During a suspend/resume, the xenwatch thread waits for all outstanding
xenstore requests and transactions to complete. This does not work
correctly for transactions started by userspace because it waits for
them to complete after freezing userspace threads which means the
transactions have no way of completing, resulting in a deadlock. This is
trivial to reproduce by running this script and then suspending the VM:

    import pyxs, time
    c = pyxs.client.Client(xen_bus_path="/dev/xen/xenbus")
    c.connect()
    c.transaction()
    time.sleep(3600)

Even if this deadlock were resolved, misbehaving userspace should not
prevent a VM from being migrated. So, instead of waiting for these
transactions to complete before suspending, store the current generation
id for each transaction when it is started. The global generation id is
incremented during resume. If the caller commits the transaction and the
generation id does not match the current generation id, return EAGAIN so
that they try again. If the transaction was instead discarded, return OK
since no changes were made anyway.

This only affects users of the xenbus file interface. In-kernel users of
xenbus are assumed to be well-behaved and complete all transactions
before freezing.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/xen/pvcalls-front.c: In function pvcalls_front_sendmsg:
drivers/xen/pvcalls-front.c:543:25: warning: variable bedata set but not used [-Wunused-but-set-variable]
drivers/xen/pvcalls-front.c: In function pvcalls_front_recvmsg:
drivers/xen/pvcalls-front.c:638:25: warning: variable bedata set but not used [-Wunused-but-set-variable]

They are never used since introduction.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

A new local variable is introduced for accessing p2m entry with lock
protection.
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

Release the newly allocated p2m entry if we detect a duplicate in the RB
tree.
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

This involves initializing the boot params EFI related fields and the
efi global variable.

Without this fix a PVH dom0 doesn't detect when booted from EFI, and
thus doesn't support accessing any of the EFI related data.
Reported-by: PGNet Dev <pgnet.dev@gmail.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org # 4.19+

Or else xen_domain() returns false despite xen_pvh being set.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org # 4.19+

Drop LIST_HEAD where the variable it declares is never used.

The declarations were introduced with the file, but the declared
variables were not used.

Fixes: 1107ba88 ("xen: add xenfs to allow usermode <-> Xen interaction")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warning:

drivers/net/xen-netfront.c: In function ‘netback_changed’:
drivers/net/xen-netfront.c:2038:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (dev->state == XenbusStateClosed)
      ^
drivers/net/xen-netfront.c:2041:2: note: here
  case XenbusStateClosing:
  ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

Notice that, in this particular case, the code comment is modified
in accordance with what GCC is expecting to find.

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Changes passing function argument 0 to NULL to avoid below sparse
warning

 CHECK   drivers/xen/xen-pciback/xenbus.c
drivers/xen/xen-pciback/xenbus.c:700:51: warning: Using plain integer as
NULL pointer
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Add a new command-line option "xen_timer_slop=<INT>" that sets the
minimum delta of virtual Xen timers. This commit does not change the
default timer slop value for virtual Xen timers.

Lowering the timer slop value should improve the accuracy of virtual
timers (e.g., better process dispatch latency), but it will likely
increase the number of virtual timer interrupts (relative to the
original slop setting).

The original timer slop value has not changed since the introduction
of the Xen-aware Linux kernel code. This commit provides users an
opportunity to tune timer performance given the refinements to
hardware and the Xen event channel processing. It also mirrors
a feature in the Xen hypervisor - the "timer_slop" Xen command line
option.

[boris: updated comment describing TIMER_SLOP]
Signed-off-by: Ryan Thibodeaux <ryan.thibodeaux@starlab.io>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Pull NFS client bugfix from Trond Myklebust:
 "Fix a regression in which an RPC call can be tagged with an error
  despite the transmission being successful"

* tag 'nfs-for-5.1-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Ignore queue transmission errors on successful transmission

Pull SCSI fixes from James Bottomley:
 "Three minor fixes: two obvious ones in drivers and a fix to the SG_IO
  path to correctly return status on error"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: aic7xxx: fix EISA support
  Revert "scsi: fcoe: clear FC_RP_STARTED flags when receiving a LOGO"
  scsi: core: set result when the command cannot be dispatched

Pull block fixes from Jens Axboe:
 "A set of small fixes that should go into this series. This contains:

   - Removal of unused queue member (Hou)

   - Overflow bvec fix (Ming)

   - Various little io_uring tweaks (me)
       - kthread parking
       - Only call cpu_possible() for verified CPU
       - Drop unused 'file' argument to io_file_put()
       - io_uring_enter vs io_uring_register deadlock fix
       - CQ overflow fix

   - BFQ internal depth update fix (me)"

* tag 'for-linus-20190420' of git://git.kernel.dk/linux-block:
  block: make sure that bvec length can't be overflow
  block: kill all_q_node in request_queue
  io_uring: fix CQ overflow condition
  io_uring: fix possible deadlock between io_uring_{enter,register}
  io_uring: drop io_file_put() 'file' argument
  bfq: update internal depth state when queue depth changes
  io_uring: only test SQPOLL cpu after we've verified it
  io_uring: park SQPOLL thread if it's percpu

Pill i3c fixes from Boris Brezillon:

 - fix the random PID check

 - fix the disable controller logic in the designware driver

 - fix I3C entry in MAINTAINERS

* tag 'i3c/fixes-for-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  MAINTAINERS: Fix the I3C entry
  i3c: dw: Fix dw_i3c_master_disable controller by using correct mask
  i3c: Fix the verification of random PID

Pull sound fixes from Takashi Iwai:
 "Two core fixes for long-standing bugs for the races at concurrent
  device creation and deletion that were (unsurprisingly) spotted by
  syzkaller with usb-fuzzer.

  The rest are usual small HD-audio fixes"

* tag 'sound-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - add two more pin configuration sets to quirk table
  ALSA: core: Fix card races between register and disconnect
  ALSA: info: Fix racy addition/deletion of nodes
  ALSA: hda: Initialize power_state field properly

Pull timer fixes from Ingo Molnar:
 "Misc clocksource driver fixes, and a sched-clock wrapping fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()
  clocksource/drivers/timer-ti-dm: Remove omap_dm_timer_set_load_start
  clocksource/drivers/oxnas: Fix OX820 compatible
  clocksource/drivers/arm_arch_timer: Remove unneeded pr_fmt macro
  clocksource/drivers/npcm: select TIMER_OF

Pull perf fixes from Ingo Molnar:
 "Misc fixes:
   - various tooling fixes
   - kretprobe fixes
   - kprobes annotation fixes
   - kprobes error checking fix
   - fix the default events for AMD Family 17h CPUs
   - PEBS fix
   - AUX record fix
   - address filtering fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Avoid kretprobe recursion bug
  kprobes: Mark ftrace mcount handler functions nokprobe
  x86/kprobes: Verify stack frame on kretprobe
  perf/x86/amd: Add event map for AMD Family 17h
  perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf()
  perf tools: Fix map reference counting
  perf evlist: Fix side band thread draining
  perf tools: Check maps for bpf programs
  perf bpf: Return NULL when RB tree lookup fails in perf_env__find_bpf_prog_info()
  tools include uapi: Sync sound/asound.h copy
  perf top: Always sample time to satisfy needs of use of ordered queuing
  perf evsel: Use hweight64() instead of hweight_long(attr.sample_regs_user)
  tools lib traceevent: Fix missing equality check for strcmp
  perf stat: Disable DIR_FORMAT feature for 'perf stat record'
  perf scripts python: export-to-sqlite.py: Fix use of parent_id in calls_view
  perf header: Fix lock/unlock imbalances when processing BPF/BTF info
  perf/x86: Fix incorrect PEBS_REGS
  perf/ring_buffer: Fix AUX record suppression
  perf/core: Fix the address filtering fix
  kprobes: Fix error check when reusing optimized probes

Pull x86 fixes from Ingo Molnar:
 "Misc fixes all over the place: a console spam fix, section attributes
  fixes, a KASLR fix, a TLB stack-variable alignment fix, a reboot
  quirk, boot options related warnings fix, an LTO fix, a deadlock fix
  and an RDT fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/intel: Lower the "ENERGY_PERF_BIAS: Set to normal" message's log priority
  x86/cpu/bugs: Use __initconst for 'const' init data
  x86/mm/KASLR: Fix the size of the direct mapping section
  x86/Kconfig: Fix spelling mistake "effectivness" -> "effectiveness"
  x86/mm/tlb: Revert "x86/mm: Align TLB invalidation info"
  x86/reboot, efi: Use EFI reboot for Acer TravelMate X514-51T
  x86/mm: Prevent bogus warnings with "noexec=off"
  x86/build/lto: Fix truncated .bss with -fdata-sections
  x86/speculation: Prevent deadlock on ssb_state::lock
  x86/resctrl: Do not repeat rdtgroup mode initialization

