A running watchdog is marked with WDOG_HW_RUNNING, not with WDOG_ACTIVE.
WDOG_ACTIVE indicates that the watchdog device has been opened from user
space.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

The description of min_hw_heartbeat_ms is misleading and needs some
improvements.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

This patch uses the new flag WDOG_HW_RUNNING in driver.
According to the definition of this flag, it should be set,
if watchdog is running after booting, before it's opened.
Signed-off-by: NPratyush Anand <panand@redhat.com>
Signed-off-by: NFu Wei <fu.wei@linaro.org>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Using max_hw_heartbeat_ms instead of max_timeout gives the flexibility to
achieve higher user "timeout". Therefore, use this new infrastructure.
Signed-off-by: NPratyush Anand <panand@redhat.com>
Signed-off-by: NFu Wei <fu.wei@linaro.org>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

When max_hw_heartbeat_ms has a none zero value, max_timeout is not used.
So it's value can be 0. In such case if a driver uses min_timeout
functionality, then check will always fail.

This patch fixes above issue.
Signed-off-by: NPratyush Anand <panand@redhat.com>
Signed-off-by: NFu Wei <fu.wei@linaro.org>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

This driver does not do anything special in module init/exit. This patch
eliminates the module init/exit boilerplate code by utilizing the
module_isa_driver macro.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Provides generic watchdog features as well as reboot support for the
Aspeed SoCs.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Signed-off-by: NJoel Stanley <joel@jms.id.au>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

If we leave set_timeout empty, the core will do exactly what is
implemented here anyway.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

And move module_init/exit to the proper place while here.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Error string and comment say we fall back to a default, but in reality
we bailed out. Refactor the code to use the core helper which then
matches the described behaviour. While updating the init message anyhow,
shorten it while we are here; no need for versioning there as well and
the name is already given via pr_fmt.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

The history is obsolete, especially since we switched to watchdog
framework. The section markers also don't make sense anymore given
the small size of the driver.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Add a maintainer for the HPE watchdog driver
Signed-off-by: NBrian Boylston <brian.boylston@hpe.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Remove Tom's email address from the documentation
Signed-off-by: NBrian Boylston <brian.boylston@hpe.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

This helps in reducing code in .remove callbacks and sometimes
dropping .remove callbacks entirely.
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Pull MTD fix from Brian Norris:
 "Late MTD fix for v4.7:

  One regression in the Device Tree handling for OMAP NAND handling of
  the ELM node.  TI migrated to using the property name "ti,elm-id", but
  forgot to keep compatibility with the old "elm_id" property.

  Also, might as well send out this MAINTAINERS fixup now"

* tag 'for-linus-20160715' of git://git.infradead.org/linux-mtd:
  mtd: nand: omap2: Add check for old elm binding
  MAINTAINERS: Add file patterns for mtd device tree bindings

Pull input fixes from Dmitry Torokhov:
 "A few last-minute updates for the input subsystem"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: ts4800-ts - add missing of_node_put after calling of_parse_phandle
  Input: synaptics-rmi4 - use of_get_child_by_name() to fix refcount
  Revert "Input: wacom_w8001 - drop use of ABS_MT_TOOL_TYPE"
  Input: xpad - validate USB endpoint count during probe
  Input: add SW_PEN_INSERTED define

Pull workqueue fix from Tejun Heo:
 "The optimization for setting unbound worker affinity masks collided
  with recent scheduler changes triggering warning messages.

  This late pull request fixes the bug by removing the optimization"

* 'for-4.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Fix setting affinity of unbound worker threads

Without this check, the following XFS_I invocations would return bad
pointers when used on non-XFS inodes (perhaps pointers into preceding
allocator chunks).

This could be used by an attacker to trick xfs_swap_extents into
performing locking operations on attacker-chosen structures in kernel
memory, potentially leading to code execution in the kernel.  (I have
not investigated how likely this is to be usable for an attack in
practice.)
Signed-off-by: NJann Horn <jann@thejh.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a memory leak on probe error of the airspy usb device driver.

The problem is triggered when more than 64 usb devices register with
v4l2 of type VFL_TYPE_SDR or VFL_TYPE_SUBDEV.

The memory leak is caused by the probe function of the airspy driver
mishandeling errors and not freeing the corresponding control structures
when an error occours registering the device to v4l2 core.

A badusb device can emulate 64 of these devices, and then through
continual emulated connect/disconnect of the 65th device, cause the
kernel to run out of RAM and crash the kernel, thus causing a local DOS
vulnerability.

