Commit 594cc251

 ("make 'user_access_begin()' do 'access_ok()'")
broke both alpha and SH booting in qemu, as noticed by Guenter Roeck.

It turns out that the bug wasn't actually in that commit itself (which
would have been surprising: it was mostly a no-op), but in how the
addition of access_ok() to the strncpy_from_user() and strnlen_user()
functions now triggered the case where those functions would test the
access of the very last byte of the user address space.

The string functions actually did that user range test before too, but
they did it manually by just comparing against user_addr_max().  But
with user_access_begin() doing the check (using "access_ok()"), it now
exposed problems in the architecture implementations of that function.

For example, on alpha, the access_ok() helper macro looked like this:

  #define __access_ok(addr, size) \
        ((get_fs().seg & (addr | size | (addr+size))) == 0)

and what it basically tests is of any of the high bits get set (the
USER_DS masking value is 0xfffffc0000000000).

And that's completely wrong for the "addr+size" check.  Because it's
off-by-one for the case where we check to the very end of the user
address space, which is exactly what the strn*_user() functions do.

Why? Because "addr+size" will be exactly the size of the address space,
so trying to access the last byte of the user address space will fail
the __access_ok() check, even though it shouldn't.  As a result, the
user string accessor functions failed consistently - because they
literally don't know how long the string is going to be, and the max
access is going to be that last byte of the user address space.

Side note: that alpha macro is buggy for another reason too - it re-uses
the arguments twice.

And SH has another version of almost the exact same bug:

  #define __addr_ok(addr) \
        ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)

so far so good: yes, a user address must be below the limit.  But then:

  #define __access_ok(addr, size)         \
        (__addr_ok((addr) + (size)))

is wrong with the exact same off-by-one case: the case when "addr+size"
is exactly _equal_ to the limit is actually perfectly fine (think "one
byte access at the last address of the user address space")

The SH version is actually seriously buggy in another way: it doesn't
actually check for overflow, even though it did copy the _comment_ that
talks about overflow.

So it turns out that both SH and alpha actually have completely buggy
implementations of access_ok(), but they happened to work in practice
(although the SH overflow one is a serious serious security bug, not
that anybody likely cares about SH security).

This fixes the problems by using a similar macro on both alpha and SH.
It isn't trying to be clever, the end address is based on this logic:

        unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b;

which basically says "add start and length, and then subtract one unless
the length was zero".  We can't subtract one for a zero length, or we'd
just hit an underflow instead.

For a lot of access_ok() users the length is a constant, so this isn't
actually as expensive as it initially looks.

Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull fscrypt updates from Ted Ts'o:
 "Add Adiantum support for fscrypt"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: add Adiantum support

Pull ext4 bug fixes from Ted Ts'o:
 "Fix a number of ext4 bugs"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix special inode number checks in __ext4_iget()
  ext4: track writeback errors using the generic tracking infrastructure
  ext4: use ext4_write_inode() when fsyncing w/o a journal
  ext4: avoid kernel warning when writing the superblock to a dead device
  ext4: fix a potential fiemap/page fault deadlock w/ inline_data
  ext4: make sure enough credits are reserved for dioread_nolock writes

Pull dma-mapping fixes from Christoph Hellwig:
 "Fix various regressions introduced in this cycles:

   - fix dma-debug tracking for the map_page / map_single
     consolidatation

   - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid
     link failures

   - fix AMD Gart direct mappings

   - setup the dma address for no kernel mappings using the remap
     allocator"

* tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations
  x86/amd_gart: fix unmapping of non-GART mappings
  dma-mapping: remove a few unused exports
  dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA
  dma-mapping: remove dmam_{declare,release}_coherent_memory
  dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs
  dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs

Merge tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform

Pull chrome platform updates from Benson Leung:

 - Changes for EC_MKBP_EVENT_SENSOR_FIFO handling.

 - Also, maintainership changes. Olofj out, Enric balletbo in.

* tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform:
  MAINTAINERS: add maintainers for ChromeOS EC sub-drivers
  MAINTAINERS: platform/chrome: Add Enric as a maintainer
  MAINTAINERS: platform/chrome: remove myself as maintainer
  platform/chrome: don't report EC_MKBP_EVENT_SENSOR_FIFO as wakeup
  platform/chrome: straighten out cros_ec_get_{next,host}_event() error codes

Pull hwspinlock updates from Bjorn Andersson:
 "This adds support for the hardware semaphores found in STM32MP1"

* tag 'hwlock-v4.21' of git://github.com/andersson/remoteproc:
  hwspinlock: fix return value check in stm32_hwspinlock_probe()
  hwspinlock: add STM32 hwspinlock device
  dt-bindings: hwlock: Document STM32 hwspinlock bindings

Add support for the Adiantum encryption mode to fscrypt.  Adiantum is a
tweakable, length-preserving encryption mode with security provably
reducible to that of XChaCha12 and AES-256, subject to a security bound.
It's also a true wide-block mode, unlike XTS.  See the paper
"Adiantum: length-preserving encryption for entry-level processors"
(https://eprint.iacr.org/2018/720.pdf) for more details.  Also see
commit 059c2a4d

 ("crypto: adiantum - add Adiantum support").

