The value of the I/O plugging (idling) timeout is used also as the
think-time threshold to decide whether a process has a short think
time.  In this respect, a good value of this timeout for rotational
drives is un the order of several ms. Yet, this is often too long a
time interval to be effective as a think-time threshold. This commit
mitigates this problem (by a lot, according to tests), by halving the
threshold.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Now that no fast path lookups in the partition table are left, there is
no point in micro-optimizing the data structure for it.  Just use a bog
standard xarray.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There is good reason to iterate backwards when deleting all partitions in
del_gendisk, just like we don't in blk_drop_partitions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Add a helper to call kobject_uevent for the disk and all partitions, and
unexport the disk_part_iter_* helpers that are now only used in the core
block code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Remove the reverse map from a sector to a partition for I/O accounting by
simply using ->bi_bdev.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Rework the I/O accounting for bio based drivers to use ->bi_bdev.  This
means all drivers can now simply use bio_start_io_acct to start
accounting, and it will take partitions into account automatically.  To
end I/O account either bio_end_io_acct can be used if the driver never
remaps I/O to a different device, or bio_end_io_acct_remapped if the
driver did remap the I/O.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There is no good reason to reassign ->bi_bdev when remapping the
partition-relative block number to the device wide one, as all the
information required by the drivers comes from the gendisk anyway.

Keeping the original ->bi_bdev alive will allow to greatly simplify
the partition-away I/O accounting.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge a few checks for whole devices vs partitions to streamline the
sanity checks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The block layer already checks for this conditions in bio_check_eod
before calling the driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The block layer already checks for this conditions in bio_check_eod
before calling the driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Unconditionally call set_disk_ro now that it only updates the hardware
state.  This allows to properly set up the Linux devices read-only when
the controller turns a previously writable namespace read-only.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Now that the hardware read-only state can't be changed by the BLKROSET
ioctl, the code in this method is not required anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Change the policy so that a BLKROSET on the whole device also affects
partitions.  To quote Martin K. Petersen:

It's very common for database folks to twiddle the read-only state of
block devices and partitions. I know that our users will find it very
counter-intuitive that setting /dev/sda read-only won't prevent writes
to /dev/sda1.

The existing behavior is inconsistent in the sense that doing:

  # blockdev --setro /dev/sda
  # echo foo > /dev/sda1

permits writes. But:

  # blockdev --setro /dev/sda
  <something triggers revalidate>
  # echo foo > /dev/sda1

doesn't.

And a subsequent:

  # blockdev --setrw /dev/sda
  # echo foo > /dev/sda1

doesn't work either since sda1's read-only policy has been inherited
from the whole-disk device.

You need to do:

  # blockdev --rereadpt

after setting the whole-disk device rw to effectuate the same change on
the partitions, otherwise they are stuck being read-only indefinitely.

However, setting the read-only policy on a partition does *not* require
the revalidate step. As a matter of fact, doing the revalidate will blow
away the policy setting you just made.

So the user needs to take different actions depending on whether they
are trying to read-protect a whole-disk device or a partition. Despite
using the same ioctl. That is really confusing.

I have lost count how many times our customers have had data clobbered
because of ambiguity of the existing whole-disk device policy. The
current behavior violates the principle of least surprise by letting the
user think they write protected the whole disk when they actually
didn't.
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Commit 20bd1d02 ("scsi: sd: Keep disk read-only when re-reading
partition") addressed a long-standing problem with user read-only
policy being overridden as a result of a device-initiated revalidate.
The commit has since been reverted due to a regression that left some
USB devices read-only indefinitely.

To fix the underlying problems with revalidate we need to keep track
of hardware state and user policy separately.

The gendisk has been updated to reflect the current hardware state set
by the device driver. This is done to allow returning the device to
the hardware state once the user clears the BLKROSET flag.

The resulting semantics are as follows:

 - If BLKROSET sets a given partition read-only, that partition will
   remain read-only even if the underlying storage stack initiates a
   revalidate. However, the BLKRRPART ioctl will cause the partition
   table to be dropped and any user policy on partitions will be lost.

 - If BLKROSET has not been set, both the whole disk device and any
   partitions will reflect the current write-protect state of the
   underlying device.

Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.
Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Only a single caller can end up in bdev_read_only, so move the check
there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

dm-thin and dm-cache also work on partitions, so use the proper
interface to check if the device is read-only.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull arch/sh updates from Rich Felker:
 "Cleanup and warning fixes"

* tag 'sh-for-5.11' of git://git.libc.org/linux-sh:
  sh/intc: Restore devm_ioremap() alignment
  sh: mach-sh03: remove duplicate include
  arch: sh: remove duplicate include
  sh: Drop ARCH_NR_GPIOS definition
  sh: Remove unused HAVE_COPY_THREAD_TLS macro
  sh: remove CONFIG_IDE from most defconfig
  sh: mm: Convert to DEFINE_SHOW_ATTRIBUTE
  sh: intc: Convert to DEFINE_SHOW_ATTRIBUTE
  arch/sh: hyphenate Non-Uniform in Kconfig prompt
  sh: dma: fix kconfig dependency for G2_DMA

Pull io_uring fixes from Jens Axboe:
 "Still need a final cancelation fix that isn't quite done done,
  expected in the next day or two. That said, this contains:

   - Wakeup fix for IOPOLL requests

   - SQPOLL split close op handling fix

   - Ensure that any use of io_uring fd itself is marked as inflight

   - Short non-regular file read fix (Pavel)

   - Fix up bad false positive warning (Pavel)

   - SQPOLL fixes (Pavel)

   - In-flight removal fix (Pavel)"

* tag 'io_uring-5.11-2021-01-24' of git://git.kernel.dk/linux-block:
  io_uring: account io_uring internal files as REQ_F_INFLIGHT
  io_uring: fix sleeping under spin in __io_clean_op
  io_uring: fix short read retries for non-reg files
  io_uring: fix SQPOLL IORING_OP_CLOSE cancelation state
  io_uring: fix skipping disabling sqo on exec
  io_uring: fix uring_flush in exit_files() warning
  io_uring: fix false positive sqo warning on flush
  io_uring: iopoll requests should also wake task ->in_idle state

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph:
      - fix a status code in nvmet (Chaitanya Kulkarni)
      - avoid double completions in nvme-rdma/nvme-tcp (Chao Leng)
      - fix the CMB support to cope with NVMe 1.4 controllers (Klaus Jensen)
      - fix PRINFO handling in the passthrough ioctl (Revanth Rajashekar)
      - fix a double DMA unmap in nvme-pci

 - lightnvm error path leak fix (Pan)

 - MD pull request from Song:
      - Flush request fix (Xiao)

* tag 'block-5.11-2021-01-24' of git://git.kernel.dk/linux-block:
  lightnvm: fix memory leak when submit fails
  nvme-pci: fix error unwind in nvme_map_data
  nvme-pci: refactor nvme_unmap_data
  md: Set prev_flush_start and flush_bio in an atomic way
  nvmet: set right status on error in id-ns handler
  nvme-pci: allow use of cmb on v1.4 controllers
  nvme-tcp: avoid request double completion for concurrent nvme_tcp_timeout
  nvme-rdma: avoid request double completion for concurrent nvme_rdma_timeout
  nvme: check the PRINFO bit before deciding the host buffer length

Merge misc fixes from Andrew Morton:
 "18 patches.

  Subsystems affected by this patch series: mm (pagealloc, memcg, kasan,
  memory-failure, and highmem), ubsan, proc, and MAINTAINERS"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  MAINTAINERS: add a couple more files to the Clang/LLVM section
  proc_sysctl: fix oops caused by incorrect command parameters
  powerpc/mm/highmem: use __set_pte_at() for kmap_local()
  mips/mm/highmem: use set_pte() for kmap_local()
  mm/highmem: prepare for overriding set_pte_at()
  sparc/mm/highmem: flush cache and TLB
  mm: fix page reference leak in soft_offline_page()
  ubsan: disable unsigned-overflow check for i386
  kasan, mm: fix resetting page_alloc tags for HW_TAGS
  kasan, mm: fix conflicts with init_on_alloc/free
  kasan: fix HW_TAGS boot parameters
  kasan: fix incorrect arguments passing in kasan_add_zero_shadow
  kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow
  mm: fix numa stats for thp migration
  mm: memcg: fix memcg file_dirty numa stat
  mm: memcg/slab: optimize objcg stock draining
  mm: fix initialization of struct page for holes in memory layout
  x86/setup: don't remove E820_TYPE_RAM for pfn 0

Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc driver fixes for 5.11-rc5:

   - habanalabs driver fixes

   - phy driver fixes

   - hwtracing driver fixes

   - rtsx cardreader driver fix

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc: rtsx: init value of aspm_enabled
  habanalabs: disable FW events on device removal
  habanalabs: fix backward compatibility of idle check
  habanalabs: zero pci counters packet before submit to FW
  intel_th: pci: Add Alder Lake-P support
  stm class: Fix module init return on allocation failure
  habanalabs: prevent soft lockup during unmap
  habanalabs: fix reset process in case of failures
  habanalabs: fix dma_addr passed to dma_mmap_coherent
  phy: mediatek: allow compile-testing the dsi phy
  phy: cpcap-usb: Fix warning for missing regulator_disable
  PHY: Ingenic: fix unconditional build of phy-ingenic-usb

Merge tag 'driver-core-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some small driver core fixes for 5.11-rc5 that resolve some
  reported problems:

   - revert of a -rc1 patch that was causing problems with some machines

   - device link device name collision problem fix (busses only have to
     name devices unique to their bus, not unique to all busses)

   - kernfs splice bugfixes to resolve firmware loading problems for
     Qualcomm systems.

   - other tiny driver core fixes for minor issues reported.

  All of these have been in linux-next with no reported problems"

* tag 'driver-core-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: Fix device link device name collision
  driver core: Extend device_is_dependent()
  kernfs: wire up ->splice_read and ->splice_write
  kernfs: implement ->write_iter
  kernfs: implement ->read_iter
  Revert "driver core: Reorder devices on successful probe"
  Driver core: platform: Add extra error check in devm_platform_get_irqs_affinity()
  drivers core: Free dma_range_map when driver probe failed

Pull staging/IIO driver fixes from Greg KH:
 "Here are some IIO driver fixes for 5.11-rc5 to resolve some reported
  problems.

  Nothing major, just a few small fixes, all of these have been in
  linux-next for a while and full details are in the shortlog"

* tag 'staging-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: sx9310: Fix semtech,avg-pos-strength setting when > 16
  iio: common: st_sensors: fix possible infinite loop in st_sensors_irq_thread
  iio: ad5504: Fix setting power-down state
  counter:ti-eqep: remove floor
  drivers: iio: temperature: Add delay after the addressed reset command in mlx90632.c
  iio: adc: ti_am335x_adc: remove omitted iio_kfifo_free()
  dt-bindings: iio: accel: bma255: Fix bmc150/bmi055 compatible
  iio: sx9310: Off by one in sx9310_read_thresh()

Pull tty/serial fixes from Greg KH:
 "Here are three small tty/serial fixes for 5.11-rc5 to resolve reported
  problems:

   - two patches to fix up writing to ttys with splice

   - mvebu-uart driver fix for reported problem

  All of these have been in linux-next with no reported problems"

* tag 'tty-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix up hung_up_tty_write() conversion
  tty: implement write_iter
  serial: mvebu-uart: fix tx lost characters at power off

Pull USB fixes from Greg KH:
 "Here are some small USB driver fixes for 5.11-rc5.  They resolve:

   - xhci issues for some reported problems

   - ehci driver issue for one specific device

   - USB gadget fixes for some reported problems

   - cdns3 driver fixes for issues reported

   - MAINTAINERS file update

   - thunderbolt minor fix

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: bdc: Make bdc pci driver depend on BROKEN
  xhci: tegra: Delay for disabling LFPS detector
  xhci: make sure TRB is fully written before giving it to the controller
  usb: udc: core: Use lock when write to soft_connect
  USB: gadget: dummy-hcd: Fix errors in port-reset handling
  usb: gadget: aspeed: fix stop dma register setting.
  USB: ehci: fix an interrupt calltrace error
  ehci: fix EHCI host controller initialization sequence
  MAINTAINERS: update Peter Chen's email address
  thunderbolt: Drop duplicated 0x prefix from format string
  MAINTAINERS: Update address for Cadence USB3 driver
  usb: cdns3: imx: improve driver .remove API
  usb: cdns3: imx: fix can't create core device the second time issue
  usb: cdns3: imx: fix writing read-only memory issue

The K: entry should ensure that Nick and I always get CC'd on patches that
touch these files but it is better to be explicit rather than implicit.