Fixes CVE-2016-5400
Signed-off-by: NJames Patrick-Evans <james@jmp-e.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit 2c1ea4c7 ("EDAC, sb_edac: Use cpu family/model in driver
detection") I broke Knights Landing because I failed to notice that it
called a wrapper macro "sbridge_get_all_devices_knl" instead of
"sbridge_get_all_devices" like all the other types.

Now that we include the processor type in the pci_id_table structure we
can skip the wrappers and just have the sbridge_get_all_devices() check
the type to decide whether to allow duplicate devices and controllers to
have registers spread across buses.

Fixes: 2c1ea4c7 ("EDAC, sb_edac: Use cpu family/model in driver detection")
Tested-by: NLukasz Odzioba <lukasz.odzioba@intel.com>
Acked-by: NAristeu Rozanski <aris@redhat.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

of_node_put needs to be called when the device node which is got
from of_parse_phandle has finished using.
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Merge misc fixes from Andrew Morton:
 "20 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  m32r: fix build warning about putc
  mm: workingset: printk missing log level, use pr_info()
  mm: thp: refix false positive BUG in page_move_anon_rmap()
  mm: rmap: call page_check_address() with sync enabled to avoid racy check
  mm: thp: move pmd check inside ptl for freeze_page()
  vmlinux.lds: account for destructor sections
  gcov: add support for gcc version >= 6
  mm, meminit: ensure node is online before checking whether pages are uninitialised
  mm, meminit: always return a valid node from early_pfn_to_nid
  kasan/quarantine: fix bugs on qlist_move_cache()
  uapi: export lirc.h header
  madvise_free, thp: fix madvise_free_huge_pmd return value after splitting
  Revert "scripts/gdb: add documentation example for radix tree"
  Revert "scripts/gdb: add a Radix Tree Parser"
  scripts/gdb: Perform path expansion to lx-symbol's arguments
  scripts/gdb: add constants.py to .gitignore
  scripts/gdb: rebuild constants.py on dependancy change
  scripts/gdb: silence 'nothing to do' message
  kasan: add newline to messages
  mm, compaction: prevent VM_BUG_ON when terminating freeing scanner

Pull rdma fixes from Doug Ledford:
 "Round three of 4.7 rc fixes:
   - two fixes for hfi1
   - two fixes for i40iw
   - one omission correction in the port table counter arrays"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  i40iw: Enable remote access rights for stag allocation
  i40iw: do not print unitialized variables in error message
  IB core: Add port_xmit_wait counter
  IB/hfi1: Fix sleep inside atomic issue in init_asic_data
  IB/hfi1: Correct issues with sc5 computation

Pull i2c fixes from Wolfram Sang:
 "Four driver bugfixes for the I2C subsystem"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mux: reg: wrong condition checked for of_address_to_resource return value
  i2c: tegra: Correct error path in probe
  i2c: remove __init from i2c_register_board_info()
  i2c: qup: Fix wrong value of index variable

Pull drm vmware fixes from Dave Airlie:
 "These are some fixes for the vmware graphics driver, that fix some
  black screen issues on at least Ubuntu 16.04, I think VMware would
  like to get these in so stable can pick them up ASAP"

* tag 'drm-fixes-for-v4.7-rc8-vmware' of git://people.freedesktop.org/~airlied/linux:
  drm/vmwgfx: Fix error paths when mapping framebuffer
  drm/vmwgfx: Fix corner case screen target management
  drm/vmwgfx: Delay pinning fbdev framebuffer until after mode set
  drm/vmwgfx: Check pin count before attempting to move a buffer
  drm/ttm: Make ttm_bo_mem_compat available
  drm/vmwgfx: Add an option to change assumed FB bpp
  drm/vmwgfx: Work around mode set failure in 2D VMs
  drm/vmwgfx: Add a check to handle host message failure

Pull drm fixes from Dave Airlie:
 "These are just some i915 and amdgpu fixes that shows up, the amdgpu
  ones are polaris fixes, and the i915 one is a major regression fix"

* tag 'drm-fixes-for-v4.7-rc8' of git://people.freedesktop.org/~airlied/linux:
  drm/amdgpu: fix power distribution issue for Polaris10 XT
  drm/amdgpu: Add a missing register to Polaris golden setting
  drm/i915: Ignore panel type from OpRegion on SKL
  drm/i915: Update ifdeffery for mutex->owner

Pull scheduler fix from Ingo Molnar:
 "Fix a CPU hotplug related corruption of the load average that got
  introduced in this merge window"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Correct off by one bug in load migration calculation

We were getting build warning:

  arch/m32r/boot/compressed/m32r_sio.c:11:13:
     warning: conflicting types for built-in function 'putc'

Here putc is used as a static function so lets just rename it to avoid
the conflict with the builtin putc.