Pull scheduler fixes from Ingo Molnar:
 "A deadline scheduler warning/race fix, and a cfs_period_us quota
  calculation workaround where the real fix looks too involved to merge
  immediately"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Correctly handle active 0-lag timers
  sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup

Pull locking fixes from Ingo Molnar:
 "A lockdep warning fix and a script execution fix when atomics are
  generated"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/atomics: Don't assume that scripts are executable
  locking/lockdep: Make lockdep_unregister_key() honor 'debug_locks' again

Pull cgroup fix from Tejun Heo:
 "A patch to fix a RCU imbalance error in the devices cgroup
  configuration error path"

* 'for-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  device_cgroup: fix RCU imbalance in error case

Pull percpu fixlet from Dennis Zhou:
 "This stops printing the base address of percpu memory on
  initialization"

* 'for-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu: stop printing kernel addresses

Pull tty/serial fixes from Greg KH:
 "Here are five small fixes for some tty/serial/vt issues that have been
  reported.

  The vt one has been around for a while, it is good to finally get that
  resolved. The others fix a build warning that showed up in 5.1-rc1,
  and resolve a problem in the sh-sci driver.

  Note, the second patch for build warning fix for the sc16is7xx driver
  was just applied to the tree, as it resolves a problem with the
  previous patch to try to solve the issue. It has not shown up in
  linux-next yet, unlike all of the other patches, but it has passed
  0-day testing and everyone seems to agree that it is correct"

* tag 'tty-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  sc16is7xx: put err_spi and err_i2c into correct #ifdef
  vt: fix cursor when clearing the screen
  sc16is7xx: move label 'err_spi' to correct section
  serial: sh-sci: Fix HSCIF RX sampling point adjustment
  serial: sh-sci: Fix HSCIF RX sampling point calculation

Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
  mm/kmemleak.c: fix unused-function warning
  init: initialize jump labels before command line option parsing
  kernel/watchdog_hld.c: hard lockup message should end with a newline
  kcov: improve CONFIG_ARCH_HAS_KCOV help text
  mm: fix inactive list balancing between NUMA nodes and cgroups
  mm/hotplug: treat CMA pages as unmovable
  proc: fixup proc-pid-vm test
  proc: fix map_files test on F29
  mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n
  mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock
  mm: swapoff: shmem_unuse() stop eviction without igrab()
  mm: swapoff: take notice of completion sooner
  mm: swapoff: remove too limiting SWAP_UNUSE_MAX_TRIES
  mm: swapoff: shmem_find_swap_entries() filter out other types
  slab: store tagged freelist for off-slab slabmgmt

Pull staging and IIO fixes from Greg KH:
 "Here is a bunch of IIO driver fixes, and some smaller staging driver
  fixes, for 5.1-rc6. The IIO fixes were delayed due to my vacation, but
  all resolve a number of reported issues and have been in linux-next
  for a few weeks with no reported issues.

  The other staging driver fixes are all tiny, resolving some reported
  issues in the comedi and most drivers, as well as some erofs fixes.

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

* tag 'staging-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (24 commits)
  staging: comedi: ni_usb6501: Fix possible double-free of ->usb_rx_buf
  staging: comedi: ni_usb6501: Fix use of uninitialized mutex
  staging: erofs: fix unexpected out-of-bound data access
  staging: comedi: vmk80xx: Fix possible double-free of ->usb_rx_buf
  staging: comedi: vmk80xx: Fix use of uninitialized semaphore
  staging: most: core: use device description as name
  iio: core: fix a possible circular locking dependency
  iio: ad_sigma_delta: select channel when reading register
  iio: pms7003: select IIO_TRIGGERED_BUFFER
  iio: cros_ec: Fix the maths for gyro scale calculation
  iio: adc: xilinx: prevent touching unclocked h/w on remove
  iio: adc: xilinx: fix potential use-after-free on probe
  iio: adc: xilinx: fix potential use-after-free on remove
  iio: dac: mcp4725: add missing powerdown bits in store eeprom
  io: accel: kxcjk1013: restore the range after resume.
  iio:chemical:bme680: Fix SPI read interface
  iio:chemical:bme680: Fix, report temperature in millidegrees
  iio: chemical: fix missing Kconfig block for sgp30
  iio: adc: at91: disable adc channel interrupt in timeout case
  iio: gyro: mpu3050: fix chip ID reading
  ...

