syzbot reports the following hang:

INFO: task syz-executor.0:12538 can't die for more than 143 seconds.
task:syz-executor.0  state:D stack:28352 pid:12538 ppid:  8423 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4324 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5075
 schedule+0xcf/0x270 kernel/sched/core.c:5154
 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x168/0x270 kernel/sched/completion.c:138
 io_sq_thread_finish+0x96/0x580 fs/io_uring.c:7152
 io_sq_offload_create fs/io_uring.c:7929 [inline]
 io_uring_create fs/io_uring.c:9465 [inline]
 io_uring_setup+0x1fb2/0x2c20 fs/io_uring.c:9550
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

which is due to exiting after the SQPOLL thread has been created, but
hasn't been started yet. Ensure that we always complete the startup
side when waiting for it to exit.

Reported-by: syzbot+c927c937cba8ef66dd4a@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Before the io-wq thread change, we maintained a hash work map and lock
per-node per-ring. That wasn't ideal, as we really wanted it to be per
ring. But now that we have per-task workers, the hash map ends up being
just per-task. That'll work just fine for the normal case of having
one task use a ring, but if you share the ring between tasks, then it's
considerably worse than it was before.

Make the hash map per ctx instead, which provides full per-ctx buffered
write serialization on hashed writes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There's a small window between lookup dropping the reference to the
worker and calling wake_up_process() on the worker task, where the worker
itself could have exited. We ensure that the worker struct itself is
valid, but worker->task may very well be gone by the time we issue the
wakeup.

Fix the race by using a completion triggered by the reference going to
zero, and having exit wait for that completion before proceeding.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

These races have always been there, they are just more apparent now that
we do early cancel of io-wq when the task exits.

Ensure that the io-wq manager sets task state correctly to not miss
wakeups for task creation. This is important if we get a wakeup after
having marked ourselves as TASK_INTERRUPTIBLE. If we do end up creating
workers, then we flip the state back to running, making the subsequent
schedule() a no-op. Also increment the wq ref count before forking the
thread, to avoid a use-after-free.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

If the task ends up doing no IO, the context list is empty and we don't
call into __io_uring_files_cancel() when the task exits. This can cause
a leak of the io-wq structures.

Ensure we always call __io_uring_files_cancel(), even if the task
context list is empty.

Fixes: 5aa75ed5 ("io_uring: tie async worker side to the task context")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In the arch addition of PF_IO_WORKER, I missed parisc and powerpc for
some reason. Fix that up, ensuring they handle PF_IO_WORKER like they do
PF_KTHREAD in copy_thread().
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Fixes: 4727dc20 ("arch: setup PF_IO_WORKER threads like PF_KTHREAD")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

At this point we're only using it for memory accounting, so there's no
need to have an extra ->limit_mem - we can just set ->user if we do
the accounting, or leave it at NULL if we don't.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We're now just using fork like we would from userspace, so there's no
need to try and impose extra restrictions or accounting on the user
side of things. That's already being done for us. That also means we
don't have to pass in the user_struct anymore, that's correctly inherited
through ->creds on fork.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

A few reasons to do this:

- The naming of the manager and worker have changed. That's a user visible
  change, so makes sense to flag it.

- Opening certain files that use ->signal (like /proc/self or /dev/tty)
  now works, and the flag tells the application upfront that this is the
  case.

- Related to the above, using signalfd will now work as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

No need to restrict these anymore, as the worker threads are direct
clones of the original task. Hence we know for a fact that we can
support anything that the regular task can.

Since the only user of proto_ops->flags was to flag PROTO_CMSG_DATA_ONLY,
kill the member and the flag definition too.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 8d4c3e76.

No longer needed, as the io-wq worker threads have the right identity.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 0d4370cf.

No longer needed, as the io-wq worker threads have the right identity.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Don't use a kthread for SQPOLL, use a forked worker just like the io-wq
workers. With that done, we can drop the various context grabbing we do
for SQPOLL, it already has everything it needs.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We want to use this in io_uring proper as well, for the SQPOLL thread.
Rename it from fork_thread() to io_wq_fork_thread(), and make it
available through the io-wq.h header.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

If the worker isn't on the free_list, don't attempt to delete it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We are no longer grabbing state, so no need to maintain an IO identity
that we COW if there are changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The async workers are siblings of the task itself, so by definition we
have all the state that we need. Remove any of the state grabbing that
we have, and requests flagging what they need.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Remove the bool return, and the checking for it in the caller.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Instead of using regular kthread kernel threads, create kernel threads
that are like a real thread that the task would create. This ensures that
we get all the context that we need, without having to carry that state
around. This greatly reduces the code complexity, and the risk of missing
state for a given request type.

