Recently people report bcache code compiled with gcc9 is broken, one of
the buggy behavior I observe is that two adjacent 4KB I/Os should merge
into one but they don't. Finally it turns out to be a stack corruption
caused by macro PRECEDING_KEY().

See how PRECEDING_KEY() is defined in bset.h,
437 #define PRECEDING_KEY(_k)                                       \
438 ({                                                              \
439         struct bkey *_ret = NULL;                               \
440                                                                 \
441         if (KEY_INODE(_k) || KEY_OFFSET(_k)) {                  \
442                 _ret = &KEY(KEY_INODE(_k), KEY_OFFSET(_k), 0);  \
443                                                                 \
444                 if (!_ret->low)                                 \
445                         _ret->high--;                           \
446                 _ret->low--;                                    \
447         }                                                       \
448                                                                 \
449         _ret;                                                   \
450 })

At line 442, _ret points to address of a on-stack variable combined by
KEY(), the life range of this on-stack variable is in line 442-446,
once _ret is returned to bch_btree_insert_key(), the returned address
points to an invalid stack address and this address is overwritten in
the following called bch_btree_iter_init(). Then argument 'search' of
bch_btree_iter_init() points to some address inside stackframe of
bch_btree_iter_init(), exact address depends on how the compiler
allocates stack space. Now the stack is corrupted.

Fixes: 0eacac22 ("bcache: PRECEDING_KEY()")
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reviewed-by: Pierre JUHEN <pierre.juhen@orange.fr>
Tested-by: Shenghui Wang <shhuiw@foxmail.com>
Tested-by: Pierre JUHEN <pierre.juhen@orange.fr>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk_mq_sched_free_requests() may be called in failure path in which
q->elevator may not be setup yet, so remove WARN_ON(!q->elevator) from
blk_mq_sched_free_requests for avoiding the false positive.

This function is actually safe to call in case of !q->elevator because
hctx->sched_tags is checked.

Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yi Zhang <yi.zhang@redhat.com>
Fixes: c3e22192 ("block: free sched's request pool in blk_cleanup_queue")
Reported-by: syzbot+b9d0d56867048c7bcfde@syzkaller.appspotmail.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

CFQ is gone. No need anymore to document its "proportional weight time
based division of disk policy".
Signed-off-by: Andreas Herrmann <aherrmann@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Remove references to CFQ and legacy block layer which are gone.
Update example with what's available under blk-mq.
Signed-off-by: Andreas Herrmann <aherrmann@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This patch removes the check in the null_blk_zoned for report zone
command, where it checks for the dev-,>zoned before executing the report
zone.

The null_zone_report() function is a block_device operation callback
which is initialized in the null_blk_main.c and gets called as a part
of blkdev for report zone IOCTL (BLKREPORTZONE).

blkdev_ioctl()
blkdev_report_zones_ioctl()
        blkdev_report_zones()
                blk_report_zones()
                        disk->fops->report_zones()
                                nullb_zone_report();

The null_zone_report() will never get executed on the non-zoned block
device, in the non zoned block device blk_queue_is_zoned() will always
be false which is first check the blkdev_report_zones_ioctl()
before actual low level driver report zone callback is executed.

Here is the detailed scenario:-

1. modprobe null_blk
null_init
null_alloc_dev
        dev->zoned = 0
null_add_dev
        dev->zoned == 0
                so we don't set the q->limits.zoned = BLK_ZONED_HR

2. blkzone report /dev/nullb0

blkdev_ioctl()
blkdev_report_zones_ioctl()
        blk_queue_is_zoned()
                blk_queue_is_zoned
                        q->limits.zoned == 0
                        return false
        if (!blk_queue_is_zoned(q)) <--- true
                return -ENOTTY;
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

When all of these checks are cleaned up, lots of the functions used in
the blk-mq-debugfs code can now return void, as no need to check the
return value of them either.

Overall, this ends up cleaning up the code and making it smaller, always
a nice win.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Opening and closing an io_uring instance leaks a UNIX domain socket
inode.  This is because the ->file of the io_uring instance's internal
UNIX domain socket is set to point to the io_uring file, but then
sock_release() sees the non-NULL ->file and assumes the inode reference
is held by the file so doesn't call iput().  That's not the case here,
since the reference is still meant to be held by the socket; the actual
inode of the io_uring file is different.

