The irq variable is defined as unsigned int. If the platform_get_irq()
returns a negative value, data type cast may result in error.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi (CGEL ZTE) <lv.ruyi@zte.com.cn>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220308025054.2077162-1-lv.ruyi@zte.com.cnSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This patch adds matrix keypad support for Mediatek SoCs.
Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220303154302.252041-3-mkorpershoek@baylibre.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

This patch add devicetree bindings for Mediatek matrix keypad driver.
Signed-off-by: fengping.yu <fengping.yu@mediatek.com>
Reviewed-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220303154302.252041-2-mkorpershoek@baylibre.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Use devm_delayed_work_autocancel() instead of hand-writing it.
This saves a few lines of code.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Link: https://lore.kernel.org/r/a76ac3f4c7aee205395b89b5b3f587e30a48df96.1645205312.git.christophe.jaillet@wanadoo.frSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Because there is no way to detect if the touchscreen has pen support,
the driver is allocating and registering the input_pen input_dev on
receiving the first pen event.

But this means that the input_dev gets allocated after the request_irq()
call which means that the devm framework will free it before disabling
the irq, leaving a window where the irq handler may run and reference the
free-ed input_dev.

To fix this move the allocation of the input_pen input_dev to before
the request_irq() call, while still only registering it on the first pen
event so that the driver does not advertise pen capability on touchscreens
without it (most goodix touchscreens do not have pen support).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220131143539.109142-4-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Use the new input_copy_abs() helper and move the 2 input_abs_set_res()
calls up to be directly after the 2 input_copy_abs() calls, so that
the calls initializing the X and Y axis are all together.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220131143539.109142-3-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Add a new helper function to copy absinfo from one input_dev to
another input_dev.

This is useful to e.g. setup a pen/stylus input-device for combined
touchscreen/pen hardware where the pen uses the same coordinates as
the touchscreen.
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220131143539.109142-2-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The input core's error handling for input_alloc_absinfo() failures
is based on ignoring the error until input_register_device() runs
and then checks for the failure like this:

        if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
                dev_err(&dev->dev, ...);
                return -EINVAL;
        }

This relies on EV_ABS actually getting set in dev->evbit even
if input_alloc_absinfo() fails, change input_set_abs_params() and
input_set_capability() to actually adhere to this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220131143539.109142-1-hdegoede@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Sync up with mainline to get the latest changes in HID subsystem.

Since Commit ed7c9870 ("Input: of_touchscreen - add support for
inverted / swapped axes"), the of_touchscreen interface supports axis
inverting and swapping through device tree properties. Make use of this
feature.
Signed-off-by: Yunus Bas <y.bas@phytec.de>
Link: https://lore.kernel.org/r/20220209223933.1672782-1-y.bas@phytec.deSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Change the name of controller to a more meaningful one.
Signed-off-by: Marcos Alano <marcoshalano@gmail.com>
Link: https://lore.kernel.org/r/20220212191014.1754721-1-marcoshalano@gmail.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The PS/2 bus defines the data and clock line be open drain, therefore
for both enforce the particular GPIO flags in the driver.

Without enforcing to flag at least the clock gpio as open drain we run
into the following warning:

WARNING: CPU: 1 PID: 40 at drivers/gpio/gpiolib.c:3175 gpiochip_enable_irq+0x54/0x90

gpiochip_enable_irq() warns on a GPIO being configured as output while
serving as IRQ source without being flagged as open drain.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215180829.63543-4-danilokrummrich@dk-develop.deSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Sending the data before processing the stop bit from the device already
saves the data of the current xfer in case the stop bit is missed.

However, when TX xfers are enabled this introduces a race condition when
a peripheral driver using the bus immediately requests a TX xfer from IRQ
context.

Therefore the data must be send after receiving the stop bit, although
it is possible the data is lost when missing the stop bit.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-5-danilokrummrich@dk-develop.deSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Actually, there's no extra clock pulse to wait for.

The assumption of an extra clock pulse was mistakenly derived from the
fact that by the time this driver was introduced the GPIO controller of
the test machine (bcm2835) generated spurious interrupts.

