The task structure is freed while get_mem_cgroup_from_mm() holds
rcu_read_lock() and dereferences mm->owner.

  get_mem_cgroup_from_mm()                failing fork()
  ----                                    ---
  task = mm->owner
                                          mm->owner = NULL;
                                          free(task)
  if (task) *task; /* use after free */

The fix consists in freeing the task with RCU also in the fork failure
case, exactly like it always happens for the regular exit(2) path.  That
is enough to make the rcu_read_lock hold in get_mem_cgroup_from_mm()
(left side above) effective to avoid a use after free when dereferencing
the task structure.

An alternate possible fix would be to defer the delivery of the
userfaultfd contexts to the monitor until after fork() is guaranteed to
succeed.  Such a change would require more changes because it would
create a strict ordering dependency where the uffd methods would need to
be called beyond the last potentially failing branch in order to be
safe.  This solution as opposed only adds the dependency to common code
to set mm->owner to NULL and to free the task struct that was pointed by
mm->owner with RCU, if fork ends up failing.  The userfaultfd methods
can still be called anywhere during the fork runtime and the monitor
will keep discarding orphaned "mm" coming from failed forks in userland.

This race condition couldn't trigger if CONFIG_MEMCG was set =n at build
time.

[aarcange@redhat.com: improve changelog, reduce #ifdefs per Michal]
  Link: http://lkml.kernel.org/r/20190429035752.4508-1-aarcange@redhat.com
Link: http://lkml.kernel.org/r/20190325225636.11635-2-aarcange@redhat.com
Fixes: 893e26e6 ("userfaultfd: non-cooperative: Add fork() event")
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Tested-by: Nzhong jiang <zhongjiang@huawei.com>
Reported-by: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: zhong jiang <zhongjiang@huawei.com>
Cc: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the user downloads and applies patch-5.1.gz using patch(1), the x bit
on kernel/gen_ikh_data.sh is not set.

  /bin/sh: 1: ./kernel/gen_ikh_data.sh: Permission denied

Fix this by using CONFIG_SHELL.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull backlight updates from Lee Jones:
 "Fix-ups:
   - Remove unused BACKLIGHT_LCD_SUPPORT symbol
   - Remove unused BACKLIGHT_CLASS_DEVICE dependencies
   - Add DT support to lm3630a_bl

  Bug Fixes:
   - Fix error path issues in lm3630a_bl"

* tag 'backlight-next-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: lm3630a: Add firmware node support
  dt-bindings: backlight: Add lm3630a bindings
  backlight: lm3630a: Return 0 on success in update_status functions
  video: lcd: Remove useless BACKLIGHT_CLASS_DEVICE dependencies
  video: backlight: Remove useless BACKLIGHT_LCD_SUPPORT kernel symbol

Pull MFD updates from Lee Jones:
 "Core Framework:
   - Document (kerneldoc) core mfd_add_devices() API

  New Drivers:
   - Altera SOCFPGA System Manager
   - Maxim MAX77650/77651 PMIC
   - Maxim MAX77663 PMIC
   - ST Multi-Function eXpander (STMFX)

  New Device Support:
   - LEDs support in Intel Cherry Trail Whiskey Cove PMIC
   - RTC support in SAMSUNG Electronics S2MPA01 PMIC
   - SAM9X60 support in Atmel HLCDC (High-end LCD Controller)
   - USB X-Powers AXP 8xx PMICs
   - Integrated Sensor Hub (ISH) in ChromeOS EC
   - USB PD Logger in ChromeOS EC
   - AXP223 in X-Powers AXP series PMICs
   - Power Supply in X-Powers AXP 803 PMICs
   - Comet Lake in Intel Low Power Subsystem
   - Fingerprint MCU in ChromeOS EC
   - Touchpad MCU in ChromeOS EC
   - Move TI LM3532 support to LED

  New Functionality:
   - max77650, max77620: Add/extend DT support
   - max77620 power-off
   - syscon clocking
   - croc_ec host sleep event

  Fix-ups:
   - Trivial; Formatting, spelling, etc; Kconfig, sec-core, ab8500-debugfs
   - Remove unused functionality; rk808, da9063-*
   - SPDX conversion; da9063-*, atmel-*,
   - Adapt/add new register definitions; cs47l35-tables, cs47l90-tables, imx6q-iomuxc-gpr
   - Fix-up DT bindings; ti-lmu, cirrus,lochnagar
   - Simply obtaining driver data; ssbi, t7l66xb, tc6387xb, tc6393xb