Link: http://lkml.kernel.org/r/1466977046-24724-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by: NSudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 612e4493 ("mm: workingset: eviction buckets for bigmem/lowbit
machines") added a printk without a log level.  Quieten it by using
pr_info().

Link: http://lkml.kernel.org/r/1466982072-29836-2-git-send-email-anton@ozlabs.orgSigned-off-by: NAnton Blanchard <anton@samba.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The VM_BUG_ON_PAGE in page_move_anon_rmap() is more trouble than it's
worth: the syzkaller fuzzer hit it again.  It's still wrong for some THP
cases, because linear_page_index() was never intended to apply to
addresses before the start of a vma.

That's easily fixed with a signed long cast inside linear_page_index();
and Dmitry has tested such a patch, to verify the false positive.  But
why extend linear_page_index() just for this case? when the avoidance in
page_move_anon_rmap() has already grown ugly, and there's no reason for
the check at all (nothing else there is using address or index).

Remove address arg from page_move_anon_rmap(), remove VM_BUG_ON_PAGE,
remove CONFIG_DEBUG_VM PageTransHuge adjustment.

And one more thing: should the compound_head(page) be done inside or
outside page_move_anon_rmap()? It's usually pushed down to the lowest
level nowadays (and mm/memory.c shows no other explicit use of it), so I
think it's better done in page_move_anon_rmap() than by caller.

Fixes: 0798d3c0 ("mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()")
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1607120444540.12528@eggly.anvilsSigned-off-by: NHugh Dickins <hughd@google.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org>	[4.5+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The previous patch addresses the race between split_huge_pmd_address()
and someone changing the pmd.  The fix is only for splitting of normal
thp (i.e.  pmd-mapped thp,) and for splitting of pte-mapped thp there
still is the similar race.

For splitting pte-mapped thp, the pte's conversion is done by
try_to_unmap_one(TTU_MIGRATION).  This function checks
page_check_address() to get the target pte, but it can return NULL under
some race, leading to VM_BUG_ON() in freeze_page().  Fortunately,
page_check_address() already has an argument to decide whether we do a
quick/racy check or not, so let's flip it when called from
freeze_page().

Link: http://lkml.kernel.org/r/1466990929-7452-2-git-send-email-n-horiguchi@ah.jp.nec.comSigned-off-by: NNaoya 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>

I found a race condition triggering VM_BUG_ON() in freeze_page(), when
running a testcase with 3 processes:
  - process 1: keep writing thp,
  - process 2: keep clearing soft-dirty bits from virtual address of process 1
  - process 3: call migratepages for process 1,

The kernel message is like this:

  kernel BUG at /src/linux-dev/mm/huge_memory.c:3096!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: cfg80211 rfkill crc32c_intel ppdev serio_raw pcspkr virtio_balloon virtio_console parport_pc parport pvpanic acpi_cpufreq tpm_tis tpm i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi floppy virtio_pci virtio_ring virtio
  CPU: 0 PID: 28863 Comm: migratepages Not tainted 4.6.0-v4.6-160602-0827-+ #2
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff880037320000 ti: ffff88007cdd0000 task.ti: ffff88007cdd0000
  RIP: 0010:[<ffffffff811f8e06>]  [<ffffffff811f8e06>] split_huge_page_to_list+0x496/0x590
  RSP: 0018:ffff88007cdd3b70  EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff88007c7b88c0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000700000200 RDI: ffffea0003188000
  RBP: ffff88007cdd3bb8 R08: 0000000000000001 R09: 00003ffffffff000
  R10: ffff880000000000 R11: ffffc000001fffff R12: ffffea0003188000
  R13: ffffea0003188000 R14: 0000000000000000 R15: 0400000000000080
  FS:  00007f8ec241d740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000             CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f8ec1f3ed20 CR3: 000000003707b000 CR4: 00000000000006f0
  Call Trace:
    ? list_del+0xd/0x30
    queue_pages_pte_range+0x4d1/0x590
    __walk_page_range+0x204/0x4e0
    walk_page_range+0x71/0xf0
    queue_pages_range+0x75/0x90
    ? queue_pages_hugetlb+0x190/0x190
    ? new_node_page+0xc0/0xc0
    ? change_prot_numa+0x40/0x40
    migrate_to_node+0x71/0xd0
    do_migrate_pages+0x1c3/0x210
    SyS_migrate_pages+0x261/0x290
    entry_SYSCALL_64_fastpath+0x1a/0xa4
  Code: e8 b0 87 fb ff 0f 0b 48 c7 c6 30 32 9f 81 e8 a2 87 fb ff 0f 0b 48 c7 c6 b8 46 9f 81 e8 94 87 fb ff 0f 0b 85 c0 0f 84 3e fd ff ff <0f> 0b 85 c0 0f 85 a6 00 00 00 48 8b 75 c0 4c 89 f7 41 be f0 ff
  RIP   split_huge_page_to_list+0x496/0x590