On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and
the NH hash function.  These algorithms are fast even on processors
without dedicated crypto instructions.  Adiantum makes it feasible to
enable storage encryption on low-end mobile devices that lack AES
instructions; currently such devices are unencrypted.  On ARM Cortex-A7,
on 4096-byte messages Adiantum encryption is about 4 times faster than
AES-256-XTS encryption; decryption is about 5 times faster.

In fscrypt, Adiantum is suitable for encrypting both file contents and
names.  With filenames, it fixes a known weakness: when two filenames in
a directory share a common prefix of >= 16 bytes, with CTS-CBC their
encrypted filenames share a common prefix too, leaking information.
Adiantum does not have this problem.

Since Adiantum also accepts long tweaks (IVs), it's also safe to use the
master key directly for Adiantum encryption rather than deriving
per-file keys, provided that the per-file nonce is included in the IVs
and the master key isn't used for any other encryption mode.  This
configuration saves memory and improves performance.  A new fscrypt
policy flag is added to allow users to opt-in to this configuration.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Pull documentation fixes from Jonathan Corbet:
 "A handful of late-arriving documentation fixes"

* tag 'docs-5.0-fixes' of git://git.lwn.net/linux:
  doc: filesystems: fix bad references to nonexistent ext4.rst file
  Documentation/admin-guide: update URL of LKML information link
  Docs/kernel-api.rst: Remove blk-tag.c reference

Pull firewire fixlet from Stefan Richter:
 "Remove an explicit dependency in Kconfig which is implied by another
  dependency"

* tag 'firewire-update' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: Remove depends on HAS_DMA in case of platform dependency

Pull block updates and fixes from Jens Axboe:

 - Pulled in MD changes that Shaohua had queued up for 4.21.

   Unfortunately we lost Shaohua late 2018, I'm sending these in on his
   behalf.

 - In conjunction with the above, I added a CREDITS entry for Shaoua.

 - sunvdc queue restart fix (Ming)

* tag 'for-linus-20190104' of git://git.kernel.dk/linux-block:
  Add CREDITS entry for Shaohua Li
  block: sunvdc: don't run hw queue synchronously from irq context
  md: fix raid10 hang issue caused by barrier
  raid10: refactor common wait code from regular read/write request
  md: remvoe redundant condition check
  lib/raid6: add option to skip algo benchmarking
  lib/raid6: sort algos in rough performance order
  lib/raid6: check for assembler SSSE3 support
  lib/raid6: avoid __attribute_const__ redefinition
  lib/raid6: add missing include for raid6test
  md: remove set but not used variable 'bi_rdev'

Pull drm fixes from Dave Airlie:
 "Happy New Year, just decloaking from leave to get some stuff from the
  last week in before rc1:

  core:
   - two regression fixes for damage blob and atomic

  i915 gvt:
   - Some missed GVT fixes from the original pull

  amdgpu:
   - new PCI IDs
   - SR-IOV fixes
   - DC fixes
   - Vega20 fixes"

* tag 'drm-next-2019-01-05' of git://anongit.freedesktop.org/drm/drm: (53 commits)
  drm: Put damage blob when destroy plane state
  drm: fix null pointer dereference on null state pointer
  drm/amdgpu: Add new VegaM pci id
  drm/ttm: Use drm_debug_printer for all ttm_bo_mem_space_debug output
  drm/amdgpu: add Vega20 PSP ASD firmware loading
  drm/amd/display: Fix MST dp_blank REG_WAIT timeout
  drm/amd/display: validate extended dongle caps
  drm/amd/display: Use div_u64 for flip timestamp ns to ms
  drm/amdgpu/uvd:Change uvd ring name convention
  drm/amd/powerplay: add Vega20 LCLK DPM level setting support
  drm/amdgpu: print process info when job timeout
  drm/amdgpu/nbio7.4: add hw bug workaround for vega20
  drm/amdgpu/nbio6.1: add hw bug workaround for vega10/12
  drm/amd/display: Optimize passive update planes.
  drm/amd/display: verify lane status before exiting verify link cap
  drm/amd/display: Fix bug with not updating VSP infoframe
  drm/amd/display: Add retry to read ddc_clock pin
  drm/amd/display: Don't skip link training for empty dongle
  drm/amd/display: Wait edp HPD to high in detect_sink
  drm/amd/display: fix surface update sequence
  ...

Pull rdma fixes from Jason Gunthorpe:
 "Over the break a few defects were found, so this is a -rc style pull
  request of various small things that have been posted.