  Bug Fixes:
   - Fix incorrect defined values; max77620, da9063
   - Fix device initialisation; twl6040
   - Reset device on init; intel-lpss
   - Fix build warnings when !OF; sun6i-prcm
   - Register OF match tables; tps65912-spi
   - Fix DMI matching; intel_quark_i2c_gpio"

* tag 'mfd-next-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (65 commits)
  mfd: Use dev_get_drvdata() directly
  mfd: cros_ec: Instantiate properly CrOS Touchpad MCU device
  mfd: cros_ec: Instantiate properly CrOS FP MCU device
  mfd: cros_ec: Update the EC feature codes
  mfd: intel-lpss: Add Intel Comet Lake PCI IDs
  mfd: lochnagar: Add links to binding docs for sound and hwmon
  mfd: ab8500-debugfs: Fix a typo ("deubgfs")
  mfd: imx6sx: Add MQS register definition for iomuxc gpr
  dt-bindings: mfd: LMU: Fix lm3632 dt binding example
  mfd: intel_quark_i2c_gpio: Adjust IOT2000 matching
  mfd: da9063: Fix OTP control register names to match datasheets for DA9063/63L
  mfd: tps65912-spi: Add missing of table registration
  mfd: axp20x: Add USB power supply mfd cell to AXP803
  mfd: sun6i-prcm: Fix build warning for non-OF configurations
  mfd: intel-lpss: Set the device in reset state when init
  platform/chrome: Add support for v1 of host sleep event
  mfd: cros_ec: Add host_sleep_event_v1 command
  mfd: cros_ec: Instantiate the CrOS USB PD logger driver
  mfd: cs47l90: Make DAC_AEC_CONTROL_2 readable
  mfd: cs47l35: Make DAC_AEC_CONTROL_2 readable
  ...

Pull PCI updates from Bjorn Helgaas:
 "Enumeration changes:

   - Add _HPX Type 3 settings support, which gives firmware more
     influence over device configuration (Alexandru Gagniuc)

   - Support fixed bus numbers from bridge Enhanced Allocation
     capabilities (Subbaraya Sundeep)

   - Add "external-facing" DT property to identify cases where we
     require IOMMU protection against untrusted devices (Jean-Philippe
     Brucker)

   - Enable PCIe services for host controller drivers that use managed
     host bridge alloc (Jean-Philippe Brucker)

   - Log PCIe port service messages with pci_dev, not the pcie_device
     (Frederick Lawler)

   - Convert pciehp from pciehp_debug module parameter to generic
     dynamic debug (Frederick Lawler)

  Peer-to-peer DMA:

   - Add whitelist of Root Complexes that support peer-to-peer DMA
     between Root Ports (Christian König)

  Native controller drivers:

   - Add PCI host bridge DMA ranges for bridges that can't DMA
     everywhere, e.g., iProc (Srinath Mannam)

   - Add Amazon Annapurna Labs PCIe host controller driver (Jonathan
     Chocron)

   - Fix Tegra MSI target allocation so DMA doesn't generate unwanted
     MSIs (Vidya Sagar)

   - Fix of_node reference leaks (Wen Yang)

   - Fix Hyper-V module unload & device removal issues (Dexuan Cui)

   - Cleanup R-Car driver (Marek Vasut)

   - Cleanup Keystone driver (Kishon Vijay Abraham I)

   - Cleanup i.MX6 driver (Andrey Smirnov)

  Significant bug fixes:

   - Reset Lenovo ThinkPad P50 GPU so nouveau works after reboot (Lyude
     Paul)

   - Fix Switchtec firmware update performance issue (Wesley Sheng)

   - Work around Pericom switch link retraining erratum (Stefan Mätje)"