Fix this leak by NULL-ing out ->file before releasing the socket.

Reported-by: syzbot+111cb28d9f583693aefa@syzkaller.appspotmail.com
Fixes: 2b188cc1 ("Add io_uring IO interface")
Cc: <stable@vger.kernel.org> # v5.1+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In most use cases of zoned block devices (aka SMR disks), the
mq-deadline scheduler is mandatory as it implements sequential write
command processing guarantees with zone write locking. So make sure that
this scheduler is always enabled if CONFIG_BLK_DEV_ZONED is selected.
Tested-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There's some discussion on how to do this the best, and Tejun prefers
that BFQ just create the file itself instead of having cgroups support
a symlink feature.

Hence revert commit 54b7b868 and 19e9da9e for 5.2, and this
can be done properly for 5.3.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull ceph fixes from Ilya Dryomov:
 "A change to call iput() asynchronously to avoid a possible deadlock
  when iput_final() needs to wait for in-flight I/O (e.g. readahead) and
  a fixup for a cleanup that went into -rc1"

* tag 'ceph-for-5.2-rc4' of git://github.com/ceph/ceph-client:
  ceph: fix error handling in ceph_get_caps()
  ceph: avoid iput_final() while holding mutex or in dispatch thread
  ceph: single workqueue for inode related works

Pull xen fix from Juergen Gross:
 "Just one fix for the Xen block frontend driver avoiding allocations
  with order > 0"

* tag 'for-linus-5.2b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-blkfront: switch kcalloc to kvcalloc for large array allocation

Pull s390 fixes from Heiko Carstens:

 - fix stack unwinder: the stack unwinder rework has on off-by-one bug
   which prevents following stack backchains over more than one context
   (e.g. irq -> process).

 - fix address space detection in exception handler: if user space
   switches to access register mode, which is not supported anymore, the
   exception handler may resolve to the wrong address space.

* tag 's390-5.2-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/unwind: correct stack switching during unwind
  s390/mm: fix address space detection in exception handling

Pull MIPS fixes from Paul Burton:

 - Declare ginvt() __always_inline due to its use of an argument as an
   inline asm immediate.

 - A VDSO build fix following Kbuild changes made this cycle.

 - A fix for boot failures on txx9 systems following memory
   initialization changes made this cycle.

 - Bounds check virt_addr_valid() to prevent it spuriously indicating
   that bogus addresses are valid, in turn fixing hardened usercopy
   failures that have been present since v4.12.

 - Build uImage.gz for pistachio systems by default, since this is the
   image we need in order to actually boot on a board.

 - Remove an unused variable in our uprobes code.

* tag 'mips_fixes_5.2_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: uprobes: remove set but not used variable 'epc'
  MIPS: pistachio: Build uImage.gz by default
  MIPS: Make virt_addr_valid() return bool
  MIPS: Bounds check virt_addr_valid
  MIPS: TXx9: Fix boot crash in free_initmem()
  MIPS: remove a space after -I to cope with header search paths for VDSO
  MIPS: mark ginvt() as __always_inline

Pull yet more SPDX updates from Greg KH:
 "Another round of SPDX header file fixes for 5.2-rc4

  These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
  added, based on the text in the files. We are slowly chipping away at
  the 700+ different ways people tried to write the license text. All of
  these were reviewed on the spdx mailing list by a number of different
  people.

  We now have over 60% of the kernel files covered with SPDX tags:
	$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
	Files checked:            64533
	Files with SPDX:          40392
	Files with errors:            0

  I think the majority of the "easy" fixups are now done, it's now the
  start of the longer-tail of crazy variants to wade through"

* tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429
  ...

Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 5.2-rc4 to resolve
  a number of reported issues.

  The most "notable" one here is the kernel headers in proc^Wsysfs
  fixes. Those changes move the header file info into sysfs and fixes
  the build issues that you reported.

  Other than that, a bunch of small habanalabs driver fixes, some fpga
  driver fixes, and a few other tiny driver fixes.

