On powerpc, __arch_get_vdso_data() clobbers the link register, requiring
the caller to save it.

As the parent function already has to set a stack frame and saves the link
register before calling the C vdso function, retrieving the vdso data
pointer there is less overhead.

Split out the functional code from the __cvdso.*() interfaces into new
static functions which can either be called from the existing interfaces
with the vdso data pointer supplied via __arch_get_vdso_data() or directly
from ASM code.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/abf97996602ef07223fec30c005df78e5ed41b2e.1580399657.git.christophe.leroy@c-s.fr
Link: https://lkml.kernel.org/r/20200207124403.965789141@linutronix.de

On powerpc/32, GCC (8.1) generates pretty bad code for the ns >>= vd->shift
operation taking into account that the shift is always <= 32 and the upper
part of the result is likely to be zero. GCC makes reversed assumptions
considering the shift to be likely >= 32 and the upper part to be like not
zero.

unsigned long long shift(unsigned long long x, unsigned char s)
{
	return x >> s;
}

results in:

00000018 <shift>:
  18:	35 25 ff e0 	addic.  r9,r5,-32
  1c:	41 80 00 10 	blt     2c <shift+0x14>
  20:	7c 64 4c 30 	srw     r4,r3,r9
  24:	38 60 00 00 	li      r3,0
  28:	4e 80 00 20 	blr
  2c:	54 69 08 3c 	rlwinm  r9,r3,1,0,30
  30:	21 45 00 1f 	subfic  r10,r5,31
  34:	7c 84 2c 30 	srw     r4,r4,r5
  38:	7d 29 50 30 	slw     r9,r9,r10
  3c:	7c 63 2c 30 	srw     r3,r3,r5
  40:	7d 24 23 78 	or      r4,r9,r4
  44:	4e 80 00 20 	blr

Even when forcing the shift to be smaller than 32 with an &= 31, it still
considers the shift as likely >= 32.

Move the default shift implementation into an inline which can be redefined
in architecture code via a macro.

[ tglx: Made the shift argument u32 and removed the __arch prefix ]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/b3d449de856982ed060a71e6ace8eeca4654e685.1580399657.git.christophe.leroy@c-s.fr
Link: https://lkml.kernel.org/r/20200207124403.857649978@linutronix.de

Some architectures have a fixed clocksource which is known at compile time
and cannot be replaced or disabled at runtime, e.g. timebase on
PowerPC. For such cases the clock mode check in the VDSO code is pointless.

Move the check for a VDSO capable clocksource into an inline function and
allow architectures to redefine it via a macro.

[ tglx: Removed the #ifdef mess ]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.748756829@linutronix.de

Move the time namespace indicator clock mode to the other ones for
consistency sake.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.656097274@linutronix.de

If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de

Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de

Switch to the generic VDSO clock mode storage.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.244684017@linutronix.de

Switch to the generic VDSO clock mode storage.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Acked-by: Paolo Bonzini <pbonzini@redhat.com> (KVM parts)
Link: https://lkml.kernel.org/r/20200207124403.152039903@linutronix.de

All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.

Provide generic storage for it. The new Kconfig symbol is intermediate and
will be removed once all architectures are converted over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.028046322@linutronix.de

All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.

X86 abuses the function which retrieves the architecture specific clock
mode storage to mark the clocksource as used in the VDSO. That's silly
because this is invoked on every tick when the VDSO data is updated.

Move this functionality to the clocksource::enable() callback so it gets
invoked once when the clocksource is installed. This allows to make the
clock mode storage generic.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>  (Hyper-V parts)
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Link: https://lkml.kernel.org/r/20200207124402.934519777@linutronix.de

Reformat the struct definition, add missing member documentation.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.825471920@linutronix.de

If neither the R4K nor the GIC timer is enabled in the kernel configuration
then let the core VDSO code drop the high resolution parts at compile time.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.714585315@linutronix.de

If the architected timer is disabled in the kernel configuration then let
the core VDSO code drop the high resolution parts at compile time.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.622587341@linutronix.de

If the architecture knows at compile time that there is no VDSO capable
clocksource supported it makes sense to optimize the guts of the high
resolution parts of the VDSO out at build time. Add a helper function to
check whether the VDSO should be high resolution capable and provide a stub
which can be overridden by an architecture.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.530143168@linutronix.de

The function is nowhere used. Aside of that this check should only cover
the high resolution parts of the VDSO which require a VDSO capable
clocksource and not the complete functionality as the name suggests. Will
be replaced with something more useful.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de

Jumping out of line for the TSC clcoksource read is creating awful
code. TSC is likely to be the clocksource at least on bare metal and the PV
interfaces are sufficiently more work that the jump over the TSC read is
just in the noise.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.328922847@linutronix.de

Pull IPMI update from Corey Minyard:
 "Minor bug fixes for IPMI

  I know this is late; I've been travelling and, well, I've been
  distracted.