* tag 'pci-v5.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (141 commits)
  MAINTAINERS: Add Karthikeyan Mitran and Hou Zhiqiang for Mobiveil PCI
  PCI: pciehp: Remove pointless MY_NAME definition
  PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition
  PCI: pciehp: Remove unused dbg/err/info/warn() wrappers
  PCI: pciehp: Log messages with pci_dev, not pcie_device
  PCI: pciehp: Replace pciehp_debug module param with dyndbg
  PCI: pciehp: Remove pciehp_debug uses
  PCI/AER: Log messages with pci_dev, not pcie_device
  PCI/DPC: Log messages with pci_dev, not pcie_device
  PCI/PME: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI/AER: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI: Replace dev_printk(KERN_DEBUG) with dev_info(), etc
  PCI: Replace printk(KERN_INFO) with pr_info(), etc
  PCI: Use dev_printk() when possible
  PCI: Cleanup setup-bus.c comments and whitespace
  PCI: imx6: Allow asynchronous probing
  PCI: dwc: Save root bus for driver remove hooks
  PCI: dwc: Use devm_pci_alloc_host_bridge() to simplify code
  PCI: dwc: Free MSI in dw_pcie_host_init() error path
  PCI: dwc: Free MSI IRQ page in dw_pcie_free_msi()
  ...

Merge misc updates from Andrew Morton:

 - a few misc things and hotfixes

 - ocfs2

 - almost all of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (139 commits)
  kernel/memremap.c: remove the unused device_private_entry_fault() export
  mm: delete find_get_entries_tag
  mm/huge_memory.c: make __thp_get_unmapped_area static
  mm/mprotect.c: fix compilation warning because of unused 'mm' variable
  mm/page-writeback: introduce tracepoint for wait_on_page_writeback()
  mm/vmscan: simplify trace_reclaim_flags and trace_shrink_flags
  mm/Kconfig: update "Memory Model" help text
  mm/vmscan.c: don't disable irq again when count pgrefill for memcg
  mm: memblock: make keeping memblock memory opt-in rather than opt-out
  hugetlbfs: always use address space in inode for resv_map pointer
  mm/z3fold.c: support page migration
  mm/z3fold.c: add structure for buddy handles
  mm/z3fold.c: improve compression by extending search
  mm/z3fold.c: introduce helper functions
  mm/page_alloc.c: remove unnecessary parameter in rmqueue_pcplist
  mm/hmm: add ARCH_HAS_HMM_MIRROR ARCH_HAS_HMM_DEVICE Kconfig
  mm/vmscan.c: simplify shrink_inactive_list()
  fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback
  xen/privcmd-buf.c: convert to use vm_map_pages_zero()
  xen/gntdev.c: convert to use vm_map_pages()
  ...

This export has been entirely unused since it was added more than 1 1/2
years ago.

Link: http://lkml.kernel.org/r/20190429115535.12793-1-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I removed the only user of this and hadn't noticed it was now unused.

Link: http://lkml.kernel.org/r/20190430152929.21813-1-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NRoss Zwisler <zwisler@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__thp_get_unmapped_area is only used in mm/huge_memory.c.  Make it static.
Tested by building and booting the kernel.

Link: http://lkml.kernel.org/r/20190504102353.GA22525@bharath12345-Inspiron-5559Signed-off-by: NBharath Vedartham <linux.bhar@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since 0cbe3e26 ("mm: update ptep_modify_prot_start/commit to take
vm_area_struct as arg") the only place that uses the local 'mm' variable
in change_pte_range() is the call to set_pte_at().

Many architectures define set_pte_at() as macro that does not use the 'mm'
parameter, which generates the following compilation warning:

 CC      mm/mprotect.o
mm/mprotect.c: In function 'change_pte_range':
mm/mprotect.c:42:20: warning: unused variable 'mm' [-Wunused-variable]
  struct mm_struct *mm = vma->vm_mm;
                    ^~

Fix it by passing vma->mm to set_pte_at() and dropping the local 'mm'
variable in change_pte_range().

[liu.song.a23@gmail.com: fix missed conversions]
  Link: http://lkml.kernel.org/r/CAPhsuW6wcQgYLHNdBdw6m0YiR4RWsS4XzfpSKU7wBLLeOCTbpw@mail.gmail.comLink: http://lkml.kernel.org/r/1557305432-4940-1-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Song Liu <liu.song.a23@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recently there have been some hung tasks on our server due to
wait_on_page_writeback(), and we want to know the details of this
PG_writeback, i.e.  this page is writing back to which device.  But it is
not so convenient to get the details.

I think it would be better to introduce a tracepoint for diagnosing the
writeback details.