With the move away from kthread, we can also dump everything related to
assigned state to the new threads.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Jens Axboe <axboe@kernel.dk>

PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Just grab it from the worker itself, which we're already passing in.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Move it outside of the io_ring_ctx, and tie it to the io_uring task
context.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We don't support attach anymore, so doesn't make sense to carry the
use_refs reference count. Get rid of it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Moving towards making the io_wq per ring per task, so we can't really
share it between rings. Which is fine, since we've now dropped some
of that fat from it.

Retain compatibility with how attaching works, so that any attempt to
attach to an fd that doesn't exist, or isn't an io_uring fd, will fail
like it did before.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When the manager thread starts up, it creates a worker per node for
the given context. Just let these get created dynamically, like we do
for adding further workers.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We hit this case when the task is exiting, and we need somewhere to
do background cleanup of requests. Instead of relying on the io-wq
task manager to do this work for us, just stuff it somewhere where
we can safely run it ourselves directly.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

* for-5.12/io_uring: (21 commits)
  io_uring: run task_work on io_uring_register()
  io_uring: fix leaving invalid req->flags
  io_uring: wait potential ->release() on resurrect
  io_uring: keep generic rsrc infra generic
  io_uring: zero ref_node after killing it
  io_uring: make the !CONFIG_NET helpers a bit more robust
  io_uring: don't hold uring_lock when calling io_run_task_work*
  io_uring: fail io-wq submission from a task_work
  io_uring: don't take uring_lock during iowq cancel
  io_uring: fail links more in io_submit_sqe()
  io_uring: don't do async setup for links' heads
  io_uring: do io_*_prep() early in io_submit_sqe()
  io_uring: split sqe-prep and async setup
  io_uring: don't submit link on error
  io_uring: move req link into submit_state
  io_uring: move io_init_req() into io_submit_sqe()
  io_uring: move io_init_req()'s definition
  io_uring: don't duplicate ->file check in sfr
  io_uring: keep io_*_prep() naming consistent
  io_uring: kill fictitious submit iteration index
  ...

Do run task_work before io_uring_register(), that might make a first
quiesce round much nicer. We generally do that for any syscall invocation
to avoid spurious -EINTR/-ERESTARTSYS, for task_work that we generate.
This patch brings io_uring_register() inline with the two other io_uring
syscalls.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull drm updates from Dave Airlie:
 "A pretty normal tree, lots of refactoring across the board, ttm, i915,
  nouveau, and bunch of features in various drivers.

  docs:
   - lots of updated docs

  core:
   - require crtc to have unique primary plane
   - fourcc macro fix
   - PCI bar quirk for bar resizing
   - don't sent hotplug on error
   - move vm code to legacy
   - nuke hose only used on old oboslete alpha

  dma-buf:
   - kernel doc updates
   - improved lock tracking

  dp/hdmi:
   - DP-HDMI2.1 protocol converter support

  ttm:
   - bo size handling cleanup
   - release a pinned bo warning
   - cleanup lru handler
   - avoid using pages with drm_prime_sg_to_page_addr_arrays

  cma-helper:
   - prime/mmap fixes

  bridge:
   - add DP support

  gma500:
   - remove gma3600 support

  i915:
   - try eDP fast/narrow link again with fallback
   - Intel eDP backlight control
   - replace display register read/write macros
   - refactor intel_display.c
   - display power improvements
   - HPD code cleanup
   - Rocketlake display fixes
   - Power/backlight/RPM fixes
   - DG1 display fix
   - IVB/BYT clear residuals security fix again
   - make i915 mitigations options via parameter
   - HSW GT1 GPU hangs fixes
   - DG1 workaround hang fixes
   - TGL DMAR hang avoidance
   - Lots of GT fixes
   - follow on fixes for residuals clear
   - gen7 per-engine-reset support
   - HDCP2.2 + HDCP1.4 GEN12 DP MST support
   - TGL clear color support
   - backlight refactoring
   - VRR/Adaptive sync enabling on DP/EDP for TGL+
   - async flips for all ilk+