  This is just a few bug fixes and adding i2c support to the IPMB
  driver, which is something I wanted from the beginning for it"

* tag 'for-linus-5.6-1' of https://github.com/cminyard/linux-ipmi:
  drivers: ipmi: fix off-by-one bounds check that leads to a out-of-bounds write
  ipmi:ssif: Handle a possible NULL pointer reference
  drivers: ipmi: Modify max length of IPMB packet
  drivers: ipmi: Support raw i2c packet in IPMB

Pull KVM fixes from Paolo Bonzini:
 "Bugfixes and improvements to selftests.

  On top of this, Mauro converted the KVM documentation to rst format,
  which was very welcome"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (44 commits)
  docs: virt: guest-halt-polling.txt convert to ReST
  docs: kvm: review-checklist.txt: rename to ReST
  docs: kvm: Convert timekeeping.txt to ReST format
  docs: kvm: Convert s390-diag.txt to ReST format
  docs: kvm: Convert ppc-pv.txt to ReST format
  docs: kvm: Convert nested-vmx.txt to ReST format
  docs: kvm: Convert mmu.txt to ReST format
  docs: kvm: Convert locking.txt to ReST format
  docs: kvm: Convert hypercalls.txt to ReST format
  docs: kvm: arm/psci.txt: convert to ReST
  docs: kvm: convert arm/hyp-abi.txt to ReST
  docs: kvm: Convert api.txt to ReST format
  docs: kvm: convert devices/xive.txt to ReST
  docs: kvm: convert devices/xics.txt to ReST
  docs: kvm: convert devices/vm.txt to ReST
  docs: kvm: convert devices/vfio.txt to ReST
  docs: kvm: convert devices/vcpu.txt to ReST
  docs: kvm: convert devices/s390_flic.txt to ReST
  docs: kvm: convert devices/mpic.txt to ReST
  docs: kvm: convert devices/arm-vgit.txt to ReST
  ...

Pull EDAC fixes from Borislav Petkov:
 "Two fixes for use-after-free and memory leaking in the EDAC core, by
  Robert Richter.

  Debug options like DEBUG_TEST_DRIVER_REMOVE, KASAN and DEBUG_KMEMLEAK
  unearthed issues with the lifespan of memory allocated by the EDAC
  memory controller descriptor due to misdesigned memory freeing, done
  partially by the EDAC core *and* the driver core, which is problematic
  to say the least.

  These two are minimal fixes to take care of stable - a proper rework
  is following which cleans up that mess properly"

* tag 'edac_urgent_for_5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/sysfs: Remove csrow objects on errors
  EDAC/mc: Fix use-after-free and memleaks during device removal

Pull block fixes from Jens Axboe:
 "Not a lot here, which is great, basically just three small bcache
  fixes from Coly, and four NVMe fixes via Keith"

* tag 'block-5.6-2020-02-16' of git://git.kernel.dk/linux-block:
  nvme: fix the parameter order for nvme_get_log in nvme_get_fw_slot_info
  nvme/pci: move cqe check after device shutdown
  nvme: prevent warning triggered by nvme_stop_keep_alive
  nvme/tcp: fix bug on double requeue when send fails
  bcache: remove macro nr_to_fifo_front()
  bcache: Revert "bcache: shrink btree node cache after bch_btree_check()"
  bcache: ignore pending signals when creating gc and allocator thread

Pull btrfs fixes from David Sterba:
 "Two races fixed, memory leak fix, sysfs directory fixup and two new
  log messages:

   - two fixed race conditions: extent map merging and truncate vs
     fiemap

   - create the right sysfs directory with device information and move
     the individual device dirs under it

   - print messages when the tree-log is replayed at mount time or
     cannot be replayed on remount"