   - An attempt to shorten RCU grace period driven delays showed crashes
     during heavier testing, and has been entirely reverted

   - A missed merge/rebase error between the advise_mr and ib_device_ops
     series

   - Some small static analysis driven fixes from Julia and Aditya

   - Missed ability to create a XRC_INI in the devx verbs interop
     series"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  infiniband/qedr: Potential null ptr dereference of qp
  infiniband: bnxt_re: qplib: Check the return value of send_message
  IB/ipoib: drop useless LIST_HEAD
  IB/core: Add advise_mr to the list of known ops
  Revert "IB/mlx5: Fix long EEH recover time with NVMe offloads"
  IB/mlx5: Allow XRC INI usage via verbs in DEVX context

Pull fbdev updates from Bartlomiej Zolnierkiewicz:
 "This time the pull request is really small.

  The most notable changes are fixing fbcon to not cause crash on
  unregister_framebuffer() operation when there is more than one
  framebuffer, adding config option to center the bootup logo and making
  FB_BACKLIGHT config option tristate (which in turn uncovered incorrect
  FB_BACKLIGHT usage by DRM's nouveau driver).

  Summary:

   - fix fbcon to not cause crash on unregister_framebuffer() when there
     is more than one framebuffer (Noralf Trønnes)

   - improve support for small rotated displays (Peter Rosin)

   - fix probe failure handling in udlfb driver (Dan Carpenter)

   - add config option to center the bootup logo (Peter Rosin)

   - make FB_BACKLIGHT config option tristate (Rob Clark)

   - remove superfluous HAS_DMA dependency for goldfishfb driver (Geert
     Uytterhoeven)

   - misc fixes (Alexey Khoroshilov, YueHaibing, Colin Ian King, Lubomir
     Rintel)

   - misc cleanups (Yangtao Li, Wen Yang)

  also there is DRM's nouveau driver fix for wrong FB_BACKLIGHT config
  option usage (FB_BACKLIGHT is for internal fbdev subsystem use only)"

* tag 'fbdev-v4.21' of git://github.com/bzolnier/linux:
  drm/nouveau: fix incorrect FB_BACKLIGHT usage in Kconfig
  fbdev: fbcon: Fix unregister crash when more than one framebuffer
  fbdev: Remove depends on HAS_DMA in case of platform dependency
  pxa168fb: trivial typo fix
  fbdev: fsl-diu: remove redundant null check on cmap
  fbdev: omap2: omapfb: convert to DEFINE_SHOW_ATTRIBUTE
  fbdev: uvesafb: fix spelling mistake "memoery" -> "memory"
  fbdev: fbmem: add config option to center the bootup logo
  fbdev: fbmem: make fb_show_logo_line return the end instead of the height
  video: fbdev: pxafb: Fix "WARNING: invalid free of devm_ allocated data"
  fbdev: fbmem: behave better with small rotated displays and many CPUs
  video: clps711x-fb: release disp device node in probe()
  fbdev: make FB_BACKLIGHT a tristate
  udlfb: fix some inconsistent NULL checking

Pull i2c updates from Wolfram Sang:
 "I2C has only driver updates for you this time.

  Mostly new IDs/DT compatibles, also SPDX conversions, small cleanups.
  STM32F7 got FastMode+ and PM support, Axxia some reliabilty
  improvements"

* 'i2c/for-5.0' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (26 commits)
  i2c: Add Actions Semiconductor Owl family S700 I2C support
  dt-bindings: i2c: Add S700 support for Actions Semi Soc's
  i2c: ismt: Add support for Intel Cedar Fork
  i2c: tegra: Switch to SPDX identifier
  i2c: tegra: Add missing kerneldoc for some fields
  i2c: tegra: Cleanup kerneldoc comments
  i2c: axxia: support sequence command mode
  dt-bindings: i2c: rcar: Add r8a774c0 support
  dt-bindings: i2c: sh_mobile: Add r8a774c0 support
  i2c: sh_mobile: Add support for r8a774c0 (RZ/G2E)
  i2c: i2c-cros-ec-tunnel: Switch to SPDX identifier.
  i2c: powermac: Use of_node_name_eq for node name comparisons
  i2c-axxia: check for error conditions first
  i2c-axxia: dedicated function to set client addr
  dt-bindings: i2c: Use correct vendor prefix for Atmel
  i2c: tegra: replace spin_lock_irqsave with spin_lock in ISR
  eeprom: at24: add support for 24c2048
  dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string
  i2c: i2c-stm32f7: add PM Runtime support
  i2c: sh_mobile: add support for r8a77990 (R-Car E3)
  ...

