As Hagbard Celine reported:

Hi, this is a long standing bug that I've hit before on older kernels,
but I was not able to get the syslog saved because of the nature of
the bug. This time I had booted form a pen-drive, and was able to save
the log to it's efi-partition.
What i did to trigger it was to create a partition and format it f2fs,
then mount it with options:
"rw,relatime,lazytime,background_gc=on,disable_ext_identify,discard,heap,user_xattr,inline_xattr,acl,inline_data,inline_dentry,flush_merge,data_flush,extent_cache,mode=adaptive,active_logs=6,whint_mode=fs-based,alloc_mode=default,fsync_mode=strict".
Then I unpacked a big .tar.xz to the partition (I used a
gentoo-stage3-tarball as I was in process of installing Gentoo).

Same options just without data_flush gives no problems.

Mar 20 20:54:01 usbgentoo kernel: FAT-fs (nvme0n1p4): Volume was not
properly unmounted. Some data may be corrupt. Please run fsck.
Mar 20 21:05:23 usbgentoo kernel: kworker/dying (1588) used greatest
stack depth: 12064 bytes left
Mar 20 21:06:40 usbgentoo kernel: BUG: stack guard page was hit at
00000000a4b0733c (stack is 0000000056016422..0000000096e7463f)
Mar 20 21:06:40 usbgentoo kernel: kernel stack overflow

......

Mar 20 21:06:40 usbgentoo kernel: Call Trace:
Mar 20 21:06:40 usbgentoo kernel:  read_node_page+0x71/0xf0
Mar 20 21:06:40 usbgentoo kernel:  ? xas_load+0x8/0x50
Mar 20 21:06:40 usbgentoo kernel:  __get_node_page+0x73/0x2a0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_get_dnode_of_data+0x34e/0x580
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_inline_data+0x5e/0x2a0
Mar 20 21:06:40 usbgentoo kernel:  __write_data_page+0x421/0x690
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_cache_pages+0x1cf/0x460
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_data_pages+0x2b3/0x2e0
Mar 20 21:06:40 usbgentoo kernel:  ? f2fs_inode_chksum_verify+0x1d/0xc0
Mar 20 21:06:40 usbgentoo kernel:  ? read_node_page+0x71/0xf0
Mar 20 21:06:40 usbgentoo kernel:  do_writepages+0x3c/0xd0
Mar 20 21:06:40 usbgentoo kernel:  __filemap_fdatawrite_range+0x7c/0xb0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_sync_dirty_inodes+0xf2/0x200
Mar 20 21:06:40 usbgentoo kernel:  f2fs_balance_fs_bg+0x2a3/0x2c0
Mar 20 21:06:40 usbgentoo kernel:  ? f2fs_inode_dirtied+0x21/0xc0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_balance_fs+0xd6/0x2b0
Mar 20 21:06:40 usbgentoo kernel:  __write_data_page+0x4fb/0x690

......

Mar 20 21:06:40 usbgentoo kernel:  __writeback_single_inode+0x2a1/0x340
Mar 20 21:06:40 usbgentoo kernel:  ? soft_cursor+0x1b4/0x220
Mar 20 21:06:40 usbgentoo kernel:  writeback_sb_inodes+0x1d5/0x3e0
Mar 20 21:06:40 usbgentoo kernel:  __writeback_inodes_wb+0x58/0xa0
Mar 20 21:06:40 usbgentoo kernel:  wb_writeback+0x250/0x2e0
Mar 20 21:06:40 usbgentoo kernel:  ? 0xffffffff8c000000
Mar 20 21:06:40 usbgentoo kernel:  ? cpumask_next+0x16/0x20
Mar 20 21:06:40 usbgentoo kernel:  wb_workfn+0x2f6/0x3b0
Mar 20 21:06:40 usbgentoo kernel:  ? __switch_to_asm+0x40/0x70
Mar 20 21:06:40 usbgentoo kernel:  process_one_work+0x1f5/0x3f0
Mar 20 21:06:40 usbgentoo kernel:  worker_thread+0x28/0x3c0
Mar 20 21:06:40 usbgentoo kernel:  ? rescuer_thread+0x330/0x330
Mar 20 21:06:40 usbgentoo kernel:  kthread+0x10e/0x130
Mar 20 21:06:40 usbgentoo kernel:  ? kthread_create_on_node+0x60/0x60
Mar 20 21:06:40 usbgentoo kernel:  ret_from_fork+0x35/0x40

The root cause is that we run into an infinite recursive calling in
between f2fs_balance_fs_bg and writepage() as described below:

- f2fs_write_data_pages		--- A
 - __write_data_page
  - f2fs_balance_fs
   - f2fs_balance_fs_bg		--- B
    - f2fs_sync_dirty_inodes
     - filemap_fdatawrite
      - f2fs_write_data_pages	--- A
...
          - f2fs_balance_fs_bg	--- B
...