* tag 'for-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: sysfs, move device id directories to UUID/devinfo
  btrfs: sysfs, add UUID/devinfo kobject
  Btrfs: fix race between shrinking truncate and fiemap
  btrfs: log message when rw remount is attempted with unclean tree-log
  btrfs: print message when tree-log replay starts
  Btrfs: fix race between using extent maps and merging them
  btrfs: ref-verify: fix memory leaks

Pull cifs fixes from Steve French:
 "Four small CIFS/SMB3 fixes. One (the EA overflow fix) for stable"

* tag '5.6-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: make sure we do not overflow the max EA buffer size
  cifs: enable change notification for SMB2.1 dialect
  cifs: Fix mode output in debugging statements
  cifs: fix mount option display for sec=krb5i

Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes (all stable fodder)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: improve explanation of a mount failure caused by a misconfigured kernel
  jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer
  jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()
  ext4: add cond_resched() to ext4_protect_reserved_inode
  ext4: fix checksum errors with indexed dirs
  ext4: fix support for inode sizes > 1024 bytes
  ext4: simplify checking quota limits in ext4_statfs()
  ext4: don't assume that mmp_nodename/bdevname have NUL

Pull input updates from Dmitry Torokhov:

 - a few drivers have been updated to use flexible-array syntax instead
   of GCC extension

 - ili210x touchscreen driver now supports the 2120 protocol flavor

 - a couple more of Synaptics devices have been switched over to RMI4

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: cyapa - replace zero-length array with flexible-array member
  Input: tca6416-keypad - replace zero-length array with flexible-array member
  Input: gpio_keys_polled - replace zero-length array with flexible-array member
  Input: synaptics - remove the LEN0049 dmi id from topbuttonpad list
  Input: synaptics - enable SMBus on ThinkPad L470
  Input: synaptics - switch T470s to RMI4 by default
  Input: gpio_keys - replace zero-length array with flexible-array member
  Input: goldfish_events - replace zero-length array with flexible-array member
  Input: psmouse - switch to using i2c_new_scanned_device()
  Input: ili210x - add ili2120 support
  Input: ili210x - fix return value of is_visible function

Pull rdma fixes from Jason Gunthorpe:
 "Not too much going on here, though there are about four fixes related
  to stuff merged during the last merge window.

  We also see the return of a syzkaller instance with access to RDMA
  devices, and a few bugs detected by that squished.

   - Fix three crashers and a memory memory leak for HFI1

   - Several bugs found by syzkaller

   - A bug fix for the recent QP counters feature on older mlx5 HW

   - Locking inversion in cxgb4

   - Unnecessary WARN_ON in siw

   - A umad crasher regression during unload, from a bug fix for
     something else

   - Bugs introduced in the merge window:
       - Missed list_del in uverbs file rework, core and mlx5 devx
       - Unexpected integer math truncation in the mlx5 VAR patches
       - Compilation bug fix for the VAR patches on 32 bit"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  IB/mlx5: Use div64_u64 for num_var_hw_entries calculation
  RDMA/core: Fix protection fault in get_pkey_idx_qp_list
  RDMA/rxe: Fix soft lockup problem due to using tasklets in softirq
  RDMA/mlx5: Prevent overflow in mmap offset calculations
  IB/umad: Fix kernel crash while unloading ib_umad
  RDMA/mlx5: Fix async events cleanup flows
  RDMA/core: Add missing list deletion on freeing event queue
  RDMA/siw: Remove unwanted WARN_ON in siw_cm_llp_data_ready()
  RDMA/iw_cxgb4: initiate CLOSE when entering TERM
  IB/mlx5: Return failure when rts2rts_qp_counters_set_id is not supported
  RDMA/core: Fix invalid memory access in spec_filter_size
  IB/rdmavt: Reset all QPs when the device is shut down
  IB/hfi1: Close window for pq and request coliding
  IB/hfi1: Acquire lock to release TID entries when user file is closed
  RDMA/hfi1: Fix memory leak in _dev_comp_vect_mappings_create

Pull ARM SoC fixes from Olof Johansson:
 "A handful of fixes that have come in since the merge window:

   - Fix of PCI interrupt map on arm64 fast model (SW emulator)

   - Fixlet for sound on ST platforms and a small cleanup of deprecated
     DT properties