Since now spurious interrupts are handled properly this can and must be
removed in order to make TX xfers work properly.

While at it, remove duplicate gpiod_direction_input(). The data gpio
must already be configured to act as input when receiving the ACK bit.

This patch is tested with the original hardware (peripherals and board)
the driver was developed on.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-4-danilokrummrich@dk-develop.deSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Using jiffies for the IRQ timekeeping is not sufficient for two reasons:

(1) Usually jiffies have a resolution of 1ms to 10ms. The IRQ intervals
    based on the clock frequency of PS2 protocol specification (10kHz -
    16.7kHz) are between ~60us and 100us only. Therefore only those IRQ
    intervals can be detected which are either at the end of a transfer
    or are overly delayed. While this is sufficient in most cases, since
    we have quite a lot of ways to detect faulty transfers, it can
    produce false positives in rare cases: When the jiffies value
    changes right between two interrupt that are in time, we wrongly
    assume that we missed one or more clock cycles.

(2) Some gpio controllers (e.g. the one in the bcm283x chips) may generate
    spurious IRQs when processing interrupts in the frequency given by PS2
    devices.

Both issues can be fixed by using ktime resolution for IRQ timekeeping.

However, it is still possible to miss clock cycles without detecting
them. When the PS2 device generates the falling edge of the clock signal
we have between ~30us and 50us to sample the data line, because after
this time we reach the next rising edge at which the device changes the
data signal already. But, the only thing we can detect is whether the
IRQ interval is within the given period. Therefore it is possible to
have an IRQ latency greater than ~30us to 50us, sample the wrong bit on
the data line and still be on time with the next IRQ. However, this can
only happen when within a given transfer the IRQ latency increases
slowly.

___            ______            ______            ______            ___
   \          /      \          /      \          /      \          /
    \        /        \        /        \        /        \        /
     \______/          \______/          \______/          \______/

    |-----------------|                 |--------|
         60us/100us                      30us/50us
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-3-danilokrummrich@dk-develop.deSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Refactor struct ps2_gpio_data in order to clearly separate RX and TX
state data.

This change intends to increase code readability and does not bring any
functional change.
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Link: https://lore.kernel.org/r/20220215160208.34826-2-danilokrummrich@dk-develop.deSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Merge tag 'kbuild-fixes-v5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix the truncated path issue for HAVE_GCC_PLUGINS test in Kconfig

 - Move -Wunsligned-access to W=1 builds to avoid sprinkling warnings
   for the latest Clang

 - Fix missing fclose() in Kconfig

 - Fix Kconfig to touch dep headers correctly when KCONFIG_AUTOCONFIG is
   overridden.

* tag 'kbuild-fixes-v5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: fix failing to generate auto.conf
  kconfig: fix missing fclose() on error paths
  Makefile.extrawarn: Move -Wunaligned-access to W=1
  kconfig: let 'shell' return enough output for deep path names

Pull irq fixes from Thomas Gleixner:
 "Interrupt chip driver fixes:

   - Don't install an hotplug notifier for GICV3-ITS on systems which do
     not need it to prevent a warning in the notifier about inconsistent
     state

   - Add the missing device tree matching for the T-HEAD PLIC variant so
     the related SoC is properly supported"

* tag 'irq-urgent-2022-02-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/sifive-plic: Add missing thead,c900-plic match string
  dt-bindings: update riscv plic compatible string
  irqchip/gic-v3-its: Skip HP notifier when no ITS is registered

Pull objtool fix from Borislav Petkov:
 "Fix a case where objtool would mistakenly warn about instructions
  being unreachable"

* tag 'objtool_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bug: Merge annotate_reachable() into _BUG_FLAGS() asm

Pull scheduler fix from Borislav Petkov:
 "Fix a NULL-ptr dereference when recalculating a sched entity's weight"

* tag 'sched_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix fault in reweight_entity

Pull perf fix from Borislav Petkov:
 "Prevent cgroup event list corruption when switching events"

* tag 'perf_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix list corruption in perf_cgroup_switch()