Pull char/misc fixes from Greg KH:
 "Here are four small misc driver fixes for 5.1-rc6.

  Nothing major at all, they fix up a Kconfig issues, a SPDX invalid
  license tag, and two tiny bugfixes.

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

* tag 'char-misc-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  drivers: power: supply: goldfish_battery: Fix bogus SPDX identifier
  extcon: ptn5150: fix COMPILE_TEST dependencies
  misc: fastrpc: add checked value for dma_set_mask
  habanalabs: remove low credit limit of DMA #0

bvec->bv_offset may be bigger than PAGE_SIZE sometimes, such as,
when one bio is splitted in the middle of one bvec via bio_split(),
and bi_iter.bi_bvec_done is used to build offset of the 1st bvec of
remained bio. And the remained bio's bvec may be re-submitted to fs
layer via ITER_IBVEC, such as loop and nvme-loop.

So we have to make sure that every bvec's offset is less than
PAGE_SIZE from bio_for_each_segment_all() because some drivers(loop,
nvme-loop) passes the splitted bvec to fs layer via ITER_BVEC.

This patch fixes this issue reported by Zhang Yi When running nvme/011.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Yi Zhang <yi.zhang@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: 6dc4f100 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

all_q_node has not been used since commit 4b855ad3 ("blk-mq: Create
hctx for each present CPU"), so remove it.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull input updates from Dmitry Torokhov:

 - several new key mappings for HID

 - a host of new ACPI IDs used to identify Elan touchpads in Lenovo
   laptops

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: snvs_pwrkey - initialize necessary driver data before enabling IRQ
  HID: input: add mapping for "Toggle Display" key
  HID: input: add mapping for "Full Screen" key
  HID: input: add mapping for keyboard Brightness Up/Down/Toggle keys
  HID: input: add mapping for Expose/Overview key
  HID: input: fix mapping of aspect ratio key
  [media] doc-rst: switch to new names for Full Screen/Aspect keys
  Input: document meanings of KEY_SCREEN and KEY_ZOOM
  Input: elan_i2c - add hardware ID for multiple Lenovo laptops

The "ENERGY_PERF_BIAS: Set to 'normal', was 'performance'" message triggers
on pretty much every Intel machine. The purpose of log messages with
a warning level is to notify the user of something which potentially is
a problem, or at least somewhat unexpected.

This message clearly does not match those criteria, so lower its log
priority from warning to info.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181230172715.17469-1-hdegoede@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'perf-urgent-for-mingo-5.1-20190419' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

perf top:

  Jiri Olsa:

  - Fix 'perf top --pid', it needs PERF_SAMPLE_TIME since we switched to using
    a different thread to sort the events and then even for just a single
    thread we now need timestamps.

BPF:

  Jiri Olsa:

  - Fix bpf_prog and btf lookup functions failure path to to properly return
    NULL.

  - Fix side band thread draining, used to process PERF_RECORD_BPF_EVENT
    metadata records.

core:

  Jiri Olsa:

  - Fix map lookup by name to get a refcount when the name is already in
    the tree. Found

  Song Liu:

  - Fix __map__is_kmodule() by taking into account recently added BPF
    maps.

UAPI:

  Arnaldo Carvalho de Melo:

  - Sync sound/asound.h copy
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The core dumping code has always run without holding the mmap_sem for
writing, despite that is the only way to ensure that the entire vma
layout will not change from under it.  Only using some signal
serialization on the processes belonging to the mm is not nearly enough.
This was pointed out earlier.  For example in Hugh's post from Jul 2017:

  https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils

  "Not strictly relevant here, but a related note: I was very surprised
   to discover, only quite recently, how handle_mm_fault() may be called
   without down_read(mmap_sem) - when core dumping. That seems a
   misguided optimization to me, which would also be nice to correct"

In particular because the growsdown and growsup can move the
vm_start/vm_end the various loops the core dump does around the vma will
not be consistent if page faults can happen concurrently.