In order to fix this issue, let's detect such condition in __write_data_page()
and just skip calling f2fs_balance_fs() recursively.
Reported-by: Hagbard Celine <hagbardcelin@gmail.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs_hw_support_discard() only tests if the super block device supports
discard. However, for a multi-device volume, not all disks used may
support discard. Improve the check performed to test all devices of
the volume and report discard as supported if at least one device of
the volume supports discard. To implement this, introduce the helper
function f2fs_bdev_support_discard(), which returns true for zoned block
devices (where discard is processed as a zone reset) and for regular
disks supporting the discard command.

f2fs_bdev_support_discard() is also used in __queue_discard_cmd() to
handle discard command issuing for a particular device of the volume.
That is, prevent issuing a discard command for block devices that do
not support it.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

For zoned block devices, an array of zone types for each device is
allocated and initialized in order to determine if a section is stored
on a sequential zone (zone reset needed) or a conventional zone (no
zone reset needed and regular discard applies). Considering this usage,
the zone types stored in memory can be replaced with a bitmap to
indicate an equivalent information, that is, if a zone is sequential or
not. This reduces the memory usage for each zoned device by roughly 8:
on a 14TB disk with zones of 256 MB, the zone type array consumes
13x4KB pages while the bitmap uses only 2x4KB pages.

This patch changes the f2fs_dev_info structure blkz_type field to the
bitmap blkz_seq. Access to this bitmap is done using the helper
function f2fs_blkz_is_seq(), which is a rewrite of the function
get_blkz_type().
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

For a single device mount using a zoned block device, the zone
information for the device is stored in the sbi->devs single entry
array and sbi->s_ndevs is set to 1. This differs from a single device
mount using a regular block device which does not allocate sbi->devs
and sets sbi->s_ndevs to 0.

However, sbi->s_devs == 0 condition is used throughout the code to
differentiate a single device mount from a multi-device mount where
sbi->s_ndevs is always larger than 1. This results in problems with
single zoned block device volumes as these are treated as multi-device
mounts but do not have the start_blk and end_blk information set. One
of the problem observed is skipping of zone discard issuing resulting in
write commands being issued to full zones or unaligned to a zone write
pointer.

Fix this problem by simply treating the cases sbi->s_ndevs == 0 (single
regular block device mount) and sbi->s_ndevs == 1 (single zoned block
device mount) in the same manner. This is done by introducing the
helper function f2fs_is_multi_device() and using this helper in place
of direct tests of sbi->s_ndevs value, improving code readability.

Fixes: 7bb3a371 ("f2fs: Fix zoned block device support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull HID fixes from Jiri Kosina:

 - build dependency fix for hid-asus from Arnd Bergmann

 - addition of omitted mapping of _ASSISTANT key from Dmitry Torokhov

 - race condition fix in hid-debug inftastructure from He, Bo

 - fixed support for devices with big maximum report size from Kai-Heng
   Feng

 - deadlock fix in hid-steam from Rodrigo Rivas Costa

 - quite a few device-specific quirks

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: input: add mapping for Assistant key
  HID: i2c-hid: Disable runtime PM on Synaptics touchpad
  HID: quirks: Fix keyboard + touchpad on Lenovo Miix 630
  HID: logitech: Handle 0 scroll events for the m560
  HID: debug: fix race condition with between rdesc_show() and device removal
  HID: logitech: check the return value of create_singlethread_workqueue
  HID: Increase maximum report size allowed by hid_field_extract()
  HID: steam: fix deadlock with input devices.
  HID: uclogic: remove redudant duplicated null check on ver_ptr
  HID: quirks: Drop misused kernel-doc annotation
  HID: hid-asus: select CONFIG_POWER_SUPPLY
  HID: quirks: use correct format chars in dbg_hid

According to HUTRR89 usage 0x1cb from the consumer page was assigned to
allow launching desktop-aware assistant application, so let's add the
mapping.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Pull pidfd fix from Christian Brauner:
 "This should be an uncontroversial fix for pidfd_send_signal() by Jann
  to better align it's behavior with other signal sending functions:

  In one of the early versions of the patchset it was suggested to not
  unconditionally error out when a signal with SI_USER is sent to a
  non-current task (cf. [1]).