Pull x86 fix from Borislav Petkov:
 "Prevent softlockups when tearing down large SGX enclaves"

* tag 'x86_urgent_for_v5.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sgx: Silence softlockup detection when releasing large enclaves

Pull cifs fixes from Steve French:
 "Three small smb3 reconnect fixes and an error log clarification"

* tag '5.17-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: mark sessions for reconnection in helper function
  cifs: call helper functions for marking channels for reconnect
  cifs: call cifs_reconnect when a connection is marked
  [smb3] improve error message when mount options conflict with posix

Merge tag 'irqchip-fixes-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

 - Don't register a hotplug notifier on GICv3 systems that advertise
   LPI support, but have no ITS to make use of it

 - Add missing DT matching for the thead,c900-plic variant of the
   SiFive PLIC

Link: https://lore.kernel.org/r/20220211110038.1179155-1-maz@kernel.org

Pull SCSI fixes from James Bottomley:
 "Two minor fixes in the lpfc driver. One changing the classification of
  trace messages and the other fixing a build issue when NVME_FC is
  disabled"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: lpfc: Reduce log messages seen after firmware download
  scsi: lpfc: Remove NVMe support if kernel has NVME_FC disabled

Pull char/misc driver fixes from Greg KH:
 "Here are a small number of char/misc driver fixes for 5.17-rc4 for
  reported issues. They contain:

   - phy driver fixes

   - iio driver fix

   - eeprom driver fix

   - speakup regression fix

   - fastrpc fix

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

* tag 'char-misc-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  iio: buffer: Fix file related error handling in IIO_BUFFER_GET_FD_IOCTL
  speakup-dectlk: Restore pitch setting
  bus: mhi: pci_generic: Add mru_default for Cinterion MV31-W
  bus: mhi: pci_generic: Add mru_default for Foxconn SDX55
  eeprom: ee1004: limit i2c reads to I2C_SMBUS_BLOCK_MAX
  misc: fastrpc: avoid double fput() on failed usercopy
  phy: dphy: Correct clk_pre parameter
  phy: phy-mtk-tphy: Fix duplicated argument in phy-mtk-tphy
  phy: stm32: fix a refcount leak in stm32_usbphyc_pll_enable()
  phy: xilinx: zynqmp: Fix bus width setting for SGMII
  phy: cadence: Sierra: fix error handling bugs in probe()
  phy: ti: Fix missing sentinel for clk_div_table
  phy: broadcom: Kconfig: Fix PHY_BRCM_USB config option
  phy: usb: Leave some clocks running during suspend

Pullstaging driver fixes from Greg KH:
 "Here are two staging driver fixes for 5.17-rc4.  These are:

   - fbtft error path fix

   - vc04_services rcu dereference fix

  Both of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: fbtft: Fix error path in fbtft_driver_module_init()
  staging: vc04_services: Fix RCU dereference check

Pull tty/serial fixes from Greg KH:
 "Here are four small tty/serial fixes for 5.17-rc4.  They are:

   - 8250_pericom change revert to fix a reported regression

   - two speculation fixes for vt_ioctl

   - n_tty regression fix for polling

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

* tag 'tty-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  vt_ioctl: add array_index_nospec to VT_ACTIVATE
  vt_ioctl: fix array_index_nospec in vt_setactivate
  serial: 8250_pericom: Revert "Re-enable higher baud rates"
  n_tty: wake up poll(POLLRDNORM) on receiving data

Pull USB fixes from Greg KH:
 "Here are some small USB driver fixes for 5.17-rc4 that resolve some
  reported issues and add new device ids:

   - usb-serial new device ids

   - ulpi cleanup fixes

   - f_fs use-after-free fix

   - dwc3 driver fixes

   - ax88179_178a usb network driver fix

   - usb gadget fixes

  There is a revert at the end of this series to resolve a build problem
  that 0-day found yesterday. Most of these have been in linux-next,
  except for the last few, and all have now passed 0-day tests"