Link: https://lkml.kernel.org/r/20210114004059.2129921-1-natechancellor@gmail.comSigned-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The process_sysctl_arg() does not check whether val is empty before
invoking strlen(val).  If the command line parameter () is incorrectly
configured and val is empty, oops is triggered.

For example:
  "hung_task_panic=1" is incorrectly written as "hung_task_panic", oops is
  triggered. The call stack is as follows:
    Kernel command line: .... hung_task_panic
    ......
    Call trace:
    __pi_strlen+0x10/0x98
    parse_args+0x278/0x344
    do_sysctl_args+0x8c/0xfc
    kernel_init+0x5c/0xf4
    ret_from_fork+0x10/0x30

To fix it, check whether "val" is empty when "phram" is a sysctl field.
Error codes are returned in the failure branch, and error logs are
generated by parse_args().

Link: https://lkml.kernel.org/r/20210118133029.28580-1-nixiaoming@huawei.com
Fixes: 3db978d4 ("kernel/sysctl: support setting sysctl parameters from kernel command line")
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org>	[5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The original PowerPC highmem mapping function used __set_pte_at() to
denote that the mapping is per CPU.  This got lost with the conversion
to the generic implementation.

Override the default map function.

Link: https://lkml.kernel.org/r/20210112170411.281464308@linutronix.de
Fixes: 47da42b2 ("powerpc/mm/highmem: Switch to generic kmap atomic")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

set_pte_at() on MIPS invokes update_cache() which might recurse into
kmap_local().

Use set_pte() like the original MIPS highmem implementation did.

Link: https://lkml.kernel.org/r/20210112170411.187513575@linutronix.de
Fixes: a4c33e83 ("mips/mm/highmem: Switch to generic kmap atomic")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Paul Cercueil <paul@crapouillou.net>
Reported-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The generic kmap_local() map function uses set_pte_at(), but MIPS requires
set_pte() and PowerPC wants __set_pte_at().

Provide arch_kmap_local_set_pte() and default it to set_pte_at().

Link: https://lkml.kernel.org/r/20210112170411.056306194@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/highmem: Fix fallout from generic kmap_local
conversions".

The kmap_local conversion wreckaged sparc, mips and powerpc as it missed
some of the details in the original implementation.

This patch (of 4):

The recent conversion to the generic kmap_local infrastructure failed to
assign the proper pre/post map/unmap flush operations for sparc.

Sparc requires cache flush before map/unmap and tlb flush afterwards.

Link: https://lkml.kernel.org/r/20210112170136.078559026@linutronix.de
Link: https://lkml.kernel.org/r/20210112170410.905976187@linutronix.de
Fixes: 3293efa9 ("sparc/mm/highmem: Switch to generic kmap atomic")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Andreas Larsson <andreas@gaisler.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The conversion to move pfn_to_online_page() internal to
soft_offline_page() missed that the get_user_pages() reference taken by
the madvise() path needs to be dropped when pfn_to_online_page() fails.

Note the direct sysfs-path to soft_offline_page() does not perform a
get_user_pages() lookup.

When soft_offline_page() is handed a pfn_valid() && !pfn_to_online_page()
pfn the kernel hangs at dax-device shutdown due to a leaked reference.

Link: https://lkml.kernel.org/r/161058501210.1840162.8108917599181157327.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: feec24a6 ("mm, soft-offline: convert parameter to pfn")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Building ubsan kernels even for compile-testing introduced these
warnings in my randconfig environment:

  crypto/blake2b_generic.c:98:13: error: stack frame size of 9636 bytes in function 'blake2b_compress' [-Werror,-Wframe-larger-than=]
  static void blake2b_compress(struct blake2b_state *S,

  crypto/sha512_generic.c:151:13: error: stack frame size of 1292 bytes in function 'sha512_generic_block_fn' [-Werror,-Wframe-larger-than=]
  static void sha512_generic_block_fn(struct sha512_state *sst, u8 const *src,

  lib/crypto/curve25519-fiat32.c:312:22: error: stack frame size of 2180 bytes in function 'fe_mul_impl' [-Werror,-Wframe-larger-than=]
  static noinline void fe_mul_impl(u32 out[10], const u32 in1[10], const u32 in2[10])

  lib/crypto/curve25519-fiat32.c:444:22: error: stack frame size of 1588 bytes in function 'fe_sqr_impl' [-Werror,-Wframe-larger-than=]
  static noinline void fe_sqr_impl(u32 out[10], const u32 in1[10])

Further testing showed that this is caused by
-fsanitize=unsigned-integer-overflow, but is isolated to the 32-bit x86
architecture.