  Instead, pidfd_send_signal() currently silently changes this to a
  regular kill signal. While this is technically fine, the semantics are
  weird since the kernel just silently converts a user's request behind
  their back and also no other signal sending function allows to do
  this. It gets more hairy when we introduce sending signals to a
  specific thread soon.

  So let's align pidfd_send_signal() with all the other signal sending
  functions and error out when SI_USER signals are sent to a non-current
  task"

* tag 'pidfd-fixes-v5.1-rc3' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux:
  signal: don't silently convert SI_USER signals to non-current pidfd

Merge tag 'hwmon-for-v5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Couple of minor hwmon fixes"

* tag 'hwmon-for-v5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  dt-bindings: hwmon: (adc128d818) Specify ti,mode property size
  hwmon: (ntc_thermistor) Fix temperature type reporting
  hwmon: (occ) Fix power sensor indexing
  hwmon: (w83773g) Select REGMAP_I2C to fix build error

The @linaro version won't be valid much longer.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The current sys_pidfd_send_signal() silently turns signals with explicit
SI_USER context that are sent to non-current tasks into signals with
kernel-generated siginfo.
This is unlike do_rt_sigqueueinfo(), which returns -EPERM in this case.
If a user actually wants to send a signal with kernel-provided siginfo,
they can do that with pidfd_send_signal(pidfd, sig, NULL, 0); so allowing
this case is unnecessary.

Instead of silently replacing the siginfo, just bail out with an error;
this is consistent with other interfaces and avoids special-casing behavior
based on security checks.

Fixes: 3eb39f47 ("signal: add pidfd_send_signal() syscall")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Christian Brauner <christian@brauner.io>

Pull aio race fixes and cleanups from Al Viro.

The aio code had more issues with error handling and races with the aio
completing at just the right (wrong) time along with freeing the file
descriptor when another thread closes the file.

Just a couple of these commits are the actual fixes: the others are
cleanups to either make the fixes simpler, or to make the code legible
and understandable enough that we hope there's no more fundamental races
hiding.

* 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: move sanity checks and request allocation to io_submit_one()
  deal with get_reqs_available() in aio_get_req() itself
  aio: move dropping ->ki_eventfd into iocb_destroy()
  make aio_read()/aio_write() return int
  Fix aio_poll() races
  aio: store event at final iocb_put()
  aio: keep io_event in aio_kiocb
  aio: fold lookup_kiocb() into its sole caller
  pin iocb through aio.

Pull symlink fixes from Al Viro:
 "The ceph fix is already in mainline, Daniel's bpf fix is in bpf tree
  (1da6c4d9 "bpf: fix use after free in bpf_evict_inode"), the rest
  is in here"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  debugfs: fix use-after-free on symlink traversal
  ubifs: fix use-after-free on symlink traversal
  jffs2: fix use-after-free on symlink traversal

We have a new Dell laptop which has the synaptics I2C touchpad
(06cb:7e7e) on it. After booting up the Linux, the touchpad doesn't
work, there is no interrupt when touching the touchpad, after
disable the runtime PM, everything works well.

I also tried the quirk of I2C_HID_QUIRK_DELAY_AFTER_SLEEP, it is
better after applied this quirk, there are interrupts but data it
reports is invalid.
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

symlink body shouldn't be freed without an RCU delay.  Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback.  Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull KVM fixes from Paolo Bonzini:
 "A collection of x86 and ARM bugfixes, and some improvements to
  documentation.