* tag 'usb-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  Revert "usb: dwc2: drd: fix soft connect when gadget is unconfigured"
  usb: dwc2: drd: fix soft connect when gadget is unconfigured
  usb: gadget: rndis: check size of RNDIS_MSG_SET command
  USB: gadget: validate interface OS descriptor requests
  usb: core: Unregister device on component_add() failure
  net: usb: ax88179_178a: Fix out-of-bounds accesses in RX fixup
  usb: dwc3: gadget: Prevent core from processing stale TRBs
  USB: serial: cp210x: add CPI Bulk Coin Recycler id
  USB: serial: cp210x: add NCR Retail IO box id
  USB: serial: ftdi_sio: add support for Brainboxes US-159/235/320
  usb: gadget: f_uac2: Define specific wTerminalType
  usb: gadget: udc: renesas_usb3: Fix host to USB_ROLE_NONE transition
  usb: raw-gadget: fix handling of dual-direction-capable endpoints
  usb: usb251xb: add boost-up property support
  usb: ulpi: Call of_node_put correctly
  usb: ulpi: Move of_node_put to ulpi_dev_release
  USB: serial: option: add ZTE MF286D modem
  USB: serial: ch341: add support for GW Instek USB2.0-Serial devices
  usb: f_fs: Fix use-after-free for epfile
  usb: dwc3: xilinx: fix uninitialized return value

Pull s390 updates from Vasily Gorbik:
 "Maintainers and reviewers changes:

    - Add Alexander Gordeev as maintainer for s390.

    - Christian Borntraeger will focus on s390 KVM maintainership and
      stays as s390 reviewer.

  Fixes:

   - Fix clang build of modules loader KUnit test.

   - Fix kernel panic in CIO code on FCES path-event when no driver is
     attached to a device or the driver does not provide the path_event
     function"

* tag 's390-5.17-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/cio: verify the driver availability for path_event call
  s390/module: fix building test_modules_helpers.o with clang
  MAINTAINERS: downgrade myself to Reviewer for s390
  MAINTAINERS: add Alexander Gordeev as maintainer for s390

Pull xen fixes from Juergen Gross:

 - Two small cleanups

 - Another fix for addressing the EFI framebuffer above 4GB when running
   as Xen dom0

 - A patch to let Xen guests use reserved bits in MSI- and IO-APIC-
   registers for extended APIC-IDs the same way KVM guests are doing it
   already

* tag 'for-linus-5.17a-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pci: Make use of the helper macro LIST_HEAD()
  xen/x2apic: Fix inconsistent indenting
  xen/x86: detect support for extended destination ID
  xen/x86: obtain full video frame buffer address for Dom0 also under EFI

Pull seccomp fixes from Kees Cook:
 "This fixes a corner case of fatal SIGSYS being ignored since v5.15.
  Along with the signal fix is a change to seccomp so that seeing
  another syscall after a fatal filter result will cause seccomp to kill
  the process harder.

  Summary:

   - Force HANDLER_EXIT even for SIGNAL_UNKILLABLE

   - Make seccomp self-destruct after fatal filter results

   - Update seccomp samples for easier behavioral demonstration"

* tag 'seccomp-v5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  samples/seccomp: Adjust sample to also provide kill option
  seccomp: Invalidate seccomp mode to catch death failures
  signal: HANDLER_EXIT should clear SIGNAL_UNKILLABLE

Merge misc fixes from Andrew Morton:
 "5 patches.

  Subsystems affected by this patch series: binfmt, procfs, and mm
  (vmscan, memcg, and kfence)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kfence: make test case compatible with run time set sample interval
  mm: memcg: synchronize objcg lists with a dedicated spinlock
  mm: vmscan: remove deadlock due to throttling failing to make progress
  fs/proc: task_mmu.c: don't read mapcount for migration entry
  fs/binfmt_elf: fix PT_LOAD p_align values for loaders

When the KCONFIG_AUTOCONFIG is specified (e.g. export \
KCONFIG_AUTOCONFIG=output/config/auto.conf), the directory of
include/config/ will not be created, so kconfig can't create deps
files in it and auto.conf can't be generated.
Signed-off-by: Jing Leng <jleng@ambarella.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This reverts commit 269cbcf7.

