
  nfsd: eliminate an unnecessary acl size limit
  Deprecate nfsd fault injection
  nfsd: remove duplicated include from filecache.c
  nfsd: Fix the documentation for svcxdr_tmpalloc()
  nfsd: Fix up some unused variable warnings
  nfsd: close cached files prior to a REMOVE or RENAME that would replace target
  nfsd: rip out the raparms cache
  nfsd: have nfsd_test_lock use the nfsd_file cache
  nfsd: hook up nfs4_preprocess_stateid_op to the nfsd_file cache
  ...

Pull fuse virtio-fs support from Miklos Szeredi:
 "Virtio-fs allows exporting directory trees on the host and mounting
  them in guest(s).

  This isn't actually a new filesystem, but a glue layer between the
  fuse filesystem and a virtio based back-end.

  It's similar in functionality to the existing virtio-9p solution, but
  significantly faster in benchmarks and has better POSIX compliance.
  Further permformance improvements can be achieved by sharing the page
  cache between host and guest, allowing for faster I/O and reduced
  memory use.

  Kata Containers have been including the out-of-tree virtio-fs (with
  the shared page cache patches as well) since version 1.7 as an
  experimental feature. They have been active in development and plan to
  switch from virtio-9p to virtio-fs as their default solution. There
  has been interest from other sources as well.

  The userspace infrastructure is slated to be merged into qemu once the
  kernel part hits mainline.

  This was developed by Vivek Goyal, Dave Gilbert and Stefan Hajnoczi"

* tag 'virtio-fs-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  virtio-fs: add virtiofs filesystem
  virtio-fs: add Documentation/filesystems/virtiofs.rst
  fuse: reserve values for mapping protocol

Pull 9p updates from Dominique Martinet:
 "Some of the usual small fixes and cleanup.

  Small fixes all around:
   - avoid overlayfs copy-up for PRIVATE mmaps
   - KUMSAN uninitialized warning for transport error
   - one syzbot memory leak fix in 9p cache
   - internal API cleanup for v9fs_fill_super"

* tag '9p-for-5.4' of git://github.com/martinetd/linux:
  9p/vfs_super.c: Remove unused parameter data in v9fs_fill_super
  9p/cache.c: Fix memory leak in v9fs_cache_session_get_cookie
  9p: Transport error uninitialized
  9p: avoid attaching writeback_fid on mmap with type PRIVATE

Pull more RISC-V updates from Paul Walmsley:
 "Some additional RISC-V updates.

  This includes one significant fix:

   - Prevent interrupts from being unconditionally re-enabled during
     exception handling if they were disabled in the context in which
     the exception occurred

  Also a few other fixes:

   - Fix a build error when sparse memory support is manually enabled

   - Prevent CPUs beyond CONFIG_NR_CPUS from being enabled in early boot

  And a few minor improvements:

   - DT improvements: in the FU540 SoC DT files, improve U-Boot
     compatibility by adding an "ethernet0" alias, drop an unnecessary
     property from the DT files, and add support for the PWM device

   - KVM preparation: add a KVM-related macro for future RISC-V KVM
     support, and export some symbols required to build KVM support as
     modules

   - defconfig additions: build more drivers by default for QEMU
     configurations"

* tag 'riscv/for-v5.4-rc1-b' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Avoid interrupts being erroneously enabled in handle_exception()
  riscv: dts: sifive: Drop "clock-frequency" property of cpu nodes
  riscv: dts: sifive: Add ethernet0 to the aliases node
  RISC-V: Export kernel symbols for kvm
  KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface
  arch/riscv: disable excess harts before picking main boot hart
  RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig
  RISC-V: Fix building error when CONFIG_SPARSEMEM_MANUAL=y
  riscv: dts: Add DT support for SiFive FU540 PWM driver

Pull nios2 fix from Ley Foon Tan:
 "Make sure the command line buffer is NUL-terminated"

* tag 'nios2-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  nios2: force the string buffer NULL-terminated

Pull more KVM updates from Paolo Bonzini:
 "x86 KVM changes:

   - The usual accuracy improvements for nested virtualization

   - The usual round of code cleanups from Sean

   - Added back optimizations that were prematurely removed in 5.2 (the
     bare minimum needed to fix the regression was in 5.3-rc8, here
     comes the rest)

   - Support for UMWAIT/UMONITOR/TPAUSE

   - Direct L2->L0 TLB flushing when L0 is Hyper-V and L1 is KVM

   - Tell Windows guests if SMT is disabled on the host

   - More accurate detection of vmexit cost

   - Revert a pvqspinlock pessimization"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (56 commits)
  KVM: nVMX: cleanup and fix host 64-bit mode checks
  KVM: vmx: fix build warnings in hv_enable_direct_tlbflush() on i386
  KVM: x86: Don't check kvm_rebooting in __kvm_handle_fault_on_reboot()
  KVM: x86: Drop ____kvm_handle_fault_on_reboot()
  KVM: VMX: Add error handling to VMREAD helper
  KVM: VMX: Optimize VMX instruction error and fault handling
  KVM: x86: Check kvm_rebooting in kvm_spurious_fault()
  KVM: selftests: fix ucall on x86
  Revert "locking/pvqspinlock: Don't wait if vCPU is preempted"
  kvm: nvmx: limit atomic switch MSRs
  kvm: svm: Intercept RDPRU
  kvm: x86: Add "significant index" flag to a few CPUID leaves
  KVM: x86/mmu: Skip invalid pages during zapping iff root_count is zero
  KVM: x86/mmu: Explicitly track only a single invalid mmu generation
  KVM: x86/mmu: Revert "KVM: x86/mmu: Remove is_obsolete() call"
  KVM: x86/mmu: Revert "Revert "KVM: MMU: reclaim the zapped-obsolete page first""
  KVM: x86/mmu: Revert "Revert "KVM: MMU: collapse TLB flushes when zap all pages""
  KVM: x86/mmu: Revert "Revert "KVM: MMU: zap pages in batch""
  KVM: x86/mmu: Revert "Revert "KVM: MMU: add tracepoint for kvm_mmu_invalidate_all_pages""
  KVM: x86/mmu: Revert "Revert "KVM: MMU: show mmu_valid_gen in shadow page related tracepoints""
  ...

Merge tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "Besides one new driver being added for the PWM controller found in
  various Spreadtrum SoCs, this series of changes brings a slew of,
  mostly minor, fixes and cleanups for existing drivers, as well as some
  enhancements to the core code.

  Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS
  file, making official his role as a reviewer"

* tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (34 commits)
  MAINTAINERS: Add myself as reviewer for the PWM subsystem
  MAINTAINERS: Add patchwork link for PWM entry
  MAINTAINERS: Add a selection of PWM related keywords to the PWM entry
  pwm: mediatek: Add MT7629 compatible string
  dt-bindings: pwm: Update bindings for MT7629 SoC
  pwm: mediatek: Update license and switch to SPDX tag
  pwm: mediatek: Use pwm_mediatek as common prefix
  pwm: mediatek: Allocate the clks array dynamically
  pwm: mediatek: Remove the has_clks field
  pwm: mediatek: Drop the check for of_device_get_match_data()
  pwm: atmel: Consolidate driver data initialization
  pwm: atmel: Remove unneeded check for match data
  pwm: atmel: Remove platform_device_id and use only dt bindings
  pwm: stm32-lp: Add check in case requested period cannot be achieved
  pwm: Ensure pwm_apply_state() doesn't modify the state argument
  pwm: fsl-ftm: Don't update the state for the caller of pwm_apply_state()
  pwm: sun4i: Don't update the state for the caller of pwm_apply_state()
  pwm: rockchip: Don't update the state for the caller of pwm_apply_state()
  pwm: Let pwm_get_state() return the last implemented state
  pwm: Introduce local struct pwm_chip in pwm_apply_state()
  ...