  amdgpu:
   - rework IH ring handling (Vega/Navi)
   - rework HDP handling (Vega/Navi)
   - swSMU updates for renoir/vangogh
   - Sienna Cichild overdrive support
   - FP16 on DCE8-11 support
   - GPU reset on navy flounder/vangogh
   - SMU profile fixes for APU
   - SR-IOV fixes
   - Vangogh SMU fixes
   - fan speed control fixes

  amdkfd:
   - config handling fix
   - buffer free fix
   - recursive lock warnings fix

  nouveau:
   - Turing MMU fault recovery fixes
   - mDP connectors reporting fix
   - audio locking fixes
   - rework engines/instances code to support new scheme

  tegra:
   - VIC newer firmware support
   - display/gr2d fixes for older tegra
   - pm reference leak fix

  mediatek:
   - SOC MT8183 support
   - decouple sub driver + share mtk mutex driver

  radeon:
   - PCI resource fix for some platforms

  ingenic:
   - pm support
   - 8-bit delta RGB panels

  vmwgfx:
   - managed driver helpers

  vc4:
   - BCM2711 DSI1 support
   - converted to atomic helpers
   - enable 10/12 bpc outputs
   - gem prime mmap helpers
   - CEC fix

  omap:
   - use degamma table
   - CTM support
   - rework DSI support

  imx:
   - stack usage fixes
   - drm managed support
   - imx-tve clock provider leak fix
-

  rcar-du:
   - default mode fixes
   - conversion to managed API

  hisilicon:
   - use simple encoder

  vkms:
   - writeback connector support

  d3:
   - BT2020 support"

* tag 'drm-next-2021-02-19' of git://anongit.freedesktop.org/drm/drm: (1459 commits)
  drm/amdgpu: Set reference clock to 100Mhz on Renoir (v2)
  drm/radeon: OLAND boards don't have VCE
  drm/amdkfd: Fix recursive lock warnings
  drm/amd/display: Add FPU wrappers to dcn21_validate_bandwidth()
  drm/amd/display: Fix potential integer overflow
  drm/amdgpu/display: remove hdcp_srm sysfs on device removal
  drm/amdgpu: fix CGTS_TCC_DISABLE register offset on gfx10.3
  drm/i915/gt: Correct surface base address for renderclear
  drm/i915: Disallow plane x+w>stride on ilk+ with X-tiling
  drm/nouveau/top/ga100: initial support
  drm/nouveau/top: add ioctrl/nvjpg
  drm/nouveau/privring: rename from ibus
  drm/nouveau/nvkm: remove nvkm_subdev.index
  drm/nouveau/nvkm: determine subdev id/order from layout
  drm/nouveau/vic: switch to instanced constructor
  drm/nouveau/sw: switch to instanced constructor
  drm/nouveau/sec2: switch to instanced constructor
  drm/nouveau/sec: switch to instanced constructor
  drm/nouveau/pm: switch to instanced constructor
  drm/nouveau/nvenc: switch to instanced constructor
  ...

Pull sound updates from Takashi Iwai:
 "A relatively calm release at this time, and no massive code changes
  are found in the stats, while a wide range of code refactoring and
  cleanup have been done.

  Note that this update includes the tree-wide trivial changes for
  dropping the return value from ISA remove callbacks, too.

  Below lists up some highlight:

  ALSA Core:
   - Support for the software jack injection via debugfs
   - Fixes for sync_stop PCM operations

  HD-audio and USB-audio:
   - A few usual HD-audio device quirks
   - Updates for Tegra HD-audio
   - More quirks for Pioneer and other USB-audio devices
   - Stricter state checks at USB-audio disconnection

  ASoC:
   - Continued code refactoring, cleanup and fixes in ASoC core API
   - A KUnit testsuite for the topology code
   - Lots of ASoC Intel driver Realtek codec updates, quirk additions
     and fixes
   - Support for Ingenic JZ4760(B), Intel AlderLake-P, DT configured
     nVidia cards, Qualcomm lpass-rx-macro and lpass-tx-macro
   - Removal of obsolete SIRF prima/atlas, Txx9 and ZTE zx drivers