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

* tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  habanalabs: Read upper bits of trace buffer from RWPHI
  habanalabs: Fix virtual address access via debugfs for 2MB pages
  fpga: zynqmp-fpga: Correctly handle error pointer
  habanalabs: fix bug in checking huge page optimization
  habanalabs: Avoid using a non-initialized MMU cache mutex
  habanalabs: fix debugfs code
  uapi/habanalabs: add opcode for enable/disable device debug mode
  habanalabs: halt debug engines on user process close
  test_firmware: Use correct snprintf() limit
  genwqe: Prevent an integer overflow in the ioctl
  parport: Fix mem leak in parport_register_dev_model
  fpga: dfl: expand minor range when registering chrdev region
  fpga: dfl: Add lockdep classes for pdata->lock
  fpga: dfl: afu: Pass the correct device to dma_mapping_error()
  fpga: stratix10-soc: fix use-after-free on s10_init()
  w1: ds2408: Fix typo after 49695ac4 (reset on output_write retry with readback)
  kheaders: Do not regenerate archive if config is not changed
  kheaders: Move from proc to sysfs
  lkdtm/bugs: Adjust recursion test to avoid elision
  lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical

Pull i2c fixes from Wolfram Sang:
 "I2C has a driver bugfix and a MAINTAINERS fix"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: Karthikeyan Ramasubramanian is MIA
  i2c: xiic: Add max_read_len quirk

Pull dmaengine fixes from Vinod Koul:

 - jz4780 transfer fix for acking descriptors early

 - fsl-qdma: clean registers on error

 - dw-axi-dmac: null pointer dereference fix

 - mediatek-cqdma: fix sleeping in atomic context

 - tegra210-adma: fix bunch os issues like crashing in driver probe,
   channel FIFO configuration etc.

 - sprd: Fixes for possible crash on descriptor status, block length
   overflow. For 2-stage transfer fix incorrect start, configuration and
   interrupt handling.

* tag 'dmaengine-fix-5.2-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: sprd: Add interrupt support for 2-stage transfer
  dmaengine: sprd: Fix the right place to configure 2-stage transfer
  dmaengine: sprd: Fix block length overflow
  dmaengine: sprd: Fix the incorrect start for 2-stage destination channels
  dmaengine: sprd: Add validation of current descriptor in irq handler
  dmaengine: sprd: Fix the possible crash when getting descriptor status
  dmaengine: tegra210-adma: Fix spelling
  dmaengine: tegra210-adma: Fix channel FIFO configuration
  dmaengine: tegra210-adma: Fix crash during probe
  dmaengine: mediatek-cqdma: sleeping in atomic context
  dmaengine: dw-axi-dmac: fix null dereference when pointer first is null
  dmaengine: fsl-qdma: Add improvement
  dmaengine: jz4780: Fix transfers being ACKed too soon

Pull block fixes from Jens Axboe:

 - Allow symlink from the bfq.weight cgroup parameter to the general
   weight (Angelo)

 - Damien is new skd maintainer (Bart)

 - NVMe pull request from Sagi, with a few small fixes.

 - Ensure we set DMA segment size properly, dma-debug is now tripping on
   these (Christoph)

 - Remove useless debugfs_create() return check (Greg)

 - Remove redundant unlikely() check on IS_ERR() (Kefeng)

 - Fixup request freeing on exit (Ming)

* tag 'for-linus-20190608' of git://git.kernel.dk/linux-block:
  block, bfq: add weight symlink to the bfq.weight cgroup parameter
  cgroup: let a symlink too be created with a cftype file
  block: free sched's request pool in blk_cleanup_queue
  nvme-rdma: use dynamic dma mapping per command
  nvme: Fix u32 overflow in the number of namespace list calculation
  mmc: also set max_segment_size in the device
  mtip32xx: also set max_segment_size in the device
  rsxx: don't call dma_set_max_seg_size
  nvme-pci: don't limit DMA segement size
  block: Drop unlikely before IS_ERR(_OR_NULL)
  block: aoe: no need to check return value of debugfs_create functions
  nvmet: fix data_len to 0 for bdev-backed write_zeroes
  MAINTAINERS: Hand over skd maintainership
  nvme-tcp: fix queue mapping when queue count is limited
  nvme-rdma: fix queue mapping when queue count is limited

Pull SCSI fixes from James Bottomley:
 "Two bug fixes, both for fairly serious problems; the UFS one looks
  like it could be used to exfiltrate data from the kernel, although
  probably only a privileged user has access to the command management
  interface and the missing unlock in smartpqi is long standing and
  probably a little used error path"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: smartpqi: unlock on error in pqi_submit_raid_request_synchronous()
  scsi: ufs: Check that space was properly alloced in copy_query_response