Pull more io_uring updates from Jens Axboe:
 "Just two things in here:

   - Improvement to the io_uring CQ ring wakeup for batched IO (me)

   - Fix wrong comparison in poll handling (yangerkun)

  I realize the first one is a little late in the game, but it felt
  pointless to hold it off until the next release. Went through various
  testing and reviews with Pavel and peterz"

* tag 'for-5.4/io_uring-2019-09-27' of git://git.kernel.dk/linux-block:
  io_uring: make CQ ring wakeups be more efficient
  io_uring: compare cached_cq_tail with cq.head in_io_uring_poll

Pull block fixes from Jens Axboe:
 "A few fixes/changes to round off this merge window. This contains:

   - Small series making some functional tweaks to blk-iocost (Tejun)

   - Elevator switch locking fix (Ming)

   - Kill redundant call in blk-wbt (Yufen)

   - Fix flush timeout handling (Yufen)"

* tag 'for-linus-2019-09-27' of git://git.kernel.dk/linux-block:
  block: fix null pointer dereference in blk_mq_rq_timed_out()
  rq-qos: get rid of redundant wbt_update_limits()
  iocost: bump up default latency targets for hard disks
  iocost: improve nr_lagging handling
  iocost: better trace vrate changes
  block: don't release queue's sysfs lock during switching elevator
  blk-mq: move lockdep_assert_held() into elevator_exit

Pull thermal management updates from Zhang Rui:

 - Add Amit Kucheria as thermal subsystem Reviewer (Amit Kucheria)

 - Fix a use after free bug when unregistering thermal zone devices (Ido
   Schimmel)

 - Fix thermal core framework to use put_device() when device_register()
   fails (Yue Hu)

 - Enable intel_pch_thermal and MMIO RAPL support for Intel Icelake
   platform (Srinivas Pandruvada)

 - Add clock operations in qorip thermal driver, for some platforms with
   clock control like i.MX8MQ (Anson Huang)

 - A couple of trivial fixes and cleanups for thermal core and different
   soc thermal drivers (Amit Kucheria, Christophe JAILLET, Chuhong Yuan,
   Fuqian Huang, Kelsey Skunberg, Nathan Huckleberry, Rishi Gupta,
   Srinivas Kandagatla)

* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  MAINTAINERS: Add Amit Kucheria as reviewer for thermal
  thermal: Add some error messages
  thermal: Fix use-after-free when unregistering thermal zone device
  thermal/drivers/core: Use put_device() if device_register() fails
  thermal_hwmon: Sanitize thermal_zone type
  thermal: intel: Use dev_get_drvdata
  thermal: intel: int3403: replace printk(KERN_WARN...) with pr_warn(...)
  thermal: intel: int340x_thermal: Remove unnecessary acpi_has_method() uses
  thermal: int340x: processor_thermal: Add Ice Lake support
  drivers: thermal: qcom: tsens: Fix memory leak from qfprom read
  thermal: tegra: Fix a typo
  thermal: rcar_gen3_thermal: Replace devm_add_action() followed by failure action with devm_add_action_or_reset()
  thermal: armada: Fix -Wshift-negative-value
  dt-bindings: thermal: qoriq: Add optional clocks property
  thermal: qoriq: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
  thermal: qoriq: Use devm_platform_ioremap_resource() instead of of_iomap()
  thermal: qoriq: Fix error path of calling qoriq_tmu_register_tmu_zone fail
  thermal: qoriq: Add clock operations
  drivers: thermal: processor_thermal_device: Export sysfs interface for TCC offset

Pull watchdog updates from Wim Van Sebroeck:

 - addition of AST2600, i.MX7ULP and F81803 watchdog support

 - removal of the w90x900 and ks8695 drivers

 - ziirave_wdt improvements

 - small fixes and improvements

* tag 'linux-watchdog-5.4-rc1' of git://www.linux-watchdog.org/linux-watchdog: (51 commits)
  watchdog: f71808e_wdt: Add F81803 support
  watchdog: qcom: remove unnecessary variable from private storage
  watchdog: qcom: support pre-timeout when the bark irq is available
  watchdog: imx_sc: this patch just fixes whitespaces
  watchdog: apseed: Add access_cs0 option for alt-boot
  watchdog: aspeed: add support for dual boot
  watchdog: orion_wdt: use timer1 as a pretimeout
  watchdog: Add i.MX7ULP watchdog support
  dt-bindings: watchdog: Add i.MX7ULP bindings
  dt-bindings: watchdog: sun4i: Add the watchdog clock
  dt-bindings: watchdog: sun4i: Add the watchdog interrupts
  dt-bindings: watchdog: Convert Allwinner watchdog to a schema
  dt-bindings: watchdog: Add YAML schemas for the generic watchdog bindings
  watchdog: aspeed: Add support for AST2600
  dt-bindings: watchdog: Add ast2600 compatible
  watchdog: ziirave_wdt: Update checked I2C functionality mask
  watchdog: ziirave_wdt: Drop ziirave_firm_write_block_data()
  watchdog: ziirave_wdt: Fix DOWNLOAD_START payload
  watchdog: ziirave_wdt: Drop status polling code
  watchdog: ziirave_wdt: Fix RESET_PROCESSOR payload
  ...

Pull drm fixes from Dave Airlie:
 "Fixes built up over the past 1.5 weeks or so, it's two weeks of
  amdgpu, some core cleanups and some panfrost fixes. I also finally
  figured out why my desktop was slow to do a bunch of stuff (someone
  gave it an IPv6 address which can't reach anything!).

  core:
   - Some cleanups and fixes in the self-refresh helpers
   - Some cleanups and fixes in the atomic helpers

  amdgpu:
   - Fix a 64 bit divide
   - Prevent a memory leak in a failure case in dc
   - Load proper gfx firmware on navi14 variants
   - Add more navi12 and navi14 PCI ids
   - Misc fixes for renoir
   - Fix bandwidth issues with multiple displays on vega20
   - Support for Dali
   - Fix a possible oops with KFD on hawaii
   - Fix for backlight level after resume on some APUs
   - Other misc fixes

  panfrost:
   - Multiple panfrost fixes for regulator support and page fault
     handling"

* tag 'drm-next-2019-09-27' of git://anongit.freedesktop.org/drm/drm: (34 commits)
  drm/amd/display: prevent memory leak
  drm/amdgpu/gfx10: add support for wks firmware loading
  drm/amdgpu/display: include slab.h in dcn21_resource.c
  drm/amdgpu/display: fix 64 bit divide
  drm/panfrost: Prevent race when handling page fault
  drm/panfrost: Remove NULL checks for regulator
  drm/panfrost: Fix regulator_get_optional() misuse
  drm: Measure Self Refresh Entry/Exit times to avoid thrashing
  drm: Fix kerneldoc and remove unused struct member in self_refresh helper
  drm/atomic: Rename crtc_state->pageflip_flags to async_flip
  drm/atomic: Reject FLIP_ASYNC unconditionally
  drm/atomic: Take the atomic toys away from X
  drm/amdgpu: flag navi12 and 14 as experimental for 5.4
  drm/kms: Duct-tape for mode object lifetime checks
  drm/amdgpu: add navi12 pci id
  drm/amdgpu: add navi14 PCI ID for work station SKU
  drm/amdkfd: Swap trap temporary registers in gfx10 trap handler
  drm/amd/powerplay: implement sysfs for getting dpm clock
  drm/amd/display: Restore backlight brightness after system resume
  drm/amd/display: Implement voltage limitation for dali
  ...

Pull NTB updates from Jon Mason:
 "A few bugfixes and support for new AMD NTB hardware"

* tag 'ntb-5.4' of git://github.com/jonmason/ntb:
  NTB: fix IDT Kconfig typos/spellos
  ntb_hw_amd: Add memory window support for new AMD hardware
  ntb_hw_amd: Add a new NTB PCI device ID
  NTB: ntb_transport: remove redundant assignment to rc
  ntb_hw_switchtec: make ntb_mw_set_trans() work when addr == 0
  ntb: point to right memory window index

To address a major procedural concern on Linus's part the keyrings needs
a co-maintainer.
Suggested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We got a null pointer deference BUG_ON in blk_mq_rq_timed_out()
as following:

[  108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040
[  108.827059] PGD 0 P4D 0
[  108.827313] Oops: 0000 [#1] SMP PTI
[  108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431
[  108.829503] Workqueue: kblockd blk_mq_timeout_work
[  108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330
[  108.838191] Call Trace:
[  108.838406]  bt_iter+0x74/0x80
[  108.838665]  blk_mq_queue_tag_busy_iter+0x204/0x450
[  108.839074]  ? __switch_to_asm+0x34/0x70
[  108.839405]  ? blk_mq_stop_hw_queue+0x40/0x40
[  108.839823]  ? blk_mq_stop_hw_queue+0x40/0x40
[  108.840273]  ? syscall_return_via_sysret+0xf/0x7f
[  108.840732]  blk_mq_timeout_work+0x74/0x200
[  108.841151]  process_one_work+0x297/0x680
[  108.841550]  worker_thread+0x29c/0x6f0
[  108.841926]  ? rescuer_thread+0x580/0x580
[  108.842344]  kthread+0x16a/0x1a0
[  108.842666]  ? kthread_flush_work+0x170/0x170
[  108.843100]  ret_from_fork+0x35/0x40

The bug is caused by the race between timeout handle and completion for
flush request.

When timeout handle function blk_mq_rq_timed_out() try to read
'req->q->mq_ops', the 'req' have completed and reinitiated by next
flush request, which would call blk_rq_init() to clear 'req' as 0.

After commit 12f5b931 ("blk-mq: Remove generation seqeunce"),
normal requests lifetime are protected by refcount. Until 'rq->ref'
drop to zero, the request can really be free. Thus, these requests
cannot been reused before timeout handle finish.

However, flush request has defined .end_io and rq->end_io() is still
called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq'
can be reused by the next flush request handle, resulting in null
pointer deference BUG ON.

We fix this problem by covering flush request with 'rq->ref'.
If the refcount is not zero, flush_end_io() return and wait the
last holder recall it. To record the request status, we add a new
entry 'rq_status', which will be used in flush_end_io().

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: stable@vger.kernel.org # v4.18+
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>

-------
v2:
 - move rq_status from struct request to struct blk_flush_queue
v3:
 - remove unnecessary '{}' pair.
v4:
 - let spinlock to protect 'fq->rq_status'
v5:
 - move rq_status after flush_running_idx member of struct blk_flush_queue
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We have updated limits after calling wbt_set_min_lat(). No need to
update again.
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull timer fix from Ingo Molnar:
 "Fix a timer expiry bug that would cause spurious delay of timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Read jiffies once when forwarding base clk

Pull more perf updates from Ingo Molnar:
 "The only kernel change is comment typo fixes.

  The rest is mostly tooling fixes, but also new vendor event additions
  and updates, a bigger libperf/libtraceevent library and a header files
  reorganization that came in a bit late"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits)
  perf unwind: Fix libunwind build failure on i386 systems
  perf parser: Remove needless include directives
  perf build: Add detection of java-11-openjdk-devel package
  perf jvmti: Include JVMTI support for s390
  perf vendor events: Remove P8 HW events which are not supported
  perf evlist: Fix access of freed id arrays
  perf stat: Fix free memory access / memory leaks in metrics
  perf tools: Replace needless mmap.h with what is needed, event.h
  perf evsel: Move config terms to a separate header
  perf evlist: Remove unused perf_evlist__fprintf() method
  perf evsel: Introduce evsel_fprintf.h
  perf evsel: Remove need for symbol_conf in evsel_fprintf.c
  perf copyfile: Move copyfile routines to separate files
  libperf: Add perf_evlist__poll() function
  libperf: Add perf_evlist__add_pollfd() function
  libperf: Add perf_evlist__alloc_pollfd() function
  libperf: Add libperf_init() call to the tests
  libperf: Merge libperf_set_print() into libperf_init()
  libperf: Add libperf dependency for tests targets
  libperf: Use sys/types.h to get ssize_t, not unistd.h
  ...