  On top of this, a cleanup of kvm_para.h headers, which were exported
  by some architectures even though they not support KVM at all. This is
  responsible for all the Kbuild changes in the diffstat"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
  Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION
  KVM: doc: Document the life cycle of a VM and its resources
  KVM: selftests: complete IO before migrating guest state
  KVM: selftests: disable stack protector for all KVM tests
  KVM: selftests: explicitly disable PIE for tests
  KVM: selftests: assert on exit reason in CR4/cpuid sync test
  KVM: x86: update %rip after emulating IO
  x86/kvm/hyper-v: avoid spurious pending stimer on vCPU init
  kvm/x86: Move MSR_IA32_ARCH_CAPABILITIES to array emulated_msrs
  KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts
  kvm: don't redefine flags as something else
  kvm: mmu: Used range based flushing in slot_handle_level_range
  KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported
  KVM: x86: remove check on nr_mmu_pages in kvm_arch_commit_memory_region()
  kvm: nVMX: Add a vmentry check for HOST_SYSENTER_ESP and HOST_SYSENTER_EIP fields
  KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)
  KVM: Reject device ioctls from processes other than the VM's creator
  KVM: doc: Fix incorrect word ordering regarding supported use of APIs
  KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size'
  KVM: nVMX: Do not inherit quadrant and invalid for the root shadow EPT
  ...

Pull x86 fixes from Thomas Gleixner:
 "A pile of x86 updates:

   - Prevent exceeding he valid physical address space in the /dev/mem
     limit checks.

   - Move all header content inside the header guard to prevent compile
     failures.

   - Fix the bogus __percpu annotation in this_cpu_has() which makes
     sparse very noisy.

   - Disable switch jump tables completely when retpolines are enabled.

   - Prevent leaking the trampoline address"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/realmode: Make set_real_mode_mem() static inline
  x86/cpufeature: Fix __percpu annotation in this_cpu_has()
  x86/mm: Don't exceed the valid physical address space
  x86/retpolines: Disable switch jump tables when retpolines are enabled
  x86/realmode: Don't leak the trampoline kernel address
  x86/boot: Fix incorrect ifdeffery scope
  x86/resctrl: Remove unused variable

Pull perf tooling fixes from Thomas Gleixner:
 "Core libraries:
   - Fix max perf_event_attr.precise_ip detection.
   - Fix parser error for uncore event alias
   - Fixup ordering of kernel maps after obtaining the main kernel map
     address.

  Intel PT:
   - Fix TSC slip where A TSC packet can slip past MTC packets so that
     the timestamp appears to go backwards.
   - Fixes for exported-sql-viewer GUI conversion to python3.

  ARM coresight:
   - Fix the build by adding a missing case value for enumeration value
     introduced in newer library, that now is the required one.

  tool headers:
   - Syncronize kernel headers with the kernel, getting new io_uring and
     pidfd_send_signal syscalls so that 'perf trace' can handle them"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf pmu: Fix parser error for uncore event alias
  perf scripts python: exported-sql-viewer.py: Fix python3 support
  perf scripts python: exported-sql-viewer.py: Fix never-ending loop
  perf machine: Update kernel map address and re-order properly
  tools headers uapi: Sync powerpc's asm/kvm.h copy with the kernel sources
  tools headers: Update x86's syscall_64.tbl and uapi/asm-generic/unistd
  tools headers uapi: Update drm/i915_drm.h
  tools arch x86: Sync asm/cpufeatures.h with the kernel sources
  tools headers uapi: Sync linux/fcntl.h to get the F_SEAL_FUTURE_WRITE addition
  tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h
  perf evsel: Fix max perf_event_attr.precise_ip detection
  perf intel-pt: Fix TSC slip
  perf cs-etm: Add missing case value

Pull CPU hotplug fixes from Thomas Gleixner:
 "Two SMT/hotplug related fixes:

   - Prevent crash when HOTPLUG_CPU is disabled and the CPU bringup
     aborts. This is triggered with the 'nosmt' command line option, but
     can happen by any abort condition. As the real unplug code is not
     compiled in, prevent the fail by keeping the CPU in zombie state.

   - Enforce HOTPLUG_CPU for SMP on x86 to avoid the above situation
     completely. With 'nosmt' being a popular option it's required to
     unplug the half brought up sibling CPUs (due to the MCE wreckage)
     completely"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/smp: Enforce CONFIG_HOTPLUG_CPU when SMP=y
  cpu/hotplug: Prevent crash when CPU bringup fails on CONFIG_HOTPLUG_CPU=n

Pull locking fixlet from Thomas Gleixner:
 "Trivial update to the maintainers file"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Remove deleted file from futex file pattern

Pull core fixes from Thomas Gleixner:
 "A small set of core updates:

   - Make the watchdog respect the selected CPU mask again. That was
     broken by the rework of the watchdog thread management and caused
     inconsistent state and NMI watchdog being unstoppable.

   - Ensure that the objtool build can find the libelf location.