Link: http://lkml.kernel.org/r/1556274402-19018-1-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

trace_reclaim_flags and trace_shrink_flags are almost the same.
We can simplify them to avoid redundant code.

Link: http://lkml.kernel.org/r/1556169203-5858-1-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The help describing the memory model selection is outdated.  It still says
that SPARSEMEM is experimental and DISCONTIGMEM is a preferred over
SPARSEMEM.

Update the help text for the relevant options:
* add a generic help for the "Memory Model" prompt
* add description for FLATMEM
* reduce the description of DISCONTIGMEM and add a deprecation note
* prefer SPARSEMEM over DISCONTIGMEM

Link: http://lkml.kernel.org/r/1556188531-20728-1-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can use __count_memcg_events() directly because this callsite is alreay
protected by spin_lock_irq().

Link: http://lkml.kernel.org/r/1556093494-30798-1-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Most architectures do not need the memblock memory after the page
allocator is initialized, but only few enable ARCH_DISCARD_MEMBLOCK in the
arch Kconfig.

Replacing ARCH_DISCARD_MEMBLOCK with ARCH_KEEP_MEMBLOCK and inverting the
logic makes it clear which architectures actually use memblock after
system initialization and skips the necessity to add ARCH_DISCARD_MEMBLOCK
to the architectures that are still missing that option.

Link: http://lkml.kernel.org/r/1556102150-32517-1-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Continuing discussion about 58b6e5e8 ("hugetlbfs: fix memory leak for
resv_map") brought up the issue that inode->i_mapping may not point to the
address space embedded within the inode at inode eviction time.  The
hugetlbfs truncate routine handles this by explicitly using inode->i_data.
However, code cleaning up the resv_map will still use the address space
pointed to by inode->i_mapping.  Luckily, private_data is NULL for address
spaces in all such cases today but, there is no guarantee this will
continue.

Change all hugetlbfs code getting a resv_map pointer to explicitly get it
from the address space embedded within the inode.  In addition, add more
comments in the code to indicate why this is being done.

Link: http://lkml.kernel.org/r/20190419204435.16984-1-mike.kravetz@oracle.comSigned-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reported-by: NYufen Yu <yuyufen@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that we are not using page address in handles directly, we can make
z3fold pages movable to decrease the memory fragmentation z3fold may
create over time.

This patch starts advertising non-headless z3fold pages as movable and
uses the existing kernel infrastructure to implement moving of such pages
per memory management subsystem's request.  It thus implements 3 required
callbacks for page migration:

* isolation callback: z3fold_page_isolate(): try to isolate the page by
  removing it from all lists.  Pages scheduled for some activity and
  mapped pages will not be isolated.  Return true if isolation was
  successful or false otherwise

* migration callback: z3fold_page_migrate(): re-check critical
  conditions and migrate page contents to the new page provided by the
  memory subsystem.  Returns 0 on success or negative error code otherwise

* putback callback: z3fold_page_putback(): put back the page if
  z3fold_page_migrate() for it failed permanently (i.  e.  not with
  -EAGAIN code).

[lkp@intel.com: z3fold_page_isolate() can be static]
  Link: http://lkml.kernel.org/r/20190419130924.GA161478@ivb42
Link: http://lkml.kernel.org/r/20190417103922.31253da5c366c4ebe0419cfc@gmail.comSigned-off-by: NVitaly Wool <vitaly.vul@sony.com>
Signed-off-by: Nkbuild test robot <lkp@intel.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For z3fold to be able to move its pages per request of the memory
subsystem, it should not use direct object addresses in handles.  Instead,
it will create abstract handles (3 per page) which will contain pointers
to z3fold objects.  Thus, it will be possible to change these pointers
when z3fold page is moved.

Link: http://lkml.kernel.org/r/20190417103826.484eaf18c1294d682769880f@gmail.comSigned-off-by: NVitaly Wool <vitaly.vul@sony.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current z3fold implementation only searches this CPU's page lists for
a fitting page to put a new object into.  This patch adds quick search for
very well fitting pages (i.  e.  those having exactly the required number
of free space) on other CPUs too, before allocating a new page for that
object.

Link: http://lkml.kernel.org/r/20190417103733.72ae81abe1552397c95a008e@gmail.comSigned-off-by: NVitaly Wool <vitaly.vul@sony.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "z3fold: support page migration", v2.