  Others:
   - Drop return value from ISA driver remove callback
   - Cleanup with DIV_ROUND_UP() macro
   - FireWire updates, HDSP output loopback support"

* tag 'sound-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (322 commits)
  ALSA: hda: intel-dsp-config: add Alder Lake support
  ASoC: soc-pcm: fix hw param limits calculation for multi-DAI
  ASoC: Intel: bytcr_rt5640: Add quirk for the Acer One S1002 tablet
  ASoC: Intel: bytcr_rt5651: Add quirk for the Jumper EZpad 7 tablet
  ASoC: Intel: bytcr_rt5640: Add quirk for the Voyo Winpad A15 tablet
  ASoC: Intel: bytcr_rt5640: Add quirk for the Estar Beauty HD MID 7316R tablet
  ASoC: soc-pcm: fix hwparams min/max init for dpcm
  ALSA: hda/realtek: Quirk for HP Spectre x360 14 amp setup
  ALSA: usb-audio: Add implicit fb quirk for BOSS GP-10
  ALSA: hda: Add another CometLake-H PCI ID
  ASoC: soc-pcm: add soc_pcm_hw_update_format()
  ASoC: soc-pcm: add soc_pcm_hw_update_chan()
  ASoC: soc-pcm: add soc_pcm_hw_update_rate()
  ASoC: wm_adsp: Remove unused control callback structure
  ASoC: SOF: relax ABI checks and avoid unnecessary warnings
  ASoC: codecs: lpass-tx-macro: add dapm widgets and route
  ASoC: codecs: lpass-tx-macro: add support for lpass tx macro
  ASoC: qcom: dt-bindings: add bindings for lpass tx macro codec
  ASoC: codecs: lpass-rx-macro: add iir widgets
  ASoC: codecs: lpass-rx-macro: add dapm widgets and route
  ...

Pull media updates from Mauro Carvalho Chehab:

 - some core fixes in VB2 mem2mem support

 - some improvements and cleanups in V4L2 async kAPI

 - newer controls in V4L2 API for H-264 and HEVC codecs

 - allegro-dvt driver was promoted from staging

 - new i2c sendor drivers: imx334, ov5648, ov8865

 - new automobile camera module: rdacm21

 - ipu3 cio2 driver started gained support for some ACPI BIOSes

 - new ATSC frontend: MaxLinear mxl692 VSB tuner/demod

 - the SMIA/CCS driver gained more support for CSS standard

 - several driver fixes, updates and improvements

* tag 'media/v5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (362 commits)
  media: v4l: async: Fix kerneldoc documentation for async functions
  media: i2c: max9271: Add MODULE_* macros
  media: i2c: Kconfig: Make MAX9271 a module
  media: imx334: 'ret' is uninitialized, should have been PTR_ERR()
  media: i2c: Add imx334 camera sensor driver
  media: dt-bindings: media: Add bindings for imx334
  media: ov8856: Configure sensor for GRBG Bayer for all modes
  media: i2c: imx219: Implement V4L2_CID_LINK_FREQ control
  media: ov5675: fix vflip/hflip control
  media: ipu3-cio2: Build bridge only if ACPI is enabled
  media: Remove the legacy v4l2-clk API
  media: ov6650: Use the generic clock framework
  media: mt9m111: Use the generic clock framework
  media: ov9640: Use the generic clock framework
  media: pxa_camera: Drop the v4l2-clk clock register
  media: mach-pxa: Register the camera sensor fixed-rate clock
  media: i2c: imx258: get clock from device properties and enable it via runtime PM
  media: i2c: imx258: simplify getting state container
  media: i2c: imx258: add support for binding via device tree
  media: dt-bindings: media: imx258: add bindings for IMX258 sensor
  ...