Pull PCI updates from Bjorn Helgaas:

 - Remove unused lists from ASPM pcie_link_state (Frederick Lawler)

 - Fix Broadcom CNB20LE host bridge unintended sign extension (Colin Ian
   King)

 - Expand Kconfig "PF" acronyms (Randy Dunlap)

 - Update MAINTAINERS for arch/x86/kernel/early-quirks.c (Bjorn Helgaas)

 - Add missing include to drivers/pci.h (Alexandru Gagniuc)

 - Override Synopsys USB 3.x HAPS device class so dwc3-haps can claim it
   instead of xhci (Thinh Nguyen)

 - Clean up P2PDMA documentation (Randy Dunlap)

 - Allow runtime PM even if driver doesn't supply callbacks (Jarkko
   Nikula)

 - Remove status check after submitting Switchtec MRPC Firmware Download
   commands to avoid Completion Timeouts (Kelvin Cao)

 - Set Switchtec coherent DMA mask to allow 64-bit DMA (Boris Glimcher)

 - Fix Switchtec SWITCHTEC_IOCTL_EVENT_IDX_ALL flag overwrite issue
   (Joey Zhang)

 - Enable write combining for Switchtec MRPC Input buffers (Kelvin Cao)

 - Add Switchtec MRPC DMA mode support (Wesley Sheng)

 - Skip VF scanning on powerpc, which does this in firmware (Sebastian
   Ott)

 - Add Amlogic Meson PCIe controller driver and DT bindings (Yue Wang)

 - Constify histb dw_pcie_host_ops structure (Julia Lawall)

 - Support multiple power domains for imx6 (Leonard Crestez)

 - Constify layerscape driver data (Stefan Agner)

 - Update imx6 Kconfig to allow imx6 PCIe in imx7 kernel (Trent Piepho)

 - Support armada8k GPIO reset (Baruch Siach)

 - Support suspend/resume support on imx6 (Leonard Crestez)

 - Don't hard-code DesignWare DBI/ATU offst (Stephen Warren)

 - Skip i.MX6 PHY setup on i.MX7D (Andrey Smirnov)

 - Remove Jianguo Sun from HiSilicon STB maintainers (Lorenzo Pieralisi)

 - Mask DesignWare interrupts instead of disabling them to avoid lost
   interrupts (Marc Zyngier)

 - Add locking when acking DesignWare interrupts (Marc Zyngier)

 - Ack DesignWare interrupts in the proper callbacks (Marc Zyngier)

 - Use devm resource parser in mediatek (Honghui Zhang)

 - Remove unused mediatek "num-lanes" DT property (Honghui Zhang)

 - Add UniPhier PCIe controller driver and DT bindings (Kunihiko
   Hayashi)

 - Enable MSI for imx6 downstream components (Richard Zhu)

* tag 'pci-v4.21-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (40 commits)
  PCI: imx: Enable MSI from downstream components
  s390/pci: skip VF scanning
  PCI/IOV: Add flag so platforms can skip VF scanning
  PCI/IOV: Factor out sriov_add_vfs()
  PCI: uniphier: Add UniPhier PCIe host controller support
  dt-bindings: PCI: Add UniPhier PCIe host controller description
  PCI: amlogic: Add the Amlogic Meson PCIe controller driver
  dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller
  arm64: dts: mt7622: Remove un-used property for PCIe
  arm: dts: mt7623: Remove un-used property for PCIe
  dt-bindings: PCI: MediaTek: Remove un-used property
  PCI: mediatek: Remove un-used variant in struct mtk_pcie_port
  MAINTAINERS: Remove Jianguo Sun from HiSilicon STB DWC entry
  PCI: dwc: Don't hard-code DBI/ATU offset
  PCI: imx: Add imx6sx suspend/resume support
  PCI: armada8k: Add support for gpio controlled reset signal
  PCI: dwc: Adjust Kconfig to allow IMX6 PCIe host on IMX7
  PCI: dwc: layerscape: Constify driver data
  PCI: imx: Add multi-pd support
  PCI: Override Synopsys USB 3.x HAPS device class
  ...

Pull HID updates from Jiri Kosina:

 - high-resolution scrolling support that gracefully handles differences
   between MS and Logitech implementations in HW, from Peter Hutterer
   and Harry Cutts

 - MSI IRQ support for intel-ish driver, from Song Hongyan

 - support for new hardware (Cougar 700K, Odys Winbook 13, ASUS FX503VD,
   ASUS T101HA) from Daniel M. Lambea, Hans de Goede and Aleix Roca
   Nonell

 - other small assorted fixups

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (22 commits)
  HID: i2c-hid: Add Odys Winbook 13 to descriptor override
  HID: lenovo: Add checks to fix of_led_classdev_register
  HID: intel-ish-hid: add MSI interrupt support
  HID: debug: Change to use DEFINE_SHOW_ATTRIBUTE macro
  HID: doc: fix wrong data structure reference for UHID_OUTPUT
  HID: intel-ish-hid: fixes incorrect error handling
  HID: asus: Add support for the ASUS T101HA keyboard dock
  HID: logitech: Use LDJ_DEVICE macro for existing Logitech mice
  HID: logitech: Enable high-resolution scrolling on Logitech mice
  HID: logitech: Add function to enable HID++ 1.0 "scrolling acceleration"
  HID: logitech-hidpp: fix typo, hiddpp to hidpp
  HID: input: use the Resolution Multiplier for high-resolution scrolling
  HID: core: process the Resolution Multiplier
  HID: core: store the collections as a basic tree
  Input: add `REL_WHEEL_HI_RES` and `REL_HWHEEL_HI_RES`
  HID: input: support Microsoft wireless radio control hotkey
  HID: use macros in IS_INPUT_APPLICATION
  HID: asus: Add support for the ASUS FX503VD laptop
  HID: asus: Add event handler to catch unmapped Asus Vendor UsagePage codes
  HID: cougar: Add support for Cougar 700K Gaming Keyboard
  ...