Merge tag 'linux-kselftest-5.2-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest fix from Shuah Khan:
 "This consists of a single fix for a vm test build failure regression
  when it is built by itself"

* tag 'linux-kselftest-5.2-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: vm: Fix test build failure when built by itself

Pull drm fixes from Dave Airlie:
 "A small bit more lively this week but not majorly so. I'm away in
  Japan next week for family holiday, so I'll be pretty disconnected,
  I've asked Daniel to do fixes for the week while I'm out.

  The nouveau firmware changes are a bit large, but they address a big
  problem where a whole set of boards don't load with the driver, and
  the new firmware fixes that, so I think it's worth trying to land it
  now.

  core:
   - Allow fb changes in async commits (drivers as well)

  udmabuf:
   - Unmap scatterlist when unmapping udmabuf

  nouveau:
   - firmware loading fixes for secboot firmware on new GPU revision.

  komeda:
   - oops, dma mapping and warning fixes

  arm-hdlcd:
   - clock fixes
   - mode validation fix

  i915:
   - Add a missing Icelake workaround
   - GVT - DMA map fault fix and enforcement fixes

  amdgpu:
   - DCE resume fix
   - New raven variation updates"

* tag 'drm-fixes-2019-06-07-1' of git://anongit.freedesktop.org/drm/drm: (33 commits)
  drm/nouveau/secboot/gp10[2467]: support newer FW to fix SEC2 failures on some boards
  drm/nouveau/secboot: enable loading of versioned LS PMU/SEC2 ACR msgqueue FW
  drm/nouveau/secboot: split out FW version-specific LS function pointers
  drm/nouveau/secboot: pass max supported FW version to LS load funcs
  drm/nouveau/core: support versioned firmware loading
  drm/nouveau/core: pass subdev into nvkm_firmware_get, rather than device
  drm/komeda: Potential error pointer dereference
  drm/komeda: remove set but not used variable 'kcrtc'
  drm/amd/amdgpu: add RLC firmware to support raven1 refresh
  drm/amd/powerplay: add set_power_profile_mode for raven1_refresh
  drm/amdgpu: fix ring test failure issue during s3 in vce 3.0 (V2)
  udmabuf: actually unmap the scatterlist
  drm/arm/hdlcd: Allow a bit of clock tolerance
  drm/arm/hdlcd: Actually validate CRTC modes
  drm/arm/mali-dp: Add a loop around the second set CVAL and try 5 times
  drm/komeda: fixing of DMA mapping sg segment warning
  drm: don't block fb changes for async plane updates
  drm/vc4: fix fb references in async update
  drm/msm: fix fb references in async update
  drm/amd: fix fb references in async update
  ...

A mail just bounced back with "user unknown":

550 5.1.1 <kramasub@codeaurora.org> User doesn't exist

I also couldn't find a more recent address in git history. So, remove
this stale entry.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This driver does not support reading more than 255 bytes at once because
the register for storing the number of bytes to read is only 8 bits. Add
a max_read_len quirk to enforce this.

This was found when using this driver with the SFP driver, which was
previously reading all 256 bytes in the SFP EEPROM in one transaction.
This caused a bunch of hard-to-debug errors in the xiic driver since the
driver/logic was treating the number of bytes to read as zero.
Rejecting transactions that aren't supported at least allows the problem
to be diagnosed more easily.
Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Merge tag 'hwmon-for-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Fix a couple of inconsistencies and locking problems in pmbus driver

 - Register with thermal subsystem only on systems supporting devicetree

* tag 'hwmon-for-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (pmbus/core) Treat parameters as paged if on multiple pages
  hwmon: (pmbus/core) mutex_lock write in pmbus_set_samples
  hwmon: (core) add thermal sensors only if dev->of_node is present

The lockref cmpxchg loop is unbound as long as the spinlock is not
taken. Depending on the hardware implementation of compare-and-swap
a high number of loop retries might happen.

Add an upper bound to the loop to force the fallback to spinlocks
after some time. A retry value of 100 should not impact any hardware
that does not have this issue.