This patchset implements page migration support and slightly better buddy
search.  To implement page migration support, z3fold has to move away from
the current scheme of handle encoding.  i.  e.  stop encoding page address
in handles.  Instead, a small per-page structure is created which will
contain actual addresses for z3fold objects, while pointers to fields of
that structure will be used as handles.

Thus, it will be possible to change the underlying addresses to reflect
page migration.

To support migration itself, 3 callbacks will be implemented:

1: isolation callback: z3fold_page_isolate(): try to isolate the page
   by removing it from all lists.  Pages scheduled for some activity and
   mapped pages will not be isolated.  Return true if isolation was
   successful or false otherwise

2: migration callback: z3fold_page_migrate(): re-check critical
   conditions and migrate page contents to the new page provided by the
   system.  Returns 0 on success or negative error code otherwise

3: putback callback: z3fold_page_putback(): put back the page if
   z3fold_page_migrate() for it failed permanently (i.  e.  not with
   -EAGAIN code).

To make sure an isolated page doesn't get freed, its kref is incremented
in z3fold_page_isolate() and decremented during post-migration compaction,
if migration was successful, or by z3fold_page_putback() in the other
case.

Since the new handle encoding scheme implies slight memory consumption
increase, better buddy search (which decreases memory consumption) is
included in this patchset.

This patch (of 4):

Introduce a separate helper function for object allocation, as well as 2
smaller helpers to add a buddy to the list and to get a pointer to the
pool from the z3fold header.  No functional changes here.

Link: http://lkml.kernel.org/r/20190417103633.a4bb770b5bf0fb7e43ce1666@gmail.comSigned-off-by: NVitaly Wool <vitaly.vul@sony.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Because rmqueue_pcplist() is only called when order is 0, we don't need to
use order as a parameter.

Link: http://lkml.kernel.org/r/1555591709-11744-1-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NPankaj Gupta <pagupta@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add 2 new Kconfig variables that are not used by anyone.  I check that
various make ARCH=somearch allmodconfig do work and do not complain.  This
new Kconfig needs to be added first so that device drivers that depend on
HMM can be updated.

Once drivers are updated then I can update the HMM Kconfig to depend on
this new Kconfig in a followup patch.

This is about solving Kconfig for HMM given that device driver are
going through their own tree we want to avoid changing them from the mm
tree.  So plan is:

1 - Kernel release N add the new Kconfig to mm/Kconfig (this patch)
2 - Kernel release N+1 update driver to depend on new Kconfig ie
    stop using ARCH_HASH_HMM and start using ARCH_HAS_HMM_MIRROR
    and ARCH_HAS_HMM_DEVICE (one or the other or both depending
    on the driver)
3 - Kernel release N+2 remove ARCH_HASH_HMM and do final Kconfig
    update in mm/Kconfig

Link: http://lkml.kernel.org/r/20190417211141.17580-1-jglisse@redhat.comSigned-off-by: NJérôme Glisse <jglisse@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This merges together duplicated patterns of code.  Also, replace
count_memcg_events() with its irq-careless namesake, because they are
already called in interrupts disabled context.

Link: http://lkml.kernel.org/r/2ece1df4-2989-bc9b-6172-61e9fdde5bfd@virtuozzo.comSigned-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

23d01270 ("fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE
writeback") claims that sync_file_range(2) syscall was "created for
userspace to be able to issue background writeout and so waiting for
in-flight IO is undesirable there" and changes the writeback (back) to
WB_SYNC_NONE.

This claim is only partially true.  It is true for users that use the flag
SYNC_FILE_RANGE_WRITE by itself, as does PostgreSQL, the user that was the
reason for changing to WB_SYNC_NONE writeback.

However, that claim is not true for users that use that flag combination
SYNC_FILE_RANGE_{WAIT_BEFORE|WRITE|_WAIT_AFTER}.  Those users explicitly
requested to wait for in-flight IO as well as to writeback of dirty pages.

Re-brand that flag combination as SYNC_FILE_RANGE_WRITE_AND_WAIT and use
WB_SYNC_ALL writeback to perform the full range sync request.

Link: http://lkml.kernel.org/r/20190409114922.30095-1-amir73il@gmail.com
Link: http://lkml.kernel.org/r/20190419072938.31320-1-amir73il@gmail.com
Fixes: 23d01270 ("fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE")
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Acked-by: NJan Kara <jack@suse.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages_zero() to map range of kernel memory to user
vma.