It causes build errors as reported by the kernel test robot.

Link: https://lore.kernel.org/r/202202112236.AwoOTtHO-lkp@intel.comReported-by: kernel test robot <lkp@intel.com>
Fixes: 269cbcf7 ("usb: dwc2: drd: fix soft connect when gadget is unconfigured")
Cc: stable@kernel.org
Cc: Amelie Delaunay <amelie.delaunay@foss.st.com>
Cc: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Cc: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The parameter kfence_sample_interval can be set via boot parameter and
late shell command, which is convenient for automated tests and KFENCE
parameter optimization.  However, KFENCE test case just uses
compile-time CONFIG_KFENCE_SAMPLE_INTERVAL, which will make KFENCE test
case not run as users desired.  Export kfence_sample_interval, so that
KFENCE test case can use run-time-set sample interval.

Link: https://lkml.kernel.org/r/20220207034432.185532-1-liupeng256@huawei.comSigned-off-by: Peng Liu <liupeng256@huawei.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian Knig <christian.koenig@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Alexander reported a circular lock dependency revealed by the mmap1 ltp
test:

  LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1))
          WARNING: possible circular locking dependency detected
          5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1 Not tainted
          ------------------------------------------------------
          mmap1/202299 is trying to acquire lock:
          00000001892c0188 (css_set_lock){..-.}-{2:2}, at: obj_cgroup_release+0x4a/0xe0
          but task is already holding lock:
          00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
          which lock already depends on the new lock.
          the existing dependency chain (in reverse order) is:
          -> #1 (&sighand->siglock){-.-.}-{2:2}:
                 __lock_acquire+0x604/0xbd8
                 lock_acquire.part.0+0xe2/0x238
                 lock_acquire+0xb0/0x200
                 _raw_spin_lock_irqsave+0x6a/0xd8
                 __lock_task_sighand+0x90/0x190
                 cgroup_freeze_task+0x2e/0x90
                 cgroup_migrate_execute+0x11c/0x608
                 cgroup_update_dfl_csses+0x246/0x270
                 cgroup_subtree_control_write+0x238/0x518
                 kernfs_fop_write_iter+0x13e/0x1e0
                 new_sync_write+0x100/0x190
                 vfs_write+0x22c/0x2d8
                 ksys_write+0x6c/0xf8
                 __do_syscall+0x1da/0x208
                 system_call+0x82/0xb0
          -> #0 (css_set_lock){..-.}-{2:2}:
                 check_prev_add+0xe0/0xed8
                 validate_chain+0x736/0xb20
                 __lock_acquire+0x604/0xbd8
                 lock_acquire.part.0+0xe2/0x238
                 lock_acquire+0xb0/0x200
                 _raw_spin_lock_irqsave+0x6a/0xd8
                 obj_cgroup_release+0x4a/0xe0
                 percpu_ref_put_many.constprop.0+0x150/0x168
                 drain_obj_stock+0x94/0xe8
                 refill_obj_stock+0x94/0x278
                 obj_cgroup_charge+0x164/0x1d8
                 kmem_cache_alloc+0xac/0x528
                 __sigqueue_alloc+0x150/0x308
                 __send_signal+0x260/0x550
                 send_signal+0x7e/0x348
                 force_sig_info_to_task+0x104/0x180
                 force_sig_fault+0x48/0x58
                 __do_pgm_check+0x120/0x1f0
                 pgm_check_handler+0x11e/0x180
          other info that might help us debug this:
           Possible unsafe locking scenario:
                 CPU0                    CPU1
                 ----                    ----
            lock(&sighand->siglock);
                                         lock(css_set_lock);
                                         lock(&sighand->siglock);
            lock(css_set_lock);
           *** DEADLOCK ***
          2 locks held by mmap1/202299:
           #0: 00000000ca3b3818 (&sighand->siglock){-.-.}-{2:2}, at: force_sig_info_to_task+0x38/0x180
           #1: 00000001892ad560 (rcu_read_lock){....}-{1:2}, at: percpu_ref_put_many.constprop.0+0x0/0x168
          stack backtrace:
          CPU: 15 PID: 202299 Comm: mmap1 Not tainted 5.17.0-20220113.rc0.git0.f2211f194038.300.fc35.s390x+debug #1
          Hardware name: IBM 3906 M04 704 (LPAR)
          Call Trace:
            dump_stack_lvl+0x76/0x98
            check_noncircular+0x136/0x158
            check_prev_add+0xe0/0xed8
            validate_chain+0x736/0xb20
            __lock_acquire+0x604/0xbd8
            lock_acquire.part.0+0xe2/0x238
            lock_acquire+0xb0/0x200
            _raw_spin_lock_irqsave+0x6a/0xd8
            obj_cgroup_release+0x4a/0xe0
            percpu_ref_put_many.constprop.0+0x150/0x168
            drain_obj_stock+0x94/0xe8
            refill_obj_stock+0x94/0x278
            obj_cgroup_charge+0x164/0x1d8
            kmem_cache_alloc+0xac/0x528
            __sigqueue_alloc+0x150/0x308
            __send_signal+0x260/0x550
            send_signal+0x7e/0x348
            force_sig_info_to_task+0x104/0x180
            force_sig_fault+0x48/0x58
            __do_pgm_check+0x120/0x1f0
            pgm_check_handler+0x11e/0x180
          INFO: lockdep is turned off.