Pull tracing fix from Steven Rostedt:
 "Srikar Dronamraju fixed a bug in the newmulti probe code"

* tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/probe: Fix same probe event argument matching

Naresh Kamboju reported, that on the i386 build pr_err()
doesn't get defined properly due to header ordering:

  perf-in.o: In function `libunwind__x86_reg_id':
  tools/perf/util/libunwind/../../arch/x86/util/unwind-libunwind.c:109:
  undefined reference to `pr_err'
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull usercopy fix from Kees Cook:
 "Fix hardened usercopy under CONFIG_DEBUG_VIRTUAL"

* tag 'usercopy-v5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  usercopy: Avoid HIGHMEM pfn warning

Merge tag 'linux-kselftest-5.4-rc1.1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest updates from Shuah Khan:
 "Fixes to existing tests"

* tag 'linux-kselftest-5.4-rc1.1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: tpm2: install python files
  selftests: livepatch: add missing fragments to config
  selftests: watchdog: cleanup whitespace in usage options
  selftest/ftrace: Fix typo in trigger-snapshot.tc
  selftests: watchdog: Add optional file argument
  selftests/seccomp: fix build on older kernels
  selftests: use "$(MAKE)" instead of "make"

Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - Dequeue the request from the receive queue while we're re-encoding
     # v4.20+
   - Fix buffer handling of GSS MIC without slack # 5.1

  Features:
   - Increase xprtrdma maximum transport header and slot table sizes
   - Add support for nfs4_call_sync() calls using a custom
     rpc_task_struct
   - Optimize the default readahead size
   - Enable pNFS filelayout LAYOUTGET on OPEN

  Other bugfixes and cleanups:
   - Fix possible null-pointer dereferences and memory leaks
   - Various NFS over RDMA cleanups
   - Various NFS over RDMA comment updates
   - Don't receive TCP data into a reset request buffer
   - Don't try to parse incomplete RPC messages
   - Fix congestion window race with disconnect
   - Clean up pNFS return-on-close error handling
   - Fixes for NFS4ERR_OLD_STATEID handling"

* tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (53 commits)
  pNFS/filelayout: enable LAYOUTGET on OPEN
  NFS: Optimise the default readahead size
  NFSv4: Handle NFS4ERR_OLD_STATEID in LOCKU
  NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE
  NFSv4: Fix OPEN_DOWNGRADE error handling
  pNFS: Handle NFS4ERR_OLD_STATEID on layoutreturn by bumping the state seqid
  NFSv4: Add a helper to increment stateid seqids
  NFSv4: Handle RPC level errors in LAYOUTRETURN
  NFSv4: Handle NFS4ERR_DELAY correctly in return-on-close
  NFSv4: Clean up pNFS return-on-close error handling
  pNFS: Ensure we do clear the return-on-close layout stateid on fatal errors
  NFS: remove unused check for negative dentry
  NFSv3: use nfs_add_or_obtain() to create and reference inodes
  NFS: Refactor nfs_instantiate() for dentry referencing callers
  SUNRPC: Fix congestion window race with disconnect
  SUNRPC: Don't try to parse incomplete RPC messages
  SUNRPC: Rename xdr_buf_read_netobj to xdr_buf_read_mic
  SUNRPC: Fix buffer handling of GSS MIC without slack
  SUNRPC: RPC level errors should always set task->tk_rpc_status
  SUNRPC: Don't receive TCP data into a request buffer that has been reset
  ...

When brk was moved for binaries without an interpreter, it should have
been limited to ET_DYN only. In other words, the special case was an
ET_DYN that lacks an INTERP, not just an executable that lacks INTERP.
The bug manifested for giant static executables, where the brk would end
up in the middle of the text area on 32-bit architectures.
Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in>
Fixes: bbdc6076 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull xfs fixes from Darrick Wong:
 "There are a couple of bug fixes and some small code cleanups that came
  in recently:

   - Minor code cleanups

   - Fix a superblock logging error

   - Ensure that collapse range converts the data fork to extents format
     when necessary

   - Revert the ALLOC_USERDATA cleanup because it caused subtle behavior
     regressions"

* tag 'xfs-5.4-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: avoid unused to_mp() function warning
  xfs: log proper length of superblock
  xfs: revert 1baa2800 ("xfs: remove the unused XFS_ALLOC_USERDATA flag")
  xfs: removed unneeded variable
  xfs: convert inode to extent format after extent merge due to shift