The one in blake2b immediately overflows the 8KB stack area
architectures, so better ensure this never happens by disabling the
option for 32-bit x86.

Link: https://lkml.kernel.org/r/20210112202922.2454435-1-arnd@kernel.org
Link: https://lore.kernel.org/lkml/20201230154749.746641-1-arnd@kernel.org/
Fixes: d0a3ac54 ("ubsan: enable for all*config builds")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Marco Elver <elver@google.com>
Cc: George Popescu <georgepope@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A previous commit added resetting KASAN page tags to
kernel_init_free_pages() to avoid false-positives due to accesses to
metadata with the hardware tag-based mode.

That commit did reset page tags before the metadata access, but didn't
restore them after.  As the result, KASAN fails to detect bad accesses
to page_alloc allocations on some configurations.

Fix this by recovering the tag after the metadata access.

Link: https://lkml.kernel.org/r/02b5bcd692e912c27d484030f666b350ad7e4ae4.1611074450.git.andreyknvl@google.com
Fixes: aa1ef4d7 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A few places where SLUB accesses object's data or metadata were missed
in a previous patch.  This leads to false positives with hardware
tag-based KASAN when bulk allocations are used with init_on_alloc/free.

Fix the false-positives by resetting pointer tags during these accesses.

(The kasan_reset_tag call is removed from slab_alloc_node, as it's added
 into maybe_wipe_obj_freeptr.)

Link: https://linux-review.googlesource.com/id/I50dd32838a666e173fe06c3c5c766f2c36aae901
Link: https://lkml.kernel.org/r/093428b5d2ca8b507f4a79f92f9929b35f7fada7.1610731872.git.andreyknvl@google.com
Fixes: aa1ef4d7 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The initially proposed KASAN command line parameters are redundant.

This change drops the complex "kasan.mode=off/prod/full" parameter and
adds a simpler kill switch "kasan=off/on" instead.  The new parameter
together with the already existing ones provides a cleaner way to
express the same set of features.

The full set of parameters with this change:

  kasan=off/on             - whether KASAN is enabled
  kasan.fault=report/panic - whether to only print a report or also panic
  kasan.stacktrace=off/on  - whether to collect alloc/free stack traces

Default values:

  kasan=on
  kasan.fault=report
  kasan.stacktrace=on  (if CONFIG_DEBUG_KERNEL=y)
  kasan.stacktrace=off (otherwise)

Link: https://linux-review.googlesource.com/id/Ib3694ed90b1e8ccac6cf77dfd301847af4aba7b8
Link: https://lkml.kernel.org/r/4e9c4a4bdcadc168317deb2419144582a9be6e61.1610736745.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kasan_remove_zero_shadow() shall use original virtual address, start and
size, instead of shadow address.

Link: https://lkml.kernel.org/r/20210103063847.5963-1-lecopzer@gmail.com
Fixes: 0207df4f ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During testing kasan_populate_early_shadow and kasan_remove_zero_shadow,
if the shadow start and end address in kasan_remove_zero_shadow() is not
aligned to PMD_SIZE, the remain unaligned PTE won't be removed.

In the test case for kasan_remove_zero_shadow():

    shadow_start: 0xffffffb802000000, shadow end: 0xffffffbfbe000000

    3-level page table:
      PUD_SIZE: 0x40000000 PMD_SIZE: 0x200000 PAGE_SIZE: 4K

0xffffffbf80000000 ~ 0xffffffbfbdf80000 will not be removed because in
kasan_remove_pud_table(), kasan_pmd_table(*pud) is true but the next
address is 0xffffffbfbdf80000 which is not aligned to PUD_SIZE.

In the correct condition, this should fallback to the next level
kasan_remove_pmd_table() but the condition flow always continue to skip
the unaligned part.

Fix by correcting the condition when next and addr are neither aligned.

Link: https://lkml.kernel.org/r/20210103135621.83129-1-lecopzer@gmail.com
Fixes: 0207df4f ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>