   - A stack buffer overflow fix for moxtet

   - Fuse driver build fix for Tegra194

   - A few config updates to turn on new drivers merged this cycle"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  bus: moxtet: fix potential stack buffer overflow
  soc/tegra: fuse: Fix build with Tegra194 configuration
  ARM: dts: sti: fixup sound frame-inversion for stihxxx-b2120.dtsi
  ARM: dts: sti: Remove deprecated snps PHY properties for stih410-b2260
  arm64: defconfig: Enable DRM_SUN6I_DSI
  arm64: defconfig: Enable CONFIG_SUN8I_THERMAL
  ARM: sunxi: Enable CONFIG_SUN8I_THERMAL
  arm64: defconfig: Set bcm2835-dma as built-in
  ARM: configs: Cleanup old Kconfig options
  ARM: npcm: Bring back GPIOLIB support
  arm64: dts: fast models: Fix FVP PCI interrupt-map property

Pull s390 updates from Vasily Gorbik:

 - Enable paes-s390 cipher selftests in testmgr (acked-by Herbert Xu).

 - Fix protected key length update in PKEY_SEC2PROTK ioctl and increase
   card/queue requests counter to 64-bit in crypto code.

 - Fix clang warning in get_tod_clock.

 - Fix ultravisor info length extensions handling.

 - Fix style of SPDX License Identifier in vfio-ccw.

 - Avoid unnecessary GFP_ATOMIC and simplify ACK tracking in qdio.

* tag 's390-5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  crypto/testmgr: enable selftests for paes-s390 ciphers
  s390/time: Fix clk type in get_tod_clock
  s390/uv: Fix handling of length extensions
  s390/qdio: don't allocate *aob array with GFP_ATOMIC
  s390/qdio: simplify ACK tracking
  s390/zcrypt: fix card and queue total counter wrap
  s390/pkey: fix missing length of protected key on return
  vfio-ccw: Use the correct style for SPDX License Identifier

Merge tag 'hwmon-for-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Fix compatible string typos in the xdpe12284 driver, and a wrong bit
  value in the ltc2978 driver"

* tag 'hwmon-for-v5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (pmbus/xdpe12284) fix typo in compatible strings
  hwmon: (pmbus/ltc2978) Fix PMBus polling of MFR_COMMON definitions.

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes all over the place:

   - Fix NUMA over-balancing between lightly loaded nodes. This is
     fallout of the big load-balancer rewrite.

   - Fix the NOHZ remote loadavg update logic, which fixes anomalies
     like reported 150 loadavg on mostly idle CPUs.

   - Fix XFS performance/scalability

   - Fix throttled groups unbound task-execution bug

   - Fix PSI procfs boundary condition

   - Fix the cpu.uclamp.{min,max} cgroup configuration write checks

   - Fix DocBook annotations

   - Fix RCU annotations

   - Fix overly CPU-intensive housekeeper CPU logic loop on large CPU
     counts"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix kernel-doc warning in attach_entity_load_avg()
  sched/core: Annotate curr pointer in rq with __rcu
  sched/psi: Fix OOB write when writing 0 bytes to PSI files
  sched/fair: Allow a per-CPU kthread waking a task to stack on the same CPU, to fix XFS performance regression
  sched/fair: Prevent unlimited runtime on throttled group
  sched/nohz: Optimize get_nohz_timer_target()
  sched/uclamp: Reject negative values in cpu_uclamp_write()
  sched/fair: Allow a small load imbalance between low utilisation SD_NUMA domains
  timers/nohz: Update NOHZ load in remote tick
  sched/core: Don't skip remote tick for idle CPUs

Pull perf fixes from Ingo Molnar:
 "Fixes and HW enablement patches:

   - Tooling fixes, most of which are tooling header synchronization
     with v5.6 changes

   - Fix kprobes fallout on ARM

   - Add Intel Elkhart Lake support and extend Tremont support, these
     are relatively simple and should only affect those models

   - Fix the AMD family 17h generic event table"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  perf llvm: Fix script used to obtain kernel make directives to work with new kbuild
  tools headers kvm: Sync linux/kvm.h with the kernel sources
  tools headers kvm: Sync kvm headers with the kernel sources
  tools arch x86: Sync asm/cpufeatures.h with the kernel sources
  tools headers x86: Sync disabled-features.h
  tools include UAPI: Sync sound/asound.h copy
  tools headers UAPI: Sync asm-generic/mman-common.h with the kernel
  perf tools: Add arm64 version of get_cpuid()
  tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
  tools headers uapi: Sync linux/fscrypt.h with the kernel sources
  tools headers UAPI: Sync sched.h with the kernel
  perf trace: Resolve prctl's 'option' arg strings to numbers
  perf beauty prctl: Export the 'options' strarray
  tools headers UAPI: Sync prctl.h with the kernel sources
  tools headers UAPI: Sync copy of arm64's asm/unistd.h with the kernel sources
  perf maps: Move kmap::kmaps setup to maps__insert()
  perf maps: Fix map__clone() for struct kmap
  perf maps: Mark ksymbol DSOs with kernel type
  perf maps: Mark module DSOs with kernel type
  tools include UAPI: Sync x86's syscalls_64.tbl, generic unistd.h and fcntl.h to pick up openat2 and pidfd_getfd
  ...