Pull livepatch update from Jiri Kosina:
 "Return value checking fixup in livepatching samples, from Nicholas Mc
  Guire"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: check kzalloc return values

Pull thermal management updates from Zhang Rui:

 - Add locking for cooling device sysfs attribute in case the cooling
   device state is changed by userspace and thermal framework
   simultaneously. (Thara Gopinath)

 - Fix a problem that passive cooling is reset improperly after system
   suspend/resume. (Wei Wang)

 - Cleanup the driver/thermal/ directory by moving intel and qcom
   platform specific drivers to platform specific sub-directories. (Amit
   Kucheria)

 - Some trivial cleanups. (Lukasz Luba, Wolfram Sang)

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal/intel: fixup for Kconfig string parsing tightening up
  drivers: thermal: Move QCOM_SPMI_TEMP_ALARM into the qcom subdir
  drivers: thermal: Move various drivers for intel platforms into a subdir
  thermal: Fix locking in cooling device sysfs update cur_state
  Thermal: do not clear passive state during system sleep
  thermal: zx2967_thermal: simplify getting .driver_data
  thermal: st: st_thermal: simplify getting .driver_data
  thermal: spear_thermal: simplify getting .driver_data
  thermal: rockchip_thermal: simplify getting .driver_data
  thermal: int340x_thermal: int3400_thermal: simplify getting .driver_data
  thermal: remove unused function parameter

Pull thermal SoC updates from Eduardo Valentin:

 - Tegra DT binding documentation for Tegra194

 - Armada now supports ap806 and cp110

 - RCAR thermal now supports R8A774C0 and R8A77990

 - Fixes on thermal_hwmon, IMX, generic-ADC, ST, RCAR, Broadcom,
   Uniphier, QCOM, Tegra, PowerClamp, and Armada thermal drivers.

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal: (22 commits)
  thermal: generic-adc: Fix adc to temp interpolation
  thermal: rcar_thermal: add R8A77990 support
  dt-bindings: thermal: rcar-thermal: add R8A77990 support
  thermal: rcar_thermal: add R8A774C0 support
  dt-bindings: thermal: rcar-thermal: add R8A774C0 support
  dt-bindings: cp110: document the thermal interrupt capabilities
  dt-bindings: ap806: document the thermal interrupt capabilities
  MAINTAINERS: thermal: add entry for Marvell MVEBU thermal driver
  thermal: armada: add overheat interrupt support
  thermal: st: fix Makefile typo
  thermal: uniphier: Convert to SPDX identifier
  thermal/intel_powerclamp: Change to use DEFINE_SHOW_ATTRIBUTE macro
  thermal: tegra: soctherm: Change to use DEFINE_SHOW_ATTRIBUTE macro
  dt-bindings: thermal: tegra-bpmp: Add Tegra194 support
  thermal: imx: save one condition block for normal case of nvmem initialization
  thermal: imx: fix for dependency on cpu-freq
  thermal: tsens: qcom: do not create duplicate regmap debugfs entries
  thermal: armada: Use PTR_ERR_OR_ZERO in armada_thermal_probe_legacy()
  dt-bindings: thermal: rcar-gen3-thermal: All variants use 3 interrupts
  thermal: broadcom: use devm_thermal_zone_of_sensor_register
  ...

Pull ftrace sh build fix from Steven Rostedt:
 "It appears that the zero-day bot did find a bug in my sh build.

  And that I didn't have the bad code in my config file when I cross
  compiled it, although there are a few other errors in sh that makes it
  not build for me, I missed that I added one more"

* tag 'trace-v4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  sh: ftrace: Fix missing parenthesis in WARN_ON()

Pull smb3 fixes from Steve French:
 "Three fixes, one for stable, one adds the (most secure) SMB3.1.1
  dialect to default list requested"

* tag '4.21-smb3-small-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: add smb3.1.1 to default dialect list
  cifs: fix confusing warning message on reconnect
  smb3: fix large reads on encrypted connections

Pull iomap maintainer update from Darrick Wong:
 "Christoph Hellwig and I have decided to take responsibility for the fs
  iomap code rather than let it languish further"

* tag 'iomap-4.21-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: take responsibility for the filesystem iomap code

Pull xfs fixlets from Darrick Wong:
 "Remove a couple of unnecessary local variables"

* tag 'xfs-4.21-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: xfs_fsops: drop useless LIST_HEAD
  xfs: xfs_buf: drop useless LIST_HEAD