Pull jffs2 fix from Al Viro:
 "braino fix for mount API conversion for jffs2"

* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jffs2: Fix mounting under new mount API

Pull more s390 updates from Vasily Gorbik:

 - Fix three kasan findings

 - Add PERF_EVENT_IOC_PERIOD ioctl support

 - Add Crypto Express7S support and extend sysfs attributes for pkey

 - Minor common I/O layer documentation corrections

* tag 's390-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/cio: exclude subchannels with no parent from pseudo check
  s390/cio: avoid calling strlen on null pointer
  s390/topology: avoid firing events before kobjs are created
  s390/cpumf: Remove mixed white space
  s390/cpum_sf: Support ioctl PERF_EVENT_IOC_PERIOD
  s390/zcrypt: CEX7S exploitation support
  s390/cio: fix intparm documentation
  s390/pkey: Add sysfs attributes to emit AES CIPHER key blobs

Pull xen update from Juergen Gross:
 "Only two small patches this time:

   - a small cleanup for swiotlb-xen

   - a fix for PCI initialization for some platforms"

* tag 'for-linus-5.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pci: reserve MCFG areas earlier
  swiotlb-xen: Convert to use macro

Merge more updates from Andrew Morton:

 - almost all of the rest of -mm

 - various other subsystems

Subsystems affected by this patch series:
  memcg, misc, core-kernel, lib, checkpatch, reiserfs, fat, fork,
  cpumask, kexec, uaccess, kconfig, kgdb, bug, ipc, lzo, kasan, madvise,
  cleanups, pagemap

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (77 commits)
  arch/sparc/include/asm/pgtable_64.h: fix build
  mm: treewide: clarify pgtable_page_{ctor,dtor}() naming
  ntfs: remove (un)?likely() from IS_ERR() conditions
  IB/hfi1: remove unlikely() from IS_ERR*() condition
  xfs: remove unlikely() from WARN_ON() condition
  wimax/i2400m: remove unlikely() from WARN*() condition
  fs: remove unlikely() from WARN_ON() condition
  xen/events: remove unlikely() from WARN() condition
  checkpatch: check for nested (un)?likely() calls
  hexagon: drop empty and unused free_initrd_mem
  mm: factor out common parts between MADV_COLD and MADV_PAGEOUT
  mm: introduce MADV_PAGEOUT
  mm: change PAGEREF_RECLAIM_CLEAN with PAGE_REFRECLAIM
  mm: introduce MADV_COLD
  mm: untag user pointers in mmap/munmap/mremap/brk
  vfio/type1: untag user pointers in vaddr_get_pfn
  tee/shm: untag user pointers in tee_shm_register
  media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get
  drm/radeon: untag user pointers in radeon_gem_userptr_ioctl
  drm/amdgpu: untag user pointers
  ...

A last-minute fixlet which I'd failed to merge at the appropriate time
had the predictable effect.

Fixes: f672e2c217e2d4b2 ("lib: untag user pointers in strn*_user")
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.comSigned-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"likely(!IS_ERR(x))" is excessive. IS_ERR() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-11-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(IS_ERR_OR_NULL(x))" is excessive. IS_ERR_OR_NULL() already uses
unlikely() internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-8-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-7-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-6-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-5-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

"unlikely(WARN(x))" is excessive. WARN() already uses unlikely()
internally.

Link: http://lkml.kernel.org/r/20190829165025.15750-4-efremov@linux.comSigned-off-by: Denis Efremov <efremov@linux.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The mounting of jffs2 is broken due to the changes from the new mount API
because it specifies a "source" operation, but then doesn't actually
process it.  But because it specified it, it doesn't return -ENOPARAM and
the caller doesn't process it either and the source gets lost.

Fix this by simply removing the source parameter from jffs2 and letting the
VFS deal with it in the default manner.

To test it, enable CONFIG_MTD_MTDRAM and allow the default size and erase
block size parameters, then try and mount the /dev/mtdblock<N> file that
that creates as jffs2.  No need to initialise it.

Fixes: ec10a24f ("vfs: Convert jffs2 to use the new mount API")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>