   - Remove dead kcore stub code"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog: Respect watchdog cpumask on CPU hotplug
  objtool: Query pkg-config for libelf location
  proc/kcore: Remove unused kclist_add_remap()

Pull powerpc fixes from Michael Ellerman:
 "Three non-regression fixes.

   - Our optimised memcmp could read past the end of one of the buffers
     and potentially trigger a page fault leading to an oops.

   - Some of our code to read energy management data on PowerVM had an
     endian bug leading to bogus results.

   - When reporting a machine check exception we incorrectly reported
     TLB multihits as D-Cache multhits due to a missing entry in the
     array of causes.

  Thanks to: Chandan Rajendra, Gautham R. Shenoy, Mahesh Salgaonkar,
  Segher Boessenkool, Vaidyanathan Srinivasan"

* tag 'powerpc-5.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/mce: Fix misleading print for TLB mutlihit
  powerpc/pseries/energy: Use OF accessor functions to read ibm,drc-indexes
  powerpc/64: Fix memcmp reading past the end of src/dest

Pull dmaengine fixes from Vinod Koul:

 - Revert "dmaengine: stm32-mdma: Add a check on read_u32_array" as that
   caused regression

 - Fix MAINTAINER file uniphier-mdmac.c file path

* tag 'dmaengine-fix-5.1-rc3' of git://git.infradead.org/users/vkoul/slave-dma:
  MAINTAINERS: Fix uniphier-mdmac.c file path
  dmaengine: stm32-mdma: Revert "dmaengine: stm32-mdma: Add a check on read_u32_array"

Merge tag 'led-fixes-for-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fixes from Jacek Anaszewski:

 - fix refcnt leak on interface rename

 - use memcpy in device_name_store() to avoid including garbage from a
   previous, longer value in the device_name

 - fix a potential NULL pointer dereference in case of_match_device()
   cannot find a match

* tag 'led-fixes-for-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: trigger: netdev: use memcpy in device_name_store
  leds: pca9532: fix a potential NULL pointer dereference
  leds: trigger: netdev: fix refcnt leak on interface rename

Pull GPIO fixes from Linus Walleij:
 "As you can see [in the git history] I was away on leave and Bartosz
  kindly stepped in and collected a slew of fixes, I pulled them into my
  tree in two sets and merged some two more fixes (fixing my own caused
  bugs) on top.

  Summary:

   - Revert the extended use of gpio_set_config() and think about how we
     can do this properly.

   - Fix up the SPI CS GPIO handling so it now works properly on the SPI
     bus children, as intended.

   - Error paths and driver fixes"

* tag 'gpio-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mockup: use simple_read_from_buffer() in debugfs read callback
  gpio: of: Fix of_gpiochip_add() error path
  gpio: of: Check for "spi-cs-high" in child instead of parent node
  gpio: of: Check propname before applying "cs-gpios" quirks
  gpio: mockup: fix debugfs read
  Revert "gpio: use new gpio_set_config() helper in more places"
  gpio: aspeed: fix a potential NULL pointer dereference
  gpio: amd-fch: Fix bogus SPDX identifier
  gpio: adnp: Fix testing wrong value in adnp_gpio_direction_input
  gpio: exar: add a check for the return value of ida_simple_get fails

If userspace doesn't end the input with a newline (which can easily
happen if the write happens from a C program that does write(fd,
iface, strlen(iface))), we may end up including garbage from a
previous, longer value in the device_name. For example

# cat device_name

# printf 'eth12' > device_name
# cat device_name
eth12
# printf 'eth3' > device_name
# cat device_name
eth32

I highly doubt anybody is relying on this behaviour, so switch to
simply copying the bytes (we've already checked that size is <
IFNAMSIZ) and unconditionally zero-terminate it; of course, we also
still have to strip a trailing newline.

This is also preparation for future patches.

Fixes: 06f502f5 ("leds: trigger: Introduce a NETDEV trigger")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

In case of_match_device cannot find a match, return -EINVAL to avoid
NULL pointer dereference.

Fixes: fa4191a6 ("leds: pca9532: Add device tree support")
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for 5.1-rc3, and one driver
  removal.

  The biggest thing here is the removal of the mt7621-eth driver as a
  "real" network driver was merged in 5.1-rc1 for this hardware, so this
  old driver can now be removed.

  Other than that, there are just a number of small fixes, all resolving
  reported issues and some potential corner cases for error handling
  paths.