The input_read function declares the size of the hex array relative to
sizeof(buf), but buf is a pointer argument of the function. The hex
array is meant to contain hexadecimal representation of the bin array.

Link: https://lore.kernel.org/r/20200215142130.22743-1-marek.behun@nic.cz
Fixes: 5bc7f990 ("bus: Add support for Moxtet bus")
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reported-by: sohu0106 <sohu0106@126.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

If CONFIG_QFMT_V2 is not enabled, but CONFIG_QUOTA is enabled, when a
user tries to mount a file system with the quota or project quota
enabled, the kernel will emit a very confusing messsage:

    EXT4-fs warning (device vdc): ext4_enable_quotas:5914: Failed to enable quota tracking (type=0, err=-3). Please run e2fsck to fix.
    EXT4-fs (vdc): mount failed

We will now report an explanatory message indicating which kernel
configuration options have to be enabled, to avoid customer/sysadmin
confusion.

Link: https://lore.kernel.org/r/20200215012738.565735-1-tytso@mit.edu
Google-Bug-Id: 149093531
Fixes: 7c319d32 ("ext4: make quota as first class supported feature")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

Merge tag 'perf-urgent-for-mingo-5.6-20200214' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

BPF:

  Arnaldo Carvalho de Melo:

  - Fix script used to obtain kernel make directives to work with new kbuild
    used for building BPF programs.

maps:

  Jiri Olsa:

  - Fixup kmap->kmaps backpointer in kernel maps.

arm64:

  John Garry:

  - Add arm64 version of get_cpuid() to get proper, arm64 specific output from
    'perf list' and other tools.

perf top:

  Kim Phillips:

  - Update kernel idle symbols so that output in AMD systems is in line with
    other systems.

perf stat:

  Kim Phillips:

  - Don't report a null stalled cycles per insn metric.

tools headers:

  Arnaldo Carvalho de Melo:

  - Sync tools/ headers with the kernel sources to get things like syscall
    numbers and new arguments so that 'perf trace' can decode and use them in
    tracepoint filters, e.g. prctl's new PR_{G,S}ET_IO_FLUSHER options.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214172132.GA28389@embeddedorSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214172022.GA27490@embeddedorSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200214171907.GA26588@embeddedorSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Pull NFS client bugfixes from Anna Schumaker:
 "The only stable fix this time is the DMA scatter-gather list bug fixed
  by Chuck.

  The rest fix up races and refcounting issues that have been found
  during testing.

  Stable fix:
   - fix DMA scatter-gather list mapping imbalance

  The rest:
   - fix directory verifier races
   - fix races between open and dentry revalidation
   - fix revalidation of dentries with delegations
   - fix "cachethis" setting for writes
   - fix delegation and delegation cred pinning"

* tag 'nfs-for-5.6-2' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  NFSv4: Ensure the delegation cred is pinned when we call delegreturn
  NFSv4: Ensure the delegation is pinned in nfs_do_return_delegation()
  NFSv4.1 make cachethis=no for writes
  xprtrdma: Fix DMA scatter-gather list mapping imbalance
  NFSv4: Fix revalidation of dentries with delegations
  NFSv4: Fix races between open and dentry revalidation
  NFS: Fix up directory verifier races

Pull ceph fixes from Ilya Dryomov:

 - make O_DIRECT | O_APPEND combination work better

 - redo the server path canonicalization patch that went into -rc1

 - fix the 'noacl' mount option that got broken by the conversion to the
   new mount API in 5.5

* tag 'ceph-for-5.6-rc2' of https://github.com/ceph/ceph-client:
  ceph: noacl mount option is effectively ignored
  ceph: canonicalize server path in place
  ceph: do not execute direct write in parallel if O_APPEND is specified