I'm not sure of the full scenario of the reproduction, but my debug
showed that split_huge_pmd_address(freeze=true) returned without running
main code of pmd splitting because pmd_present(*pmd) in precheck somehow
returned 0.  If this happens, the subsequent try_to_unmap() fails and
returns non-zero (because page_mapcount() still > 0), and finally
VM_BUG_ON() fires.  This patch tries to fix it by prechecking pmd state
inside ptl.

Link: http://lkml.kernel.org/r/1466990929-7452-1-git-send-email-n-horiguchi@ah.jp.nec.comSigned-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: NKirill 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>

If CONFIG_KASAN is enabled and gcc is configured with
--disable-initfini-array and/or gold linker is used, gcc emits
.ctors/.dtors and .text.startup/.text.exit sections instead of
.init_array/.fini_array.  .dtors section is not explicitly accounted in
the linker script and messes vvar/percpu layout.

We want:
  ffffffff822bfd80 D _edata
  ffffffff822c0000 D __vvar_beginning_hack
  ffffffff822c0000 A __vvar_page
  ffffffff822c0080 0000000000000098 D vsyscall_gtod_data
  ffffffff822c1000 A __init_begin
  ffffffff822c1000 D init_per_cpu__irq_stack_union
  ffffffff822c1000 A __per_cpu_load
  ffffffff822d3000 D init_per_cpu__gdt_page

We got:
  ffffffff8279a600 D _edata
  ffffffff8279b000 A __vvar_page
  ffffffff8279c000 A __init_begin
  ffffffff8279c000 D init_per_cpu__irq_stack_union
  ffffffff8279c000 A __per_cpu_load
  ffffffff8279e000 D __vvar_beginning_hack
  ffffffff8279e080 0000000000000098 D vsyscall_gtod_data
  ffffffff827ae000 D init_per_cpu__gdt_page

This happens because __vvar_page and .vvar get different addresses in
arch/x86/kernel/vmlinux.lds.S:

	. = ALIGN(PAGE_SIZE);
	__vvar_page = .;

	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
		/* work around gold bug 13023 */
		__vvar_beginning_hack = .;

Discard .dtors/.fini_array/.text.exit, since we don't call dtors.
Merge .text.startup into init text.

Link: http://lkml.kernel.org/r/1467386363-120030-1-git-send-email-dvyukov@google.comSigned-off-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>	[4.0+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Link: http://lkml.kernel.org/r/20160701130914.GA23225@styxhpSigned-off-by: NFlorian Meier <Florian.Meier@informatik.uni-erlangen.de>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Tested-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

early_page_uninitialised looks up an arbitrary PFN.  While a machine
without node 0 will boot with "mm, page_alloc: Always return a valid
node from early_pfn_to_nid", it works because it assumes that nodes are
always in PFN order.  This is not guaranteed so this patch adds
robustness by always checking if the node being checked is online.

Link: http://lkml.kernel.org/r/1468008031-3848-4-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>	[4.2+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

early_pfn_to_nid can return node 0 if a PFN is invalid on machines that
has no node 0.  A machine with only node 1 was observed to crash with
the following message:

   BUG: unable to handle kernel paging request at 000000000002a3c8
   PGD 0
   Modules linked in:
   Hardware name: Supermicro H8DSP-8/H8DSP-8, BIOS 080011  06/30/2006
   task: ffffffff81c0d500 ti: ffffffff81c00000 task.ti: ffffffff81c00000
   RIP: reserve_bootmem_region+0x6a/0xef
   CR2: 000000000002a3c8 CR3: 0000000001c06000 CR4: 00000000000006b0
   Call Trace:
      free_all_bootmem+0x4b/0x12a
      mem_init+0x70/0xa3
      start_kernel+0x25b/0x49b

The problem is that early_page_uninitialised uses the early_pfn_to_nid
helper which returns node 0 for invalid PFNs.  No caller of
early_pfn_to_nid cares except early_page_uninitialised.  This patch has
early_pfn_to_nid always return a valid node.

Link: http://lkml.kernel.org/r/1468008031-3848-3-git-send-email-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>	[4.2+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>