Pretty much all users calling mmget_not_zero()/get_task_mm() and then
taking the mmap_sem had the potential to introduce unexpected side
effects in the core dumping code.

Adding mmap_sem for writing around the ->core_dump invocation is a
viable long term fix, but it requires removing all copy user and page
faults and to replace them with get_dump_page() for all binary formats
which is not suitable as a short term fix.

For the time being this solution manually covers the places that can
confuse the core dump either by altering the vma layout or the vma flags
while it runs.  Once ->core_dump runs under mmap_sem for writing the
function mmget_still_valid() can be dropped.

Allowing mmap_sem protected sections to run in parallel with the
coredump provides some minor parallelism advantage to the swapoff code
(which seems to be safe enough by never mangling any vma field and can
keep doing swapins in parallel to the core dumping) and to some other
corner case.

In order to facilitate the backporting I added "Fixes: 86039bd3"
however the side effect of this same race condition in /proc/pid/mem
should be reproducible since before 2.6.12-rc2 so I couldn't add any
other "Fixes:" because there's no hash beyond the git genesis commit.

Because find_extend_vma() is the only location outside of the process
context that could modify the "mm" structures under mmap_sem for
reading, by adding the mmget_still_valid() check to it, all other cases
that take the mmap_sem for reading don't need the new check after
mmget_not_zero()/get_task_mm().  The expand_stack() in page fault
context also doesn't need the new check, because all tasks under core
dumping are frozen.

Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com
Fixes: 86039bd3 ("userfaultfd: add new syscall to provide memory externalization")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The only references outside of the #ifdef have been removed, so now we
get a warning in non-SMP configurations:

  mm/kmemleak.c:1404:13: error: unused function 'scan_large_block' [-Werror,-Wunused-function]

Add a new #ifdef around it.

Link: http://lkml.kernel.org/r/20190416123148.3502045-1-arnd@arndb.de
Fixes: 298a32b1 ("kmemleak: powerpc: skip scanning holes in the .bss section")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When a module option, or core kernel argument, toggles a static-key it
requires jump labels to be initialized early.  While x86, PowerPC, and
ARM64 arrange for jump_label_init() to be called before parse_args(),
ARM does not.

  Kernel command line: rdinit=/sbin/init page_alloc.shuffle=1 panic=-1 console=ttyAMA0,115200 page_alloc.shuffle=1
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:303
  page_alloc_shuffle+0x12c/0x1ac
  static_key_enable(): static key 'page_alloc_shuffle_key+0x0/0x4' used
  before call to jump_label_init()
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted
  5.1.0-rc4-next-20190410-00003-g3367c36ce744 #1
  Hardware name: ARM Integrator/CP (Device Tree)
  [<c0011c68>] (unwind_backtrace) from [<c000ec48>] (show_stack+0x10/0x18)
  [<c000ec48>] (show_stack) from [<c07e9710>] (dump_stack+0x18/0x24)
  [<c07e9710>] (dump_stack) from [<c001bb1c>] (__warn+0xe0/0x108)
  [<c001bb1c>] (__warn) from [<c001bb88>] (warn_slowpath_fmt+0x44/0x6c)
  [<c001bb88>] (warn_slowpath_fmt) from [<c0b0c4a8>]
  (page_alloc_shuffle+0x12c/0x1ac)
  [<c0b0c4a8>] (page_alloc_shuffle) from [<c0b0c550>] (shuffle_store+0x28/0x48)
  [<c0b0c550>] (shuffle_store) from [<c003e6a0>] (parse_args+0x1f4/0x350)
  [<c003e6a0>] (parse_args) from [<c0ac3c00>] (start_kernel+0x1c0/0x488)

Move the fallback call to jump_label_init() to occur before
parse_args().

The redundant calls to jump_label_init() in other archs are left intact
in case they have static key toggling use cases that are even earlier
than option parsing.

Link: http://lkml.kernel.org/r/155544804466.1032396.13418949511615676665.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Guenter Roeck <groeck@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Russell King <rmk@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Separate print_modules() and hard lockup error message.