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

* tag 'staging-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: vt6655: Remove vif check from vnt_interrupt
  staging: erofs: keep corrupted fs from crashing kernel in erofs_readdir()
  staging: octeon-ethernet: fix incorrect PHY mode
  staging: vc04_services: Fix an error code in vchiq_probe()
  staging: erofs: fix error handling when failed to read compresssed data
  staging: vt6655: Fix interrupt race condition on device start up.
  staging: rtlwifi: Fix potential NULL pointer dereference of kzalloc
  staging: rtl8712: uninitialized memory in read_bbreg_hdl()
  staging: rtlwifi: rtl8822b: fix to avoid potential NULL pointer dereference
  staging: rtl8188eu: Fix potential NULL pointer dereference of kcalloc
  staging, mt7621-pci: fix build without pci support
  staging: speakup_soft: Fix alternate speech with other synths
  staging: axis-fifo: add CONFIG_OF dependency
  staging: olpc_dcon_xo_1: add missing 'const' qualifier
  staging: comedi: ni_mio_common: Fix divide-by-zero for DIO cmdtest
  staging: erofs: fix to handle error path of erofs_vmap()
  staging: mt7621-dts: update ethernet settings.
  staging: remove mt7621-eth

Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 5.1-rc3.

  Nothing major here, just a number of potential problems fixes for
  error handling paths, as well as some other minor bugfixes for
  reported issues with 5.1-rc1.

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

* tag 'tty-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix NULL pointer issue when tty_port ops is not set
  Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc
  dt-bindings: serial: Add compatible for Mediatek MT8183
  tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped
  tty/serial: atmel: Add is_half_duplex helper
  serial: sh-sci: Fix setting SCSCR_TIE while transferring data
  serial: ar933x_uart: Fix build failure with disabled console
  tty: serial: qcom_geni_serial: Initialize baud in qcom_geni_console_setup
  sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()
  tty: mxs-auart: fix a potential NULL pointer dereference
  tty: atmel_serial: fix a potential NULL pointer dereference
  serial: max310x: Fix to avoid potential NULL pointer dereference
  serial: mvebu-uart: Fix to avoid a potential NULL pointer dereference

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 5.1-rc3.

  Nothing major at all here, just a small collection of fixes for
  reported issues, and potential problems with error handling paths.
  Also a few new device ids, as normal.

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

* tag 'usb-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
  USB: serial: option: add Olicard 600
  USB: serial: cp210x: add new device id
  usb: u132-hcd: fix resource leak
  usb: cdc-acm: fix race during wakeup blocking TX traffic
  usb: mtu3: fix EXTCON dependency
  usb: usb251xb: fix to avoid potential NULL pointer dereference
  usb: core: Try generic PHY_MODE_USB_HOST if usb_phy_roothub_set_mode fails
  phy: sun4i-usb: Support set_mode to USB_HOST for non-OTG PHYs
  xhci: Don't let USB3 ports stuck in polling state prevent suspend
  usb: xhci: dbc: Don't free all memory with spinlock held
  xhci: Fix port resume done detection for SS ports with LPM enabled
  USB: serial: mos7720: fix mos_parport refcount imbalance on error path
  USB: gadget: f_hid: fix deadlock in f_hidg_write()
  usb: gadget: net2272: Fix net2272_dequeue()
  usb: gadget: net2280: Fix net2280_dequeue()
  usb: gadget: net2280: Fix overrun of OUT messages
  usb: dwc3: pci: add support for Comet Lake PCH ID
  usb: usb251xb: Remove unnecessary comparison of unsigned integer with >= 0
  usb: common: Consider only available nodes for dr_mode
  usb: typec: tcpm: Try PD-2.0 if sink does not respond to 3.0 source-caps
  ...

Pull ACPI fix from Rafael Wysocki:
 "This corrects a previous attempt to make Linux use its own set of ACPI
  debug flags different from the upstream ACPICA's default (Erik
  Schmauss)"

* tag 'acpi-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: use different default debug value than ACPICA

Pull power management fixes from Rafael Wysocki:
 "These fix CPU base frequency reporting in the intel_pstate driver and
  a use-after-free in the scpi-cpufreq driver.

  Specifics:

   - Fix the ACPI CPPC library to actually follow the specification when
     decoding the guaranteed performance register information and make
     the intel_pstate driver to fall back to the nominal frequency when
     reporting the base frequency if the guaranteed performance register
     information is not there (Srinivas Pandruvada).