Pull JFFS2/UBIFS and UBI updates from Richard Weinberger:
 "JFFS2:
   - Fix for use-after-free in jffs2_sum_write_data()
   - Fix for out-of-bounds access in jffs2_zlib_compress()

  UBI:
   - Remove dead/useless code

  UBIFS:
   - Fix for a memory leak in ubifs_init_authentication()
   - Fix for high stack usage
   - Fix for a off-by-one error in xattrs code"

* tag 'for-linus-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubifs: Fix error return code in alloc_wbufs()
  jffs2: check the validity of dstlen in jffs2_zlib_compress()
  ubifs: Fix off-by-one error
  ubifs: replay: Fix high stack usage, again
  ubifs: Fix memleak in ubifs_init_authentication
  jffs2: fix use after free in jffs2_sum_write_data()
  ubi: eba: Delete useless kfree code
  ubi: remove dead code in validate_vid_hdr()

Pull MTD updates from Richard Weinberger:
 "MTD core changes:
   - Initial support for BCM4908 partitions

  Raw NAND controller drivers:
   - Intel: Fix an error handling path in 'ebu_dma_start()'
   - Tango: Remove the driver
   - Marvell: Convert comma to semicolon
   - MXC: Convert comma to semicolon
   - Qcom: Add support for Qcom SMEM parser

  Related MTD changes:
   - parsers: Add Qcom SMEM parser

  SPI NOR core changes:
   - Add non-uniform erase fixes.
   - Add Global Block Unlock command. It is defined by few flash
     vendors, and it is used for now just by sst.

  SPI NOR controller drivers changes:
   - intel-spi: Add support for Intel Alder Lake-P SPI serial flash.
   - hisi-sfc: Put child node np on error path"

* tag 'mtd/for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: (23 commits)
  dt-bindings: mtd: add binding for BCM4908 partitions
  dt-bindings: mtd: move partition binding to its own file
  mtd: spi-nor: sst: Add support for Global Unlock on sst26vf
  mtd: spi-nor: Add Global Block Unlock command
  mtd: spi-nor: core: Add erase size check for erase command initialization
  mtd: spi-nor: core: Fix erase type discovery for overlaid region
  mtd: spi-nor: sfdp: Fix last erase region marking
  mtd: spi-nor: sfdp: Fix wrong erase type bitmask for overlaid region
  mtd: rawnand: intel: Fix an error handling path in 'ebu_dma_start()'
  mtd: rawnand: tango: Remove the driver
  mtd: rawnand: marvell: convert comma to semicolon
  mtd: st_spi_fsm: convert comma to semicolon
  mtd: convert comma to semicolon
  mtd: parsers: afs: Fix freeing the part name memory in failure
  mtd: parser: imagetag: fix error codes in bcm963xx_parse_imagetag_partitions()
  mtd: phram: use div_u64_rem to stop overwrite len in phram_setup
  mtd: remove redundant assignment to pointer eb
  mtd: spi-nor: hisi-sfc: Put child node np on error path
  mtd: spi-nor: intel-spi: Add support for Intel Alder Lake-P SPI serial flash
  mtd: rawnand: qcom: Add support for Qcom SMEM parser
  ...

Pull UML updates from Richard Weinberger:

 - Many cleanups and fixes for our virtio code

 - Add support for a pseudo RTC

 - Fix for a possible jailbreak

 - Minor fixes (spelling, header files)

* tag 'for-linux-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: irq.h: include <asm-generic/irq.h>
  um: io.h: include <linux/types.h>
  um: add a pseudo RTC
  um: remove process stub VMA
  um: rework userspace stubs to not hard-code stub location
  um: separate child and parent errors in clone stub
  um: defer killing userspace on page table update failures
  um: mm: check more comprehensively for stub changes
  um: print register names in wait_for_stub
  um: hostfs: use a kmem cache for inodes
  mm: Remove arch_remap() and mm-arch-hooks.h
  um: fix spelling mistake in Kconfig "privleges" -> "privileges"
  um: virtio: allow devices to be configured for wakeup
  um: time-travel: rework interrupt handling in ext mode
  um: virtio: disable VQs during suspend
  um: virtio: fix handling of messages without payload
  um: virtio: clean up a comment

Pull s390 updates from Vasily Gorbik:

 - Convert to using the generic entry infrastructure.

 - Add vdso time namespace support.

 - Switch s390 and alpha to 64-bit ino_t. As discussed at

     https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/

 - Get rid of expensive stck (store clock) usages where possible.
   Utilize cpu alternatives to patch stckf when supported.

 - Make tod_clock usage less error prone by converting it to a union and
   rework code which is using it.

 - Machine check handler fixes and cleanups.

 - Drop couple of minor inline asm optimizations to fix clang build.

 - Default configs changes notably to make libvirt happy.

 - Various changes to rework and improve qdio code.