In this example a slab allocation from __send_signal() caused a
refilling and draining of a percpu objcg stock, resulted in a releasing
of another non-related objcg.  Objcg release path requires taking the
css_set_lock, which is used to synchronize objcg lists.

This can create a circular dependency with the sighandler lock, which is
taken with the locked css_set_lock by the freezer code (to freeze a
task).

In general it seems that using css_set_lock to synchronize objcg lists
makes any slab allocations and deallocation with the locked css_set_lock
and any intervened locks risky.

To fix the problem and make the code more robust let's stop using
css_set_lock to synchronize objcg lists and use a new dedicated spinlock
instead.

Link: https://lkml.kernel.org/r/Yfm1IHmoGdyUR81T@carbon.dhcp.thefacebook.com
Fixes: bf4f0599 ("mm: memcg/slab: obj_cgroup API")
Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A soft lockup bug in kcompactd was reported in a private bugzilla with
the following visible in dmesg;

  watchdog: BUG: soft lockup - CPU#33 stuck for 26s! [kcompactd0:479]
  watchdog: BUG: soft lockup - CPU#33 stuck for 52s! [kcompactd0:479]
  watchdog: BUG: soft lockup - CPU#33 stuck for 78s! [kcompactd0:479]
  watchdog: BUG: soft lockup - CPU#33 stuck for 104s! [kcompactd0:479]

The machine had 256G of RAM with no swap and an earlier failed
allocation indicated that node 0 where kcompactd was run was potentially
unreclaimable;

  Node 0 active_anon:29355112kB inactive_anon:2913528kB active_file:0kB
    inactive_file:0kB unevictable:64kB isolated(anon):0kB isolated(file):0kB
    mapped:8kB dirty:0kB writeback:0kB shmem:26780kB shmem_thp:
    0kB shmem_pmdmapped: 0kB anon_thp: 23480320kB writeback_tmp:0kB
    kernel_stack:2272kB pagetables:24500kB all_unreclaimable? yes

Vlastimil Babka investigated a crash dump and found that a task
migrating pages was trying to drain PCP lists;

  PID: 52922  TASK: ffff969f820e5000  CPU: 19  COMMAND: "kworker/u128:3"
  Call Trace:
     __schedule
     schedule
     schedule_timeout
     wait_for_completion
     __flush_work
     __drain_all_pages
     __alloc_pages_slowpath.constprop.114
     __alloc_pages
     alloc_migration_target
     migrate_pages
     migrate_to_node
     do_migrate_pages
     cpuset_migrate_mm_workfn
     process_one_work
     worker_thread
     kthread
     ret_from_fork

This failure is specific to CONFIG_PREEMPT=n builds.  The root of the
problem is that kcompact0 is not rescheduling on a CPU while a task that
has isolated a large number of the pages from the LRU is waiting on
kcompact0 to reschedule so the pages can be released.  While
shrink_inactive_list() only loops once around too_many_isolated, reclaim
can continue without rescheduling if sc->skipped_deactivate == 1 which
could happen if there was no file LRU and the inactive anon list was not
low.