This driver has ignored vm_pgoff.  We could later "fix" these drivers to
behave according to the normal vm_pgoff offsetting simply by removing the
_zero suffix on the function name and if that causes regressions, it gives
us an easy way to revert.

Link: http://lkml.kernel.org/r/acf678e81d554d01a9b590716ac0ccbdcdf71c25.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages() to map range of kernel memory to user vma.

map->count is passed to vm_map_pages() and internal API verify map->count
against count ( count = vma_pages(vma)) for page array boundary overrun
condition.

Link: http://lkml.kernel.org/r/88e56e82d2db98705c2d842e9c9806c00b366d67.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages() to map range of kernel memory to user vma.

vm_pgoff is treated in V4L2 API as a 'cookie' to select a buffer, not as a
in-buffer offset by design and it always want to mmap a whole buffer from
its beginning.

Link: http://lkml.kernel.org/r/a953fe6b3056de1cc6eab654effdd4a22f125375.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Suggested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages() to map range of kernel memory to user vma.

Link: http://lkml.kernel.org/r/80c3d220fc6ada73a88ce43ca049afb55a889258.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages() to map range of kernel memory to user vma.

Link: http://lkml.kernel.org/r/ff8e10ba778d79419c66ee8215bccf01560540fd.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages() to map range of kernel memory to user vma.

Tested on Rockchip hardware and display is working, including talking to
Lima via prime.

Link: http://lkml.kernel.org/r/7ba359eb1aceac388d05983c1f29b915bdf291f9.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages_zero() to map range of kernel memory to user
vma.

This driver has ignored vm_pgoff and mapped the entire pages.  We could
later "fix" these drivers to behave according to the normal vm_pgoff
offsetting simply by removing the _zero suffix on the function name and if
that causes regressions, it gives us an easy way to revert.

Link: http://lkml.kernel.org/r/88645f5ea8202784a8baaf389e592aeb8c505e8e.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert to use vm_map_pages() to map range of kernel memory to user vma.

Link: http://lkml.kernel.org/r/936e5e107c746a7310e3a3c471188ca3ac8f9754.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: Use vm_map_pages() and vm_map_pages_zero() API", v5.

This patch (of 5):

Previouly drivers have their own way of mapping range of kernel
pages/memory into user vma and this was done by invoking vm_insert_page()
within a loop.

As this pattern is common across different drivers, it can be generalized
by creating new functions and using them across the drivers.

vm_map_pages() is the API which can be used to map kernel memory/pages in
drivers which have considered vm_pgoff

vm_map_pages_zero() is the API which can be used to map a range of kernel
memory/pages in drivers which have not considered vm_pgoff.  vm_pgoff is
passed as default 0 for those drivers.

We _could_ then at a later "fix" these drivers which are using
vm_map_pages_zero() to behave according to the normal vm_pgoff offsetting
simply by removing the _zero suffix on the function name and if that
causes regressions, it gives us an easy way to revert.

Tested on Rockchip hardware and display is working, including talking to
Lima via prime.

Link: http://lkml.kernel.org/r/751cb8a0f4c3e67e95c58a3b072937617f338eea.1552921225.git.jrdr.linux@gmail.comSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Suggested-by: NRussell King <linux@armlinux.org.uk>
Suggested-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NMike Rapoport <rppt@linux.ibm.com>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f467c564 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:

    ...
    One side effect of (and the main motivation for) this change is making
    the following two definitions behave exactly the same:

        config FOO
                bool

        config FOO
                bool
                default n

    With this change, neither of these will generate a
    '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
    That might make it clearer to people that a bare 'default n' is
    redundant.
    ...

Link: http://lkml.kernel.org/r/c3385916-e4d4-37d3-b330-e6b7dff83a52@samsung.comSigned-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the default overcommit==guess we occasionally run into mmap
rejections despite plenty of memory that would get dropped under
pressure but just isn't accounted reclaimable. One example of this is
dying cgroups pinned by some page cache. A previous case was auxiliary
path name memory associated with dentries; we have since annotated
those allocations to avoid overcommit failures (see d79f7aa4 ("mm:
treat indirectly reclaimable memory as free in overcommit logic")).