 - Other small various fixes and improvements all over the code.

* tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits)
  s390/qdio: remove 'merge_pending' mechanism
  s390/qdio: improve handling of PENDING buffers for QEBSM devices
  s390/qdio: rework q->qdio_error indication
  s390/qdio: inline qdio_kick_handler()
  s390/time: remove get_tod_clock_ext()
  s390/crypto: use store_tod_clock_ext()
  s390/hypfs: use store_tod_clock_ext()
  s390/debug: use union tod_clock
  s390/kvm: use union tod_clock
  s390/vdso: use union tod_clock
  s390/time: convert tod_clock_base to union
  s390/time: introduce new store_tod_clock_ext()
  s390/time: rename store_tod_clock_ext() and use union tod_clock
  s390/time: introduce union tod_clock
  s390,alpha: switch to 64-bit ino_t
  s390: split cleanup_sie
  s390: use r13 in cleanup_sie as temp register
  s390: fix kernel asce loading when sie is interrupted
  s390: add stack for machine check handler
  s390: use WRITE_ONCE when re-allocating async stack
  ...

Pull KVM updates from Paolo Bonzini:
 "x86:

   - Support for userspace to emulate Xen hypercalls

   - Raise the maximum number of user memslots

   - Scalability improvements for the new MMU.

     Instead of the complex "fast page fault" logic that is used in
     mmu.c, tdp_mmu.c uses an rwlock so that page faults are concurrent,
     but the code that can run against page faults is limited. Right now
     only page faults take the lock for reading; in the future this will
     be extended to some cases of page table destruction. I hope to
     switch the default MMU around 5.12-rc3 (some testing was delayed
     due to Chinese New Year).

   - Cleanups for MAXPHYADDR checks

   - Use static calls for vendor-specific callbacks

   - On AMD, use VMLOAD/VMSAVE to save and restore host state

   - Stop using deprecated jump label APIs

   - Workaround for AMD erratum that made nested virtualization
     unreliable

   - Support for LBR emulation in the guest

   - Support for communicating bus lock vmexits to userspace

   - Add support for SEV attestation command

   - Miscellaneous cleanups

  PPC:

   - Support for second data watchpoint on POWER10

   - Remove some complex workarounds for buggy early versions of POWER9

   - Guest entry/exit fixes

  ARM64:

   - Make the nVHE EL2 object relocatable

   - Cleanups for concurrent translation faults hitting the same page

   - Support for the standard TRNG hypervisor call

   - A bunch of small PMU/Debug fixes

   - Simplification of the early init hypercall handling

  Non-KVM changes (with acks):

   - Detection of contended rwlocks (implemented only for qrwlocks,
     because KVM only needs it for x86)

   - Allow __DISABLE_EXPORTS from assembly code

   - Provide a saner follow_pfn replacements for modules"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (192 commits)
  KVM: x86/xen: Explicitly pad struct compat_vcpu_info to 64 bytes
  KVM: selftests: Don't bother mapping GVA for Xen shinfo test
  KVM: selftests: Fix hex vs. decimal snafu in Xen test
  KVM: selftests: Fix size of memslots created by Xen tests
  KVM: selftests: Ignore recently added Xen tests' build output
  KVM: selftests: Add missing header file needed by xAPIC IPI tests
  KVM: selftests: Add operand to vmsave/vmload/vmrun in svm.c
  KVM: SVM: Make symbol 'svm_gp_erratum_intercept' static
  locking/arch: Move qrwlock.h include after qspinlock.h
  KVM: PPC: Book3S HV: Fix host radix SLB optimisation with hash guests
  KVM: PPC: Book3S HV: Ensure radix guest has no SLB entries
  KVM: PPC: Don't always report hash MMU capability for P9 < DD2.2
  KVM: PPC: Book3S HV: Save and restore FSCR in the P9 path
  KVM: PPC: remove unneeded semicolon
  KVM: PPC: Book3S HV: Use POWER9 SLBIA IH=6 variant to clear SLB
  KVM: PPC: Book3S HV: No need to clear radix host SLB before loading HPT guest
  KVM: PPC: Book3S HV: Fix radix guest SLB side channel
  KVM: PPC: Book3S HV: Remove support for running HPT guest on RPT host without mixed mode support
  KVM: PPC: Book3S HV: Introduce new capability for 2nd DAWR
  KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWR
  ...