Link: https://lkml.kernel.org/r/20220203100326.GD3301@suse.de
Fixes: d818fca1 ("mm/vmscan: throttle reclaim and compaction when too may pages are isolated")
Signed-off-by: Mel Gorman <mgorman@suse.de>
Debugged-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The syzbot reported the below BUG:

  kernel BUG at include/linux/page-flags.h:785!
  invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  CPU: 1 PID: 4392 Comm: syz-executor560 Not tainted 5.16.0-rc6-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:PageDoubleMap include/linux/page-flags.h:785 [inline]
  RIP: 0010:__page_mapcount+0x2d2/0x350 mm/util.c:744
  Call Trace:
    page_mapcount include/linux/mm.h:837 [inline]
    smaps_account+0x470/0xb10 fs/proc/task_mmu.c:466
    smaps_pte_entry fs/proc/task_mmu.c:538 [inline]
    smaps_pte_range+0x611/0x1250 fs/proc/task_mmu.c:601
    walk_pmd_range mm/pagewalk.c:128 [inline]
    walk_pud_range mm/pagewalk.c:205 [inline]
    walk_p4d_range mm/pagewalk.c:240 [inline]
    walk_pgd_range mm/pagewalk.c:277 [inline]
    __walk_page_range+0xe23/0x1ea0 mm/pagewalk.c:379
    walk_page_vma+0x277/0x350 mm/pagewalk.c:530
    smap_gather_stats.part.0+0x148/0x260 fs/proc/task_mmu.c:768
    smap_gather_stats fs/proc/task_mmu.c:741 [inline]
    show_smap+0xc6/0x440 fs/proc/task_mmu.c:822
    seq_read_iter+0xbb0/0x1240 fs/seq_file.c:272
    seq_read+0x3e0/0x5b0 fs/seq_file.c:162
    vfs_read+0x1b5/0x600 fs/read_write.c:479
    ksys_read+0x12d/0x250 fs/read_write.c:619
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x44/0xae

The reproducer was trying to read /proc/$PID/smaps when calling
MADV_FREE at the mean time.  MADV_FREE may split THPs if it is called
for partial THP.  It may trigger the below race:

           CPU A                         CPU B
           -----                         -----
  smaps walk:                      MADV_FREE:
  page_mapcount()
    PageCompound()
                                   split_huge_page()
    page = compound_head(page)
    PageDoubleMap(page)

When calling PageDoubleMap() this page is not a tail page of THP anymore
so the BUG is triggered.

This could be fixed by elevated refcount of the page before calling
mapcount, but that would prevent it from counting migration entries, and
it seems overkilling because the race just could happen when PMD is
split so all PTE entries of tail pages are actually migration entries,
and smaps_account() does treat migration entries as mapcount == 1 as
Kirill pointed out.

Add a new parameter for smaps_account() to tell this entry is migration
entry then skip calling page_mapcount().  Don't skip getting mapcount
for device private entries since they do track references with mapcount.

Pagemap also has the similar issue although it was not reported.  Fixed
it as well.

[shy828301@gmail.com: v4]
  Link: https://lkml.kernel.org/r/20220203182641.824731-1-shy828301@gmail.com
[nathan@kernel.org: avoid unused variable warning in pagemap_pmd_range()]
  Link: https://lkml.kernel.org/r/20220207171049.1102239-1-nathan@kernel.org
Link: https://lkml.kernel.org/r/20220120202805.3369-1-shy828301@gmail.com
Fixes: e9b61f19 ("thp: reintroduce split_huge_page()")
Signed-off-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: syzbot+1f52b3a18d5633fa7f82@syzkaller.appspotmail.com
Acked-by: David Hildenbrand <david@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>