But trying to classify all allocated memory reliably as reclaimable
and unreclaimable is a bit of a fool's errand. There could be a myriad
of dependencies that constantly change with kernel versions.

It becomes even more questionable of an effort when considering how
this estimate of available memory is used: it's not compared to the
system-wide allocated virtual memory in any way. It's not even
compared to the allocating process's address space. It's compared to
the single allocation request at hand!

So we have an elaborate left-hand side of the equation that tries to
assess the exact breathing room the system has available down to a
page - and then compare it to an isolated allocation request with no
additional context. We could fail an allocation of N bytes, but for
two allocations of N/2 bytes we'd do this elaborate dance twice in a
row and then still let N bytes of virtual memory through. This doesn't
make a whole lot of sense.

Let's take a step back and look at the actual goal of the
heuristic. From the documentation:

   Heuristic overcommit handling. Obvious overcommits of address
   space are refused. Used for a typical system. It ensures a
   seriously wild allocation fails while allowing overcommit to
   reduce swap usage.  root is allowed to allocate slightly more
   memory in this mode. This is the default.

If all we want to do is catch clearly bogus allocation requests
irrespective of the general virtual memory situation, the physical
memory counter-part doesn't need to be that complicated, either.

When in GUESS mode, catch wild allocations by comparing their request
size to total amount of ram and swap in the system.

Link: http://lkml.kernel.org/r/20190412191418.26333-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NRoman Gushchin <guro@fb.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All callers of arch_remove_memory() ignore errors.  And we should really
try to remove any errors from the memory removal path.  No more errors are
reported from __remove_pages().  BUG() in s390x code in case
arch_remove_memory() is triggered.  We may implement that properly later.
WARN in case powerpc code failed to remove the section mapping, which is
better than ignoring the error completely right now.

Link: http://lkml.kernel.org/r/20190409100148.24703-5-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Let's just warn in case a section is not valid instead of failing to
remove somewhere in the middle of the process, returning an error that
will be mostly ignored by callers.

Link: http://lkml.kernel.org/r/20190409100148.24703-4-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Failing while removing memory is mostly ignored and cannot really be
handled.  Let's treat errors in unregister_memory_section() in a nice way,
warning, but continuing.

Link: http://lkml.kernel.org/r/20190409100148.24703-3-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/memory_hotplug: Better error handling when removing
memory", v1.

Error handling when removing memory is somewhat messed up right now.  Some
errors result in warnings, others are completely ignored.  Memory unplug
code can essentially not deal with errors properly as of now.
remove_memory() will never fail.

We have basically two choices:
1. Allow arch_remov_memory() and friends to fail, propagating errors via
   remove_memory(). Might be problematic (e.g. DIMMs consisting of multiple
   pieces added/removed separately).
2. Don't allow the functions to fail, handling errors in a nicer way.

It seems like most errors that can theoretically happen are really corner
cases and mostly theoretical (e.g.  "section not valid").  However e.g.
aborting removal of sections while all callers simply continue in case of
errors is not nice.

If we can gurantee that removal of memory always works (and WARN/skip in
case of theoretical errors so we can figure out what is going on), we can
go ahead and implement better error handling when adding memory.

E.g. via add_memory():

arch_add_memory()
ret = do_stuff()
if (ret) {
	arch_remove_memory();
	goto error;
}

Handling here that arch_remove_memory() might fail is basically
impossible.  So I suggest, let's avoid reporting errors while removing
memory, warning on theoretical errors instead and continuing instead of
aborting.

This patch (of 4):

__add_pages() doesn't add the memory resource, so __remove_pages()
shouldn't remove it.  Let's factor it out.  Especially as it is a special
case for memory used as system memory, added via add_memory() and friends.

We now remove the resource after removing the sections instead of doing it
the other way around.  I don't think this change is problematic.

add_memory()
	register memory resource
	arch_add_memory()

remove_memory
	arch_remove_memory()
	release memory resource

While at it, explain why we ignore errors and that it only happeny if
we remove memory in a different granularity as we added it.

[david@redhat.com: fix printk warning]
  Link: http://lkml.kernel.org/r/20190417120204.6997-1-david@redhat.com
Link: http://lkml.kernel.org/r/20190409100148.24703-2-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Link: http://lkml.kernel.org/r/20190304155240.19215-1-ldufour@linux.ibm.comSigned-off-by: NLaurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>