Merge tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Wei Liu:

 - VMBus hardening patches from Andrea Parri and Andres Beltran.

 - Patches to make Linux boot as the root partition on Microsoft
   Hypervisor from Wei Liu.

 - One patch to add a new sysfs interface to support hibernation on
   Hyper-V from Dexuan Cui.

 - Two miscellaneous clean-up patches from Colin and Gustavo.

* tag 'hyperv-next-signed-20210216' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (31 commits)
  Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"
  iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partition
  x86/hyperv: implement an MSI domain for root partition
  asm-generic/hyperv: import data structures for mapping device interrupts
  asm-generic/hyperv: introduce hv_device_id and auxiliary structures
  asm-generic/hyperv: update hv_interrupt_entry
  asm-generic/hyperv: update hv_msi_entry
  x86/hyperv: implement and use hv_smp_prepare_cpus
  x86/hyperv: provide a bunch of helper functions
  ACPI / NUMA: add a stub function for node_to_pxm()
  x86/hyperv: handling hypercall page setup for root
  x86/hyperv: extract partition ID from Microsoft Hypervisor if necessary
  x86/hyperv: allocate output arg pages if required
  clocksource/hyperv: use MSR-based access if running as root
  Drivers: hv: vmbus: skip VMBus initialization if Linux is root
  x86/hyperv: detect if Linux is the root partition
  asm-generic/hyperv: change HV_CPU_POWER_MANAGEMENT to HV_CPU_MANAGEMENT
  hv: hyperv.h: Replace one-element array with flexible-array in struct icmsg_negotiate
  hv_netvsc: Restrict configurations on isolated guests
  Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guests
  ...

Pull parisc updates from Helge Deller:

 - Optimize parisc page table locks by using the existing
   page_table_lock

 - Export argv0-preserve flag in binfmt_misc for usage in qemu-user

 - Fix interrupt table (IVT) checksum so firmware will call crash
   handler (HPMC)

 - Increase IRQ stack to 64kb on 64-bit kernel

 - Switch to common devmem_is_allowed() implementation

 - Minor fix to get_whan()

* 'parisc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  binfmt_misc: pass binfmt_misc flags to the interpreter
  parisc: Optimize per-pagetable spinlocks
  parisc: Replace test_ti_thread_flag() with test_tsk_thread_flag()
  parisc: Bump 64-bit IRQ stack size to 64 KB
  parisc: Fix IVT checksum calculation wrt HPMC
  parisc: Use the generic devmem_is_allowed()
  parisc: Drop out of get_whan() if task is running again

Pull MIPS updates from Thomas Bogendoerfer:

 - added support for Nintendo N64

 - added support for Realtek RTL83XX SoCs

 - kaslr support for Loongson64

 - first steps to get rid of set_fs()

 - DMA runtime coherent/non-coherent selection cleanup

 - cleanups and fixes

* tag 'mips_5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (98 commits)
  Revert "MIPS: Add basic support for ptrace single step"
  vmlinux.lds.h: catch more UBSAN symbols into .data
  MIPS: kernel: Drop kgdb_call_nmi_hook
  MAINTAINERS: Add git tree for KVM/mips
  MIPS: Use common way to parse elfcorehdr
  MIPS: Simplify EVA cache handling
  Revert "MIPS: kernel: {ftrace,kgdb}: Set correct address limit for cache flushes"
  MIPS: remove CONFIG_DMA_PERDEV_COHERENT
  MIPS: remove CONFIG_DMA_MAYBE_COHERENT
  driver core: lift dma_default_coherent into common code
  MIPS: refactor the runtime coherent vs noncoherent DMA indicators
  MIPS/alchemy: factor out the DMA coherent setup
  MIPS/malta: simplify plat_setup_iocoherency
  MIPS: Add basic support for ptrace single step
  MAINTAINERS: replace non-matching patterns for loongson{2,3}
  MIPS: Make check condition for SDBBP consistent with EJTAG spec
  mips: Replace lkml.org links with lore
  Revert "MIPS: microMIPS: Fix the judgment of mm_jr16_op and mm_jalr_op"
  MIPS: crash_dump.c: Simplify copy_oldmem_page()
  Revert "mips: Manually call fdt_init_reserved_mem() method"
  ...