Before the patch:

  NMI watchdog: Watchdog detected hard LOCKUP on cpu 1Modules linked in: nls_cp437

Link: http://lkml.kernel.org/r/20190412062557.2700-1-sergey.senozhatsky@gmail.comSigned-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The help text for CONFIG_ARCH_HAS_KCOV is stale, and describes the
feature as being enabled only for x86_64, when it is now enabled for
several architectures, including arm, arm64, powerpc, and s390.

Let's remove that stale help text, and update it along the lines of hat
for ARCH_HAS_FORTIFY_SOURCE, better describing when an architecture
should select CONFIG_ARCH_HAS_KCOV.

Link: http://lkml.kernel.org/r/20190412102733.5154-1-mark.rutland@arm.comSigned-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During !CONFIG_CGROUP reclaim, we expand the inactive list size if it's
thrashing on the node that is about to be reclaimed.  But when cgroups
are enabled, we suddenly ignore the node scope and use the cgroup scope
only.  The result is that pressure bleeds between NUMA nodes depending
on whether cgroups are merely compiled into Linux.  This behavioral
difference is unexpected and undesirable.

When the refault adaptivity of the inactive list was first introduced,
there were no statistics at the lruvec level - the intersection of node
and memcg - so it was better than nothing.

But now that we have that infrastructure, use lruvec_page_state() to
make the list balancing decision always NUMA aware.

[hannes@cmpxchg.org: fix bisection hole]
  Link: http://lkml.kernel.org/r/20190417155241.GB23013@cmpxchg.org
Link: http://lkml.kernel.org/r/20190412144438.2645-1-hannes@cmpxchg.org
Fixes: 2a2e4885 ("mm: vmscan: fix IO/refault regression in cache workingset transition")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

has_unmovable_pages() is used by allocating CMA and gigantic pages as
well as the memory hotplug.  The later doesn't know how to offline CMA
pool properly now, but if an unused (free) CMA page is encountered, then
has_unmovable_pages() happily considers it as a free memory and
propagates this up the call chain.  Memory offlining code then frees the
page without a proper CMA tear down which leads to an accounting issues.
Moreover if the same memory range is onlined again then the memory never
gets back to the CMA pool.

State after memory offline:

 # grep cma /proc/vmstat
 nr_free_cma 205824

 # cat /sys/kernel/debug/cma/cma-kvm_cma/count
 209920

Also, kmemleak still think those memory address are reserved below but
have already been used by the buddy allocator after onlining.  This
patch fixes the situation by treating CMA pageblocks as unmovable except
when has_unmovable_pages() is called as part of CMA allocation.

  Offlined Pages 4096
  kmemleak: Cannot insert 0xc000201f7d040008 into the object search tree (overlaps existing)
  Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    create_object+0x344/0x380
    __kmalloc_node+0x3ec/0x860
    kvmalloc_node+0x58/0x110
    seq_read+0x41c/0x620
    __vfs_read+0x3c/0x70
    vfs_read+0xbc/0x1a0
    ksys_read+0x7c/0x140
    system_call+0x5c/0x70
  kmemleak: Kernel memory leak detector disabled
  kmemleak: Object 0xc000201cc8000000 (size 13757317120):
  kmemleak:   comm "swapper/0", pid 0, jiffies 4294937297
  kmemleak:   min_count = -1
  kmemleak:   count = 0
  kmemleak:   flags = 0x5
  kmemleak:   checksum = 0
  kmemleak:   backtrace:
       cma_declare_contiguous+0x2a4/0x3b0
       kvm_cma_reserve+0x11c/0x134
       setup_arch+0x300/0x3f8
       start_kernel+0x9c/0x6e8
       start_here_common+0x1c/0x4b0
  kmemleak: Automatic memory scanning thread ended

[cai@lca.pw: use is_migrate_cma_page() and update commit log]
  Link: http://lkml.kernel.org/r/20190416170510.20048-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190413002623.8967-1-cai@lca.pwSigned-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Silly sizeof(pointer) vs sizeof(uint8_t[]) bug.

Link: http://lkml.kernel.org/r/20190414123009.GA12971@avx2
Fixes: e483b020 ("proc: test /proc/*/maps, smaps, smaps_rollup, statm")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>