   - Fix use-after-free in the exit callback of the scpi-cpufreq left
     after an update during the 5.0 development cycle (Vincent Stehlé)"

* tag 'pm-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: scpi: Fix use after free
  cpufreq: intel_pstate: Also use CPPC nominal_perf for base_frequency
  ACPI / CPPC: Fix guaranteed performance handling

Pull security layer fixes from James Morris:
 "Yama and LSM config fixes"

* 'fixes-v5.1-a' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  LSM: Revive CONFIG_DEFAULT_SECURITY_* for "make oldconfig"
  Yama: mark local symbols as static

Merge misc fixes from Andrew Morton:
 "22 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links
  fs: fs_parser: fix printk format warning
  checkpatch: add %pt as a valid vsprintf extension
  mm/migrate.c: add missing flush_dcache_page for non-mapped page migrate
  drivers/block/zram/zram_drv.c: fix idle/writeback string compare
  mm/page_isolation.c: fix a wrong flag in set_migratetype_isolate()
  mm/memory_hotplug.c: fix notification in offline error path
  ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK
  fs/proc/kcore.c: make kcore_modules static
  include/linux/list.h: fix list_is_first() kernel-doc
  mm/debug.c: fix __dump_page when mapping->host is not set
  mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified
  include/linux/hugetlb.h: convert to use vm_fault_t
  iommu/io-pgtable-arm-v7s: request DMA32 memory, and improve debugging
  mm: add support for kmem caches in DMA32 zone
  ocfs2: fix inode bh swapping mixup in ocfs2_reflink_inodes_lock
  mm/hotplug: fix offline undo_isolate_page_range()
  fs/open.c: allow opening only regular files during execve()
  mailmap: add Changbin Du
  mm/debug.c: add a cast to u64 for atomic64_read()
  ...

Pull arm64 fix from Catalin Marinas:
 "Use memblock_alloc() instead of memblock_alloc_low() in
  request_standard_resources(), the latter being limited to the low 4G
  memory range on arm64"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: replace memblock_alloc_low with memblock_alloc

Pull IOMMU fixes from Joerg Roedel:

 - Fix a bug in the AMD IOMMU driver not handling exclusion ranges
   correctly. In fact the driver did not reserve these ranges for IOVA
   allocations, so that dma-handles could be allocated in an exclusion
   range, leading to data corruption. Exclusion ranges have not been
   used by any firmware up to now, so this issue remained undiscovered
   for quite some time.

 - Fix wrong warning messages that the IOMMU core code prints when it
   tries to allocate the default domain for an iommu group and the
   driver does not support any of the default domain types (like Intel
   VT-d).

* tag 'iommu-fixes-v5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Reserve exclusion range in iova-domain
  iommu: Don't print warning when IOMMU driver only supports unmanaged domains

Pull driver core fix from Greg KH:
 "Here is a single driver core patch for 5.1-rc3.

  After 5.1-rc1, all of the users of BUS_ATTR() are finally removed, so
  we can now drop this macro from include/linux/device.h so that no more
  new users will be created.

  This patch has been in linux-next for a while, with no reported
  issues"

* tag 'driver-core-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: remove BUS_ATTR()

Pull char/misc driver fixes from Greg KH:
 "Here are some binder, habanalabs, and vboxguest driver fixes for
  5.1-rc3.

  The Binder fixes resolve some reported issues found by testing, first
  by the selinux developers, and then earlier today by syzbot.

  The habanalabs fixes are all minor, resolving a number of tiny things.

  The vboxguest patches are a bit larger. They resolve the fact that
  virtual box decided to change their api in their latest release in a
  way that broke the existing kernel code, despite saying that they were
  never going to do that. So this is a bit of a "new feature", but is
  good to get merged so that 5.1 will work with the latest release. The
  changes are not large and of course virtual box "swears" they will not
  break this again, but no one is holding their breath here.

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

* tag 'char-misc-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x
  binder: fix race between munmap() and direct reclaim
  binder: fix BUG_ON found by selinux-testsuite
  habanalabs: cast to expected type
  habanalabs: prevent host crash during suspend/resume
  habanalabs: perform accounting for active CS
  habanalabs: fix mapping with page size bigger than 4KB
  habanalabs: complete user context cleanup before hard reset
  habanalabs: fix bug when mapping very large memory area
  habanalabs: fix MMU number of pages calculation