With the retry limit the performance of an open-close testcase
improved between 60-70% on ThunderX2.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jan Glauber <jglauber@marvell.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Architectures that support memory tagging have a need to perform untagging
(stripping the tag) in various parts of the kernel. This patch adds an
untagged_addr() macro, which is defined as noop for architectures that do
not support memory tagging. The oncoming patch series will define it at
least for sparc64 and arm64.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull xtensa fix from Max Filippov:
 "Fix a section mismatch between memblock_reserve and mem_reserve.

  This fixes tinyconfig xtensa builds"

* tag 'xtensa-20190607' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: Fix section mismatch between memblock_reserve and mem_reserve

Pull NVMe fixes from Sagi.

* 'nvme-5.2-rc-next' of git://git.infradead.org/nvme:
  nvme-rdma: use dynamic dma mapping per command
  nvme: Fix u32 overflow in the number of namespace list calculation
  nvmet: fix data_len to 0 for bdev-backed write_zeroes
  nvme-tcp: fix queue mapping when queue count is limited
  nvme-rdma: fix queue mapping when queue count is limited

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

Pull more Kbuild fixes from Masahiro Yamada:

 - fix kselftest-merge to find config fragments in deeper directories

 - fix kconfig unit test, which was broken by SPDX tag addition

 - add + prefix to buildtar to suppress jobserver unavailable warning

 - fix checkstack.pl to recognize arch=arm64

 - suppress noisy warning from cc-cross-prefix

* tag 'kbuild-fixes-v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: use more portable 'command -v' for cc-cross-prefix
  scripts/checkstack.pl: Fix arm64 wrong or unknown architecture
  kbuild: tar-pkg: enable communication with jobserver
  kconfig: tests: fix recursive inclusion unit test
  kbuild: teach kselftest-merge to find nested config files

Pull MMC fixes from Ulf Hansson:
 "Here's a couple of MMC and MEMSTICK fixes:

  MMC host:
   - sdhci: Fix SDIO IRQ thread deadlock
   - sdhci-tegra: Fix a warning message
   - sdhci_am654: Fix SLOTTYPE write
   - meson-gx: Fix IRQ ack
   - tmio: Fix SCC error handling to avoid false positive CRC error

  MEMSTICK core:
   - mspro_block: Fix returning a correct error code"

* tag 'mmc-v5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: sdhci_am654: Fix SLOTTYPE write
  mmc: sdhci: Fix SDIO IRQ thread deadlock
  mmc: meson-gx: fix irq ack
  mmc: tmio: fix SCC error handling to avoid false positive CRC error
  mmc: tegra: Fix a warning message
  memstick: mspro_block: Fix an error code in mspro_block_issue_req()

Pull power management fixes from Rafael Wysocki:
 "These fix a crash during resume from hibernation introduced during the
  4.19 cycle, cause the new Performance and Energy Bias Hint (EPB) code
  to be built only if CONFIG_PM is set and add a few missing kerneldoc
  comments.

  Specifics:

   - Fix a crash that occurs when a kernel with 'nosmt' in the command
     line is used to resume the system from hibernation (as the
     "restore" kernel), because memory mapping differences between the
     restore and image kernels cause SMT siblings to be woken up from
     idle states and subsequently they try to fetch instructions from
     incorrect memory locations (Jiri Kosina).

   - Cause the new Performance and Energy Bias Hint (EPB) code to be
     built only if CONFIG_PM is set, because that code is not really
     necessary otherwise (Rafael Wysocki).

   - Add kerneldoc comments to documents some helper functions related
     to system-wide suspend to avoid possible confusion regarding their
     purpose (Rafael Wysocki)"

* tag 'pm-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  x86/power: Fix 'nosmt' vs hibernation triple fault during resume
  PM: sleep: Add kerneldoc comments to some functions
  x86: intel_epb: Do not build when CONFIG_PM is unset

get_desc() computes a pointer into the LDT while holding a lock that
protects the LDT from being freed, but then drops the lock and returns the
(now potentially dangling) pointer to its caller.

Fix it by giving the caller a copy of the LDT entry instead.

Fixes: 670f928b ("x86/insn-eval: Add utility function to get segment descriptor")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) Free AF_PACKET po->rollover properly, from Willem de Bruijn.

 2) Read SFP eeprom in max 16 byte increments to avoid problems with
    some SFP modules, from Russell King.