Pull ceph updates from Ilya Dryomov:
 "A fairly quiet round: a couple of messenger performance improvements
  from myself and a few cap handling fixes from Zheng"

* tag 'ceph-for-4.21-rc1' of git://github.com/ceph/ceph-client:
  ceph: don't encode inode pathes into reconnect message
  ceph: update wanted caps after resuming stale session
  ceph: skip updating 'wanted' caps if caps are already issued
  ceph: don't request excl caps when mount is readonly
  ceph: don't update importing cap's mseq when handing cap export
  libceph: switch more to bool in ceph_tcp_sendmsg()
  libceph: use MSG_SENDPAGE_NOTLAST with ceph_tcp_sendpage()
  libceph: use sock_no_sendpage() as a fallback in ceph_tcp_sendpage()
  libceph: drop last_piece logic from write_partial_message_data()
  ceph: remove redundant assignment
  ceph: cleanup splice_dentry()

Fixes build break on most ARM/ARM64 defconfigs:

  lib/genalloc.c: In function 'gen_pool_add_virt':
  lib/genalloc.c:190:10: error: implicit declaration of function 'vzalloc_node'; did you mean 'kzalloc_node'?
  lib/genalloc.c:190:8: warning: assignment to 'struct gen_pool_chunk *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
  lib/genalloc.c: In function 'gen_pool_destroy':
  lib/genalloc.c:254:3: error: implicit declaration of function 'vfree'; did you mean 'kfree'?

Fixes: 6862d2fc

 ('lib/genalloc.c: use vzalloc_node() to allocate the bitmap')
Cc: Huang Shijie <sjhuang@iluvatar.ai>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Skidanov <alexey.skidanov@intel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: ->sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_ge...

Pull trivial vfs updates from Al Viro:
 "A few cleanups + Neil's namespace_unlock() optimization"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  exec: make prepare_bprm_creds static
  genheaders: %-<width>s had been there since v6; %-*s - since v7
  VFS: use synchronize_rcu_expedited() in namespace_unlock()
  iov_iter: reduce code duplication

Pull MIPS fixes from Paul Burton:
 "A few early MIPS fixes for 4.21:

   - The Broadcom BCM63xx platform sees a fix for resetting the BCM6368
     ethernet switch, and the removal of a platform device we've never
     had a driver for.

   - The Alchemy platform sees a few fixes for bitrot that occurred
     within the past few cycles.

   - We now enable vectored interrupt support for the MediaTek MT7620
     SoC, which makes sense since they're supported by the SoC but in
     this case also works around a bug relating to the location of
     exception vectors when using a recent version of U-Boot.

   - The atomic64_fetch_*_relaxed() family of functions see a fix for a
     regression in MIPS64 kernels since v4.19.

   - Cavium Octeon III CN7xxx systems will now disable their RGMII
     interfaces rather than attempt to enable them & warn about the lack
     of support for doing so, as they did since initial CN7xx...

Pull powerpc fixes from Michael Ellerman:
 "A fix for the recent access_ok() change, which broke the build. We
  recently added a use of type in order to squash a warning elsewhere
  about type being unused.

  A handful of other minor build fixes, and one defconfig update.

  Thanks to: Christian Lamparter, Christophe Leroy, Diana Craciun,
  Mathieu Malaterre"

* tag 'powerpc-4.21-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Drop use of 'type' from access_ok()
  KVM: PPC: Book3S HV: radix: Fix uninitialized var build error
  powerpc/configs: Add PPC4xx_OCM to ppc40x_defconfig
  powerpc/4xx/ocm: Fix phys_addr_t printf warnings
  powerpc/4xx/ocm: Fix compilation error due to PAGE_KERNEL usage
  powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'

Pull parisc fix from Helge Deller:
 "Fix boot issues with a series of parisc servers since kernel 4.20.

  Remapping kernel text with set_kernel_text_rw() missed to remap from
  lowest up until the highest huge-page aligned kernel text addresss"

* 'parisc-4.21-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Remap hugepage-aligned pages in set_kernel_text_rw()

Pull h8300 fix from Yoshinori Sato:
 "Build problem fix"

* tag 'for-4.21' of git://git.sourceforge.jp/gitroot/uclinux-h8/linux:
  h8300: pci: Remove local declaration of pcibios_penalize_isa_irq

Pull more ARM SoC updates from Olof Johansson:
 "A few updates that we merged late but are low risk for regressions for
  other platforms (and a few other straggling patches):

   - I mis-tagged the 'drivers' branch, and missed 3 patches. Merged in
     here. They're for a driver for the PL353 SRAM controller and a
     build fix for the qualcomm scm driver.

   - A new platform, RDA Micro RDA8810PL (Cortex-A5 w/ integrated
     Vivante GPU, 256MB RAM, Wifi). This includes some acked
     platform-specific drivers (serial, etc). This also include DTs for
     two boards with this SoC, OrangePi 2G and OrangePi i86.