 3) Fix UDP socket lookup wrt. VRF, from Tim Beale.

 4) Handle route invalidation properly in s390 qeth driver, from Julian
    Wiedmann.

 5) Memory leak on unload in RDS, from Zhu Yanjun.

 6) sctp_process_init leak, from Neil HOrman.

 7) Fix fib_rules rule insertion semantic change that broke Android,
    from Hangbin Liu.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (33 commits)
  pktgen: do not sleep with the thread lock held.
  net: mvpp2: Use strscpy to handle stat strings
  net: rds: fix memory leak in rds_ib_flush_mr_pool
  ipv6: fix EFAULT on sendto with icmpv6 and hdrincl
  ipv6: use READ_ONCE() for inet->hdrincl as in ipv4
  Revert "fib_rules: return 0 directly if an exactly same rule exists when NLM_F_EXCL not supplied"
  net: aquantia: fix wol configuration not applied sometimes
  ethtool: fix potential userspace buffer overflow
  Fix memory leak in sctp_process_init
  net: rds: fix memory leak when unload rds_rdma
  ipv6: fix the check before getting the cookie in rt6_get_cookie
  ipv4: not do cache for local delivery if bc_forwarding is enabled
  s390/qeth: handle error when updating TX queue count
  s390/qeth: fix VLAN attribute in bridge_hostnotify udev event
  s390/qeth: check dst entry before use
  s390/qeth: handle limited IPv4 broadcast in L3 TX path
  net: fix indirect calls helpers for ptype list hooks.
  net: ipvlan: Fix ipvlan device tso disabled while NETIF_F_IP_CSUM is set
  udp: only choose unbound UDP socket for multicast when not in a VRF
  net/tls: replace the sleeping lock around RX resync with a bit lock
  ...

Pull rdma fixes from Jason Gunthorpe:
 "Things are looking pretty quiet here in RDMA, not too many bug fixes
  rolling in right now. The usual driver bug fixes and fixes for a
  couple of regressions introduced in 5.2:

   - Fix a race on bootup with RDMA device renaming and srp. SRP also
     needs to rename its internal sys files

   - Fix a memory leak in hns

   - Don't leak resources in efa on certain error unwinds

   - Don't panic in certain error unwinds in ib_register_device

   - Various small user visible bug fix patches for the hfi and efa
     drivers

   - Fix the 32 bit compilation break"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/efa: Remove MAYEXEC flag check from mmap flow
  mlx5: avoid 64-bit division
  IB/hfi1: Validate page aligned for a given virtual address
  IB/{qib, hfi1, rdmavt}: Correct ibv_devinfo max_mr value
  IB/hfi1: Insure freeze_work work_struct is canceled on shutdown
  IB/rdmavt: Fix alloc_qpn() WARN_ON()
  RDMA/core: Fix panic when port_data isn't initialized
  RDMA/uverbs: Pass udata on uverbs error unwind
  RDMA/core: Clear out the udata before error unwind
  RDMA/hns: Fix PD memory leak for internal allocation
  RDMA/srp: Rename SRP sysfs name after IB device rename trigger

Pull arm64 fixes from Will Deacon:
 "Another round of mostly-benign fixes, the exception being a boot crash
  on SVE2-capable CPUs (although I don't know where you'd find such a
  thing, so maybe it's benign too).

  We're in the process of resolving some big-endian ptrace breakage, so
  I'll probably have some more for you next week.

  Summary:

   - Fix boot crash on platforms with SVE2 due to missing register
     encoding

   - Fix architected timer accessors when CONFIG_OPTIMIZE_INLINING=y

   - Move cpu_logical_map into smp.h for use by upcoming irqchip drivers

   - Trivial typo fix in comment

   - Disable some useless, noisy warnings from GCC 9"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Silence gcc warnings about arch ABI drift
  ARM64: trivial: s/TIF_SECOMP/TIF_SECCOMP/ comment typo fix
  arm64: arch_timer: mark functions as __always_inline
  arm64: smp: Moved cpu_logical_map[] to smp.h
  arm64: cpufeature: Fix missing ZFR0 in __read_sysreg_by_encoding()

To print the pathname that will be used by shell in the current
environment, 'command -v' is a standardized way. [1]

'which' is also often used in scripts, but it is less portable.