   - i.MX8 is another new platform (NXP, 4x Cortex-A53 + Cortex-M4, 4K
     video playback offload). This is the first i.MX 64-bit SoC.

   - Some minor updates to Samsung boards (adding a few peripherals in
     DTs).

   - Small rework for SMP bootup on STi platforms.

   - A couple of TEE driver fixes.

   - A couple of new config options (bcm2835 thermal, Uniphier MDMAC)
     enabled in defconfigs"

* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (27 commits)
  ARM: multi_v7_defconfig: enable CONFIG_UNIPHIER_MDMAC
  arm64: defconfig: Re-enable bcm2835-thermal driver
  MAINTAINERS: Add entry for RDA Micro SoC architecture
  tty: serial: Add RDA8810PL UART driver
  ARM: dts: rda8810pl: Add interrupt support for UART
  dt-bindings: serial: Document RDA Micro UART
  ARM: dts: rda8810pl: Add timer support
  ARM: dts: Add devicetree for OrangePi i96 board
  ARM: dts: Add devicetree for OrangePi 2G IoT board
  ARM: dts: Add devicetree for RDA8810PL SoC
  ARM: Prepare RDA8810PL SoC
  dt-bindings: arm: Document RDA8810PL and reference boards
  dt-bindings: Add RDA Micro vendor prefix
  ARM: sti: remove pen_release and boot_lock
  arm64: dts: exynos: Add Bluetooth chip to TM2(e) boards
  arm64: dts: imx8mq-evk: enable watchdog
  arm64: dts: imx8mq: add watchdog devices
  MAINTAINERS: add i.MX8 DT path to i.MX architecture
  arm64: add support for i.MX8M EVK board
  arm64: add basic DTS for i.MX8MQ
  ...

Pull arm64 fixes from Will Deacon:
 "I'm safely chained back up to my desk, so please pull these arm64
  fixes for -rc1 that address some issues that cropped up during the
  merge window:

   - Prevent KASLR from mapping the top page of the virtual address
     space

   - Fix device-tree probing of SDEI driver

   - Fix incorrect register offset definition in Hisilicon DDRC PMU
     driver

   - Fix compilation issue with older binutils not liking unsigned
     immediates

   - Fix uapi headers so that libc can provide its own sigcontext
     definition

   - Fix handling of private compat syscalls

   - Hook up compat io_pgetevents() syscall for 32-bit tasks

   - Cleanup to arm64 Makefile (including now to avoid silly conflicts)"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: compat: Hook up io_pgetevents() for 32-bit tasks
  arm64: compat: Don't pull syscall number from regs in arm_compat_syscall
  arm64: compat: Avoid sending SIGILL for unallocated syscall numbers
  arm64/sve: Disentangle <uapi/asm/ptrace.h> from <uapi/asm/sigcontext.h>
  arm64/sve: ptrace: Fix SVE_PT_REGS_OFFSET definition
  drivers/perf: hisi: Fixup one DDRC PMU register offset
  arm64: replace arm64-obj-* in Makefile with obj-*
  arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region
  firmware: arm_sdei: Fix DT platform device creation
  firmware: arm_sdei: fix wrong of_node_put() in init function
  arm64: entry: remove unused register aliases
  arm64: smp: Fix compilation error

Pull ARM updates from Russell King:
 "Included in this update:

   - Florian Fainelli noticed that userspace segfaults caused by the
     lack of kernel-userspace helpers was hard to diagnose; we now issue
     a warning when userspace tries to use the helpers but the kernel
     has them disabled.

   - Ben Dooks wants compatibility for the old ATAG serial number with
     DT systems.

   - Some cleanup of assembly by Nicolas Pitre.

   - User accessors optimisation from Vincent Whitchurch.

   - More robust kdump on SMP systems from Yufen Wang.

   - Sebastian Andrzej Siewior noticed problems with the SMP "boot_lock"
     on RT kernels, and so we convert the Versatile series of platforms
     to use a raw spinlock instead, consolidating the Versatile
     implementation. We entirely remove the boot_lock on OMAP systems,
     where it's unnecessary. Further patches for other systems will be
     submitted for the following merge window.

  ...

Pull arch/csky updates from Guo Ren:
 "Here are three main features (cpu_hotplug, basic ftrace, basic perf)
  and some bugfixes:

  Features:
   - Add CPU-hotplug support for SMP
   - Add ftrace with function trace and function graph trace
   - Add Perf support
   - Add EM_CSKY_OLD 39
   - optimize kernel panic print.
   - remove syscall_exit_work

  Bugfixes:
   - fix abiv2 mmap(... O_SYNC) failure
   - fix gdb coredump error
   - remove vdsp implement for kernel
   - fix qemu failure to bootup sometimes
   - fix ftrace call-graph panic
   - fix device tree node reference leak
   - remove meaningless header-y
   - fix save hi,lo,dspcr regs in switch_stack
   - remove unused members in processor.h"

* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
  csky: Add perf support for C-SKY
  csky: Add EM_CSKY_OLD 39
  clocksource/drivers/c-sky: fixup ftrace call-graph panic
  csky: ftrace call graph supported.
  csky: basic ftrace supported
  csky: remove unused members in processor.h
  csky: optimize kernel panic print.
  csky: stacktrace supported.
  csky: CPU-hotplug supported for SMP
  clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
  csky: fixup save hi,lo,dspcr regs in switch_stack.
  csky: remove syscall_exit_work
  csky: fixup remove vdsp implement for kernel.
  csky: bugfix gdb coredump error.
  csky: fixup abiv2 mmap(... O_SYNC) failed.
  csky: define syscall_get_arch()
  elf-em.h: add EM_CSKY
  csky: remove meaningless header-y
  csky: Don't leak device tree node reference

Merge more updates from Andrew Morton:

 - procfs updates

 - various misc bits

 - lib/ updates

 - epoll updates

 - autofs

 - fatfs

 - a few more MM bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
  mm/page_io.c: fix polled swap page in
  checkpatch: add Co-developed-by to signature tags
  docs: fix Co-Developed-by docs
  drivers/base/platform.c: kmemleak ignore a known leak
  fs: don't open code lru_to_page()
  fs/: remove caller signal_pending branch predictions
  mm/: remove caller signal_pending branch predictions
  arch/arc/mm/fault.c: remove caller signal_pending_branch predictions
  kernel/sched/: remove caller signal_pending branch predictions
  kernel/locking/mutex.c: remove caller signal_pending branch predictions
  mm: select HAVE_MOVE_PMD on x86 for faster mremap
  mm: speed up mremap by 20x on large regions
  mm: treewide: remove unused address argument from pte_alloc functions
  initramfs: cleanup incomplete ...

We need to return a dma_addr_t even if we don't have a kernel mapping.
Do so by consolidating the phys_to_dma call in a single place and jump
to it from all the branches that return successfully.

Fixes: bfd56cd6

 ("dma-mapping: support highmem in the generic remap allocator")
Reported-by: Liviu Dudau <liviu@dudau.co.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Liviu Dudau <liviu@dudau.co.uk>

In many cases we don't have to create a GART mapping at all, which
also means there is nothing to unmap.  Fix the range check that was
incorrectly modified when removing the mapping_error method.

Fixes: 9e8aa6b5

 ("x86/amd_gart: remove the mapping_error dma_map_ops method")
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Michal Kubecek <mkubecek@suse.cz>

Some non-generic ia64 configs don't build swiotlb, and thus should not
pull in the generic non-coherent DMA infrastructure.

Fixes: 68c60834

 ("swiotlb: remove dma_mark_clean")
Reported-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This has been broken forever, and nobody ever really noticed because
it's purely a performance issue.

Long long ago, in commit 6175ddf0 ("x86: Clean up mem*io functions")
Brian Gerst simplified the memory copies to and from iomem, since on
x86, the instructions to access iomem are exactly the same as the
regular instructions.

That is technically true, and things worked, and nobody said anything.
Besides, back then the regular memcpy was pretty simple and worked fine.

Nobody noticed except for David Laight, that is.  David has a testing a
TLP monitor he was writing for an FPGA, and has been occasionally
complaining about how memcpy_toio() writes things one byte at a time.

Which is completely unacceptable from a performance standpoint, even if
it happens to technically work.

The reason it's writing one byte at a time is because while it's
technically true that accesses to iomem are the same as accesses to
regular memory on x86, the _granularity_ (and ordering) of accesses
matter to iomem in ways that they don't matter to regular cached memory.

In particular, when ERMS is set, we default to using "rep movsb" for
larger memory copies.  That is indeed perfectly fine for real memory,
since the whole point is that the CPU is going to do cacheline
optimizations and executes the memory copy efficiently for cached
memory.

With iomem? Not so much.  With iomem, "rep movsb" will indeed work, but
it will copy things one byte at a time. Slowly and ponderously.

Now, originally, back in 2010 when commit 6175ddf0

 was done, we
didn't use ERMS, and this was much less noticeable.

Our normal memcpy() was simpler in other ways too.

Because in fact, it's not just about using the string instructions.  Our
memcpy() these days does things like "read and write overlapping values"
to handle the last bytes of the copy.  Again, for normal memory,
overlapping accesses isn't an issue.  For iomem? It can be.

So this re-introduces the specialized memcpy_toio(), memcpy_fromio() and
memset_io() functions.  It doesn't particularly optimize them, but it
tries to at least not be horrid, or do overlapping accesses.  In fact,
this uses the existing __inline_memcpy() function that we still had
lying around that uses our very traditional "rep movsl" loop followed by
movsw/movsb for the final bytes.

Somebody may decide to try to improve on it, but if we've gone almost a
decade with only one person really ever noticing and complaining, maybe
it's not worth worrying about further, once it's not _completely_ broken?

Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>