When I worked on commit bd55f96f ("kbuild: refactor cc-cross-prefix
implementation"), I was eager to use 'command -v' but it did not work.
(The reason is explained below.)

I kept 'which' as before but got rid of '> /dev/null 2>&1' as I
thought it was no longer needed. Sorry, I was wrong.

It works well on my Ubuntu machine, but Alexey Brodkin reports noisy
warnings on CentOS7 when 'which' fails to find the given command in
the PATH environment.

  $ which foo
  which: no foo in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin)

Given that behavior of 'which' depends on system (and it may not be
installed by default), I want to try 'command -v' once again.

The specification [1] clearly describes the behavior of 'command -v'
when the given command is not found:

  Otherwise, no output shall be written and the exit status shall reflect
  that the name was not found.

However, we need a little magic to use 'command -v' from Make.

$(shell ...) passes the argument to a subshell for execution, and
returns the standard output of the command.

Here is a trick. GNU Make may optimize this by executing the command
directly instead of forking a subshell, if no shell special characters
are found in the command and omitting the subshell will not change the
behavior.

In this case, no shell special character is used. So, Make will try
to run it directly. However, 'command' is a shell-builtin command,
then Make would fail to find it in the PATH environment:

  $ make ARCH=m68k defconfig
  make: command: Command not found
  make: command: Command not found
  make: command: Command not found

In fact, Make has a table of shell-builtin commands because it must
ask the shell to execute them.

Until recently, 'command' was missing in the table.

This issue was fixed by the following commit:

| commit 1af314465e5dfe3e8baa839a32a72e83c04f26ef
| Author: Paul Smith <psmith@gnu.org>
| Date:   Sun Nov 12 18:10:28 2017 -0500
|
|     * job.c: Add "command" as a known shell built-in.
|
|     This is not a POSIX shell built-in but it's common in UNIX shells.
|     Reported by Nick Bowler <nbowler@draconx.ca>.

Because the latest release is GNU Make 4.2.1 in 2016, this commit is
not included in any released versions. (But some distributions may
have back-ported it.)

We need to trick Make to spawn a subshell. There are various ways to
do so:

 1) Use a shell special character '~' as dummy

    $(shell : ~; command -v $(c)gcc)

 2) Use a variable reference that always expands to the empty string
    (suggested by David Laight)

    $(shell command$${x:+} -v $(c)gcc)

 3) Use redirect

    $(shell command -v $(c)gcc 2>/dev/null)

I chose 3) to not confuse people. The stderr would not be polluted
anyway, but it will provide extra safety, and is easy to understand.

Tested on Make 3.81, 3.82, 4.0, 4.1, 4.2, 4.2.1

[1] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/command.html

Fixes: bd55f96f ("kbuild: refactor cc-cross-prefix implementation")
Cc: linux-stable <stable@vger.kernel.org> # 5.1
Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Alexey Brodkin <abrodkin@synopsys.com>

Adjust conditions in on_stack function. That fixes backchain unwinder
which was unable to read pt_regs at the very bottom of the stack and
hence couldn't follow stacks (e.g. from async stack to a task stack).

Fixes: 78c98f90 ("s390/unwind: introduce stack unwind API")
Reported-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

* pm-x86:
  x86/power: Fix 'nosmt' vs hibernation triple fault during resume
  x86: intel_epb: Do not build when CONFIG_PM is unset

Many userspace tools and services use the proportional-share policy of
the blkio/io cgroups controller. The CFQ I/O scheduler implemented
this policy for the legacy block layer. To modify the weight of a
group in case CFQ was in charge, the 'weight' parameter of the group
must be modified. On the other hand, the BFQ I/O scheduler implements
the same policy in blk-mq, but, with BFQ, the parameter to modify has
a different name: bfq.weight (forced choice until legacy block was
present, because two different policies cannot share a common parameter
in cgroups).

Due to CFQ legacy, most if not all userspace configurations still use
the parameter 'weight', and for the moment do not seem likely to be
changed. But, when CFQ went away with legacy block, such a parameter
ceased to exist.

So, a simple workaround has been proposed [1] to make all
configurations work: add a symlink, named weight, to bfq.weight. This
commit adds such a symlink.

[1] https://lkml.org/lkml/2019/4/8/555Suggested-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Angelo Ruocco <angeloruocco90@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>